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Das, Ashish Kumar, Zinia Sultana, Ahamed Kabir, and Md Shahidul Kabir. "Effect of Washing on Reducing Bacterial Loads in Common Vegetables Sold in Dhaka City." Bangladesh Journal of Microbiology 35, no. 2 (2019): 96–101. http://dx.doi.org/10.3329/bjm.v35i2.42637.
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Vegetables and fruits can be contaminated with microorganisms from different sources during production and processing. Quality of vegetables usually relies on the quality of processing water and sanitizers used to reduce microbial load and increase shelf-life of vegetables. The present study demonstrates the role of washing on reducing bacterial loads in common vegetables sold in Dhaka city. A total of seventy two samples comprising of eighteen types of fresh vegetables were collected. Total heterotrophic bacteria, coliforms and Enterobacteriaceae were determined in 72 samples including potato, tomato, carrot, cucumber, green chilli, bean, eggplant, cauliflower, turnip, radish, capsicum, pumpkin, cabbage, gourd, papaya, bitter gourd, snake gourd and ridge gourd before and after washing with tap and filtered water, halotab water, bleaching powder (0.2%) solution and bleaching powder (0.2%) with citric acid (0.1%) for 10 minutes. Tap water, filtered water, bleaching powder (0.2%), halotab solution and bleaching powder (0.2%) + citric acid (0.1%) solutions were found to be effective and significantly reduced the bacterial loads in vegetables compared to the unwashed vegetables (P<0.01). Effect of washing vegetables using tap and filtered water were found to reduce load of total viable bacteria to 0.85-2.05 log10cfu/g and 2.38-3.36 log10cfu/g, respectively compared to those of unwashed samples. The efficiency of washing for reducing the bacterial load depends on the quality of washing water used and the types of disinfectant solutions used. An appropriate washing technique can significantly reduce the bio burden in contaminated vegetables and may reduce the risk of foodborne infections associated with the consumption of vegetables.
 Bangladesh J Microbiol, Volume 35 Number 2 December 2018, pp 96-101
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Rahman, MM, AA Khan, IH Mian, AM Akanda, and MZ Alam. "Effect of some chemicals on incidence of poato soft rot disease in Bangladesh." Bangladesh Journal of Scientific and Industrial Research 52, no. 2 (2017): 135–40. http://dx.doi.org/10.3329/bjsir.v52i2.32936.
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Bactericidal effect was investigated by chemicals against potato soft rot bacteria in vitro and in storage. The chemicals were acetic acid, boric acid, bleaching powder, lactic acid, calcium hydroxide, calcium chloride, potassium chloride and sodium hypo-chloride. Among eight chemicals only three chemicals viz. acetic acid, boric acid and bleaching powder showed bactericidal activity against potato soft rot bacteria Pectobacterium carotovorum subsp. carotovorum (E. carotovora subsp. carotovora) P-138 in vitro. Based on the results of in vitro experiment three chemicals, acetic acid, boric acid and bleaching powder were used to control soft rot disease of potato in storage. Fresh potato tubers were dipped in 0.2% solution/suspensions of acetic acid, boric acid and bleaching powder for 30 min. Then soft rot bacteria Pectobacterium carotovorum subsp. carotovorum P-138 was inoculated on potato. Finally potatoes were stored for 22 weeks in net bags in sterilized condition. All the three chemicals significantly decreased the infection rate, loss in weight and increased percentage of disease reduction (PDR) of potato. Boric acid was the most effective in controlling the soft rot disease of potato in storage followed by acetic acid and bleaching powder. So these chemicals may be used for seed purpose storage of potato tubers for year round storage at farmers level.Bangladesh J. Sci. Ind. Res. 52(2), 135-140, 2017
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Sergey, Kozak. "Justification for immersion tanks usage in poultry meat processing." Poultry and Chicken Products 24, no. 2 (2022): 46–48. http://dx.doi.org/10.30975/2073-4999-2022-24-2-46-48.
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Immersion tanks usage expediency is justified in primary poultry processing department. It is proved that this tanks usage with 0.07% peracetic content solutions of technologic aid means in poultry slaughtering department gives the possibility to decrease carcasses surface insemination after defeathering by 34.7% with 10 s exposition and solution temperature 35±2°C and to decrease insemination by 48.34% before cooling bath with 9 s exposition and solution temperature 9±1°C. Additional antimicrobial carcasses treatment doesn’t change its sensory qualities except the surface weak bleaching.
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Li, Cheng-Ai, Boemjin Ko, Kwang-Hyun Park, et al. "High-Performance Electrochromic Devices Based on Size-Controlled 2D WO3 Nanosheets Prepared Using the Intercalation Method." Materials 17, no. 1 (2023): 41. http://dx.doi.org/10.3390/ma17010041.
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It is difficult to obtain ultrathin two-dimensional (2D) tungsten trioxide (WO3) nanosheets through direct exfoliation from bulk WO3 in solution due to the strong bonding between interlayers. Herein, WO3 nanosheets with controllable sizes were synthesized via K+ intercalation and the exfoliation of WO3 powder using sonication and temperature. Because of the intercalation and expansion in the interlayer distance, the intercalated WO3 could be successfully exfoliated to produce a large quantity of individual 2D WO3 nanosheets in N-methyl-2-pyrrolidone under sonication. The exfoliated ultrathin WO3 nanosheets exhibited better electrochromic performance in an electrochromic device than WO3 powder and exfoliated WO3 without intercalation. In particular, the prepared small WO3 nanosheets exhibited excellent electrochromic properties with a large optical modulation of 41.78% at 700 nm and fast switching behavior times of 9.2 s for bleaching and 10.5 s for coloring. Furthermore, after 1000 cycles, the small WO3 nanosheets still maintained 86% of their initial performance.
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K., S. Beenakumari. "Photocatalytic activity of nano sized nickel tin oxide prepared by co-precipitation method." Journal of Indian Chemical Society Vol. 91, Oct 2014 (2014): 1937–41. https://doi.org/10.5281/zenodo.5733899.
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Department of Chemistry, All Saints’ College, Thiruvananthapuram-695 007, Kerala, India <em>E-mail </em>: beenagireesh@yahoo.co.uk <em>Manuscript received online 09 May 2014, revised 21 May 2014, accepted 22 May 2014</em> Visible light induced nano sized nicke tin oxide (NiSnO<sub>3</sub>) photocatalysts was synthesized by a simple and organic free co-precipitation method from a bath contains equimolar mixture of nickel and tin ions. The crystallographic property of synthesized nickel tin oxide powder was studied using X-ray diffraction technique. The particle size calculated based on the Scherrer equation shows a particle distribution of 87 nm to 118 nm for the nickel tin oxide powder. The formation of the oxide powder was completed above 600 ºC as evident from thermo-gravimetric analysis. The photo-catalytic activity of the nickel tin oxide was measured based on the degradation of methyl orange in aqueous solution. The results show that nickel tin oxide nano powder exhibit more photocatalytic activity compared to individual addition of nickel oxide or tin oxide and even their mixtures and the rate constant also follows the same trend. The highest rate constant value of 3.6 × 10<sup>–2</sup> min<sup>–1</sup> was observed for the photo degradation of methyl orange with nickel tin oxide as photocatalyst. The photo-bleaching reaction of methyl orange follows the first order kinetics. The enhanced photocatalytic activity of the nickel tin oxide was due to the lower band gap value of the NiSnO<sub>3</sub> compared to SnO<sub>2</sub> and NiO.
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Zaror, C., V. Carrasco, L. Perez, G. Soto, M. A. Mondaca, and H. Mansilla. "Kinetics and toxicity of direct reaction between ozone and 1,2-dihydrobenzene in dilute aqueous solution." Water Science and Technology 43, no. 2 (2001): 321–26. http://dx.doi.org/10.2166/wst.2001.0106.
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The presence of toxic aromatic organic compounds in industrial wastewater affects the efficiency of conventional biological treatment. The oxidizing power of ozone represents an interesting pretreatment to reduce toxicity and increase biodegradability. At low pH, ozone is known to attack electron-rich structures by direct electrophilic reactions which open aromatic rings, and generate smaller oxidized compounds. This paper reports experimental results on kinetic and toxicity aspects of ozone direct reactions with 1,2-dihydrobenzene. This toxic compound is frequently found in cellulose bleaching effluents. Although the reaction pathway is rather complex, 4-carbon compounds, such as maleic acid, are readily formed during the first stage of ozonation. These 4-carbon compounds are further oxidized to form smaller molecules (mostly 2-carbon, such as oxalic acid). The apparent kinetics of 1,2-dihydrobenzene follows a second order law, with a rate constant around 0.36 (dm3 mmol–1s–1), at pH 2 and 20°C. Results show that the BOD:COD ratio increase five-fold as ozonation progresses. Furthermore, the mutagenicity of 1,2-dihydrobenzene totally disappears as the aromatic compound is destroyed by ozonation.
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Zhang, Dongfang. "Heterogeneous photocatalytic removal and reaction kinetics of Rhodamine-B dye with Au loaded TiO2 nanohybrid catalysts." Polish Journal of Chemical Technology 14, no. 2 (2012): 42–48. http://dx.doi.org/10.2478/v10026-012-0069-2.
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Heterogeneous photocatalytic removal and reaction kinetics of Rhodamine-B dye with Au loaded TiO2 nanohybrid catalysts Heterogeneous photocatalytic removal of Rhodamine-B (RhB) dye by metallic Au nanopatrticles deposited TiO2 photocatalyst was studied. For this study, a chemical reduction method by hydrazine hydrate for gold deposition was employed in order to synthesize Au/TiO2 nanocomposite system. For the characterization of the synthesized nanomaterials, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), the Fourier transformation infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PLS) techniques were performed. The obtained results show that the deposition of gold onto TiO2 surface could effectively inhibit the recombination of the photoinduced electron and holes, improving the absorption capability for the visible light source and leading to the increased surface OH group density. The degradation experiment reveals that the efficiency of color removal from RhB aqueous solution containing Au/TiO2 powders for the photocatalytic bleaching of RhB dye is more efficient than that of bare TiO2 sample upon UV-vis light activation. In addition, degradation kinetics of RhB dye in aqueous suspensions can be well simulated by the Langmuir-Hinshelwood model and obeys the pseudo-first order law, with a decolorization rate of 0.0252 min-1 to the photocatalytic removal of RhB dye.
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Darni, Yuli, Lia Lismeri, Muhammad Hanif, Sarkowi Sarkowi, and Dita Synthauli Evaniya. "Peningkatan Kuat Tarik Bioplastik dengan Filler Microfibrillated Cellulose dari Batang Sorgum." Jurnal Teknik Kimia Indonesia 18, no. 2 (2020): 37. http://dx.doi.org/10.5614/jtki.2019.18.2.1.
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Abstrak. Penelitian ini membahas tentang pengaruh rasio pati terhadap kitosan (dalam basis berat) dan konsentrasi microfibrillated cellulose sebagai filler dalam pembuatan bioplastik menggunakan pati sorgum, kitosan dan gliserol. Dalam penelitian ini, rasio pati terhadap kitosan yang divariasikan adalah 10:0, 9,5:0,5, 8,5:1,5, 7,5:2,5, 6,5:3,5, 5,5:4,5 (gr/gr). Microfibrillated cellulose sebagai filler disintesis dari batang sorgum dengan metode semimekanis. Perlakuan kimia diawali dengan delignifikasi batang sorgum dengan KOH 4% pada temperatur 80oC selama 1 jam untuk menghilangkan lignin. Setelah itu dicuci dan dipucatkan (bleaching) sebanyak dua kali menggunakan H2O2 6% pada suhu 70oC. Serbuk batang sorgum yang sudah kering dilanjutkan dengan perlakuan mekanis yaitu dimasukkan ke dalam disk mill selama 90 menit dan dilanjutkan dengan high energy milling (HEM) untuk mengecilkan ukurannya sampai dengan rata-rata 4-8 µm. Filler ditambahkan, dan konsentrasinya (dalam basis berat) divariasikan dari 0, 1, 2, dan 3 %. Pati dan kitosan berukuran 63 mikron (lolos ayakan), waktu pengadukan selama 35 menit pada kecepatan 375 rpm, dan penambahan 10% berat gliserol sebagai plasticizer dijaga konstan. Hasil terbaik pada penelitian ini diperoleh pada formulasi 8,5:1,5 (gr/gr). dan konsentrasi filler 3%. Produk bioplastik ini memiliki kuat tarik 11,64 MPa, persen perpanjangan 10,98%, modulus Young 105,96 MPa, densitas 0,915 gr/ml, dan penyerapan air 38,3%. Kata kunci: bioplastik, gliserol, kitosan, microfibrillated cellulose, sorgum. Abstract. The Improving of Bioplastic Tensile Strength with Microfibrillated Cellulose Filler from Sorghum Stem. This study discusses the effect of starch on chitosan ratio (in weight basis) and also the concentration of microfibrillated cellulose as a filler in the preparation of bioplastics using sorghum starch, chitosan, and glycerol. In this study, the ratio of starch to chitosan varied was 10:0, 9.5:0.5, 8.5:1.5, 7.5:2.5, 6.5:3.5, 5.5:4,5 (gr/gr). Microfibrillated cellulose as filler was encouraged from the sorghum stem by the semi-mechanical method. The delignification of sorghum stem initiated chemical treatment with a 4% KOH solution on 80oC for 1 hour to remove lignin. Bleaching is done after delignification using 6% H2O2 at 70oC. The dried sorghum powder is further followed by mechanical treatment that is put into disk mill for 90 minutes and continued with high energy milling (HEM) to reduce its size to an average of 4-8 µm. The filler is added, and the concentration (on a weight basis) varies from 0, 1, 2, and 3%. Starch and chitosan measuring 63 microns (sieve pass), stirring time for 35 minutes at a speed of 375 rpm, and the addition of 10% by weight of glycerol as a plasticizer is kept constant. The best results in this study were obtained in formulations 8.5:1.5 (gr/gr) and 3% filler concentration. This bioplastic product has 11.64 MPa tensile strength, 10.98% elongation, 105.96 MPa Young moduli, 0.915 gr/ml density, and 38.3% water uptake. Keywords: bioplastic, chitosan, glycerol, microfibrillated cellulose, sorghum.Graphical Abstract
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Razsamakin, A. V., V. I. Gots, I. I. Rudenko, and О. G. Gelevera. "THE ROLE OF CaCO3 IN THE FORMATION OF STRENGTH AND DECORATIVE PROPERTIES OF POWDER ALKALINE-ACTIVATED SLAG CEMENT CONCRETE." Modern construction and architecture, no. 9 (September 30, 2024): 71–81. http://dx.doi.org/10.31650/2786-6696-2024-9-71-81.
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The article discusses approaches to the formation of compositions of alkali-activated decorative Portland slag cements containing Portland cement type CEM1 5...45% with high performance and decorative properties. The optimization of the compositions of decorative alkali-activated Portland slag cements was carried out using statistical methods for designing experiments. Finely dispersed TiO2 and CaCO3 additives with a whiteness of 90% were used as bleaching components. The alkaline component is sodium metasilicate in the form of a non-hygroscopic powder. The research carried out made it possible to obtain decorative Portland slag cements with a whiteness of 45...77%, which allows them to be used to produce colored cements with a wide range of colors from white to black. It has been established that alkali-active decorative Portland slag cements have an activity of 37...59 MPa at the age of 28 days. All compositions have good hardening dynamics and, based on the strength at the age of 2 days 22...36.6 MPa, they can be classified as fast-hardening. Based on them, it is possible to produce dry construction mixtures. All mortar compositions based on alkali-active decorative Portland slag cements demonstrate fairly high frost resistance F200. This allows them to be used for the manufacture of products and solutions both for indoor use and when exposed to atmospheric influences without loss of design characteristics and decorative appeal. The inherent shrinkage strains of decorative alkali-activated Portland slag cements are 0.51...0.61 mm/m, which eliminates cracking and premature destruction of products. The use of the CaCO3 additive is especially effective for controlling the shrinkage deformations. Thus, the CaCO3 additive performs the functions of not only a decorative component, but also a structure-forming component. Concrete and mortar mixtures can be used to produce decorative products using the traditional method, extrusion, 3D printing on construction printers, etc. And not too long setting times and a rapid increase in strength make it possible to produce products without thermal treatment or with minimal consumption of thermal energy.
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Xu, Xianmeng, Dandan Zhang, Xiaohua Liu, Rong Zheng, and Tingqi Jiang. "Ultrasonic-Assisted Extraction and Antioxidant Evaluation of Resveratrol from Peanut Sprouts." Processes 12, no. 10 (2024): 2295. http://dx.doi.org/10.3390/pr12102295.
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The orthogonal array design method was used to optimize ultrasonic-assisted extraction of resveratrol from peanut sprouts. The results showed that the highest extraction yield of resveratrol using ultrasonic-assisted extraction could be up to 1.1%. The optimal extraction conditions were liquid to solid ratio of 30:1 (mL/g) and ethanol concentration of 80% (v/v) as solvent for 40 min at the temperature of 70 °C. AB-8 macroporous adsorption resin was used to purify the crude extract and the resveratrol content increased to 47.5% after one treatment run. The optimal adsorption parameters were initial concentrations in the sample solution of 2 mg/mL, a pH of 5.0, a flow rate of 2 mL/min, and a temperature of 25 °C. The optimal desorption parameters were 60% ethanol and a flow rate of 1 mL/min. The chemical composition of the peanut sprout’s resveratrol sample was investigated via HPLC, and the predominant constituents were found to be protocatechuic acid, catechins, caffeic acid, epicatechuic acid, resveratrol, and rutin. The antioxidant activities of the resveratrol were measured via the following different analytical methods: reducing power, 2,2-diphenyl-1-picrylhdrazyl (DPPH), hydroxyl radical-scavenger activity, superoxide radical-scavenger activity, the β-carotene bleaching test, and the scavenging nitrite test. The results indicated that the resveratrol in peanut sprouts have significant antioxidant activities and can be used as a source of potential antioxidant. And peanut sprout’s resveratrol has the potential and valuable application to be used as a new type of resveratrol resource. The finding of this study can provide some theoretical reference for the comprehensive utilization of peanut resources in the development of antioxidant health foods.
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Chang, Shui Ping, Yi Chao Lee, Chih Sheng Lee, and Nien Hsin Kao. "Using Gin Adsorption Model for Assessing the Influence of Algal Powder Bleach Process in Cu(II) Adsorption." Applied Mechanics and Materials 295-298 (February 2013): 123–28. http://dx.doi.org/10.4028/www.scientific.net/amm.295-298.123.
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The Cladophora and Spirogyra algae examined in this study belong to the Chlorophyta division. Macro filamentous algae, which are widespread in fresh water worldwide, have high potential to be developed as biological materials because of their large biomass and availability. In this study, we collected fresh algae from where they grew and produced bleached and unbleached algae powder using to adsorb Cu(II) ion solution. After the biosorption process, we noted the following four significant findings: (i) The functional groups and binding sites in the produced algae powder were affected, causing variations in the amount of copper adsorbed. The variations resulted from differences in the cell structure, the cell wall thickness of Cladophora and Spirogyra algae, cell composition, and the types and amount of epiphytic algae. (ii) Common bleaching procedures using glacial acetic acid influenced the binding sites of the functional groups and the biomass of the produced powder. Because of the bleaching, the amount of copper adsorbed by the Cladophora powder declined by 14.2%, and by 15.7% for Spirogyra powder. (iii) The carbonyl and hydroxyl groups of unbleached powder were the main elements affected during the bleaching procedures. Examining whether the biosorption experiment results fit Gin’s biosorption model, we found that the biosorption amount and equilibrium reaction of the two bleached algae powders were inferior to that of the unbleached algae powders. (iv) The bleaching procedure using glacial acetic acid was not suitable for producing algae powder to use as an adsorbent for metal ions.
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Enstrup, Marius Simon, and Ulrich Kunz. "Electrochemical Cell for in-Situ Synthesis of Hydrogen Peroxide in Household Washing Machines." ECS Meeting Abstracts MA2023-01, no. 24 (2023): 1602. http://dx.doi.org/10.1149/ma2023-01241602mtgabs.
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Hydrogen peroxide (H2O2) is used as bleaching agent in household appliances like washing machines. For the bleaching of laundry with H2O2, an alkaline environment is required in the washing machine, which is ensured by the use of an heavy-duty detergent. In powdered heavy-duty detergents for washing machines, H2O2 is provided in form of sodium percarbonate, which releases H2O2 as soon as it is dissolved in water. As long-term stability of H2O2 in liquids requires acidic environment, no sufficient amount of H2O2 based bleach can be stored in liquid heavy-duty detergents, resulting in a lower bleaching efficiency for laundry cleaning. However, liquid heavy-duty detergents can be dosed fully automatically in washing machines, which is convenient for the user and can reduce the detergent consumption by optimizing dosing amount [1]. To take advantage of a fully automatic dosing system and at the same time obtain an effective heavy-duty detergent with bleach capability, an additional in-situ bleach source is required. An attractive route for the in-situ production of H2O2 is the electrochemical reduction of oxygen (O2) at a carbon-based cathode in a flow cell. The use of a gas diffusion electrode (GDE) results in higher production rates by directly supplying gaseous O2 to the reaction site compared to a submerged cathode where O2 is dissolved in the electrolyte [2,3]. As evidenced by the lack of literature, this kind of a specific application-related flow cell design for the use in a washing machine has not yet been developed. Therefore, a compact and simple electrochemical flow cell was developed that can provide sufficient H2O2 quantities within the time scale of a washing cycle and can be installed in a washing machine. The novel cell consists of an electrolyte reservoir, which is integrated within the cell and is separated from the dimensionally stable anode (DSA) by a divided wall. The expanded metal design of the DSA allows a zero gap arrangement by allowing the separator to lie directly on the anode. Between separator and carbon-based GDE, the electrolyte can be pumped in a circuit via the reservoir. A three-way valve allows the electrolyte accumulated with H2O2 to be discharged to the washing machine. The GDE is supplied with atmospheric O2 from the non-anode-facing side. During operation, the cell is first filled with electrolyte via the filling hole. As soon as the anode chamber (between the anode and the divided wall) is completely filled, the liquid can flow over the divided wall and fill the reservoir. Subsequently, the circulation pump and the air supply of the GDE are started and the current is applied. During electrolysis, the H2O2 is produced in the GDE and accumulates in the circulated electrolyte. The divided wall and the separator prevent the direct oxidation of H2O2 at the anode. The O2 produced at the anode can escape via the gas vent. After a sufficient amount of H2O2 has been generated in the electrolyte, electrolysis is stopped and the H2O2-solution is pumped into the drum of the washing machine via the 3-way valve. The transient H2O2 faradaic efficiency and energy consumption were compared to literature data. The combination of in-situ H2O2 production with liquid heavy-duty detergent was compared to a solid heavy-duty detergent using a standard soiled cotton textiles test. [1] Smulders, E. (2001), Laundry Detergents, Wiley-VCH; 1. Edition. [2] Pérez, J. F., et al. (2016), Electroch. Com. 71, 65–68. [3] Muddemann, T., et al. (2021), Proc. 9, 1482. Figure 1
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Luchian, C. E., E. C. Scutaraşu, L. C. Colibaba, V. V. Cotea, L. Vlase, and A. M. Toiu. "Evaluation of byproducts from the wine-making industry by identification of bioactive compounds." BIO Web of Conferences 12 (2019): 04007. http://dx.doi.org/10.1051/bioconf/20191204007.
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Byproducts obtained after wine production constitute an important source for the extraction of antioxidant compounds. Phenolic compounds showed a wide spectrum of biological actions for the human health, often associated with neuroprotective, cardioprotective, antimicrobial and other health-related effects. The aim of the present study was to determine the phenolic compounds content and antioxidant activity of grape marc from selected grapes from Iaşi vineyard. The total phenolic content of the extracts was measured using the Folin-Ciocâlteu method, with some modifications. The DPPH (2,2-diphenyl-1-picrylhydrazyl) assay was used to evaluate radical scavenging activity, by bleaching of purple methanolic solution of the stable radical. All extracts were able to reduce DPPH radical with different degrees of scavenging activity. The highest radical scavenging activity was determined for the extract obtained from Merlot and Fetească Neagră (98.142 μg/mL, and 115.78 μg/mL respectively), with positive correlation between scavenging activity on DPPH and total phenolic content. The total phenolic content varied among the analysed extracts, with a higher concentration in extracts obtained from Merlot, Fetească Neagră and Traminer rosé (2.42 GAE/mL, 1.45 GAE/mL and 1.24 GAE/mL respectively), followed by Sauvignon Blanc and Muscat Ottonel extracts with comparable amounts. The FRAP (ferric reducing antioxidant power) method relies on the color change of a complex with Fe+3 ion of the 2,4,6-tri(2-pyridyl) – 1,3,5-triazine (TPTZ) radical due to the reduction of the ferric ion to the ferrous iron (Fe+2) in this complex. The highest radical scavenging activity was determined in the extract obtained from Merlot and Fetească Neagră (1164.22 μM Trolox/100 mL and 782.09 μM Trolox/100 mL respectively), a positive correlation between scavenging activity determined by FRAP method and total phenolic content being observed.Statistical analysis showed a close relationship between content of phenolic compounds and antioxidant capacity, the marc of Merlot and Fetească Neagră had the highest contents of anthocyanins. The results suggested that grape pomace may be exploited as antioxindant source.
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Rucker, James W., and David M. Cates. "2,2î-Bipyridine Catalyzed Bleaching of Cotton Fibers with Peracetic Acid." Textile Research Journal 58, no. 4 (1988): 198–210. http://dx.doi.org/10.1177/004051758805800403.
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Peracetic acid can be catalyzed to bleach cotton fibers at temperatures as low as 30°C by incorporating 2,2î-bipyridine in the bleach solution. Treatment of the fibers with HCl prior to bleaching reduces bleaching effectiveness by removing trace transition metal ions from the fibers. Sorption of individual ions (Cr+3 Mn+2, Fe+2, Fe+3 Co+2, Ni+2, Cu+2, and Zn+2) by HCl treated cotton fibers prior to bleaching indicates that the ferrous ion produces the greatest catalytic effect, and it is only effective when the metal ion is in the fiber as opposed to in solution. Ferrous ions in the fibers sorb 2,2î-bipyridine from solution to form the tris-2,2î-bipyridine ferrous ion complex that is associated with the fibers, and it is the trischelate associated with the fibers that catalyzes bleaching. The effects of pH, temperature, and concentrations of 2,2î-bipyridine, sodium lauryl sulfate, and transition metal ions (in the fibers and in solution) on bleaching effectiveness and peracetic acid decomposition have been studied, and a bleaching mechanism is proposed.
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Kimyai, Soodabeh, and Hadi Valizadeh. "Comparison of the Effect of Hydrogel and a Solution of Sodium Ascorbate on Dentincomposite Bond Strength After Bleaching." Journal of Contemporary Dental Practice 9, no. 2 (2008): 105–12. http://dx.doi.org/10.5005/jcdp-9-2-105.
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Abstract Aim The aim of this study was to compare the effects of solution and different sodium ascorbate hydrogels on dentin-resin composite shear bond strength subsequent to a bleaching procedure with 10% carbamide peroxide. Methods and Materials Sixty buccal dentin surfaces obtained from intact human third molars were randomly divided into five groups (n=12). Dentin surfaces received different treatments: (1) no treatment; (2) bleaching (10% carbamide peroxide gel); (3) bleaching + 10% sodium ascorbate solution; (4) bleaching + 10% sodium ascorbate hydrogel, and (5) bleaching + 20% sodium ascorbate hydrogel. Dentin surfaces were bonded with Single Bond™ and restored with a composite (Z100). The samples were tested for shear bond strengths. Data was analyzed using analysis of variance (ANOVA) and Tukey tests. Results Significantly higher bond strengths were observed subsequent to treatment with hydrogel and solution forms of sodium ascorbate (p<0.05). No significant differences were demonstrated between different forms of sodium ascorbate preparations. In addition, no significant differences were observed among groups with antioxidant treatment (Groups 3, 4, and 5) and Group 1 (no treatment). Conclusion Reduced bond strength to bleached dentin can be amended by the use of sodium ascorbate as an antioxidant. Clinical Significance Both hydrogel and solution forms of sodium ascorbate can significantly improve the reduced bond strength of resin composite to dentin subsequent to a bleaching procedure with 10% carbamide peroxide. Citation Kimyai S, Valizadeh H. Comparison of the Effect of Hydrogel and a Solution of Sodium Ascorbate on Dentin-composite Bond Strength After Bleaching. J Contemp Dent Pract 2008 February;(9)2:105-112.
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Luksha, O. V., N. Ch Belous, S. P. Rodtsevich, and V. M. Chernetskaya. "Hydro-phobization of fine-grained portland cement concrete with spent filtering and bleaching powders." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 60, no. 1 (2024): 63–72. http://dx.doi.org/10.29235/1561-8331-2024-60-1-63-72.
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The results of studying the chemical and phase composition of oil and fat production wastes - used filtering and bleaching powders are presented. It has been established that the crystalline phase of the powders is represented mainly by silicon dioxide, as well as aluminum, iron and titanium oxides, sodium and potassium aluminosilicates. The organic part of the spent filtering powders consists of waxes, while the bleaching powder phase contains fats and free fatty acids with unsaturated bonds. The concentration of water-soluble organic compounds in filtering powders does not exceed 30 mg/dm3, and in spent bleaching powder reaches 700–900 mg/dm3, which explains the decrease in surface tension at the solution-air interface in its presence and contributes to an increase in the effectiveness of its hydrophobic action in Portland cement systems. Analysis of the results of the study of the hardening process, strength, hydrophysical and corrosion properties of fine-grained Portland cement concretes confirmed the maximum effect of increasing the draft of the cone and mobility, due to the air entrainment of Portland cement mortars and their saturation with air microbubbles when bleaching powder is introduced. At the same time, in the presence of spent filtering powders, additional air entrainment, and, consequently, plasticization, is not observed. As a result of the formation of a protective layer in Portland cement concrete, there is difficulty in the access of water molecules to the solid phase, which leads to a significant improvement in hydrophysical properties. There is a decrease in water absorption by 45–54 %, salt absorption – by an average of 55 %, as a result, an increase in the coefficient of salt resistance of materials is recorded. The maximum effect of reducing salt corrosion and increasing the salt resistance coefficient of materials is due to the peculiarities of the capillary-porous structure of concrete in the presence of bleaching powder, the kinetics of diffusion of salt solutions in them, and the decrease in capillary suction and crystallization pressure of salts in the pores of the material.
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Wang, Lian Yuan, Hai Yan Zhu, Zhen Xing Cheng, Meng Meng Ma, Jing Liang, and Xiao Ping Zhang. "Degradation of GD and VX over Oxides Mixing with Bleaching Powder." Advanced Materials Research 616-618 (December 2012): 1702–6. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.1702.
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Nanosize oxides with acidic or basic sites could neutralize the droplets of chemical warfare agents. Refined bleaching powder was added to increase the reactivity of the nanosize oxides for degradation of GD(3,3-dimethyl-2-butyl methylphophonofluoridate or Soman) and VX(O-ehtyl S-2-(diisopropylamino)ethyl methyl-phosphonothioate). It was found that all the studied decontaminant powders exhibited room-temperature reactivity for GD and VX droplets which depends on their surface acid–base property. Decontaminant powders with basicity like nanosize MgO have the best activity towards GD and the degradation rate was improved obviously for N-MgO due to the adding of refined bleaching powder. However, surface acidity was very important for neutralizing VX over the decontaminant powders.
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Balter, Gabriel Aparecido, Tatiane Cristina Dotta, William Custódio, Alma Blasida Concepcion Elizaur Benitez, Vinícius Cappo Bianco, and Ana Paula Terossi de Godoi. "Influence of NaHCO3 powder on color and roughness of the composite submitted to bleaching and Euterpe oleracea." Journal of Oral Research 11, no. 4 (2022): 1–11. http://dx.doi.org/10.17126/joralres.2022.045.
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Aim: This study aims to evaluate the surface roughness and susceptibility to staining of bleached composite resin with 22% carbamide peroxide, as well as the effect of subsequent prophylaxis with NaHCO3 powder. Material and Methods: Forty disk-shaped (2 × 6 mm) specimens of composite resin (Z250 XT) were prepared. Half of the specimens were subjected to bleaching with 22% carbamide peroxide, and the other half were stored in artificial saliva. In sequence, all specimens were immersed in acai juice (Euterpe oleracea) for 4 h for 14 days, and subdivided into two groups. Group 1 samples were subjected to prophylaxis treatment, while group 2 samples were subjected to treatment with artificial saliva. Surface roughness (Ra) and color (ΔE*) were measured after polishing (T0), bleaching (T1), immersion in acai juice (T2), and application of NaHCO3 powder (T3) using a profilometer and a spectrophotometer. Results: Statistical analyses (analysis of variance and Tukey's test, p≤0.05) revealed that regarding color there was statistically significance for the factors in isolation, except for the factor bleaching. For both color and surface roughness there was statistically significant difference for the interaction, except for the interaction between NaHCO3 power and bleaching. Conclusion: The NaHCO3 air-powder polishing decreases the staining of the composite resin; however, it increases the surface roughness. With respect to the color variable, the whitening factor had no significant effect on the tested material; however, it increases surface roughness.
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Kagne, Srimanth, Sneha Jagtap, Dilip Thakare, Sukumar Devotta, and Sadhana S. Rayalu. "Bleaching powder: A versatile adsorbent for the removal of fluoride from aqueous solution." Desalination 243, no. 1-3 (2009): 22–31. http://dx.doi.org/10.1016/j.desal.2008.04.012.
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Lourenço, Julio Cesar, Tulio P. Porto, Igor P. C. Cruz, et al. "Towards Sustainable Hydrogen Peroxide Electroproduction: Activated Carbon from Sewage Sludge As an Eco-Friendly Electrode Material." ECS Meeting Abstracts MA2023-02, no. 61 (2023): 3315. http://dx.doi.org/10.1149/ma2023-02613315mtgabs.
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Hydrogen peroxide (H2O2) has emerged as a chemical of paramount importance, finding diverse applications as a bleaching agent, medical disinfectant, and environmentally benign oxidant [1]. The industrial production of H2O2 currently relies on the anthraquinone oxidation process, primarily executed within large-scale industrial plants [1]. Herein lies a challenge— H2O2, typically concentrated to an 80% level, introduces inherent hazards concerning storage and transportation, prompting a quest for a safer alternative. One way to overcome such problems is by the in-situ electrogeneration of H2O2, which would allow an adjustable production of the chemical on demand directly for its application, avoiding storing costs and safety issues. The in-situ electrogeneration can be done by using a gaseous-diffusion electrode (GDE), which typically enables the application of elevated current densities or substantial overpotentials, consequently facilitating the generation of high concentrations of H2O2, since there is less limitation due to O2 mass transport to the electrode surface [2]. Commonly, these electrodes are constructed from amorphous carbon materials, due to their highly active surface area with oxygenated functional groups, excellent conductivity, and innate selectivity for H2O2 electroproduction. However, a notable challenge emerges – bare carbon's selectivity for H2O2 presents its highest response at high overpotentials, entailing heightened energy consumption. The studies in this field are currently focused on using these types of carbon as support for other catalytic materials that are more active and selective towards H2O2 electroproduction [3, 4]. Numerous studies in the literature have explored the use of carbon materials, with the most commonly employed carbon supports for such applications being Printex 6L (Orion) and Vulcan XC 72R (Cabot). These materials are obtained from the incomplete combustion of heavy petroleum products at high temperatures, being non-sustainable and environmentally unfriendly. A potential solution lies in the use of environmentally conscious carbon sources. While amorphous carbon can be obtained from various carbon-rich wastes through an activation process, their utility in H2O2 electrogeneration remains underexplored. This study sought to obtain activated carbon from sewage sludge, focusing on its efficacy in H2O2 electrogeneration. Acid (H3PO4) and alkaline (KOH/NaOH mixture) carbon activators were analyzed in concentrations ranging from 0 – 30 %m/v, temperatures of 400 – 900 ºC, and activation time from 0 – 2 h at the selected temperature. The obtained materials were analyzed through linear sweep voltammetry using an RRDE setup in N2-saturated and O2-saturated, in a 0.05 M K2SO4 (pH 3) electrolyte solution. Results have shown that the most successful materials for H2O2 electrogeneration were those produced under 900 ºC for 2h impregnated with 5 % m/v H3PO4 and 597 ºC, zero of plateau time impregnated with 20 % m/V mixture of KOH/NaOH in the ratio of 50.5 KOH: NaOH. These optimized materials exhibited remarkable selectivities of ≈ 90% and ≈ 81% at -0.8 V vs. Ag/AgCl, respectively. This level of electrocatalytic performance is on par with that of the commercial reference material, Printex 6L. These findings highlight the promise of our material as a viable carbon support for in-situ H2O2 electrogeneration, offering a more sustainable alternative compared to commercial black carbons. Acknowledgments The authors are sincerely grateful to the Brazilian research funding agencies, including the Brazilian National Council for Scientific and Technological Development - CNPq (grants no. 465571/2014-0, 302874/2017-8, and 427452/2018-0), São Paulo Research Foundation (FAPESP – grants no. #2023/04230-2, #2023/07750-7, 2022/04058-2, #2021/12053-8, #2019/04421-7, #2017/10118-0, and #2013/02762-5). References [1] S. Li, J. Ma, F. Xu, L. Wei, D. He, Fundamental principles and environmental applications of electrochemical hydrogen peroxide production: A review, Chemical Engineering Journal, 452 (2023) 139371. [2] A. Francisco, B. Enric, C. Pere-Llui's, Oxygen Reduction on Uncatalyzed Carbon-\ PTFE\ Gas Diffusion Cathode in Alkaline Medium, Journal of The Electrochemical Society, 149 (2002) E64 , publisher = The Electrochemical Society. [3] G.V. Fortunato, E. Pizzutilo, A.M. Mingers, O. Kasian, S. Cherevko, E.S.F. Cardoso, K.J.J. Mayrhofer, G. Maia, M. Ledendecker, Impact of Palladium Loading and Interparticle Distance on the Selectivity for the Oxygen Reduction Reaction toward Hydrogen Peroxide, The Journal of Physical Chemistry C, 122 (2018) 15878-15885. [4] L.C. Trevelin, R.B. Valim, J.C. Lourenço, A. De Siervo, R.S. Rocha, M.R.V. Lanza, Using ZrNb and ZrMo oxide nanoparticles as catalytic activity boosters supported on Printex L6 carbon for H2O2 production, Advanced Powder Technology, 34 (2023) 104108. Figure 1
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Usman, Muhammad, Elisa Julianti, and Jenny Elisabeth. "IMPROVEMENT OF CPO QUALITY USING PHYSICAL PURIFICATION MATERIAL OF SHELL POWDER FOR RED COOKING OIL PRODUCTION." BIOLINK (Jurnal Biologi Lingkungan Industri Kesehatan) 11, no. 2 (2025): 197–208. https://doi.org/10.31289/biolink.v11i2.13913.
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The production of CPO (Crude Palm Oil) generated and utilized by the industry must consider market demand, prioritizing the quality of the final CPO product that complies with the SNI 01-2901-2021 standard. It includes free fatty acid (FFA) content, water, and impurities, with maximum limits of 5%, 0.25%, and 0.25%, respectively. Another parameter affecting CPO quality is the Deterioration of Bleachability Index (DOBI) value. This study investigates the potential use of calcium oxide (CaO) derived from seashells to improve CPO quality in the production of Red Cooking Oil (M3). The study design employed a Completely Randomized Design (CRD) with a non-factorial method. The treatment factor in this study was seashell powder heated at 600°C with varying concentrations: 0%, 1%, 2%, 3%, and 4%, as well as 1% Bleaching Earth commonly used at neutral pH (6-7 ). The treatments applied included K0 (no treatment), K1 (1% Bleaching Earth), K2 (1% Seashell Powder), K3 (2% Seashell Powder), K4 (3% Seashell Powder), and K5 (4% Seashell Powder) . The results showed that seashell powder significantly reduced free fatty acid content in K5 by 13.51%, decreased water content in K4 and K5 by 47.05%, and increased the DOBI value by 47.05%.
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Lelis, Martynas, Simona Tuckute, Marius Urbonavicius, Sarunas Varnagiris, and Emilija Demikyte. "Non-Conventional Synthesis and Repetitive Application of Magnetic Visible Light Photocatalyst Powder Consisting of Bi-Layered C-Doped TiO2 and Ni Particles." Catalysts 13, no. 1 (2023): 169. http://dx.doi.org/10.3390/catal13010169.
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In the current study, a non-conventional application of the magnetron sputtering technique was proposed. A four-step synthesis procedure allowed us to produce a magnetic photocatalyst powder consisting of bi-layered particles with carbon-doped TiO2 on one side, and metallic Ni on the other side. XRD, SEM and EDS methods were used for sample characterization. It was determined, that after the sputtering process optimization, the bandgap of carbon-doped TiO2 was reduced to approximately 3.1 eV and its light adsorption increased over the whole visible light spectrum. The repetitive Rhodamine B solution bleaching with magnetic photocatalyst powder and visible light showed interesting evolvement of photocatalyst efficiency. After the first cycle, Rhodamine B concentration was reduced by just 35%. However, after the second cycle, the reduction had already reached nearly 50%. Photocatalytic bleaching efficiency continued to improve rapidly until higher than 95% of Rhodamine B concentration reduction was achieved (at tenth cycle). For the next ten cycles, photocatalytic bleaching efficiency remained relatively stable. The initial gain in efficiency was attributed to the magnetic photocatalyst particle size reduction from an initial diameter of 100–150 µm to 5 µm. Naturally, the 20–30 times size reduction resulted in a remarkably increased active surface area, which was a key factor for the increased performance.
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Hidayati, Sri, Ribut Sugiharto, and Sutopo Hadi. "Bleaching Process on Oil Palm Empty Bunches by Pulping Using Formacell Liquid Waste." Revista de Chimie 71, no. 9 (2020): 242–50. http://dx.doi.org/10.37358/rc.20.9.8334.
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The formacell process produces black liquor that damages the environment. Previous research has shown that black liquor can be used as a cooking solution for pulping. The pulping process using formacell waste on oil palm empty bunches produces a dark color; therefore, it requires a bleaching process. The aim of this study was to determine the effect of the type of cooking solution (fresh pulping solution and leachate residual from pulping) and bleaching time (0.5, 1, 1.5, 2, and 2.5 h) on pulp yield, cellulose content, permanganate number, and score on whiteness degree. The bleaching process used 35% peracetic acid and was conducted at 80�C. The best results were obtained at a bleaching time of 2 h, which resulted in yields of 76.1%�81.2%, cellulose contents of 53%�62.5%, permanganate numbers of 6.3�7.4, and scores of color of 3.78 (yellowish white) to 4.7 (white).
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Franco, MC, JLS Uehara, BM Meroni, GS Zuttion, and MS Cenci. "The Effect of a Charcoal-based Powder for Enamel Dental Bleaching." Operative Dentistry 45, no. 6 (2020): 618–23. http://dx.doi.org/10.2341/19-122-l.
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Clinical Relevance Charcoal based-powders are not effective for dental bleaching. SUMMARY Charcoal-based dentifrices for dental whitening are a novelty in the market. Manufacturers claim that such charcoal-based products have whitening, remineralization, antimicrobial, and antifungal properties of charcoal in such products. However, there is no substantial scientific evidence for these claims. This laboratory randomized study was designed to evaluate the whitening properties of a charcoal-based toothpowder. A total of 45 bovine dental enamel discs were randomly distributed into three groups (n=15): group 1, mechanical brushing with a 1450-ppm F toothpaste (control group); group 2, mechanical brushing with an activated charcoal-based powder; group 3, bleaching per the standard protocol using 10% carbamide peroxide. The surface roughness and color of each specimen were analyzed at baseline and after 14 days of experiment. The surface of one randomly selected specimen from each group was examined using a scanning electron microscope (SEM). The Kruskal-Wallis test was used to compare groups at a significance level of 5%. Only group 3 promoted a statistically significant effect on ΔE compared with groups 1 and 2 (p&lt;0.001 and p=0.003, respectively). No statistically significant difference was found between groups for surface roughness (p&gt;0.05). SEM revealed a more irregular surface in group 1 specimens compared with group 2 and 3 specimens. The charcoal-based powder did not seem to have any bleaching effect.
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Михаилиди (Mikhailidi), Александра (Aleksandra) Михайловна (Mikhailovna), Вадим (Vadim) Иванович (Ivanovich) Маркин (Markin), Нина (Nina) Ефимовна (Efimovna) Котельникова (Kotel'nikova), and Shahriar Karim Saurov. "FUNCTIONAL MATERIALS FROM PAPER WASTES. I. FROM WASTE NEWSPRINT PAPER AND CARDBOARD TO HIGH-GRADE CELLULOSE FIBERS." chemistry of plant raw material, no. 2 (February 6, 2018): 27–35. http://dx.doi.org/10.14258/jcprm.2018023693.
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Utilization of paper wastes as renewable resource of lignocellulosic constituents has the opportunity to promote a cleaner environment and to prepare valuable materials. This paper describes our study on an isolation of low-fiber powder cellulose from two grades of wastes as feedstocks: waste newsprint paper and cardboard wrapper through recycling including a thermal defibration, an alkali treatment with a solution of NaOH with a concentration from 0.03 to 1.00 М, a bleaching with a solution of Н2О2 with a concentration from 0.8 to 2.6 М followed with an acid hydrolysis of the pretreated species with a solution of HNO3 of 1.5 and 3.0 M. An impact of the pretreatment on sizes of fibers was evaluated with a stereoscopic microscopy. The powder celluloses obtained as a result of the acid hydrolysis exhibited the structure of cellulose I revealed with a WAXS method and were of a high-grade purity, according to EDXA. Sorption capacities of the powder celluloses from the waste cardboard and newsprint towards a dye methylene blue were 6.67 mg∙g-1 and 8.75 mg∙g-1 correspondingly.
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Lismeri, Lia, Hertantri Yulia Rahmi, Nada Afifah Gomiyati, Yuli Darni, Panca Nugrahini Febriningrum, and Azhar Azhar. "Preparation and Characterization of Nanocrystalline Cellulose from Cassava Stem Wastes by Electromagnetic Induction." Jurnal Rekayasa Kimia & Lingkungan 16, no. 2 (2021): 109–17. http://dx.doi.org/10.23955/rkl.v16i2.21927.
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Cassava stems were one of the largest agricultural by products in Indonesia, especially in Lampung Province. It is known that cassava stems have a fairly high lignocellulose content, especially cellulose which reaches 39.29%. The high cellulose content in cassava stems has great potential to be used as raw material for Nanocrystalline Cellulose (NCC). The preparation of nanocrystalline cellulose consists of four main stages, namely: pre-hydrolysis, delignification, bleaching, and acid hydrolysis. The pre-hydrolysis stage was carried out by boiling a solution of CH3COOH and cassava stem powder for 60 minutes at a temperature of 105oC. Cassava stem powder was then delignified using a 25% NaOH solution heated to a temperature of 105oC for 1 hour. The bleaching stage used a 3.5% NaOCl solution at a temperature of 50oC for 60 minutes and was carried out twice. The last step is acid hydrolysis using 2.5N HCl solution for 15 minutes at a temperature of 105oC, then the electromagnetic induction treatment is varied with temperature variations of 30oC, 50oC, and 70oC for 60 minutes. The prepared nanocrystalline cellulose were tested for lignocellulose, XRD and PSA. From the test results, the best variation of nanocrystal cellulose preparation was acid hydrolysis treatment with 70oC electromagnetic induction for 60 minutes, namely an increase in the percentage of cellulose 62.93%, crystallinity 90.68%, and an average particle size of 18.04µm with some particles measuring nanometers. From the results of the research, it was concluded that electromagnetic induction increased crystallinity and decreased the size of nanocrystalline cellulose.
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Sari, Odina Nadya, Yeni Rahmawati, Fadlilatul Taufany, Yu-Cheng Chiu, and Siti Nurkhamidah. "THE EFFECTS OF NaClO2 AND H2O2 AS BLEACHING AGENTS IN THE SYNTHESIS OF CELLULOSE ACETATE FROM OIL PALM EMPTY FRUIT BUNCH." ASEAN Engineering Journal 14, no. 3 (2024): 137–42. http://dx.doi.org/10.11113/aej.v14.21327.
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Indonesia is one of the largest palm oil-producing countries in the world. The results of palm oil processing produce a lot of waste, such as oil palm empty fruit bunches (OPEFB). The utilization of OPEFB in Indonesia is minimal, so it needs further development. OPEFB has a very high α-cellulose content, so that it can be used as raw material for manufacturing cellulose acetate. Making cellulose acetate from OPEFB consists of three main steps: delignification, bleaching, and acetylation. This study aims to compare the effects of the concentration of NaClO2 or H2O2 in the bleaching process on the physical properties of cellulose acetate from OPEFB. In the delignification process, 100 mesh-sized OPEFB powder is reacted with 5% sodium hydroxide (NaOH) at 100oC for 2 hours. The residue from deliglinfication was washed using distilled water until pH 7, filtered using filter paper, and dried using an oven at 50oC. The next step is the bleaching process using NaClO2 or H2O2 with concentration variations (1%, 2%, 3%, 4% and 5%). The bleaching process was carried out at 90oC for 1.5 hours. After filtration, the bleached residue was washed using distilled water until pH 7, filtered using filter paper, and dried using an oven at 50oC. After the bleaching process, α-cellulose powder was produced. The next step is acetylation, containing three main steps. The first step is the reaction between α-cellulose powder with acetic acid (CH3COOH) and sulfuric acid (H2SO4) at 40oC for 1.5 hours to perform activation. The second step is the addition of anhydrous cellulose in a ratio of 1:10 and mixed at 40oC for 1.5 hours. The third step is the addition of distilled water, acetic acid, and sodium acetate (CH3COONa) at 40oC for 5 minutes. Then, followed by filtration, the residue was washed using distilled water and methanol until pH 7 and dried at 50oC. The best result is using NaClO2 as a bleaching agent with a concentration of 2%, resulting in cellulose acetate yielding 98.85%, density of 1.954 g/mL, and L value of 91.897 for colorimetric test results. The density and L-value were close to commercial cellulose acetate (Sigma Aldrich). From the results of FTIR analysis, it can be concluded that the acetylation of α-cellulose into cellulose acetate has been successful, as evidenced by the formation of carbonyl groups (C=O).
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Moosavi, Horieh, and Fatemeh Darvishzadeh. "The Influence of Post Bleaching Treatments in Stain Absorption and Microhardness." Open Dentistry Journal 10, no. 1 (2016): 69–78. http://dx.doi.org/10.2174/1874210616021000069.
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Objectives: This study investigated the effects of post bleaching treatments to prevent restaining and the change of enamel surface microhardness after dental bleaching in vitro. Methods: Sixty intact human incisor teeth were stained in tea solution and randomly assigned into four groups (n=15). Then samples were bleached for two weeks (8 hours daily) by 15% carbamide peroxide. Tooth color was determined both with a spectrophotometer and visually before bleaching (T1) and immediately after bleaching (T2). Next, it was applied in group 1 fluoride (Naf 2%) gel for 2 minutes, and in group 2 a fractional CO2 laser (10 mJ, 200 Hz, 10 s), and in group 3, nanohydroxyapatite gel for 2 minutes. The bleached teeth in group 4 remained untreated (control group). Then teeth placed in tea solution again. Color examinations were repeated after various post bleaching treatments (T3) and restaining with tea (T4) and color change values recorded. The microhardness was measured at the enamel surface of samples. Data was analyzed using ANOVA, Tukey HSD test and Dunnett T3 (α = 0.05). Results: Directly after bleaching (ΔE T3-T2), the treatment with nanohydroxyapatite showed significantly the least color lapse in colorimetric evaluation. In experimental groups, the color change between T3 and T4 stages (ΔE T4-T3) was significantly lower than control group (P < 0.05). Different methods of enamel treatment caused a significant increase in surface microhardness compared to control group (P < 0.05). Significance: Application of fluoride, fractional CO2 laser and nanohydroxyapatite as post bleaching treatments are suggested for prevention of stain absorption and increasing the hardening of bleached enamel.
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Rakshit, Ameta, Pandey Aryamitra, B. Punjabi P., and C. Ameta Suresh. "Modification of photocatalytic activity of antimony(III) sulphide in presence of sodium bicarbonate/ carbonate." Journal of Indian Chemical Society Vol. 82, Sep 2005 (2005): 807–10. https://doi.org/10.5281/zenodo.5827455.
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Photochemistry Laboratory, Department of Chemistry, University College of Science, M. L. Sukhadia University, Udaipur-313 002, India <em>E-mail</em> : ameta_sc@yahoo.com <em>Fax </em>: 91-294-2423191 <em>Manuscript received 10 March 2005, revised 8 June 2005, accepted 21 June 2005</em> A comparative study of photocatalytic bleaching of azure-B over Sb<sub>2</sub>S<sub>3</sub> powder was carried out in the presence and absence of sodium bicarbonate/carbonate. The photocatalytic bleaching was observed to be more efficient in the presence of bicarbonate/carbonate ions. The effect of various parameters has been studied and a tentative mechanism for the photocatalytic bleaching has been proposed.
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Suryanto, Heru, Uun Yanuhar, Poppy Puspitasari, et al. "Morphology and structure of sawdust waste after adding magnetic nanoparticles." E3S Web of Conferences 473 (2024): 03001. http://dx.doi.org/10.1051/e3sconf/202447303001.
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Sengon (Albizia chinensis) is a type of forest plant that grows quickly and is widely used to meet human needs. The large number of uses of Sengon wood causes sengon wood waste, such as sawdust, to increase. The study’s aim is to analyze the morphology and structure of sawdust waste after adding magnetic (Fe3O4) nanoparticles. The methods include collecting sawdust waste from wood (Sengon) was conducted by the crushing process to get smaller sawdust sizes. Alkalization was applied to sawdust and followed by a bleaching process. The powder is then immersed in a solution containing magnetic (Fe3O4) nanoparticles of 10wt%, and then dried. Sawdust composite powder the analyzed using X-ray diffraction and electron microscope instruments. The result indicates that magnetic nanoparticles deposit on sawdust powder and then make the powder become rougher. Higher content of magnetic nanoparticles causes higher agglomeration. The diffraction pattern with 2θ of 14, 16, and 22 indicates that the structure of sawdust is cellulose 1β. The degree of crystalline of sawdust powder reduces from 76.1% to 73.3% after adding magnetic nanoparticle. In the future, these composite powder results will develop as flocculants for wastewater treatment.
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Dicle, A. Tunc, E. Eliguzeloglu Dalkılıc, and E. Akyol. "Effects of Experimental Nanohydroxyapatite Gel on Enamel Surface After Bleaching." Operative Dentistry 50, no. 2 (2025): 218–28. https://doi.org/10.2341/24-008-l.
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SUMMARY The purpose of this study was to investigate the effect of chitosan-added experimental nanohydroxyapatite (n-HA) gel on the physical and morphological changes of the enamel surface after the use of two different vital bleaching agents. Fifty-two intact, caries-free human maxillary incisors were embedded in acrylic resin. Chitosan-added n-HA powder was synthesized using a high-temperature oxidation method and then mixed with phosphate-buffered saline solution (PBS) to form a gel. The teeth were divided into four groups: Group B: Biowhiten in-office 40% n-HP (BioWhiten, Biodent Ltd, Istanbul, Turkey); Group O: Opalescence Boost 40% HP (Ultradent Products Inc., South Jordan, UT, USA); Group BN: Biowhiten in-office 40% n-HP+n-HA gel; Group ON: Opalescence Boost 40% HP+n-HA gel. Color change, surface microhardness, and surface roughness (Ra) measurements were taken before, immediately after, and one week after bleaching. Three specimens from each group were also subjected to scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) analysis. The data were statistically analyzed using an analysis of variance (ANOVA) and Bonferroni post hoc test (p&lt;0.05). After bleaching, all groups showed a noticeable change in color (p&lt;0.05), but with no differences among the treatment groups (p&gt;0.05). After bleaching, the highest Ra values were determined in Group O (p&lt;0.05). Group ON showed a statistically lower Ra value than Group O (p&lt;0.05). The lowest microhardness value after bleaching was observed in Group O (p&lt;0.05), which also had the lowest calcium/phosphorus (Ca/P) value. After the experimental chitosan-added n-HA gel application, the Ca/P ratio increased. The use of experimental chitosan-added n-HA gel after bleaching improved the physical and morphological properties of the enamel surface without reducing the effectiveness of bleaching.
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Qi, Lihong, Guomin Zuo, Zhenxing Cheng, Haiyan Zhu, and Shanmao Li. "Oxidative degradation of chemical warfare agents in water by bleaching powder." Water Science and Technology 66, no. 7 (2012): 1377–83. http://dx.doi.org/10.2166/wst.2012.287.
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Degradation of sulfur mustard (HD), S-2-(di-isopropylamino)ethyl O-ethyl methylphosphonothioate (VX) and Soman (GD) in water by bleaching powder was investigated. The degradation products were comprehensively analyzed by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and ion chromatography. Degradation pathways were deduced based on the identified products. The product analysis results indicated that HD could be degraded through oxidation and chlorination reactions, and a small portion of sulfur atoms could be mineralized into SO42− ion. Oxidative degradation of VX could finally generate O-ethyl methylphosphonate acid (EMPA), sulfonic acids, SO42− and NO3− ions. GD would be converted into non-toxic pinacolyl methylphosphonate via nucleophilic substitution.
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Ndiffo, Gervais B. Y., Serges A. Djepang, Romaric L. Seutcha, and Samuel Laminsi. "Plasma-catalytic Efficiency on the Discolouration of Sunset Yellow FCF in a Glidarc Plasma Reactor in Presence of WO₃ Used as Catalyst." European Journal of Advanced Chemistry Research 2, no. 1 (2021): 8–13. http://dx.doi.org/10.24018/ejchem.2021.2.1.45.
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In this work, we highlight the plasma-catalytic effect of gliding arc discharge on the bleaching of azo dye sunset yellow FCF in aqueous solution. The effect has been studied in the presence of tungsten oxide as a catalyst in the glidarc reactor. The catalyst has been synthesized via acid precipitation process. The product obtained was characterized by X-ray powder diffraction (XRD), Fourier Transform Infrared (FTIR) and Nitrogen Physisorption. The results showed firstly monoclinic structure of WO3 catalyst. The maximum bleaching rates obtained are 17% and 52.5% after 30 min for initial dye concentration of 25 mg.L-1 for plasma alone and plasma-catalyst, respectively. These results have clearly shown that gliding arc discharge has a double effect, in on hand as a source of hydroxyl radical and on other hands as a source of radiation able to excite the catalyst. The effects of initial pH and photocatalyst loading have been studied.
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Rahman, M. S., P. C. Sarker, M. A. Hossain, M. S. Reza, M. K. A. Nadim, and M. J. Hasan. "Influence of chemicals and crude plant materials as pre-storage treatment on seed quality of onion (Allium cepa L.)." Bangladesh Journal of Agriculture 48, no. 2 (2023): 54–62. http://dx.doi.org/10.3329/bjagri.v48i2.70158.
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Fresh onion seeds dried to 7.0% seed moisture content were stored with crude plant materials (red chili powder@20g/kg of seed; neem leaf powder@ 20g/kg of seed, lemon leaf powder @ 20g/kg seed), and chemicals (common bleaching powder and mancozeb @ 2g/kg of seed). The germination potential of onion seeds was found satisfactory in treated seeds. Water uptake during imbibition was maximum in lemon leaf treated seed which indicates better germination as the imbibition of water is an essential part of germination. A high correlation between EC measurements and germination was found; which indicates that conductivity readings have the potential to provide a rapid assessment of standard laboratory germination. In terms of seed-associated pathogens during storage, chemicals have shown better results in suppressing pathogens. Bangladesh J. Agri. 2023, 48(2): 54-62
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Ranganath, LM, B. Sunil Rao, AG Rajesh, and KS Prem Kumar. "Surface Morphological Changes in Human Enamel Following Bleaching: An in vitro Scanning Electron Microscopic Study." Journal of Contemporary Dental Practice 13, no. 3 (2012): 405–15. http://dx.doi.org/10.5005/jp-journals-10024-1159.
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ABSTRACT Objective The purpose of this study was to evaluate, using scanning electron microscopy (SEM), the morphological and structural changes of the enamel induced by three bleaching agents namely old McInnes solution, modified McInnes solution and 10% carbamide peroxide gel at different time intervals. Materials and methods Fifteen freshly extracted noncarious human central incisors with intact enamel surface were selected. The teeth were sectioned at the cementoenamel junction separating the crown portion from the root using a diamond separating disk. Following this, the samples were subjected to three different bleaching agents: Group 1: Old McInnes solution, group 2: modified McInnes solution and group 3: 10% carbamide peroxide for a period of 15, 30 and 60 minutes, 24 and 30 hours time interval. The sample stubs were subjected to scanning electron microscope and were photographed at 2000 and 10,000 magnifications. Conclusion The present study revealed no indication of either etching or significant change in surface morphology of enamel when evaluated under scanning electron microscope after 6 weeks treatment with various bleaching agents. Clinical significance Morphological alterations in bleached enamel are both concentration and time dependent. How to cite this article Rajesh AG, Ranganath LM, Kumar KSP, Rao BS. Surface Morphological Changes in Human Enamel Following Bleaching: An in vitro Scanning Electron Microscopic Study. J Contemp Dent Pract 2012;13(3):405-415.
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Onutai, Sujitra, Takaomi Kobayashi, Parjaree Thavorniti, and Sirithan Jiemsirilers. "Removal of Pb2+, Cu2+, Ni2+, Cd2+ from Wastewater using Fly Ash Based Geopolymer as an Adsorbent." Key Engineering Materials 773 (July 2018): 373–78. http://dx.doi.org/10.4028/www.scientific.net/kem.773.373.
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This work aims to evaluate the effectiveness of fly ash based geopolymer powder as an adsorbent for heavy metals in aqueous solution. The structure of synthesized geopolymer was found to be highly amorphous due to the dissolution of fly ash phase. Moreover, the fly ash geopolymer powder has higher surface area compares to original fly ash with specific surface area of 85.01 m²/g and 0.83 m2/g, respectively. For this reason, the geopolymer powder has much higher removal efficiency compared to the original fly ash powder. The removal efficiency was affected by contact time, geopolymer amount, heavy metal initial concentration, pH, and temperature. The four heavy metals were chosen (Pb2+, Cu2+, Ni2+, Cd2+) for adsorption test. The highest heavy metal removal capacity was obtained at pH 5. The geopolymer powder adsorbed metal cations in the order of Pb2+>Cu2+>Cd2+>Ni2+. In addition, Langmuir model is more suitable for fly ash geopolymer powder adsorption of heavy metal ions in aqueous solution than Freundlich model. The results showed that the fly ash geopolymer powder has high efficiency for removal metal which could be employed excellent alternative for wastewater treatment.
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Hafez, Randa, Doa Ahmed, Mai Yousry, Wafa El-Badrawy, and Omar El-Mowafy. "Effect of In-Office Bleaching on Color and Surface Roughness of Composite Restoratives." European Journal of Dentistry 04, no. 02 (2010): 118–27. http://dx.doi.org/10.1055/s-0039-1697819.
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Objectives: The purpose of this study was to determine color changes and surface roughness of composites when they were subjected to in-office bleaching.Methods: 12 discs 15 mm in diameter and 2 mm thick were prepared from two shades (A2 & A4) of two composites, Durafil VS (DF) and TPH3 (TPH). Specimens were polished and stored in distilled water for 24 hours at 37°C before being subjected to bleaching, staining, and re-bleaching. Each of the groups of specimens (DF-A2, DF-A4, TPH-A2 and TPH-A4) were subdivided into three subgroups (n=4) and bleached with Beyond, LumaWhite-Plus, and Opalescence-Boost. Specimens were then stained by immersing them in a coffee solution for 48 hours at 37°C, and then they were re-bleached. Colorimetric measurements were performed at baseline, after bleaching, after staining, and after rebleaching. Surface roughness was determined with environmental SEM before and after bleaching. Data were statistically-analyzed.Results: None of the bleaching systems notably changed the color of composites (delta-E<2). Coffee staining affected DF specimens more than TPH. Stained specimens showed variable responses to whitening with no significant color change observed with TPH (delta-E<2) and significant changes observed with DF. Surface roughness significantly changed with bleaching, but the degree varied according to composite shade and bleaching agent.Conclusions: Three in-office bleaching agents had no significant color changes on two composites. DF showed more color change than TPH when immersed in coffee. Stained composites showed different degrees of whitening, with DF showing more response. Bleaching may adversely affect the surface texture of composites. Dentists should take into consideration that composite restorations may not respond to bleaching in the same way that natural teeth do. (Eur J Dent 2010;4:118-127)
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Demirel, Mehmet Gökberkkaan, Hakan Yasin Gönder, and Makbule Tuğba Tunçdemir. "Analysis of Monomer Release from Different Composite Resins after Bleaching by HPLC." Life 12, no. 11 (2022): 1713. http://dx.doi.org/10.3390/life12111713.
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(1) Background: This study aimed to examine the effect of bleaching agents on the release of triethylenae glycol dimethacrylate, 2-hydroxyethyl methacrylate, bisphenol A, urethane dimethacrylate, and bisphenol A-glycidyl methacrylate monomers, which are released from different composite resins, using the high-performance liquid chromatography (HPLC) method. (2) Methods: Ninety disc-shaped specimens were produced and immersed in artificial saliva. After different bleaching applications [office type bleaching (OB) and home type bleaching (HB)], the specimens were immersed in a 75 wt% ethanol/water solution, and the released monomers were analyzed by HPLC at predefined time intervals: 1, 7, and 28 days. The Kruskal–Wallis and Mann–Whitney U tests were conducted for statistical analysis (p = 0.05). (3) Results: The monomers were released at all times from all composite specimens. The monomer release was increased over time. The highest monomer release was detected on day 28. Bleaching applications affected monomer release. No statistical difference was found between OB and HB applications (p > 0.05). The most released monomer was Bisphenol-A in all composites. (4) Conclusion: Given that a residual monomer release from composite resins has a toxic effect and that bleaching treatments increase this release, a treatment protocol should be made in accordance with the manufacturer’s instructions.
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Damasceno, Janaina Emanuela, Priscila Matos Pedreira, Thiago Ozi Bueno, Mariana Valerio Pallone, Thais Escobar Fava, and Giselle Maria Marchi. "Conservative Esthetic Approach of Anterior Teeth Using Minimal Intervention and Preservation of all Sound Tooth Tissue: a Case Report." Journal of Health Sciences 21, no. 5 (2019): 489–93. http://dx.doi.org/10.17921/2447-8938.2019v21n5p489-493.
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AbstractThis clinical case report describes a conservative approach to a smile harmony rehabilitation performing a gingivoplasty, dental bleaching and resin-based composites to finalize the case. This clinical article describes the case report of a patient in need of an esthetic and corrective solution for the anterior teeth, which presented a disharmonic smile, in its shape and color, besides the gingival smile. As a result, gingivoplasty, dental bleaching and restoration with composite resin were done. Gingivoplasty with bone preservation was possible because there was a large volume of soft tissue, and a distance ≥ 2 mm from the bone crest to the junction cementum enamel was confirmed. Bleaching was performed with the use of associated techniques: office (Whiteness HP 35%) and supervised at-home (Whiteness Perfect 10%) bleaching were performed, and then the "buccolingual technique" using a nanocomposite resin IPS was used from a diagnostic wax-up to perform the restorative procedure for the anterior teeth. The use of minimally invasive techniques is an effective alternative for the anterior teeth rehabilitation. As in this case, the gingivoplasty, dental bleaching with associated techniques, and restorations with nanocomposites allowed satisfactory esthetic results, even more so in relation to dental preservation, mainly in young patients. Keywords: Tooth Bleaching. Gingivoplasty. Esthetic. Dental RestorationAbstractThis clinical case report describes a conservative approach to a smile harmony rehabilitation performing a gingivoplasty, dental bleaching and resin-based composites to finalize the case. This clinical article describes the case report of a patient in need of an esthetic and corrective solution for the anterior teeth, which presented a disharmonic smile, in its shape and color, besides the gingival smile. As a result, gingivoplasty, dental bleaching and restoration with composite resin were done. Gingivoplasty with bone preservation was possible because there was a large volume of soft tissue, and a distance ≥ 2 mm from the bone crest to the junction cementum enamel was confirmed. Bleaching was performed with the use of associated techniques: office (Whiteness HP 35%) and supervised at-home (Whiteness Perfect 10%) bleaching were performed, and then the "buccolingual technique" using a nanocomposite resin IPS was used from a diagnostic wax-up to perform the restorative procedure for the anterior teeth. The use of minimally invasive techniques is an effective alternative for the anterior teeth rehabilitation. As in this case, the gingivoplasty, dental bleaching with associated techniques, and restorations with nanocomposites allowed satisfactory esthetic results, even more so in relation to dental preservation, mainly in young patients. Keywords: Tooth Bleaching. Gingivoplasty. Esthetic. Dental Restoration
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Mokhnache, Kamel, Soraya Madoui, Hanane Khither, El-Khamsa Soltani, Noureddine Charef, and Arrar Lekhmici. "Synthesis, Characterization, Hydrolytic Cleavage, and Biological Activity Studies of 2-[(1e)-N-{2-[(2-{(Z)-[1-(2-Hydroxyphenyl)Ethylidene] Amino}Ethyl)Amino]Ethyl}Ethanimidoyl]Phenol." Journal of Drug Delivery and Therapeutics 9, no. 5-s (2019): 25–29. http://dx.doi.org/10.22270/jddt.v9i5-s.3621.
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A Schiff base ligand 2-[(1E)-N-{2-[(2-{(Z)-[1-(2-hydroxyphenyl) ethylidene] amino}ethyl)amino]ethyl} ethanimidoyl]phenol L was hydrolyzed by copper cation which lead to formation of 8,8-dichloro-2H,3H,5H,6H-1,3-diaza-2-cupracyclopenta[1,3-a]1,3-diaza-2-cupracyclopentane hydrate (Complex), characterized by UV, IR, Powder XRD and by elemental analysis. In vitro antioxidant and anticoagulant, activities of L were evaluated. Antioxidant potential of L was assessed by DPPH scavenging, β-carotene bleaching test, hydroxyl radical scavenging method, ABTS radical scavenging test, and by reducing power test. In vitro anticoagulant effect of L at the 84 µg/mL; showed the maximum prolongation of plasma recalcification time which is comparable with that of the anticoagulant drug; heparin. In conclusion, results of the present investigation indicate that the ligand L can be a potential anticoagulant agent.
 Keywords: Schiff base; Antioxidant; Free radicals; Anticoagulant.
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Araújo, GSA, FS Naufel, RCB Alonso, DANL Lima, and RM Puppin-Rontani. "Influence of Staining Solution and Bleaching on Color Stability of Resin Used for Caries Infiltration." Operative Dentistry 40, no. 6 (2015): E250—E256. http://dx.doi.org/10.2341/14-290-l.
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SUMMARY Objective The objective of this study was to evaluate the color stability of Icon-infiltrated white spot lesions after staining and the bleaching effect on the infiltrated and stained surfaces. Methods and Materials Enamel-dentin specimens (N=30, 5 × 5 × 3 mm, 1-mm enamel + 2-mm dentin thickness) were prepared from bovine incisors and randomly allocated into three groups (n=10): control, demineralized, and infiltrated. Artificial enamel subsurface lesions were created using 50 mL of 0.05 M acetate buffer solution. Specimens were produced by Icon application in enamel caries-like lesions, according to the manufacturer's instruction. Baseline color readings were assessed using a spectrophotometer, and CIE L*a*b* measurements of each specimen were performed using a white background. To simulate extrinsic dietary staining, specimens were placed into a 4-mL coffee infusion, three times daily for 15 minutes, for 14 days. After the staining procedure, color measurements were performed again. Then, bleaching procedures were performed using 16% carbamide peroxide gel for four hours daily for 21 days, and a final color assessment was performed. To compare the baseline and final measurements, t-test was used (α =0.05). The statistical comparison between the groups was performed using the one-way analysis of variance and Tukey tests (α =0.05). Results Coffee staining provided a significant reduction of L* values and an increase of a* and b* in all groups (control, decayed, and infiltrated). The bleaching procedure provided a significant increase in L* and decrease of a* and b* values in all groups. There was no significant difference in ΔE values between decayed and infiltrated groups before bleaching, and after bleaching, the infiltrated group showed the lowest ΔE values. Conclusion It can be concluded that enamel infiltrated with Icon presents significant alteration of color after staining when compared with sound enamel. However, if there is discoloration of the infiltrant, the bleaching treatment can be used successfully.
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Sawada, Ryoji, Yuya Katou, Hirofumi Shibata, Max Katayama, and Toru Nonami. "Evaluation of Photocatalytic and Protein Adsorption Properties of Anodized Titanium Plate Immersed in Simulated Body Fluid." International Journal of Biomaterials 2019 (July 1, 2019): 1–8. http://dx.doi.org/10.1155/2019/7826373.
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Titanium-based materials are widely used for implant treatments such as artificial dental roots. Surface treatment has the potential to improve not only the biocompatibility but also the chemical and mechanical durability of the surface without changing the mechanical properties of the metal. A relatively thick titanium oxide film can be formed by the anodic oxidation method. Phosphoric acid or sulfuric acid electrolytic solution has previously been used for anodic oxidation. Such anodized films have excellent film hardness, abrasion resistance, and adhesion. In this study, titanium plate was anodized using an aqueous solution of sulfuric acid in which titanium oxide powder was suspended. A 2800-nm-thick titanium oxide film was formed, which was thicker than that obtained using phosphoric acid electrolyte. The titanium plate was immersed in simulated body fluid for 1 day to evaluate the photocatalytic activity and protein adsorption ability, and a homogeneous crack-free hydroxyapatite layer was formed. This titanium plate showed high methylene blue bleaching capacity. The adsorption ability of the acidic protein of the anodized titanium plate subjected to the above treatment was high. This suggests that this titanium plate has antimicrobial properties and protein adsorption ability. Thus, we report that a titanium plate, anodized with a sulfuric acid aqueous electrolyte solution containing suspended TiO2 powder and immersed in simulated body fluid, might behave as an antibacterial and highly biocompatible implant material.
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Wulansari, Devi Sepmita, and Supranto Supranto. "Pengaruh Waktu dan Konsentrasi NaOH pada Proses Delignifikasi Wheat Bran." Jurnal Rekayasa Proses 10, no. 2 (2016): 48. http://dx.doi.org/10.22146/jrekpros.33337.
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There are approximately 14.5% of whole wheat which belongs to bran and contains cellulose (33.7-40%), hemicellulose (21-26%), lignin (11–22.9%) and the other components. Cellulose is polysaccharide which is composed of 2000-3000 unit of glucose. Cellulose purification from the wheat bran can be done by the hydrolysis, followed by the processes of delignification and bleaching. The experiments were perfomed first by hydrolizing 20 grams of wheat bran using 250 mL of 2.5 N HCl solution for 2 hours at temperature of 80oC. The next process was delignification using 400 mL of NaOH solution and was conducted by varying the time in 1 hour, 1,5 hours, 2 hours, and 2.5 hours and the concentration of NaOH solution in 0.5 N; 1 N; 1.5 N; 2 N. For the last process, bleaching was performed by using 300 mL of H2O2 10% solution in temperature of 80oC for 1 hour. The sample was then dried in order to remove water content by getting the sample in the oven for 1 hour at temperature of 40oC. The goals of the experiments were to find the correlation between the variation of time and NaOH concentration to the cellulose quality in terms of the color and the structure of cellulose sample and and to the quantitative measure which was the yield of the sample. The best product was obtained at the optimum operation of 2.5 hours delignification and 1.55 N of NaOH concentration. Keywords: wheat bran, cellulose, hydrolysis, delignification, bleaching Wheat bran merupakan kulit luar gandum dengan jumlah sekitar 14,5% dari total keseluruhan gandum selain mengandung selulosa (33,7-40%), hemiselulosa (21-26%), lignin (11–22,9%) dan komponen-komponen lainnya. Selulosa merupakan polisakarida yang terdiri dari 2000-3000 unit glukosa. Pengambilan selulosa dari wheat bran dapat dilakukan dengan beberapa tahapan yakni dimulai dengan proses hidrolisis dilanjutkan dengan proses delignifikasi dan yang terakhir adalah proses bleaching. Percobaan dilakukan dengan menghidrolisis wheat bran sebanyak 20 gram menggunakan larutan HCl 2,5 N sebanyak 250 mL dalam waktu 2 jam pada suhu 80oC. Dilanjutkan dengan proses delignifikasi wheat bran pada suhu 80oC dengan menggunakan larutan NaOH sebanyak 400 mL. Proses delignifikasi dilakukan dengan membuat variasi waktu percobaan dan konsentrasi NaOH. Waktu percobaan divariasikan 1 jam; 1,5 jam; 2 jam; 2,5 jam sedangkan konsentrasi NaOH divariasikan 0,5 N; 1 N, 1,5 N; 2 N. Tahapan terakhir adalah bleaching larutan H2O2 10% sebanyak 300 mL, dan proses ini dilakukan selama 1 jam pada suhu 80oC. Hasil akhir dihilangkan kadar airnya dengan mengoven sampel selama 1 jam dalam oven bersuhu 400 C. Hasil yang akan dianalisis dari percobaan ini adalah kualitas dengan parameter struktur dan warna sampel selulosa serta kuantitas selulosa dengan parameter yield. Dari hasil penelitian diperoleh kondisi optimum untuk proses delignifikasi untuk nilai total tertinggi adalah 2,5 jam dan konsentrasi sebesar 1,55 N. Kata kunci: wheat bran, selulosa, hidrolisis,delignifikasi, bleaching
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Yalinkilic, Ahmet C., Eyup Aksoy, Musa Atar, Hamza Cinar, and Hakan Keskin. "ECO-DESIGN: IMPACTS OF BLEACHING CHEMICALS AND VARNISHES ON THE AMOUNT OF CARBON DIOXIDE IN THE COMBUSTION OF ORIENTAL BEECH (FAGUS ORIENTALIS LIPSKY)." WOOD RESEARCH 66(3) 2021 66, no. 3 (2021): 379–90. http://dx.doi.org/10.37763/wr.1336-4561/66.3.379390.
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This study was carried out to determine the effects of bleaching chemicals and varnishes on the amount of carbon dioxide (CO2) in the combustion of oriental beech (Fagus orientalis Lipsky). For this purpose, samples of Oriental beech prepared according to ASTM D 358 contain 18% R1 = (NaOH + H2O2), R2 = (NaOH + Ca(OH)2 + H2O2), R3 = (Na2S2O5 + H2C2O4), R4 = (NaSiO3 + H2O2), R5 = (KMnO4 + Na2S2O5 + H2O2) solution groups, after bleaching with solution groups, water based, synthetic, polyurethane and acrylic varnish were applied according to ASTM D 3023 and combustion tests were carried out in accordance with ASTM E 160-50. Gas measurements were made with the SIGMA 74172 NSU flue gas device during the combustion process. As a result, in respect to the burning types; the highest amount of CO2 (ppm) was found in the self-combustion (8.468 ppm) while the lowest was obtained from the flame combustion source (4.599 ppm). In respect to the types of bleaching; the highest in R5 (7.458 ppm) and the lowest in R3 (4.059 ppm) were found. According to the varnish types; the highest value was found in the synthetic varnish (8.261), and the lowest value was found in the acrylic varnish (4.772 ppm). According to combustion type + bleaching solution + varnish type interaction, the highest values were found for without flame combustion (II) + R3 + Sn (18.40 ppm) and lowest for flame source combustion (I) + R5 + Pu (0.600 ppm). Consequently, the highest values for combustion gases were found in samples of oriental beech wood samples treated with water-based varnish with R1 solution. According to this, in terms of human health and life safety, possibility of fire in places, R3 solution and acrylic varnish may be used in the related industries.
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International, Journal of Medical Science and Advanced Clinical Research (IJMACR). "A Questionnaire Based Assessment of Skin Bleaching Practice Among Female Medical Students in A Tertiary Care Institute: A Cross Sectional Study." International Journal of Medical Science and Advanced Clinical Research (IJMACR) 8, no. 2 (2025): 118–28. https://doi.org/10.5281/zenodo.15240337.
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<strong>Abstract</strong> <strong>Introduction: </strong>Skin bleaching involves the application of chemicals such as ammonia, hydrogen peroxide, and hypochlorite, either in salons or at home, with repeated treatments over time. Skin bleaching products often contain hazardous ingredients that can lead to adverse outcomes, including rashes, dryness, sunburns, and more severe long-term effects such as DNA damage and increased vulnerability to skin cancers. Despite these effects there is a scarcity of medical research and literature focused on their misuse.<sup> (1)</sup> <strong>Aims and objectives</strong> 1. To estimate the prevalence of ‘skin bleaching’ among female medical students. 2. To assess the pattern of practices regarding ‘skin bleaching’ in female medical students. <strong>Materials & Methods:</strong> A cross-sectional study was conducted among 103 female medical students in a tertiary care medical college in Mangalore, using a preformed digital questionnaire. It included socio-demographic questionnaire, and questions related to use of bleaching agents, pattern of use, and side effect following use. Ethical committee clearance was obtained prior to the study. <strong>Results: </strong>The most common bleaching products used were cream bleach (35.3%), oxybleach (17.6%), milk bleach (11.8%), or powder bleach (5.9%). Post procedure protective measures like moisturizer, sunscreen, avoiding sunlight and soaps (88.2%) were practiced by majority of cases. While, 70.6% didn’t have any side effects, rashes (23.6%), burning sensation (11.8%), dryness (11.8%), and darkening on exposure to sunlight (5.9%) were the most common complains noted. <strong>Conclusion: </strong>Around one sixth of female medical students used bleaching products at some time of life. While majority of participants used occasionally, around half of them did the procedure in salon, and post-procedural protective measures were carried in most cases. Despite that, around one-fourth of the participants complained of some degree of side effects. Awareness of potential risks and effects of skin bleaching remains limited, even among well-educated youth and medical students<strong>.</strong>
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Afsar, Begum Rokeya. "Clinical Evaluation of Carbamide Peroxide and Hydrogen Peroxide as Vehicle of Intracoronal Bleaching Agent in A3 or Darker Shaded Discolored Teeth." Journal of Dentistry and Allied Science 7, no. 2 (2025): 33–40. https://doi.org/10.3329/jdas.v7i2.80569.
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Introduction: 10% carbamide peroxide gel has been tried as an alternative intracoronal bleaching agent and it was found effective. The objectives of the study were to evaluate and compare the efficacy of carbamide peroxide and hydrogen peroxide as vehicle of dental bleaching agents when mixed with sodium perborate powder in patients having teeth of A3 or darker shades. Materials and methods: On the basis of predetermined inclusion and exclusion criteria, 11 patients could be scrutinized whose teeth shade were A3 or darker than A3. According to the bleaching agents to be evaluated, patients were allocated under 2 groups. The shade of adjacent normal tooth was used as control. Preoperative and postoperative color assessments of the discolored teeth were done weekly by three clinicians independently using a standard clinical shade guide. Evaluation was continued up to achieving the shade of the adjacent control tooth or a maximum of 5 weeks by using a scale of evaluation. Collected data of the weekly efficacy score were analyzed using a statistical software SPSS version 11.5. Results: The difference of treatment outcome between the groups on the study patients after 5 weeks of treatment was not statistically significant and also, neither of the two bleaching agents was significantly superior to each other in changing the shades among the patients having A3/darker shades. On comparing the weekly average efficacy score pattern between the groups, Hydrogen peroxide group revealed statistically significant score at the end of 4th week while at the same time Carbamide peroxide group revealed its most unsatisfactory score. Conclusions: Within the study period, both the bleaching agents were able to bleach satisfactorily all the patients up to the desired normal shade. While comparing average efficacy score after 5 weeks, there was no statistically significant difference between the materials. Journal of Dentistry and Allied Science, Vol. 7 No 2: 33-40
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Hariani, Poedji Loekitowati, Fahma Riyanti, and Riski Dita Asmara. "Extraction of Cellulose from Kepok Banana Peel (Musa parasidiaca L.) for Adsorption Procion Dye." Molekul 11, no. 1 (2016): 135. http://dx.doi.org/10.20884/1.jm.2016.11.1.202.
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The aim of the research was to extract a cellulose from kepok banana peel (Musa parasidiaca L.) and application to removal Procion dye. The extracted cellulose was prepared by dewaxing process to releasing of lignin, bleaching and hemicellulose removal. The cellulose identified by FTIR and SEM-EDS. The efficiency of the cellulose to adsorp Procion dye was evaluated by variation in the initial concentration of dye (5, 10, 15, 20, 25, 30, 35, 40, 45 and 50 mg/L), solution pH (3, 4, 5, 6, 7, 8 and 9), and the contact time (15, 30, 45, 60, 75 and 90 minutes) at room temperature. The result showed that FTIR spectra of cellulose from kepok banana peel were similar with FTIR spectra of standardcellulose. The morphology of cellulose more homogenous than kepok banana peel powder. It was observed that the optimum adsorption of Procion dye by cellulose was on the initial concentration of 30 mg/L, pH solution of 5 and contact time within 30 minutes. The obtained result that cellulose has removal percentage to adsorp Procion dye more higher than kepok banana peel powder. The adsorption equilibrium showed the Langmuir isotherm was described well for adsorption process (R2 = 0.991) than Freundlich isotherm (R2 = 0.922).
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Torres, Carlos Rocha Gomes, Maria Filomena Rocha Lima Huhtala, Ana Paula Martins Gomes, et al. "Effect of Bleaching Agents on the Sealing of Cervical Barrier in Intracoronal Bleaching Procedures." World Journal of Dentistry 4, no. 4 (2013): 235–40. http://dx.doi.org/10.5005/jp-journals-10015-1238.
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ABSTRACT Discoloration of nonvital teeth is an esthetic deficiency frequently requiring bleaching treatment. The purpose of this study was to evaluate in vitro the effect of bleaching agents on two different cervical barriers in order to minimize or prevent the leakage along the root canal filling in the intracoronal bleaching procedures. Ninety-six extracted human molars were used which were biomechanically prepared, filled and divided into eight groups. The cervical barriers tested were zinc phosphate cement (ZPC) and resin-modified glass ionomer cement (RMGIC) applied (3 mm of thickness) at the cementoenamel junction level. Forty-eight specimens were divided into four groups for each cervical barrier: (1) control group without bleaching agent, (2) a mixture of sodium perborate and distilled water, (3) a mixture of sodium perborate and 10% carbamide peroxide and (4) a mixture of sodium perborate and 35% carbamide peroxide. The bleaching agents were placed inside the pulp chamber for 7 and 14 days, and the access opening was sealed with Cimpat. After 21 days, microleakage evaluation of 2% rhodamine B dye solution at dentin-cervical barrier interface was performed by a stereomicroscope. Data were submitted to Kruskal-Wallis, Dunn's and Dunnett's tests, with a significance level of 0.05. The results demonstrated no statistically significant differences among the control group and the experimental groups for each cervical barrier (ZPC and RMGIC); there were no significant differences among the bleaching agents for the same barrier and RMGIC barrier provided better sealing than ZPC (p < 0.05). Therefore, the bleaching agents demonstrated similar performance when tested for the same cervical barrier and RMGIC barrier provided better sealing than the ZPC barrier, regardless of the association of bleaching agents used. How to cite this article Yui KCK, Huhtala MFRL, da Silva EG, Ramos CJ, Torres CRG, de Paiva Gongalves SE, Gomes APM. Effect of Bleaching Agents on the Sealing of Cervical Barrier in Intracoronal Bleaching Procedures. World J Dent 2013;4(4): 235-240.
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Yacob, N., M. R. Yusof, A. Z. Mohamed, and K. Badri. "Changes in crystallinity of sago palm (Metroxylon sago spp.) waste during cellulose extraction." IOP Conference Series: Materials Science and Engineering 1308, no. 1 (2024): 012014. http://dx.doi.org/10.1088/1757-899x/1308/1/012014.
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Abstract Sago palm (Metroxylon sago spp.) is one of the major agricultural plants in Malaysia. Sago pith waste (SPW), which is left behind after sago starch extraction, is disposed of by washing off into the nearby river. Reuse of SPW provides a solution to the problem of discarding the waste. In this study, cellulose has been extracted from SPW. The fibers were pretreated with 2% of aqueous sodium hydroxide (NaOH) solution before bleaching with an acidified sodium chlorite (NaClO2) and acetate buffer solution. The influence of NaOH and bleaching treatment on the cellulose crystallinity of SPW has been investigated using chemical analysis, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). From XRD analysis, the crystallinity index (CI) was calculated. The CI of SPW increased significantly by 110% after the chemical treatments. The FTIR analysis proved the dissolution of the non-cellulosic components by NaOH and NaClO2 treatments.
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Endoma, Leonilo F., Loda M. Nacional, and Rovilla J. Luhan. "Solar irradiation as an alternative bleaching process for agar extracted from Gracilariopsis heteroclada in Iloilo, Philippines." Botanica Marina 62, no. 6 (2019): 605–13. http://dx.doi.org/10.1515/bot-2018-0120.
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Abstract The current industrial practice of using chemical bleach to achieve the pure white colour of agar is deleterious to both human and environmental health. This study evaluates the potential of solar irradiation as an alternative bleaching process for agar extracted from Gracilariopsis heteroclada in Iloilo, Philippines. The physico-chemical properties of agar obtained from alkaline-treated seaweed after exposure to different bleaching conditions (e.g. solar irradiation, hypochlorite solution, and ultraviolet and fluorescent lights) were examined and compared with commercial bacteriological agar. Photobleaching through solar irradiation produced agar with superior gel strength (1038.61 g cm−2), high 3,6-anhydrogalactose content (41.44%) and low total inorganic sulphate content (1.87%) without compromising agar yield (19.37%). Solar irradiation offers very promising results as a simple, low-cost, environmentally friendly alternative to the chlorine bleaching process for agar extraction.