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Journal articles on the topic 'Polymer solution purification'
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1
Schuett, Timo, Julian Kimmig, Stefan Zechel, and Ulrich S. Schubert. "Automated Polymer Purification Using Dialysis." Polymers 12, no. 9 (September 15, 2020): 2095. http://dx.doi.org/10.3390/polym12092095.
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The automated dialysis of polymers in synthetic robots is described as a first approach for the purification of polymers using an automated protocol. For this purpose, a dialysis apparatus was installed within a synthesis robot. Therein, the polymer solution could be transferred automatically into the dialysis tube. Afterwards, a permanent running dialysis could be started, enabling the removal of residual monomer. Purification efficiency was studied using chromatography and NMR spectroscopy, showing that the automated dialysis requires less solvent and is faster compared to the classical manual approach.
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Обуздина, Marina Obuzdina, Руш, E. Rush, Шалунц, and L. Shalunc. "Sorption Purification of Effluent Water From Heavy Metal Ions by Modified Natural Zeolites." Safety in Technosphere 6, no. 2 (August 21, 2017): 56–61. http://dx.doi.org/10.12737/article_598d7af88ce043.55438902.
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Features of sorption method of effluent water purification are considered. Analysis of technologies of effluent water purification from heavy metalsionsis presented. Physico-chemical regularities of sorption of Zn, Ni, Cu ions are investigated. As sorbents it is proposed to use zeolites of Holinsky deposits, modified by sulfur polymer, obtained from waste of epichlorohydrin production. This will allow simultaneously solving two problems: elimination of waste and wastewater purification, which is significantly advantageous from the economic point of view. Kinetic curves of sorption of Zn, Ni, Cu ions in different solution concentrations are presented. Also the adsorption process of heavy metal ions from solutions of chemically modified zeolites in the evaluation of the influence of various factors (the contact time of sorbent with solution, pH and temperature) are investigated.
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Mbui, Damaris W., Dickson M. Andala, Deborah A. Abong’o, and John N. Mmbaga. "Design and Fabrication of Polymer Layered Silicate Nanocomposites for Water Purification." MRS Advances 3, no. 36 (2018): 2099–107. http://dx.doi.org/10.1557/adv.2018.169.
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ABSTRACTZeolite and cellulose-acetate nanocomposites were fabricated in this study using a combination of melt blending and solution mixing. The nanocomposites were optimized for heavy metal adsorption using spiked lead and cadmium solutions. Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Powder X-Ray diffraction crystallography were used for physical characterization. Fourier Transform Infrared spectra showed a reduction of the hydroxyl peak for cellulose acetate and that of the residual silanol group for zeolites symbolizing bonding during nanocomposite formation. Scanning Electron Microscope results showed an increase in voids with zeolite loading in the nanocomposites, a useful characteristic of good adsorbents. Powder X-ray diffraction crystallography results showed a reduction in 2 theta values for the nanocomposites due to penetration of the polymer into the silicate lattice e.g. zeolite 2 theta peak at 7.44°reduced to 7.09°in the nanocomposites signifying an increase in crystal lattice d- spacing from 1.188 nm to 1.247 nm. The nanocomposites adsorbed a maximum of 97.20% lead ions and 85.06% cadmium ions from solution.
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Chen, Zhi-Liang, Yi Lin, Chun-Nan Zhu, Zhi-Ling Zhang, and Dai-Wen Pang. "A salt-out strategy for purification of amphiphilic polymer-coated quantum dots." New Journal of Chemistry 44, no. 36 (2020): 15341–44. http://dx.doi.org/10.1039/d0nj03541f.
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Ferraz, Natalia, Daniel O. Carlsson, Jaan Hong, Rolf Larsson, Bengt Fellström, Leif Nyholm, Maria Strømme, and Albert Mihranyan. "Haemocompatibility and ion exchange capability of nanocellulose polypyrrole membranes intended for blood purification." Journal of The Royal Society Interface 9, no. 73 (February 2012): 1943–55. http://dx.doi.org/10.1098/rsif.2012.0019.
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Composites of nanocellulose and the conductive polymer polypyrrole (PPy) are presented as candidates for a new generation of haemodialysis membranes. The composites may combine active ion exchange with passive ultrafiltration, and the large surface area (about 80 m 2 g −1 ) could potentially provide compact dialysers. Herein, the haemocompatibility of the novel membranes and the feasibility of effectively removing small uraemic toxins by potential-controlled ion exchange were studied. The thrombogenic properties of the composites were improved by applying a stable heparin coating. In terms of platelet adhesion and thrombin generation, the composites were comparable with haemocompatible polymer polysulphone, and regarding complement activation, the composites were more biocompatible than commercially available membranes. It was possible to extract phosphate and oxalate ions from solutions with physiological pH and the same tonicity as that of the blood. The exchange capacity of the materials was found to be 600 ± 26 and 706 ± 31 μmol g −1 in a 0.1 M solution (pH 7.4) and in an isotonic solution of phosphate, respectively. The corresponding values with oxalate were 523 ± 5 in a 0.1 M solution (pH 7.4) and 610 ± 1 μmol g −1 in an isotonic solution. The heparinized PPy–cellulose composite is consequently a promising haemodialysis material, with respect to both potential-controlled extraction of small uraemic toxins and haemocompatibility.
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Parlow, John J., Rajesh V. Devraj, and Michael S. South. "ChemInform Abstract: Solution-Phase Chemical Library Synthesis Using Polymer-Assisted Purification Techniques." ChemInform 30, no. 44 (June 13, 2010): no. http://dx.doi.org/10.1002/chin.199944333.
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Grachek, V. I., A. P. Polikarpov, A. A. Shunkevich, R. V. Martsynkevich, and O. I. Isakovich. "Synthesis and investigation of properties of new chelate sorbent for water purification." Doklady of the National Academy of Sciences of Belarus 63, no. 3 (June 28, 2019): 298–303. http://dx.doi.org/10.29235/1561-8323-2019-63-3-298-303.
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Polymer analogous transformations of a “nitron” fiber were established and a new amino carboxylic fibrous cation exchanger FIBAN X-2 was obtained. It is shown that FIBAN X-2 is an effective sorbent of heavy and non-ferrous metals from multi-ionic aqueous solutions, regardless of the method of fiber amination. The cation exchanger obtained by amination of a “nitron” fiber in the vapor phase absorbs Mn+2 twice as much as the ion exchanger obtained by amination in the aqueous solution.
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Lazarev, S. I., A. A. Levin, S. V. Kovalev, M. I. Mikhailin, V. Yu Ryzhkin, and T. A. Khromova. "Voltamper and Permeable Characteristics of Electrobaro-Membrane Purification of Galvanic Wastes from Mg2+, Fe2+, Ions." Vestnik Tambovskogo gosudarstvennogo tehnicheskogo universiteta 26, no. 4 (2020): 629–36. http://dx.doi.org/10.17277/vestnik.2020.04.pp.629-636.
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The analysis of literature data on current-voltage characteristics (CVCs) and permeability of electromembrane systems in the processing of technological solutions of various industries is given. It is noted that electromembrane systems containing porous semi-permeable polymer membranes are insufficiently studied. The results of experimental studies on the CVCs of a membrane system equipped with an anode UAM-100, MGA-95 and near-cathode UAM-100, MGA-95 membranes during the separation of a model solution containing Mg2+, Fe2+, ions are presented. It is shown that in the study of membrane systems equipped with porous membranes, under the action of voltage and transmembrane pressure, as a result of the treatment of the model solution, two characteristic periods are noted on the CVCs (out-of-limit mode, intense electroosmotic transfer).
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FLYNN, D. L., R. V. DEVRAJ, and J. J. PARLOW. "ChemInform Abstract: Recent Advances in Polymer-Assisted Solution-Phase Chemical Library Synthesis and Purification." ChemInform 29, no. 51 (June 18, 2010): no. http://dx.doi.org/10.1002/chin.199851335.
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Paneysar, Joginder Singh, Stephen Barton, Sudeshna Chandra, Premlata Ambre, and Evans Coutinho. "Novel thermoresponsive assemblies of co-grafted natural and synthetic polymers for water purification." Water Science and Technology 75, no. 5 (December 21, 2016): 1084–97. http://dx.doi.org/10.2166/wst.2016.599.
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Water contamination and its purification are a global problem. The current approach to purify water is reduction of impurities to acceptable levels. One of the ways to achieve this is by use of water-soluble polymers that extract organic and metallic contaminants, from water. This paper presents a blend of composite polymers that eliminates both the contaminants simultaneously by the principle of adsorption at lower critical solution temperature. These composite polymers have been synthesized by grafting poly(N,N-diethylacrylamide), poly(N-isopropylacrylamide) and poly(N-vinylcaprolactam) on-to the natural polymer chitosan or its derivatives, giving smart graft polymeric assemblies (GPAs). One of the graft polymers, GPA-2, exhibits excellent adsorption properties able to remove metal ions like cadmium, cobalt, copper, lead, iron and also organic impurities like chlorophenol and phthalic anhydride. Studies reveal that 6 mg/ml GPA-2 is able to effect a 100% removal of organic impurities – chlorophenol (50 ppm) and phthalic anhydride (70 ppm) – from water, while complete removal of the heavy metal ions (Cu+2, Co+2 and Cd+2) together at 30 ppm concentration has been achieved with 7.5 mg/ml GPA-2. The reduction in level of impurities along with recyclability and reproducibility in the elimination spectrum makes these assemblies promising materials in water treatment.
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Han, Juan, Yun Wang, Tong Chen, Xiaowei Hu, Lei Gu, Xu Tang, Lei Wang, and Liang Ni. "Heat-induced coacervation for purification of Lycium barbarum polysaccharide based on amphiphilic polymer–protein complex formation." Canadian Journal of Chemistry 95, no. 8 (August 2017): 837–44. http://dx.doi.org/10.1139/cjc-2017-0008.
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Heat-induced coacervation of triblock copolymer solution was described, and its application in the purification of Lycium barbarum polysaccharide (LBP) was investigated. The formation of coacervate micelles–protein complex combined with the incompatibility between coacervate micelles and polysaccharide made it an ideal system for the separation of protein and LBP. This separation process was governed by a series of parameters including polymer concentration, amount of crude LBP solution, and pH. In the primary coacervation extraction process, LBP was preferentially distributed to dilute phase with a high recovery ratio of 82%, whereas 87% of protein was partitioned to the coacervate phase. The coacervate micelles–protein interaction and the interphase potential was regulated by temperature and electrolytes, respectively, which contributed to the recovery and recycling of the polymer. After phase separation, LBP was precipitated with the addition of ethanol. The FTIR spectrum was used to identify LBP. In addition, the antioxidant activity of LBP was measured.
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Lee, Sang Hyun, and Sung Su Kim. "A New Hollow-Fiber Adsorbent Material for Removing Arsenic from Groundwater." Journal of Chemistry 2019 (May 13, 2019): 1–9. http://dx.doi.org/10.1155/2019/2715093.
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To optimize the arsenic-adsorption efficiency and the mechanical strength of a hollow-fiber-type adsorbent, the optimal condition of polymeric solution was determined as 32 wt.% TiO2 and 17 wt.% polymer. A micropore-sponge form was developed at the slurry-extrusion speed of 2.500 ml/min and the internal coagulant-solution-extrusion speed of 1.250 ml/min, and the arsenic-adsorption efficiency improved. Given the result under conditions in natural groundwater containing various ions, the hollow-fiber-type adsorbent can be applied to real groundwater purification processes.
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Alshabanat, Mashael Nasser, and Murefah M. AL-Anazy. "An Experimental Study of Photocatalytic Degradation of Congo Red Using Polymer Nanocomposite Films." Journal of Chemistry 2018 (December 2, 2018): 1–8. http://dx.doi.org/10.1155/2018/9651850.
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Eco-friendly polymer nanocomposite films were synthesized using biodegradable polymers of chitosan and polyvinyl alcohol as polymeric matrices and carbon black nanoparticles as the reinforcement. These films were applied to study their applicability to industrial wastewater purification as a photocatalyst for degradation of Congo red as a target pollutant and to study the effect of the polymeric matrix types of the films on their performance as a semiconductor photocatalyst. Fourier-transform infrared (FT-IR) spectra and X-ray diffraction (XRD) were used to characterize the films. Visible light photocatalytic degradation of Congo red as a pollutant under various operational conditions of pH, dye concentration, contact time, and light intensity was performed. Photocatalytic results revealed that the polymeric substrate type does not play a major role in the photodegradation of the dye, and the best operational conditions were at a pH of 6 and a dye solution concentration of 8 mg/L.
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Marjanovic, Vesna, Aleksandra Peric-Grujic, Mirjana Ristic, Aleksandar Marinkovic, Radmila Markovic, Antonije Onjia, and Marija Sljivic-Ivanovic. "Selenate Adsorption from Water Using the Hydrous Iron Oxide-Impregnated Hybrid Polymer." Metals 10, no. 12 (December 4, 2020): 1630. http://dx.doi.org/10.3390/met10121630.
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Hybrid adsorbent, based on the cross-linked copolymer impregnated with hydrous iron oxide, was applied for the first time for Se(VI) adsorption from water. The influence of the initial solution pH, selenate concentration and contact time to adsorption capacity was investigated. Adsorbent regeneration was explored using a full factorial experimental design in order to optimize the volume, initial pH value and concentration of the applied NaCl solution as a reagent. Equilibrium state was described using the Langmuir model, while kinetics fitted the pseudo-first order. The maximum adsorption capacity was found to be 28.8 mg/g. Desorption efficiency increased up to 70%, and became statistically significant with the reagent concentration and pH increase, while the applied solution volume was found to be insignificant in the investigated range. Based on the results obtained, pH influence to the adsorption capacity, desorption efficiency, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis of loaded adsorbent, it was concluded that the outer- and inner-sphere complexation are mechanisms responsible for Se(VI) separation from water. In addition to the experiments with synthetic solutions, the adsorbent performances in drinking water samples were explored, showing the purification efficiency up to 25%, depending on the initial Se(VI) concentration and water pH. Determined sorption capacity of the cross-linked copolymer impregnated with hydrous iron oxide and its ability for regeneration, candidate this material for further research, as a promising anionic species sorbent.
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Goncharuk, Vladislav, Dmitry Kucheruk, Liubov Dubrovina, Oleksii Vyshnevskyi, Igor Dubrovin, and Volodymyr Ogenko. "MODIFICATION OF TUBULAR CERAMIC MEMBRANES BY PYROCARBON FROM CARBONIZED POLYMERS." Ukrainian Chemistry Journal 85, no. 6 (July 31, 2019): 97–103. http://dx.doi.org/10.33609/0041-6045.85.6.2019.97-103.
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The tubular ceramic membranes of clay minerals were modified with pyrocarbon, which was obtained by carbonizing of polymer precursors at 750 ° С in an argon flow. The precursor to carbonization of membrane II was polyurethane, obtained from laprol and polyisocyanate. A precursor to carbonization of the membrane III was a mixture of polymers formed by the reaction of components of an aqueous solution of a dry solution with NCO-groups of polyisocyanate. As a result of the modification, the membranes became black with a metallic luster. The composition and structure of the membranes were studied by XRF and SEM. The modifier of the membrane II is located in the pore space in the form of sintered agglomerates. The modifier of the membrane III is represented not only by the same agglomerates, but also envelops the structural elements of the membrane material. The apparent density and open porosity for the unmodified membrane are 1.80 g/cm3 and 44.9 %, for membrane II - 1.67 g/cm3 and 39.9 %, for membrane III - 1.68 g/cm3 and 38.3 %. Testing of modified membranes was carried out by water purification from Ca2 + and Fe3 + using the baromembrane method. The concentration of Ca2 + and Fe3 + in aqueous solutions of CaCl2 and FeCl3 was 100 mg/dm3. The period of time until the establishment of dynamic equilibrium in systems during water purification is (1–3 h). After reaching equilibrium the retention factor (R) of Ca2 + during water purification with membrane II is 30% at a pressure of 0.6 MPa, and at a pressure of 1.1 MPa – 18 %. The specific productivity increases with increasing pressure from 10 to 18 dm3/(m2×h). The R of Ca2 + in water purification with membrane III is 22 % at a pressure of 0.4 MPa, and the specific productivity is 47 dm3/(m2×h). The unmodified membrane does not inhibit Ca2 + at all, and its specific productivity at a working pressure of 0.7 MPa decreases from 755 to 500 dm3/(m2×h) in 2-3 hours. The coefficient of retention of Fe3 + by membrane III after 5 hours at a working pressure of 0.4 MPa is 98 % The specific productivity in this case is 8 dm3/(m2×h).
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Kareem, Safaradeen Olateju, Olayinka Quadri Adio, and Michael Bamitale Osho. "Immobilization of Aspergillus niger F7-02 Lipase in Polysaccharide Hydrogel Beads of Irvingia gabonensis Matrix." Enzyme Research 2014 (December 31, 2014): 1–7. http://dx.doi.org/10.1155/2014/967056.
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The potential of polysaccharide Irvingia gabonensis matrix as enzyme immobilization support was investigated. Lipase of Aspergillus niger F7-02 was immobilized by entrapment using glutaraldehyde as the cross-linking agent and stabilized in ethanolic-formaldehyde solution. The pH and temperature stability and activity yield of the immobilized enzyme were determined. Such parameters as enzyme load, bead size, number of beads, and bead reusability were also optimized. Adequate gel strength to form stabilized beads was achieved at 15.52% (w/v) Irvingia gabonensis powder, 15% (v/v) partially purified lipase, 2.5% (v/v) glutaraldehyde, and 3 : 1 (v/v) ethanolic-formaldehyde solution. There was 3.93-fold purification when the crude enzyme was partially purified in two-step purification using Imarsil and activated charcoal. Optimum lipase activity 75.3 Ug−1 was achieved in 50 mL test solution containing 15 beads of 7 mm bead size. Relative activity 80% was retained at eight repeated cycles. The immobilization process gave activity yield of 59.1% with specific activity of 12.3 Umg−1 and stabilized at optimum pH 4.5 and temperature 55°C. Thus the effectiveness and cost-efficiency of I. gabonensis as a polymer matrix for lipase immobilization have been established.
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Russo, Francesca, Tiziana Marino, Francesco Galiano, Lassaad Gzara, Amalia Gordano, Hussam Organji, and Alberto Figoli. "Tamisolve® NxG as an Alternative Non-Toxic Solvent for the Preparation of Porous Poly (Vinylidene Fluoride) Membranes." Polymers 13, no. 15 (August 3, 2021): 2579. http://dx.doi.org/10.3390/polym13152579.
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Tamisolve® NxG, a well-known non-toxic solvent, was used for poly(vinylidene fluoride) (PVDF) membranes preparation via a non-solvent-induced phase separation (NIPS) procedure with water as a coagulation bath. Preliminary investigations, related to the study of the physical/chemical properties of the solvent, the solubility parameters, the gel transition temperature and the viscosity of the polymer–solvent system, confirmed the power of the solvent to solubilize PVDF polymer for membranes preparation. The role of polyvinylpyrrolidone (PVP) and/or poly(ethylene glycol) (PEG), as pore former agents in the dope solution, was studied along with different polymer concentrations (10 wt%, 15 wt% and 18 wt%). The produced membranes were then characterized in terms of morphology, thickness, porosity, contact angle, atomic force microscopy (AFM) and infrared spectroscopy (ATR-FTIR). Pore size measurements, pore size distribution and water permeability (PWP) tests placed the developed membranes in the ultrafiltration (UF) and microfiltration (MF) range. Finally, PVDF membrane performances were investigated in terms of rejection (%) and permeability recovery ratio (PRR) using methylene blue (MB) in water solution to assess their potential application in separation and purification processes.
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Gomes Ferreira da Silva, Laffert, Hualan Patrício Pacheco, Judes Gonçalves dos Santos, and Luciene Batista da Silveira. "A Hybrid Nanocomposite from γ-Fe2O3 Nanoparticles Functionalized in the Amazon Oil Polymers matrix." International Journal for Innovation Education and Research 8, no. 6 (June 1, 2020): 418–25. http://dx.doi.org/10.31686/ijier.vol8.iss6.2435.
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In recent years, there was a crescent increase in studies involving hybrid magnetic nanocomposites from renewable resources, because of its importance in the synthesis of new organic biomaterials. Herein, we report a synthesis of Magnetic Nanocomposites (MNCs) from superparamagnetic nanoparticles based on iron oxide of maghemite (γ-Fe2O3) coated by a polymeric matrix. In this study, we used γ-Fe2O3 which are prepared using co-precipitation method, where salts with ions Fe+2 and Fe+3 are dissolved in distilled water and stirred until they reach about 60 ° C. Shortly after the mixture is add a solution of NH4OH. After this step, the magnetite solute (Fe3O4) is left in oxidizing solution, thus forming nanoparticles of γ-Fe2O3. For activation of the functional groups and extraction of the polymer we used polycondensation method, wherein the oil extracted from Carapa Guianensis Aubl. is diluted in ethylene glycol (C2H6O2). After that, the mixture undergoes processes: hydrothermal and isobaric-isothermal. Then, purification was performed polymer, thus obtaining a polymer of natural oil. The nanoparticles was coated for the polymeric matrix using dispersion method and freeze drying, thereby forming a hybrid MNCs ready for characterization. For the samples characterization was utilized X-ray diffraction (XRD) and spectroscopy: UV-Vis, Fourier Transform Infrared (FTIR), EDX and PAS. The results indicate that magnetic-polymeric nanocomposites structure formed was type core/shell, wherein the core was formed γ-Fe2O3 nanoparticles, coated by the polymer matrix, which presents some characteristics of the natural oil used in their synthesis. In recent years, there was a crescent increase in studies involving hybrid magnetic nanocomposites from renewable resources, because of its importance in the synthesis of new organic biomaterials. Herein, we report a synthesis of Magnetic Nanocomposites (MNCs) from superparamagnetic nanoparticles based on iron oxide of maghemite (γ-Fe2O3) coated by a polymeric matrix. In this study, we used γ-Fe2O3 which are prepared using co-precipitation method, where salts with ions Fe+2 and Fe+3 are dissolved in distilled water and stirred until they reach about 60 ° C. Shortly after the mixture is add a solution of NH4OH. After this step, the magnetite solute (Fe3O4) is left in oxidizing solution, thus forming nanoparticles of γ-Fe2O3. For activation of the functional groups and extraction of the polymer we used polycondensation method, wherein the oil extracted from Carapa Guianensis Aubl. is diluted in ethylene glycol (C2H6O2). After that, the mixture undergoes processes: hydrothermal and isobaric-isothermal. Then, purification was performed polymer, thus obtaining a polymer of natural oil. The nanoparticles was coated for the polymeric matrix using dispersion method and freeze drying, thereby forming a hybrid MNCs ready for characterization. For the samples characterization was utilized X-ray diffraction (XRD) and spectroscopy: UV-Vis, Fourier Transform Infrared (FTIR), EDX and PAS. The results indicate that magnetic-polymeric nanocomposites structure formed was type core/shell, wherein the core was formed γ-Fe2O3 nanoparticles, coated by the polymer matrix, which presents some characteristics of the natural oil used in their synthesis.
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Solodovnik, Tetyana Volodymyrivna, Valentyna Serhiivna Kultenko, and Andrii Anatoliiovych Slis. "RESEARCH ON THE EFFICIENCY OF USE OF NATURAL POLYMER FLOCCULANTS IN THE PROCESS OF WATER SOLUTION PURIFICATION." Вісник Черкаського державного технологічного університету, no. 1 (February 28, 2020): 50–56. http://dx.doi.org/10.24025/2306-4412.1.2020.181072.
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Dembczyński, Radosław, Wojciech Białas, and Tomasz Jankowski. "Determination of phase diagrams and thermoseparation behaviour of aqueous two-phase systems composed of ethylene oxide–propylene oxide random copolymer and potassium phosphate." Chemical and Process Engineering 33, no. 3 (October 1, 2012): 411–29. http://dx.doi.org/10.2478/v10176-012-0036-8.
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Abstract The application of aqueous two-phase systems (ATPS) is a cost-effective and simple method of protein separation (including enzymes) from complex systems. The first stage of designing the protein purification process in an ATPS involves the identification of the conditions for the formation of a given extraction system. For this purpose, the conditions for the formation of ATPSs in a thermoseparating EO50PO50 polymer/potassium phosphates system have been studied. Factors determining the ATPS formation comprised: separation temperature (4ºC or 20ºC), phosphate solution pH (6, 7.5 or 9) as well as the concentration of NaCl introduced into the systems (0.085 M, 0.475 M and 0.85 M). ATPS without NaCl were prepared as well. The conditions for the formation of the primary EO50PO50/potassium phosphate ATPS were determined with their phase diagrams. It was observed that with an increase of phosphate pH and NaCl concentration in the system, there was a decrease of the EO50PO50 and phosphate concentrations necessary to form a primary ATPS. After the primary two-phase separation, the top phase (rich in the EO50PO50 polymer) was partitioned from the bottom phase (rich in phosphates). Next, by means of polymer phase thermoseparation, a secondary two-phase system was formed. In the secondary EO50PO50/phosphate ATPS, the bottom phase was formed by the concentrated EO50PO50 polymer (30-80% concentration), while the top phase by a solution composed mainly of water, containing phosphate ions and remains of EO50PO50 polymer (3-7%).
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Klimonda, A., and I. Kowalska. "Application of polymeric membranes for the purification of solutions containing cationic surfactants." Water Science and Technology 79, no. 7 (April 1, 2019): 1241–52. http://dx.doi.org/10.2166/wst.2019.115.
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Abstract The aim of the study was to examine physicochemical properties of three cationic surfactants and to evaluate the effectiveness of their removal with the use of polymeric membranes. The experiments were performed in a laboratory scale set-up with the use of Microdyn-Nadir® nanofiltration and ultrafiltration membranes. Cetrimonium bromide (CTAB), benzalkonium chloride (BAC) and Tequat LC90i (TEAQ) were chosen for the test. In the experiments, surfactant solutions in a wide range of concentration were treated (50–3,000 mg L−1). The experimental research included evaluation of the effect of membrane type and solution parameters (surfactant type and concentration, presence of inorganic compounds) on the process efficiency (retention coefficient and permeate flux). It was shown that surfactant removal by means of the pressure-driven membrane processes is an extensive issue and its efficiency depends on many factors. Ultrafiltration and nanofiltration membranes proved to be usable in CTAB removal (separation exceeded 90%); however, the process effectiveness was affected by surfactant concentration, membrane polymer type and membrane pore size. Separation obtained for BAC was on the lower level – the use of nanofiltration membranes brought maximum retention of 70%. TEAQ separation was very high and reached 100% with the use of ultrafiltration membranes. Mineral salt addition led to significant drop in surfactant retention.
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Guerrero, Jorge, Amanda Carrillo, María Mota, Roberto Ambrosio, and Francisco Aguirre. "Purification and Glutaraldehyde Activation Study on HCl-Doped PVA–PANI Copolymers with Different Aniline Concentrations." Molecules 24, no. 1 (December 25, 2018): 63. http://dx.doi.org/10.3390/molecules24010063.
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In this work, we report the synthesis and purification of polyvinyl alcohol-polyaniline (PVA–PANI) copolymers at different aniline concentrations, and their molecular (1H-NMR and FTIR), thermal (TGA/DTG/DSC), optical (UV–Vis-NIR), and microstructural (XRD and SEM) properties before and after activation with glutaraldehyde (GA) in order to obtain an active membrane. The PVA–PANI copolymers were synthesized by chemical oxidation of aniline using ammonium persulfate (APS) in an acidified (HCl) polyvinyl alcohol matrix. The obtained copolymers were purified by dialysis and the precipitation–redispersion method in order to eliminate undesired products and compare changes due to purification. PVA–PANI products were analyzed as gels, colloidal dispersions, and thin films. 1H-NMR confirmed the molecular structure of PVA–PANI as the proposed skeletal formula, and FTIR of the obtained purified gels showed the characteristic functional groups of PVA gels with PANI nanoparticles. After exposing the material to a GA solution, the presence of the FTIR absorption bands at 1595 cm−1, 1650 cm−1, and 1717 cm−1 confirmed the activation of the material. FTIR and UV–Vis-NIR characterization showed an increase of the benzenoid section of PANI with GA exposure, which can be interpreted as a reduction of the polymer with the time of activation and concentration of the solution.
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Jang, Wongi, Jaehan Yun, Yejun Park, In Kee Park, Hongsik Byun, and Chang Hyun Lee. "Polyacrylonitrile Nanofiber Membrane Modified with Ag/GO Composite for Water Purification System." Polymers 12, no. 11 (October 22, 2020): 2441. http://dx.doi.org/10.3390/polym12112441.
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Silver nanoparticle-modified graphene oxide (Ag/GO) was reliably prepared by using sodium borohydride (NaBH4) in the presence of citric acid capping agent via a simple wet chemistry method. This rapidly formed Ag/GO composite exhibited good dispersity in a solution containing hydrophilic polyacrylonitrile (PAN). Subsequent electrospinning of this precursor solution resulted in the successful formation of nanofibers without any notable defects. The Ag/GO-incorporated PAN nanofibers showed thinner fiber strands (544 ± 82 nm) compared to those of GO-PAN (688 ± 177 nm) and bare-PAN (656 ± 59 nm). Subsequent thermal treatment of nanofibers resulted in the preparation of thin membranes to possess the desired pore property and outstanding wettability. The Ag/GO-PAN nanofiber membrane also showed 30% higher water flux value (390 LMH) than that of bare-PAN (300 LMH) for possible microfiltration (MF) application. In addition, the resulting Ag/GO-PAN nanofiber membrane exhibited antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Furthermore, this composite membrane exhibited outstanding anti-fouling property compared to the GO-PAN nanofiber membrane in the wastewater treatment. Therefore, the simple modification strategy allows for the effective formation of Ag/GO composite as a filler that can be reliably incorporated into polymer nanofiber membranes to possess improved overall properties for wastewater treatment applications.
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Khan, Muhammad Yasir, Ali Dad Chandio, Muhammad Sohail, Syed Zeeshan Abbas, Rao Shakeel Ahmed, Shahid Bhutto, and Syed Junaid Mehmood. "Removal of Heavy Metals (Lead, Cadmium and Iron) from Low-Grade Nanoscale Zinc Oxide Using Ammonium Carbonate Solution as a Leaching Agent." Key Engineering Materials 778 (September 2018): 132–36. http://dx.doi.org/10.4028/www.scientific.net/kem.778.132.
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This study investigated the purification and refining method for producing a nanometer size zinc oxide (ZnO) from the low-grade ZnO commercial powder using low cost ammonium carbonate solution as a leaching agent. The atomic absorption spectroscopy results show that the concentration of iron, lead and cadmium can be dramatically reduced by ammonium carbonate leaching and washing. X-ray diffraction (XRD) and scanning electron microscope (SEM) results show that structural properties can improve the degree of the preferential c-axis orientation, grain size, and surface morphology of ZnO by solvent evaporation. All physical and chemical results are of particular significance for the preparation of purified ZnO for device fabrication in photovoltaic industry, functional ZnO coatings, and polymer nanocomposite applications.
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Meng, Xiang Fu, Zhi Wei Zhang, Ying Zhang, Zhi Chang Xiao, and Qing Li Wei. "Preparation of Polyacrylic Acid/TiO2 Nanocomposites and its Application in Photodegradation of Methyl Orange." Materials Science Forum 694 (July 2011): 234–38. http://dx.doi.org/10.4028/www.scientific.net/msf.694.234.
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In this paper, polyacrylic acid (PAA)/TiO2 nanocomposites with photocatalytic activity were prepared via in-situ growth of anatase TiO2 nanoparticles in polyacrylic acid matrix using a simple hydrothermal method. First, water-soluble titania xerogel was prepared by a modified sol-gel procedure involving hydrolyzation of titania precursor, tetra-n-butyl titanate (TBT), in trifluoroacetic acid solution. Then, titania xerogel was dissolved in water and formed a homogeneous solution. Sequentely, polyacrylic acid as an adsorbed polymer was put into the solution and a hydrogel containing titania xerogel was obtained. After hydrothermal treatment for 10h at 100 °C, polyacrylic acid/TiO2 nanocomposites were obtained. The structure and morphology of as-prepared samples were characterized by Raman, SEM, and TEM. The photocatalytic activity of nanocomposites was evaluated by photodegradation of methyl orange under UV irradiation. The result showed that TiO2 nanocomparticles in anatase phase was in-situ generated inside PAA matrix and revealed a high photocatalytic activity, which can be used in environment purification and water treatment.
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Takai, Ryo, Rio Kurimoto, Yasuhiro Nakagawa, Yohei Kotsuchibashi, Koki Namekawa, and Mitsuhiro Ebara. "Towards a Rational Design of Zeolite-Polymer Composite Nanofibers for Efficient Adsorption of Creatinine." Journal of Nanomaterials 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/5638905.
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This report describes the compositional and structural design strategy of a zeolite-polymer composite nanofiber mesh for the efficient removal of uremic toxins towards blood purification application. The nanofiber is fabricated by electrospinning composite solution of biocompatible poly(ethylene-co-vinyl alcohol) (EVOH) and zeolite particles which are capable of selectively adsorbing uremic toxins such as creatinine. By controlling electrospinning conditions carefully, the incorporated zeolites in EVOH were found to correspond closely to the feed ratios. Elemental mapping images of Si show that zeolites were uniformly blended within the fibers. The fabricated composite fibers successfully adsorbed creatinine from solution and the adsorption capacity reached a maximum at 12 h. The crystallinity of the nanofiber was also controlled by varying the composition of ethylene content in EVOH. Less crystallinity resulted in higher creatinine adsorption capacity due to the barrier property of EVOH. Cytotoxicity assay demonstrated that the composite fibers showed less toxicity than free zeolite particles which killed more than 95% of cells. The proposed composite fibers, therefore, have the potential to be utilized as a new approach to removing creatinine selectively from the bloodstream.
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Hanafi, Achmad, Harry Budiman, and Fauzan Aulia. "The Influence of Heat and Two Stages Precipitation in the Process of Natural Polymer Purification from the Byproduct of Bioethanol Process Base on Empty Palm Fruit Bunch." Advanced Materials Research 1123 (August 2015): 177–81. http://dx.doi.org/10.4028/www.scientific.net/amr.1123.177.
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The biopolymer material, lignin, was recovered from the black liquor by acidification of the black liquor using sulfuric acid. Several purification techniques were carried out to produce the high purity of lignin such as gradual precipitation of lignin from black liquor (first stage: precipitation at pH 7, second stage: precipitation at pH 2) and the diluting of crude lignin by sodium hydroxide then followed by re-precipitation at different temperature. Subsequently, the impurities of lignin product resulted from each purification techniques was determined as ash content that analyzed using temperature program furnace; and the content of lignin was investigated using spectrophotometer UV-Vis. The result showed that the content of lignin of material produced from gradual precipitation was approximately 77.6%. It was higher than the content of lignin about 3.4% of material produced from direct precipitation to pH 2. In addition, the elevating of temperature from 40 to 60°C was no considerably affect to the content of lignin in precipitate produced from re-precipitation of crude lignin solution in sodium hydroxide. Nonetheless, the content of lignin of precipitate improved 15% when the temperature of re-precipitation of crude lignin solution in sodium hydroxide was raised from room temperature to 40-60°C.
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Munzhelele, Elisa Pandelani, Wasiu Babatunde Ayinde, Rabelani Mudzielwana, and Wilson Mugera Gitari. "Synthesis of Fe Doped Poly p-Phenylenediamine Composite: Co-Adsorption Application on Toxic Metal Ions (F− and As3+) and Microbial Disinfection in Aqueous Solution." Toxics 9, no. 4 (April 1, 2021): 74. http://dx.doi.org/10.3390/toxics9040074.
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Water is regarded as an important natural resource to sustain life, and its purification is an important criterion that determines its quality and usefulness. In this study, the incorporation of Fe3+ oxide onto a phenylenediamine (pPD) polymer matrix through chemical co-polymerization was prepared, and its arsenite and fluoride removal potentials at optimal conditions from aqueous solution were evaluated. The morphology and structural analysis of the synthesized Fe-doped pPD (Fe-pPD) were comparatively evaluated using the FT-IR, SEM, EDS, and XRD techniques. Fe was successfully incorporated onto pPD matrix as confirmed by different morphological characterizations. The rate of adsorption of F− and As3+ onto the Fe-pPD composite best followed the pseudo-second-order kinetic model. The experimental data for both As3+ and F− onto the Fe-pPD composite better fit the Freundlich isotherm model at different operating temperatures. Overall, the synthesized composite exhibited a strong affinity towards fluoride uptake (96.6%) than arsenite uptake (71.14%) with a maximum capacity of 6.79 (F−) and 1.86 (As3+) mg/g. Additionally, the synthesized adsorbent showed some level of antimicrobial activity against common water-borne bacterial. Therefore, the Fe-doped pPD composite has the potential ability for inorganic metal species pollutants remediation and bacterial disinfection in community-level water purification processes.
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Ratnaningsih, Enny, Sulistiya Nirta Sunaryo, Idris Idris, and Rindia Maharani Putri. "Recombinant Production and One-Pot Purification for Enhancing Activity of Haloacid Dehalogenase from Bacillus cereus IndB1." Reaktor 21, no. 2 (August 1, 2021): 59–64. http://dx.doi.org/10.14710/reaktor.21.2.59-64.
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In recent years we have witnessed the emergence of organohalogen utilization in various chemical-based industries, particularly polymer-based, agricultural, and pharmaceutical sectors. Despite this, organohalogen compounds are actually very dangerous to the environment, as they are difficult to be naturally degraded and generally toxic to organisms. A green and biocompatible method to overcome this issue is by employing enzymes that could convert organohalogens into non-toxic compounds, such as the class of enzymes known as haloacid dehalogenases. To enhance the activity of haloacid dehalogenase isolated from local strains of Bacillus cereus IndB1, we have developed a recombinant expression system using pET-bcfd1 plasmid in E. coli BL21 (DE3) host cells. Following enzyme production, we also demonstrated a one-pot purification system for the expressed dehalogenase, harnessing the presence of His-tag in the recombinant clones. Purification was carried out using Ni-NTA affinity column chromatography, using imidazole eluent with a concentration gradient of 10 mM to 500 mM. The enzyme activity was tested against the monochloroacetic acid (MCA) substrate according to the Bergmann and Sanik method, and the protein content in the solution was measured using the Bradford method. The purity of the enzyme after one-pot purification was confirmed by SDS-PAGE analyses, showing a single band of 40 kDa in size. Remarkably, the purified haloacid dehalogenase specific activity was increased by 12-fold compared to its crude enzyme extract. Therefore, the expression and purification system developed in this study allow further exploration of dehalogenases from local strains as an efficient catalyst for MCA biodegradation.Keywords: recombinant expression, haloacid dehalogenase, monochloroacetic acid, enzyme purification
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Squeo, Benedetta Maria, Francesco Carulli, Elisa Lassi, Francesco Galeotti, Umberto Giovanella, Silvia Luzzati, and Mariacecilia Pasini. "Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices." Pure and Applied Chemistry 91, no. 3 (March 26, 2019): 477–88. http://dx.doi.org/10.1515/pac-2018-0925.
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Abstract Polar semiconducting polymers based on a conjugated polymer backbone endowed with chemically anchored polar groups on the side chains have proved to be particularly interesting as optimization layer at organic/cathode interface in optoelectronic devices. In particular, the pendant phosphonate groups impart water-alcohol solubility allowing easy solution processing, and improve electron injection thanks to both a favorable interfacial dipole of phosphonate groups and an intense coordination interaction between the phosphonate groups and Al cathode. In this work we synthesize alternating fluorene-benzothiadiazole copolymers by proposing a post-polymerization reaction to insert the phosphonate groups. Thanks to this approach it is possible to use standard Suzuki coupling conditions, simplifying the process of synthesis, purification and characterization. The polymer Poly[9,9-bis(6′-diethoxylphosphorylhexyl)-alt-benzothiadiazole] (P2), is tested in conventional organic solar cells as cathode interfacial layers showing, with respect to the control device, an increasing of all the photovoltaic parameters, with a final power conversion efficiency that reaches 5.35% starting from 4.6%. The same trend is observed for multilayered polymer light-emitting diodes with an external quantum efficiency of the P2-based PLED enhanced of 1.5 times with respect to the basic devices with bare Al cathode, and negligible roll-off efficiency. The synergic effects of energy gap modulation and of polar phosphonated pendant functionalities of P2 are compared with the corresponding fluorene-based polar homopolymer. Our results show that, not only a proper selection of side functionalities, but also the tailoring of the energy gap of cathode interfacial materials (CIMs) is a possible effective strategy to engineer cathode of different optoelectronic devices and enhance their performance.
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Gholamvand, Zahra, Seyed Hamed Aboutalebi, and Mansoor Keyanpour-Rad. "PHOTOCATALYTIC OXIDATION OF VOLATILE ORGANIC COMPOUNDS OVER ELECTROSPUN ACTIVATED TIO2/CARBON NANOFIBER COMPOSITE." International Journal of Modern Physics: Conference Series 05 (January 2012): 622–29. http://dx.doi.org/10.1142/s2010194512002553.
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In this study, TiO 2/ PAN -based fibers were prepared by electrospinning a composite solution containing both the desirable contents of TiO 2 and a 10 wt. % PAN polymer solution dissolved in N , N -dimethylformamide. The TiO 2 loaded electrospun PAN nanofibers were then carbonized at 1000 °C in N 2 atmosphere furnace after stabilization at 230 °C in air. Then CNF / TiO 2 nanofibers were oxidized at 450 °C in air. The morphology and structure of the TiO 2-embeded carbon nanofibers were investigated by SEM and Raman spectroscopy. Specific surface area was determined using BET equation from N 2 adsorption analysis. Photocatalytic tests were conducted in a UV illuminated set-up specialized for the filters using ethanol vapor. The results have shown that ethanol vapor was efficiently degraded on TiO 2/ CNF composite nanofiber mat under UV illumination. The aim of this study was to further investigate the feasibility of TiO 2/ ACF for practical indoor air purification.
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Ghosh, Somnath, Tasneem Kausar Ranebennur, and H. N. Vasan. "Study of Antibacterial Efficacy of Hybrid Chitosan-Silver Nanoparticles for Prevention of Specific Biofilm and Water Purification." International Journal of Carbohydrate Chemistry 2011 (January 11, 2011): 1–11. http://dx.doi.org/10.1155/2011/693759.
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Antibacterial efficacy of silver nanoparticles (Ag NPs) deposited alternatively layer by layer (LBL) on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip has been studied. An eight-bilayer chitosan/silver (Cs/Ag)8 hybrid was prepared having a known concentration of silver. Techniques such as UV-visible spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), and atomic force microscopy (AFM) were carried out to understand and elucidate the physical nature of the film. Gram-negative bacteria, Escherichia coli (E. coli), were used as a test sample in saline solution for antibacterial studies. The growth inhibition at different intervals of contact time and, more importantly, the antibacterial properties of the hybrid film on repeated cycling in saline solution have been demonstrated. AFM studies are carried out for the first time on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months) are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. The hybrid can be a promising bioactive material for the prevention of biofilms specific to E. coli and in purification of water for safe drinking.
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TAO, CHUN-TE, and TAI-HORNG YOUNG. "THERMOSENSITIVE NANOPARTICLES CONJUGATING WITH CD34 ANTIBODY AND ITS SOLUTION PEROPERTIES." Biomedical Engineering: Applications, Basis and Communications 18, no. 05 (October 25, 2006): 222–28. http://dx.doi.org/10.4015/s101623720600035x.
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Poly N-isopropylacrylamide (PNIPAAm) is a well-known temperature-sensitive polymer. When the temperature is higher than the lower critical solution temperature (LCST), PNIPAAm aquous solution is cloudy (phase separation occurred). In contrast, when the temperature is lower than the LCST, PNIPAAm is soluble in water (a homogeneous solution). The lower critical solution temperature (LCST) in aqueous solution of PNIPAAm was about 32~33°C. We prepared nano-scaled PNIPAAm particles containing carboxylic group on their surfaces by introducing acrylic acid monomer. The carboxylic groups were applied to conjugate with the amino group of the CD34 antibody. This immuno-conjugate can be applied on targeting the human CD34 positive cells, peripheral blood progenitor cells included, for cell purification and drug controlled release. In order to the active responding of controlled release of the conjugate in the body influenced by temperature, we hope to estimate the shifting of the gel-collapse temperature or cloud point of the immuno-conjugates by dynamic light scattering (DLS) and UV absorption. The results show that the gel-collapse temperature of the nano-particle was not significantly affected by the content of AA between 1.5~5 mol%. However, cloud point of the solution was elevated by the conjugation of CD34 antibody to 37°C. When CD34-conjugated particle was subsequently incorporated with recombinant FLT3-ligand, which is a smaller molecule compare to CD34 antibody, cloud point of the solution was not affected.
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Kusworo, Tutuk Djoko, Widayat Widayat, and Dani Puji Utomo. "Fabrication and Characterization of Nano Hybrid Cellulose Acetate-nanoTiO2/crosslinked Polyvinyl Alcohol Coated Membrane for Crude Clove Oil Purification." Periodica Polytechnica Chemical Engineering 64, no. 3 (July 2, 2019): 304–19. http://dx.doi.org/10.3311/ppch.13871.
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The application of membranes for clove oil purification has the potential to improve the efficiency and effectiveness of processing. The main problem that occurs is the polymer-based membranes tend to change in properties such as weakening, dissolving, and swelling when contact with clove oil. In this study, cellulose acetate membrane was developed with TiO2 nano-particles to reduce swelling effect and coating with polyvinyl alcohol (PVA) to modify membrane surface. The membranes were prepared using dry-wet phase inversion method from dope solution with polymer concentration of 14–20 wt% and nano-particles of TiO2 with a concentration of 0–1.5 wt% in total solid. The formed membrane was coated with PVA with a concentration of 2–5 wt% crosslinked using glutaraldehyde. The SEM results show that prepared membrane are asymmetric membranes and show the coated layer of PVA on the surface. The FTIR spectra confirm that the PVA is successfully crosslinked and the addition of nano-particles TiO2 decreases the membrane swelling degree, significantly. In the addition of 0.5 wt% of nano-TiO2 can increase the flux from 0.54 to 0.66 L × m−2 × h−1 × bar−1. The coated membrane surface using PVA increases the selectivity of the membrane to produce clove oil permeates with eugenol content of 82.5 % from 68 %.
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Peregudov, Yu S., A. V. Timkova, E. M. Gorbunova, and S. E. Plotnicova. "Use of ion-exchange fiber at the purification stage of wastewater of electroplating." Proceedings of the Voronezh State University of Engineering Technologies 80, no. 4 (March 21, 2019): 330–36. http://dx.doi.org/10.20914/2310-1202-2018-4-330-336.
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In the electroplating industry, large volumes of water are used, which are polluted at various stages in the process. Waste water containing transition metal ions is not only a dangerous source of environmental pollution, but also valuable waste. Taking into account the problems associated with the ecology and the rational use of natural resources, it is necessary to create low- and non-waste production, in particular, to develop new technological processes and appropriate equipment, to introduce water-circulation cycles. This paper presents the results of a study of the sorption of copper (II) and nickel (II) cations by the FIBAN X-1 ion exchange fiber. Calorimetric studies of the thermal effects of the interaction of FIBAN X-1 fiber with solutions of copper (II) and nickel (II) nitrates were carried out. It is shown that the power, thermal effect and time of the process depend on the nature and concentration of metal ions in the solution. Based on the experimental data, the enthalpy of the process was calculated. The endothermic effect of the process is explained by the energy costs associated with dehydration effects and changes in the conformation of the polymer fiber chains. Sorption isotherms of these ions were obtained. It has been established that at all concentrations studied, Ni2 + ions under these conditions are absorbed by ion exchange fibers better than Cu2 + cations. The calculated sorption constants for copper (II) and nickel (II) are greater than 1. It is shown that the Langmuir equation describes the sorption isotherm better than the Freundlich equation. For deep purification of waste water from metal ions, it was proposed to use the fibrous sorbent FIBAN X-1.
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Vasil’kov, Alexander, Margarita Rubina, Alexander Naumkin, Mikhail Buzin, Pavel Dorovatovskii, Georgy Peters, and Yan Zubavichus. "Cellulose-Based Hydrogels and Aerogels Embedded with Silver Nanoparticles: Preparation and Characterization." Gels 7, no. 3 (July 2, 2021): 82. http://dx.doi.org/10.3390/gels7030082.
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The paper presents the preparation and characterization of novel composite materials based on microcrystalline cellulose (MCC) with silver nanoparticles (Ag NPs) in powder and gel forms. We use a promising synthetic conception to form the novel composite biomaterials. At first MCC was modified with colloidal solution of Ag NPs in isopropyl alcohol prepared via metal vapor synthesis. Then Ag-containing MCC powder was used as precursor for further preparation of the gels. The hydrogels were prepared by dissolving pristine MCC and MCC-based composite at low temperatures in aqueous alkali solution and gelation at elevated temperature. To prepare aerogels the drying in supercritical carbon dioxide was implemented. The as-prepared cellulose composites were characterized in terms of morphology, structure, and phase composition. Since many functional properties, including biological activity, in metal-composites are determined by the nature of the metal-to-polymer matrix interaction, the electronic state of the metal was carefully studied. The studied cellulose-based materials containing biologically active Ag NPs may be of interest for use as wound healing or water-purification materials.
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Shaari, Nor Shamimi, Napisah Sapiai, Aidah Jumahat, and Muhammad Hussain Ismail. "Functionalization of Multi-Wall Carbon Nanotubes in Chemical Solution of H2SO4/HNO3 and its Dispersion in Different Media." Materials Science Forum 882 (January 2017): 103–7. http://dx.doi.org/10.4028/www.scientific.net/msf.882.103.
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The usage of multi-wall carbon nanotubes (MWCNTs) as reinforcement has been limited due to difficulties associated with dispersion of MWCNTs during the processing and poor adhesion between MWCNTs and matrix. In this paper, the effect of chemical functionalization with strong acid on the dispersion of MWCNTs were studied. The functionalization of MWCNTs were performed in chemical solution of sulphuric acid (H2SO4) and nitric acid (HNO3) with ratio of 3:1 and prepared at 80°C for 4 hours. The pristine MWCNTs (PMWCNTs) and acid treated MWCNTs (AMWCNTs) were analyzed using TEM, XRD, FTIR and Pycnometer density. The effect of dispersion of PMWCNTs and AMWCNTs was studied in three different matrices which are in aqueous media (distilled water), metal matrix and polymer matrix. The XRD results determined that the impurities in pristine MWCNTs such as NiZn3 have been removed after the purification process. The presence of carboxylic acid (-COOH) and hydroxyl (-OH) functional groups were determined using FT-IR. Based on the dispersion analysis in aqueous media, PMWCNTs were poor in suspension stability. While, the TEM images showed less agglomeration of the AMWCNTs compared to PMWCNTs and obtained a uniform dispersion in metal matrix (Cu) and polymer (epoxy) matrix composites.
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Ishihara, Ryo, Shiho Asai, and Kyoichi Saito. "Recent Progress in Charged Polymer Chains Grafted by Radiation-Induced Graft Polymerization; Adsorption of Proteins and Immobilization of Inorganic Precipitates." Quantum Beam Science 4, no. 2 (April 13, 2020): 20. http://dx.doi.org/10.3390/qubs4020020.
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Radiation-induced graft polymerization provides industrially superior functionalization schemes by selection of existing polymer substrates and design of graft chains. In this review, by a pre-irradiation method of the radiation-induced graft polymerization and subsequent chemical modifications, charged polymer chains grafted onto various components and shapes of the polymer substrates are described. The charged graft chains immobilized onto a porous hollow-fiber membrane captured proteins in multilayers via multipoint binding. A membrane onto which positively charged graft chains are immobilized, i.e., an anion-exchange porous hollow-fiber membrane, was commercialized in 2011 for the removal of undesirable proteins in the purification of pharmaceuticals. On the other hand, a membrane onto which negatively charged graft chains are immobilized, i.e., a cation-exchange porous hollow-fiber membrane, exhibited a low permeation flux for pure water; however, the prepermeation of an aqueous solution of magnesium chloride through the membrane restored the permeation flux because of ionic crosslinking of graft chains with magnesium ions. The charged graft chains provide a precipitation field for inorganic compounds such as insoluble cobalt ferrocyanide. The graft chains entangle or penetrate a precipitate owing to electrostatic interactions with the surface charge on the precipitate. Braids and wound filters composed of insoluble-cobalt-ferrocyanide-impregnated fibers are used for the removal of radiocesium from contaminated water at Tokyo Electric Power Co. (TEPCO) Fukushima Daiichi Nuclear Power Plant.
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Nechifor, Aurelia Cristina, Alexandru Goran, Vlad-Alexandru Grosu, Andreia Pîrțac, Paul Constantin Albu, Ovidiu Oprea, Alexandra Raluca Grosu, et al. "Reactional Processes on Osmium–Polymeric Membranes for 5–Nitrobenzimidazole Reduction." Membranes 11, no. 8 (August 17, 2021): 633. http://dx.doi.org/10.3390/membranes11080633.
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Membranes are associated with the efficient processes of separation, concentration and purification, but a very important aspect of them is the realization of a reaction process simultaneously with the separation process. From a practical point of view, chemical reactions have been introduced in most membrane systems: with on-liquid membranes, with inorganic membranes or with polymeric and/or composite membranes. This paper presents the obtaining of polymeric membranes containing metallic osmium obtained in situ. Cellulose acetate (CA), polysulfone (PSf) and polypropylene hollow fiber membranes (PPM) were used as support polymer membranes. The metallic osmium is obtained directly onto the considered membranes using a solution of osmium tetroxide (OsO4), dissolved in tert–butyl alcohol (t–Bu–OH) by reduction with molecular hydrogen. The composite osmium–polymer (Os–P)-obtained membranes were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), energy-dispersive spectroscopy analysis (EDAX), Fourier Transform Infra-Red (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The process performance was tested for reduction of 5–nitrobenzimidazole to 5–aminobenzimidazole with molecular hydrogen. The paper presents the main aspects of the possible mechanism of transformation of 5–nitrobenzimidazole to 5–aminobenzimidazole with hydrogen gas in the reaction system with osmium–polymer membrane (Os–P).
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Smith, Phil M., Indorica Sutradhar, Maxwell Telmer, Rishikesh Magar, Amir Barati Farimani, and B. Reeja-Jayan. "Isolating Specific vs. Non-Specific Binding Responses in Conducting Polymer Biosensors for Bio-Fingerprinting." Sensors 21, no. 19 (September 22, 2021): 6335. http://dx.doi.org/10.3390/s21196335.
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A longstanding challenge for accurate sensing of biomolecules such as proteins concerns specifically detecting a target analyte in a complex sample (e.g., food) without suffering from nonspecific binding or interactions from the target itself or other analytes present in the sample. Every sensor suffers from this fundamental drawback, which limits its sensitivity, specificity, and longevity. Existing efforts to improve signal-to-noise ratio involve introducing additional steps to reduce nonspecific binding, which increases the cost of the sensor. Conducting polymer-based chemiresistive biosensors can be mechanically flexible, are inexpensive, label-free, and capable of detecting specific biomolecules in complex samples without purification steps, making them very versatile. In this paper, a poly (3,4-ethylenedioxyphene) (PEDOT) and poly (3-thiopheneethanol) (3TE) interpenetrating network on polypropylene–cellulose fabric is used as a platform for a chemiresistive biosensor, and the specific and nonspecific binding events are studied using the Biotin/Avidin and Gliadin/G12-specific complementary binding pairs. We observed that specific binding between these pairs results in a negative ΔR with the addition of the analyte and this response increases with increasing analyte concentration. Nonspecific binding was found to have the opposite response, a positive ΔR upon the addition of analyte was seen in nonspecific binding cases. We further demonstrate the ability of the sensor to detect a targeted protein in a dual-protein analyte solution. The machine-learning classifier, random forest, predicted the presence of Biotin with 75% accuracy in dual-analyte solutions. This capability of distinguishing between specific and nonspecific binding can be a step towards solving the problem of false positives or false negatives to which all biosensors are susceptible.
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Waiman, Carolina V., Rodrigo E. Palacios, Hernán A. Montejano, Carlos A. Chesta, and María Lorena Gómez. "Photophysical Behavior of Modified Xanthenic Dyes Embedded into Silsesquioxane Hybrid Films: Application in Photooxidation of Organic Molecules." International Journal of Photoenergy 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/5758140.
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Polymeric materials based on a bridged silsesquioxane with pendant dodecyl chains were synthesized and modified with different xanthenic dyes with the aim of developing a material with potential application in photooxidation of organic compounds. The employed dyes constitute a family of novel xanthenic chromophores with outstanding properties as singlet oxygen photosensitizers. The hybrid matrix was chosen for its enhanced properties such as flexibility and chemical resistance. The employed dyes were easily incorporated into the hybrid polymer obtaining homogeneous, transparent, and low-refractive-index materials. The polymeric films were characterized using UV-Vis absorption, fluorescence, and laser flash photolysis techniques. The ability of these materials to produce singlet oxygen was tested following the photooxidation of 9,10-dimethylanthracene which is a well-known chemical trap for singlet oxygen. High photooxidation efficiencies were observed for these materials, which present the advantage of being easily removed/collected from the solution where photooxidation takes place. While photobleaching of the incorporated dyes is commonly observed in the solution, it takes place very slowly when dyes are embedded in the hybrid matrix. These properties bode well for the potential use of these materials in novel wastewater purification strategies.
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Ermolenko, Anna, Maria Vikulova, Alexey Shevelev, Elena Mastalygina, Peter Ogbuna Offor, Yuri Konyukhov, Anton Razinov, Alexander Gorokhovsky, and Igor Burmistrov. "Sorbent Based on Polyvinyl Butyral and Potassium Polytitanate for Purifying Wastewater from Heavy Metal Ions." Processes 8, no. 6 (June 13, 2020): 690. http://dx.doi.org/10.3390/pr8060690.
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Currently, the rapid development of industry leads to an increase in negative anthropogenic impacts on the environment, including water ecosystems. This circumstance entails toughening environmental standards and, in particular, requirements for the content of pollutants in wastewater. As a result, developing technical and cost-effective ways for wastewater purification becomes relevant. This study is devoted to the development of a novel composite sorbent, based on polyvinyl butyral and potassium polytitanate, designed to purify water from heavy metal ions. The co-deposition of a mixture based on a polymer solution and a filler suspension was used to obtain a composite material. In this work, the influence of the deposition conditions on the structure and properties of the resulting composites was studied, as well as the optimal ratio of components, including solvent, precipitant, polymer binder, and filler, were established. In the course of this study on the sorption properties of the developed composite materials using various sorption models, the sorption capacity of the obtained material, the sorption mechanism, and the limiting stage of the sorption process were determined. The developed sorbent can be suitably used in the wastewater treatment systems of galvanic industries, enterprises producing chemical current sources, and in other areas.
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Wang, Xiaoxiao, Jennifer Coyne Albrecht, Jennifer S. Lin, and Annelise E. Barron. "Monodisperse, “Highly” Positively Charged Protein Polymer Drag-Tags Generated in an Intein-Mediated Purification System Used in Free-Solution Electrophoretic Separations of DNA." Biomacromolecules 13, no. 1 (December 23, 2011): 117–23. http://dx.doi.org/10.1021/bm2013313.
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Sakdapipanich, Jitladdat, Patjaree Suksawad, Kittipong Insom, and Seiichi Kawahara. "Preparation of Functionalized Low Molecular Weight Natural Rubber Latex Using Solid Nanometric TiO3 Film as a Photocatalyst." Rubber Chemistry and Technology 78, no. 4 (September 1, 2005): 597–605. http://dx.doi.org/10.5254/1.3547900.
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Abstract Natural rubber (NR) is a high molecular weight (MW) hydrophobic polymer, which can not be easily dissolved in several kinds of solvents, leading to the limitation of usage. NR latex containing low MW and reactive-terminal groups is another interesting form to extend the applications of NR. In this study, a photochemical degradation of NR using H2O2, nanometric TiO2 film and UV irradiation was applied to prepare the hydroxylated low MW NR (LNR). A solid nanometric TiO2 film prepared from titanium solution was applied in the present work. The photosensitivity of the self-assembled TiO2 film was determined by the decomposition rate of methylene blue stock solution using UV/VIS spectrophotometer. The effect of type of NR latex used, H2O2, UV light and TiO2 film on the molecular weight reduction was studied, based on change in intrinsic viscosity determined by Ubbelohde solution viscosity. The structural characterization of the resulting LNR was analyzed by FT-IR and NMR techniques. It was found that hydroxylated LNR with number average molecular weight of 1 × 104 g/mol was obtained by UV irradiation (40 W) of deproteinized natural rubber (DPNR) latex (10% DRC) containing 30% w/w H2O2, on a petri dish coated with TiO2 film for 5 hr. The advantage of this method is that the obtained hydroxylated LNR in either latex or dry rubber form is very clean without further purification.
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Zhang, Wenluan, Zijun Wang, and Xiaobo Liu. "A novel poly(arylene ether nitrile) ultrafiltration membrane for water purification and its antifouling property with in situ-generated SiO2 nanoparticles." High Performance Polymers 31, no. 8 (December 4, 2018): 977–85. http://dx.doi.org/10.1177/0954008318815214.
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In this work, poly(arylene ether nitrile) (PEN) was utilized to fabricate a separation membrane to remove dye molecules and oil/water emulsions for the very first time. Specifically, 15 wt% polyethylene glycol ([Formula: see text] = 800 Da) was added to the casting solution as a pore-forming agent to enhance the flux. In situ-generated SiO2 nanoparticles (NPs) were utilized to improve the membrane surface hydrophilicity by the hydrolyzation of tetraethyl orthosilicate under weak acid conditions. However, the surface hydrophilicity improvement was not significant. It may be because the strong mechanical strength of PEN caused most of the SiO2 NPs to be buried within the polymer matrix or SiO2 NPs were lost by dissolution in the acidic water bath. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were performed to study the membrane surface chemical features. Scanning electron microscopy images were obtained to observe the membrane cross-section morphology.
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Phan, Thi Tuong Vy. "A Novel One-Step Green Method to Synthesis of Palladium Nanoparticles." Materials Proceedings 4, no. 1 (November 15, 2020): 57. http://dx.doi.org/10.3390/iocn2020-07860.
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Palladium nanoparticles (PdNPs) are one of the most attractive metal nanomaterials because of their excellent physicochemical properties. PdNPs have been studied for many different applications such as Suzuki cross-coupling reactions, hydrogen purification/storage/sensing, CO oxidation, fuel cells, prodrug activation, and antimicrobial therapy. Recently, PdNPs have been explored as photoabsorbers for photothermal therapy and photoacoustic imaging in the treatment of cancer. Herein, we reported a scalable, efficient, green, and one-step method to synthesize PdNPs. The chitosan polymer was used as a stabilizer and vitamin C was used as a reducing agent. Interestingly, the reaction temperature can be adjusted to the size of PdNPs. When the reaction temperature was increased from 25 °C to 95 °C, the morphology of resulted PdNPs changed from a flower shape to a spherical shape and their nanoparticles’ sizes decreased from 64 nm to 29 nm. The characterization revealed that the obtained PdNPs were relatively uniform in size, shape, and stability in an aqueous solution.
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Arahman, Nasrul, Bastian Arifin, and Fachrul Razi. "Profil Permeabilitas Berdasarkan Struktur Morfologi Membran Polietersulfon pada Pemekatan Larutan Tokoferol (Permeability Profile based on Morphology Structure of Polyethersulfone Membrane on Concentrating the Tocopherol Solution)." Agritech 36, no. 4 (February 25, 2017): 416. http://dx.doi.org/10.22146/agritech.16765.
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Separation technique by membrane technology has been widely applied for separation and purification of minor components from vegetable oil. Membrane was prepared and modified in several way in order to improve the filtration performance in purification process of vegetable oil. In this work, the filtration performance of three types of polyethersulfone hollow fiber membrane was investigated. The main objective of this research was to study the effect of membranes type on the filtration performance of tocopherol solution. Three series of filtration experiment were conducted by using fabricated membrane by dissolving of polyethersulfone (PES) in N-methyl pyrrolydone (NMP) with different polymer composition. The membranes was M1 = PES 20 % + NMP, M2 = PES 18 % + NMP, and M3= PES 20 %+ Polyvinyl pyrrolidone (PVP 5 %) + NMP. The difference structure of membrans was confirmed by scanning electron microscopy measurement. The permeability profile of tocopherol solution of 500 ppm was observed by using a single module of hollow fiber membrane with filtration flow of pressure driven inside (PDI). It is shown that, the permeability of tocopherol solution was maximum and stable using PES membrane was composed by M3 system. Moreover, the improvement of tocopherol concentration in retentate solution was about two times higher than that the original solution that was obtained from filtration system of M1 membrane.ABSTRAKTeknik separasi dengan membran teknologi telah diaplikasikan secara luas untuk pemisahan dan pemurnian komponen minor dari minyak tumbuh-tumbuhan. Membran telah dibuat dan dimodifikasikan dengan berbagai cara untuk meningkatkan kinerja filtrasi pada proses pemurnian minyak tumbuh-tumbuhan. Pada penelitian ini, dipelajari kinerja filtrasi tiga jenis membran hollow fiber yang terbuat dari polimer polietersulfon. Tujuan utama penelitian adalah untuk melihat pengaruh jenis membran terhadap kinerja filtrasi larutan tokoferol. Tiga seri penelitian ultrafiltrasi telah dirancang dengan menggunakan membran yang dibuat dengan melarutkan polietersulfon (PES) dalam N-metil pirolidon (NMP) dengan komposisi polimer yang berbeda. Ketiga jenis membran yang digunakan adalah M1 = PES 20 % + NMP, M2 = PES 18 % + NMP, dan M3 = PES 20 % + Polivinil pirolidon (PVP 5 %) + NMP. Perbedaan struktur morfologi membran telah dikonfirmasikan dengan analisis scanning electron microscopy. Profil permeabilitas larutan tokoferol 500 ppm diobservasi menggunakan modul tunggal membran hollow fiber dengan tipe aliran pressure driven inside (PDI). Hasil penelitian menunjukkan bahwa permeabilitas larutan tokoferol tertinggi dihasilkan dengan menggunakan membran M3. Lebih lanjut, peningkatan konsentrasi larutan tokoferol sekitar dua kali lebih tinggi dari konsentrasi awal dicapai dari proses filtrasi dengan membran M1.
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Mukhitdinova, B. A., E. E. Ergozhin, G. S. Polimbetova, and A. K. Borangazieva. "The Synthesis of Organophosphorus Compounds from Phosphine and Alcohols in the Presence of Quinones and Redox Polymers on their Basis." Eurasian Chemico-Technological Journal 14, no. 3 (May 23, 2012): 191. http://dx.doi.org/10.18321/ectj114.
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<p>This article presents the synthesis of phosphoric acid esters from phosphoric hydrogen РН3 and aliphatic alcohols. The process is based on the oxidation of phosphine by quinones and redox polymers on the basis of mono- and disubstituted quinoid derivatives of monoethanolamine vinyl ether. Molecular iodine is used as a catalyst. Two-, three-, four- and multicomp onent systems are studied in order to determine optimal conditions of the oxidation of phosphine quinones and repoxpolymers on their basis. The rate and selectivity of reaction were monitored by the absorption of РН<sub>3</sub>. As alcohols used aliphatic alcohols: BuOH, PrOH, EtOH, MeOH. Organophosphorus compounds were analyzed by a chromatographic method. It was established that alcohol solutions of individual components of reactionary system (quinones, redox ionites or iodine) are characterized by a low activity in relation to phosphine. Organophosphorus compounds are formed in insignificant quantities. In the mixed alcohol<br /> solution of benzoquinone takes place PH<sub>3</sub> oxidation forming trialkylphosphates. Conversion of phosphine constitutes 80-100%. Increasing the concentration of reagents of catalytic system has a positive effect on the process as a whole. Similar patterns were obtained when redox monomers and polymers on the base of quinones in the presence of iodine were used as oxidants. Esters of phosphoric acid – dialkylphosphites and esters of phosphorous acid – trialkylphosphates were identified as organophosphorus compounds. By selecting a redox agent in a zone of the catalysis it is possible to direct process in the desirable direction. The most activity in the oxidation of phosphine by iodine-alcohol solutions of quinoid monomers and polymers, is exhibited by 2-[N-(2-vinyloxy) ethyl]amino-NQ and polymer on their basis. Results of our experiments and literature data on oxidation-reduction processes with participation of iodine and quinones in organic solutions allowed to propose the separate oxidation-reduction mechanism of formation of organophosphorus compounds. In investigated multicomponent systems, the synergetic effect is manifested which is reached at the expense of distribution of oxidation-reduction functions among iodine, quinones and its derivatives. In this report, for the first time, it is established reactionary ability of quinones and redox ionites on their basis in an oxidizing alkoxylation of phosphine to valuable esters of acids of phosphorus. Reaction can be used for purification of exhaust and technological gases from phosphine and its utilization.</p>
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Matysiak, W., T. Tański, and W. Smok. "Electrospinning of PAN and composite PAN-GO nanofibres." Journal of Achievements in Materials and Manufacturing Engineering 1, no. 91 (November 1, 2018): 18–26. http://dx.doi.org/10.5604/01.3001.0012.9653.
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Purpose: The aim of this study was to present the influence of used reinforcement phase – graphene oxide (GO) and the electrospinning process parameters (the distance between the nozzle and collector) on the morphology and the structure of the obtained composite PAN-GO nanofibres. Design/methodology/approach: To produce pure polymer nanofibers, a 10% (wt.) electrospinning solution the polyacrylonitrile (PAN) was dissolved in N, N-dimethylformamide (DMF). The spinning solution used for electrospinning PAN-GO composite fibres was made by dissolving the PAN in a mixture of GO and DMF. By changing the configuration of the distance between the nozzle and collector (10 and 20 cm) and maintaining the remaining parameters (solution flow rate and potential difference between the electrodes), four samples in the form of nanofibrous mats were made. In order to identify the structure and morphology of the reinforcing phase, X-ray microanalysis (EDX) and scanning electron microscopy (SEM) were performed. In addition, the structure of graphene oxide microparticles was investigated by a Raman spectrometer. In order to determine the influence of the distance between the nozzle and the collector used in the electrospinning process and the addition of the reinforcing phase to the morphology and structure of the obtained PAN polymer nanofibres and PAN-GO composite nanofibres, they were examined using SEM. The analysis of the chemical composition of PAN and PAN-GO fibres was carried out using X-ray microanalysis. Findings: The morphology and structure analysis indicated that polymer nanofibres PAN for both the distances between the nozzle and the collector show no structural defects and presented same diameter over the entire length of the fibre. Nanofibres with the addition of GO obtained at both distances between the electrodes, showed defects in the form of beads. In addition, it was observed that with increasing distance between the nozzle and collector the diameter of obtained nanofibres is smaller for both pure PAN and composite PAN-GO samples. Research limitations/implications: The paper is the basis for further research in the field of the use of PAN-GO composite nanofibres as water purification materials. Originality/value: The electrospinning method can be an alternative to conventional methods for the production of filtering membranes due to the ease of carrying out the process and the fact that a material with a high specific surface area is obtained.
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Agócs, Tamás Zoltán, István Puskás, Erzsébet Varga, Mónika Molnár, and Éva Fenyvesi. "Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants." Beilstein Journal of Organic Chemistry 12 (December 28, 2016): 2873–82. http://dx.doi.org/10.3762/bjoc.12.286.
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Advanced oxidation processes (AOPs) are considered highly competitive water treatment technologies for the removal of organic pollutants. Among AOP techniques, photocatalysis has recently been the most widely studied. Our aims were to investigate how the dispersion of nanosized titanium dioxide (nanoTiO2) applied in photodegradation-based procedures can be stabilized with cyclodextrins in order to obtain a new, more efficient photocatalyst for the purification of waters polluted by xenobiotics applying UV irradiation. During our work, on the one hand, we studied the behavior and stability of nanoTiO2 in cyclodextrin solutions. On the other hand, we used various monomer and polymer cyclodextrin derivatives, and assessed the options for nanoTiO2 stabilization in the presence of various salts and tap water on the basis of turbidity tests. The physical stability of nanoTiO2 dispersions is diminished in the presence of the salts found in tap water (and occurring also in surface waters and ground water) and they are precipitated immediately. This colloidal instability can be improved by cyclodextrin derivatives. Based on the results of our studies we have selected carboxymethyl β-cyclodextrin polymer (CMBCD-P) for stabilization of nanoTiO2 dispersions. The photocatalytic degradation of methylene blue and ibuprofen as model organic pollutants in various media (distilled water, NaCl solution and tap water) has been studied using nanoTiO2 as catalyst stabilized by CMBCD-P. CMBCD-P itself showed a catalytic effect on the UV degradation of methylene blue. In addition to enhancing the colloid stability of nanoTiO2 CMBCD-P showed also synergistic effects in catalyzing the photodecomposition process of the dye. On the other hand, ibuprofen as a model pharmaceutical, a pollutant of emerging concern (EP), was protected by CMBCD-P against the photocatalytic degradation showing that inclusion complex formation can result in opposite effects depending on the structure of the host–guest complex.