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1
Fernández-Peña, Laura, Boutaina Z. El Mojahid, Eduardo Guzmán, Francisco Ortega, and Ramón G. Rubio. "Performance of Oleic Acid and Soybean Oil in the Preparation of Oil-in-Water Microemulsions for Encapsulating a Highly Hydrophobic Molecule." Colloids and Interfaces 5, no. 4 (November 22, 2021): 50. http://dx.doi.org/10.3390/colloids5040050.
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This work analyzes the dispersion of a highly hydrophobic molecule, (9Z)-N-(1,3-dihydroxyoctadecan-2-yl)octadec-9-enamide (ceramide-like molecule), with cosmetic and pharmaceutical interest, by exploiting oil-in-water microemulsions. Two different oils, oleic acid and soybean oil, were tested as an oil phase while mixtures of laureth-5-carboxylic acid (Akypo) and 2-propanol were used for the stabilization of the dispersions. This allowed us to obtain stable aqueous-based formulations with a relatively reduced content of oily phase (around 3% w/w), that may enhance the bioavailability of this molecule by its solubilization in nanometric oil droplets (with a size range of 30–80 nm), that allow the incorporation of a ceramide-like molecule of up to 3% w/w, to remain stable for more than a year. The nanometric size of the droplet containing the active ingredient and the stability of the formulations provide the basis for evaluating the efficiency of microemulsions in preparing formulations to enhance the distribution and availability of ceramide-like molecules, helping to reach targets in cosmetic and pharmaceutical formulations.
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Thonglerth, P., P. Sujaridworakun, and O. Boondamnoen. "Preparation of ZnO Nanoparticles Water-based Dispersion." Journal of Physics: Conference Series 2175, no. 1 (January 1, 2022): 012029. http://dx.doi.org/10.1088/1742-6596/2175/1/012029.
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Abstract In this work, an attempt was made to stabilize ZnO NPs as water-based dispersion. The dispersing agents used are 3-glycidoxypropyltrimethoxysilane (GPTMS), polyvinyl alcohol (PVA) and oleic acid (OA). These dispersing agents were combined with sodium dodecyl sulfate (SDS) to facilitate better dispersion stability. Different wt% content of modified ZnO NPs such as 0.2, 0.4, 1 and 3% w/v was used at a fixed ratio of ZnO NPs:SDS:dispersing agent. The highest dispersion stability was achieved at 1% w/v content of modified ZnO NP, whereas some precipitate was observed at 3% w/v. The result reveals that sonication at 30 minutes produced the highest dispersion stability whereas extended sonication led to re-agglomeration of ZnO NPs. The optimum ratio of ZnO NPs:SDS:dispersing agent which produced about 98% dispersion stability was at 1:0.25:0.2. The zeta potential (ZP) values of ZnO NPs/GPTMS, ZnO NPs/PVA, and ZnO NPs/OA dispersions are -51, -29 and -15 mV, respectively. The ZP values was influenced by the electrical charge surrounding the particles which was also caused by the functional group of the dispersing agents. However, the stabilization mechanisms of modified ZnO NPs in water was complicated. It did not only depend on the electrostatic value but also on electrosteric stabilization caused by the steric effects hindering the dispersing agents. Interactions between the dispersing agents and ZnO NPs was confirmed through FTIR analysis.
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Guevara, Mairis, Ronald Mercado, Katty Vega, Antonio Cardenas, and Ana Forgiarini. "Rheology and Phase Behavior of Surfactant–Oil–Water Systems and Their Relationship with O/W Nano-Emulsion’s Characteristics Obtained by Dilution." Nanomanufacturing 3, no. 1 (January 19, 2023): 20–35. http://dx.doi.org/10.3390/nanomanufacturing3010002.
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In order to study the relationship between the rheology of a surfactant’s concentrated dispersions and the oil and water liquid crystals from which O/W nanoemulsions (NEs) can be produced by water dilution, the phase diagram of a model SOW (surfactant–oil–water) system was constructed. The dispersion’s compositions to be characterized by rheology were chosen in the diagram’s regions that contain liquid crystal phases. For this, the dilution lines S/O = 25/75, 55/45, and 70/30 with a water content of 20 and 40 wt% (corresponding to surfactant concentrations between 15 and 55 wt%) were chosen. By adding these dispersions to a water pool, NEs were obtained, and it was shown that droplet size distribution depends on the amount of the liquid crystal phase in the initial dispersion and its rheology. The study of the oscillatory amplitude of the dispersion showed a linear viscoelastic plateau (G’ > G”) and a softening deformation region (G” > G’), indicating a viscoelastic behavior of the dispersions. The study was carried out at a constant temperature of 30 °C, and the results show that rheological characterization by itself is not enough to predict that monomodal droplet distributions are obtained. However, the presence and quantity of lamellar liquid crystal phase are important to obtain monodisperse and kinetically stable NEs.
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Lewis, Alun, Per S. Daling, Tove Strøm-Kristiansen, Atle B. Nordvik, and Robert J. Fiocco. "WEATHERING AND CHEMICAL DISPERSION OF OIL AT SEA." International Oil Spill Conference Proceedings 1995, no. 1 (February 1, 1995): 157–64. http://dx.doi.org/10.7901/2169-3358-1995-1-157.
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ABSTRACT Small-scale laboratory methods were used to simulate the weathering processes that occur when crude oil is spilled at sea. Changes caused by evaporation and water-in-oil (w/o) emulsification were studied separately. W/o emulsions were assessed for chemical dispersibility using the Institut Français du Petrole (IFP) and Mackay-Nadeau-Steel-man (MNS) methods. Larger scale experiments were performed in a meso-scale flume. Crude oil was weathered for three days and then sprayed with dispersant. The results show that emulsion breaking is an important part of the mechanism of chemical dispersion. IFP, MNS, and Warren Spring Laboratory (WSL) tests, conducted on w/o emulsions recovered from the flume, produced much lower levels of dispersion than did treatment in the flume. The standard test procedures do not permit emulsion breaking to proceed to the extent observed in the flume. A sea trial also was conducted. Preliminary evaluation of the results shows that dispersant application partially broke the w/o emulsion that had rapidly formed. Dispersion proceeded at a slow rate but the treated slick was removed from the surface more rapidly than the control slick. The degree of dispersion was difficult to quantify by visual observation due to the weather conditions. A combination of remote sensing, surface sampling, and subsurface fluorometry provided a more reliable estimate.
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Cassen, Audrey, Jean-François Fabre, Eric Lacroux, Muriel Cerny, Guadalupe Vaca-Medina, Zéphirin Mouloungui, Othmane Merah, and Romain Valentin. "Aqueous Integrated Process for the Recovery of Oil Bodies or Fatty Acid Emulsions from Sunflower Seeds." Biomolecules 12, no. 2 (January 18, 2022): 149. http://dx.doi.org/10.3390/biom12020149.
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An aqueous integrated process was developed to obtain several valuable products from sunflower seeds. With a high-shear rate crusher, high-pressure homogenization and centrifugation, it is possible to process 600× g of seeds in 1400× g of water to obtain a concentrated cream phase with a dry matter (dm) content of 46%, consisting of 74 (w/w dm) lipids in the form of an oil-body dispersion (droplet size d(0.5): 2.0 µm) rich in proteins (13% w/w dm, with membranous and extraneous proteins). The inclusion of an enzymatic step mediated by a lipase made possible the total hydrolysis of trigylcerides into fatty acids. The resulting cream had a slightly higher lipid concentration, a ratio lipid/water closer to 1, with a dry matter content of 57% consisting of 69% (w/w) lipids, a more complex structure, as observed on Cryo-SEM, with a droplet size slightly greater (d(0.5): 2.5 µm) than that of native oil bodies and a conserved protein concentration (12% w/w dm) but an almost vanished phospholipid content (17.1 ± 4.4 mg/g lipids compared to 144.6 ± 6 mg/g lipids in the oil-body dispersion and 1811.2 ± 122.2 mg/g lipids in the seed). The aqueous phases and pellets were also characterized, and their mineral, lipid and protein contents provide new possibilities for valorization in food or technical applications.
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Nunez, Cristian, Ramin Dabirian, Ilias Gavrielatos, Ram Mohan, and Ovadia Shoham. "Methodology for Breaking Up Nanoparticle-Stabilized Oil/Water Emulsion." SPE Journal 25, no. 03 (March 12, 2020): 1057–69. http://dx.doi.org/10.2118/199892-pa.
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Summary A state-of-the-art portable dispersion characterization rig (P-DCR) is applied to study emulsions with Exxsol™ mineral oil (ExxonMobil Chemical Company, Houston, Texas, USA), commercial distilled water, and hydrophobic silica nanoparticles (NPs) as emulsifiers. The emulsion is prepared in the P-DCR batch-separator vessel, whereby the separation kinetics are observed and recorded. In this study, emulsion breakup by the integration of oil extraction/water addition and a stirring process is investigated, which is formed with 25% water cut (WC) and 0.01% w/w hydrophobic NPs (dispersed in the oil phase). The experimental data are divided into three data sets: oil extraction only, oil-extraction/pure-water addition, and oil-extraction/water with hydrophilic NP addition. For oil extraction only (Data Set 1), the WC of the fluid mixture increases, and for a sufficient volume extraction, phase inversion occurs that results in a complete separation of the oil and water. The minimum final required NP concentration for a fast separation, defined as the minimum concentration of NP required to begin the phase separation of the emulsion, is approximately 0.0045%. The acquired data for oil-extraction/pure-water-addition (Data Set 2) result in a faster breakup of the emulsion, as compared with oil extraction only. The oil-extraction/pure-water-addition process increases the system WC faster, reaching the phase-inversion point sooner. For the oil-extraction/pure-water-addition, the final lowest WC and NP concentrations are approximately 37% and 0.006% w/w, respectively, for fast separation. Thus, it can be concluded that the NP concentration and the WC are related. Repetitive oil-extraction/pure-water-addition cycles enable determination of the combined effects of the WC and NP on the separation process. A relatively stable emulsion is reached after approximately 2 minutes from the beginning of each cycle, which enables determining whether a quick separation occurs at the current cycle. Data Set 3 (oil-extraction/water with hydrophilic NP addition) results reveal that dispersing hydrophilic NPs in water does not promote emulsion breakup. On the contrary, the NPs produce a slightly more stable emulsion. The separation process, however, does not differ significantly even for high hydrophilic NP concentrations, emphasizing the dominant role of the hydrophobic particles (dispersed in the base-case emulsion).
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Wardhono, Endarto Yudo, Mekro Permana Pinem, Hadi Wahyudi, and Sri Agustina. "Calorimetry Technique for Observing the Evolution of Dispersed Droplets of Concentrated Water-in-Oil (W/O) Emulsion during Preparation, Storage and Destabilization." Applied Sciences 9, no. 24 (December 4, 2019): 5271. http://dx.doi.org/10.3390/app9245271.
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In this work, the evolution of dispersed droplets in a water-in-oil (W/O) emulsion during formation, storage, and destabilization was observed using a calorimetry technique. The emulsion was prepared by dispersing drop by drop an aqueous phase into an oil continuous phase at room temperature using a rotor-stator homogenizer. The evolution of droplets during (1) preparation; (2) storage; and (3) destabilization was observed using differential scanning calorimetry (DSC). The samples were gently cooled-down below its solid-liquid equilibrium temperature then heated back above the melting point to determine its freezing temperature. The energy released during the process was recorded in order to get information about the water droplet dispersion state. The mean droplet size distribution of the sample emulsion was correlated to its freezing temperature and the morphology was followed by optical microscopy. The results indicated that the calorimetry technique is so far a very good technique of characterization concentrated W/O emulsions.
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Indirasvari K. S., Natalie, I. Dewa Gede Mayun Permana, and I. Ketut Suter. "STABILITAS MIKROEMULSI VCO DALAM AIR PADA VARIASI HLB DARI TIGA SURFAKTAN SELAMA PENYIMPANAN." Jurnal Ilmu dan Teknologi Pangan (ITEPA) 7, no. 4 (December 17, 2018): 184. http://dx.doi.org/10.24843/itepa.2018.v07.i04.p05.
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Microemulsion is a dispersion system developed from emulsions, which is an oil dispersion system in water, stabilized by a surfactant. Oil-in-water (o/w) microemulsion is an emulsion system suitable for encapsulation and carrier of lipophilic components in the beverage industry. The food grade microemulsion formulation is limited by the type of surfactant that can be used. This research aims to obtain an o/w microemulsion formulation which is stable during storage using three surfactants. In this study, 3 types of food grade surfactants were used, Tween 80, Tween 20, and Span 80, and the oil used is Virgin Coconut Oil (VCO). This research is done in two stages. The first stage of research was the determination of the best microemulsion of 5 variations of HLB: 11, 12, 13, 14, and 15. The second stage is the storage stability test of the microemulsion chosen in the first stage for 7 weeks with observation every week. The data obtained were analyzed by ANOVA. The results of the study shows that HLB 11, 12, 13, 14, and 15 obtained by using 3 surfactants can produce microemulsions. The optimum HLB to obtain the best microemulsion stability is HLB 13. The microemulsion with HLB 13 obtained using 3 surfactants is stable during time of 7 weeks storage.
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Qu, Guanzheng, Jian Su, Tao Shi, Rui Guo, and Jiao Peng. "Effect Evaluation of Nanosilica Particles on O/W Emulsion Properties." Geofluids 2022 (May 24, 2022): 1–10. http://dx.doi.org/10.1155/2022/2339395.
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O/W emulsion reinforced by nanosilica particle has good application in hydrocarbon development. However, there are few reports on the influence of nanosilica particles on the oil-water interface of O/W emulsion. The effect of nanosilica particles on the interfacial properties of O/W emulsion was indirectly investigated by measuring the interfacial properties between aqueous dispersion of nanosilica particles and kerosene, and the properties of O/W emulsion reinforced by nanosilica particle were studied. The results showed that the aqueous dispersion of nanosilica particles could significantly reduce the interface tension (with kerosene) by more than 50%, and the interface tension between the aqueous dispersion and kerosene decreased with the increase in nanosilica content. The aqueous dispersion of nanosilica particles could significantly change rock wettability. When the content of nanosilica particles increased from 0.1% to 0.7%, the contact angle decreased from 44.89° to 27.62°. The surface tension of O/W emulsion prepared by the aqueous dispersion of nanosilica particles and kerosene was among 25 mN/m~30 mN/m. The contact angle was also particularly small, with an average of about 20.00°, a minimum of 12.50°. The salts had little effect on the interface tension of emulsions but had a significant influence on the contact angle and its stability. Magnesium salt could reduce the three-phase contact angle and increase the hydrophilic properties of O/W emulsion, while calcium salt had the opposite effect. Calcium salt and magnesium salt could reduce the stability of the emulsion, and calcium salt had a greater influence. The oil-water stratification adding either calcium salt or magnesium salt was about 1 day~3 days earlier than that without salts. In the experiment, when the content of nanosilica particles was among 0.3%~0.7%, the viscosity of O/W emulsion increased with the increase in nanosilica particles. When the content was 0.9%, the viscosity suddenly decreased, and the extent of reduction was about 21.7%. The findings of this study can help for better understanding the application of nanosilica particles in O/W emulsion, giving some suggestions for the application of nanoparticles in hydrocarbon development.
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Fernández-Peña, Laura, Sonia Gutiérrez-Muro, Eduardo Guzmán, Alejandro Lucia, Francisco Ortega, and Ramón G. Rubio. "Oil-In-Water Microemulsions for Thymol Solubilization." Colloids and Interfaces 3, no. 4 (December 2, 2019): 64. http://dx.doi.org/10.3390/colloids3040064.
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Essential oil compounds (EOCs) are molecules with well-known antimicrobial and antipest activity. However, such molecules possess limited solubility in water, making their handling difficult. This work aimed to enhance the distribution of a solid essential oil compound, thymol, using oil-in-water (o/w) microemulsions for its solubilization. The use of mixtures formed by an alkyl polyglucoside (APG) and soybean lecithin (SL) allowed for stabilization of the o/w microemulsions in a broad range of compositions, with the total concentration of the mixture of the two surfactants (APG+SL) and the APG:SL ratio both being essential for controlling the nature of the obtained dispersions. The microemulsions obtained using oleic acid as the oil phase and with compositions far from those corresponding to the onset of the emulsion region showed a good efficiency for thymol solubilization. This is an advantage from a stability point of view, as well as for ease of thymol preparation. The present work opens new alternatives for designing eco-sustainable formulations for EOC solubilization, with the possibility of preparing the formulations at the place of use, thereby saving transport costs and reducing the emission of pollutants.
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Sari, Novita, Erwin Samsul, and Angga Cipta Narsa. "Pengaruh Trietanolamin pada Basis Krim Minyak dalam Air yang Berbahan Dasar Asam Stearat dan Setil Alkohol." Proceeding of Mulawarman Pharmaceuticals Conferences 14 (December 31, 2021): 70–75. http://dx.doi.org/10.25026/mpc.v14i1.573.
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The cream is a semi-solid preparation with one or more ingredients dispersed in two types of emulsions, water-in-oil (W/O) and oil-in-water (O/W) type creams. Oil-in-water type cream has a high water content so that it can provide a hydration effect that can increase the penetration of the active substance. Triethanolamine in topical preparations is used as an emulsifier and alkalizing agent to form a homogeneous and stable cream. The purpose of this research was to determine the effect of triethanolamine on an oil-in-water cream base based on stearic acid and cetyl alcohol. Making the base is done by making preparations using four concentrations of triethanolamine 0.5% (F1), 1% (F2), 1.5% (F3), and 2% (F4). The cream base was then evaluated for its physical properties including organoleptic, homogeneity, pH, viscosity, spreadability, adhesion, and phase separation test. The results showed that in the organoleptic test cream bases were white, had a characteristic aroma with a semisolid form. The cream base has a homogeneity dispersion with an average pH between 6.53-7.29, viscosity between 3.5792396-3.8001904 (Pa.s), spreadability between 5.43-5.78 cm, and adhesion between 4.47-6.25 seconds. The cream base did not have phase separation and was stable in storage for 4 weeks at room temperature.
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Ojala, Jonna, Miikka Visanko, Ossi Laitinen, Monika Österberg, Juho Sirviö, and Henrikki Liimatainen. "Emulsion Stabilization with Functionalized Cellulose Nanoparticles Fabricated Using Deep Eutectic Solvents." Molecules 23, no. 11 (October 25, 2018): 2765. http://dx.doi.org/10.3390/molecules23112765.
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In this experiment, the influence of the morphology and surface characteristics of cellulosic nanoparticles (i.e., cellulose nanocrystals [CNCs] and cellulose nanofibers [CNFs]) on oil-in-water (o/w) emulsion stabilization was studied using non-modified or functionalized nanoparticles obtained following deep eutectic solvent (DES) pre-treatments. The effect of the oil-to-water ratio (5, 10, and 20 wt.-% (weight percent) of oil), the type of nanoparticle, and the concentration of the particles (0.05–0.2 wt.-%) on the oil-droplet size (using laser diffractometry), o/w emulsion stability (via analytical centrifugation), and stabilization mechanisms (using field emission scanning electron microscopy with the model compound—i.e., polymerized styrene in water emulsions) were examined. All the cellulosic nanoparticles studied decreased the oil droplet size in emulsion (sizes varied from 22.5 µm to 8.9 µm, depending on the nanoparticle used). Efficient o/w emulsion stabilization against coalescence and an oil droplet-stabilizing web-like structure were obtained only, however, with surface-functionalized CNFs, which had a moderate hydrophilicity level. CNFs without surface functionalization did not prevent either the coalescence or the creaming of emulsions, probably due to the natural hydrophobicity of the nanoparticles and their instability in water. Moderately hydrophilic CNCs, on the other hand, distributed evenly and displayed good interaction with both dispersion phases. The rigid structure of CNCs meant, however, that voluminous web structures were not formed on the surface of oil droplets; they formed in flat, uniform layers instead. Consequently, emulsion stability was lower with CNCs, when compared with surface-functionalized CNFs. Tunable cellulose nanoparticles can be used in several applications such as in enhanced marine oil response.
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Xu, Ke, Yongjun Lu, Jin Chang, Dingwei Weng, and Yang Li. "Progress of Development and Application of Drag Reduction Agents for Slick-Water Fracturing." Journal of Physics: Conference Series 2097, no. 1 (November 1, 2021): 012022. http://dx.doi.org/10.1088/1742-6596/2097/1/012022.
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Abstract Fracturing technology is the key technology of shale oil and gas exploitation in the United States. The key of hydraulic fracturing lies in the formulation of fracturing fluid, which can improve the permeability of shale gas layer, reduce pumping resistance, optimize production conditions, reduce strata damage and other purposes. Slick-water is widely used in water-based fracturing for unconventional oil and gas exploitation, which can reduce the friction resistance. As the core of the slickwater fracturing fluid, the friction reducer determine the fluid’s performances. Combining with the related literature at home and abroad, this paper analyzes the mechanism of friction reducer, introduces the research and application progress of natural polysaccharide, surfactant and polyacrylamide. It is considered that both the instant powder polymer and W/W dispersion polymer have great application potential. The friction reducer with high-efficiency sand-carrying and salt resistance is the focus of future research.
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Henriet, Pauline, Flemming Jessen, Mar Vall-llosera, Rodolphe Marie, Mastaneh Jahromi, Mohammad Amin Mohammadifar, Hanne Lilian Stampe-Villadsen, et al. "Physical Stability of Oil-In-Water Emulsion Stabilized by Gelatin from Saithe (Pollachius virens) Skin." Foods 9, no. 11 (November 23, 2020): 1718. http://dx.doi.org/10.3390/foods9111718.
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The objective of the present study was to investigate the physical stability of an oil-in-water (O/W) emulsion stabilized with gelatin from saithe (Pollachius virens) skin obtained with three different extraction protocols compared to two commercial fish skin gelatins. We first investigated the gelatin powder composition, and then produced the O/W emulsions at pH 3 by mechanical dispersion followed by an ultrasonication process. Sodium dodecyl sulfate (SDS) profiles for commercial samples indicated that extensive and unspecific hydrolysis of collagen occurred during the production process, whereas gelatin extracted from saithe fish skin showed typical electrophoresis patterns of type I collagen, with the presence of γ- and β-chains. Emulsions obtained with commercial samples presented high physical stability over 7 days, with particle size of ~200 nm. However, emulsions obtained with saithe fish skin presented particle size between 300 and 450 nm. Slight differences were observed in viscosity, with values between ~1 and ~4 mPa·s. Interfacial tension measurements presented values between 13 and 17 mN·m−1 with three different regimes for all the systems.
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Su, Qian, Jie Li, and Zhenxing Liu. "Flow Pattern Identification of Oil–Water Two-Phase Flow Based on SVM Using Ultrasonic Testing Method." Sensors 22, no. 16 (August 16, 2022): 6128. http://dx.doi.org/10.3390/s22166128.
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A flow pattern identification method combining ultrasonic transmission attenuation with an ultrasonic reflection echo is proposed for oil–water two-phase flow in horizontal pipelines. Based on the finite element method, two-dimensional geometric simulation models of typical oil–water two-phase flow patterns are established, using multiphysics coupling simulation technology. An ultrasonic transducer test system of a horizontal pipeline with an inner 50 mm diameter was built, and flow pattern simulation experiments of oil–water two-phase flow were carried out in the tested field area. The simulation results show that the ultrasonic attenuation coefficient is extracted to identify the W/O&O/W dispersion flow using the ultrasonic transmission attenuation method, and the identification accuracy is 100%. By comparison, using the ultrasonic reflection echo method, the echo duration is extracted as an input feature vector of support vector machine (SVM), and the identification accuracy of the stratified flow and dispersed flow is 95.45%. It was proven that the method of the ultrasonic transmission attenuation principle combined with the ultrasonic reflection echo principle can identify oil–water two-phase flow patterns accurately and effectively, which provides a theoretical basis for the flow pattern identification of liquid–liquid multiphase flow.
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Bago Rodriguez, Ana Maria, Bernard P. Binks, and Tomoko Sekine. "Novel stabilisation of emulsions by soft particles: polyelectrolyte complexes." Faraday Discussions 191 (2016): 255–85. http://dx.doi.org/10.1039/c6fd00011h.
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We put forward the concept of a novel particle stabiliser of oil–water emulsions, being the polyelectrolyte complex (PEC) formed between oppositely charged water-soluble polymers in cases where either polymer alone is incapable of stabilising an emulsion. Using poly(4-styrene sulfonate) sodium salt, PSSNa and poly(diallyldimethylammonium chloride), PDADMAC, of low polydispersity and similar molecular mass, we correlate the behaviour of their mixtures in water with that of emulsions after addition of oil. In aqueous mixtures, spherical particles of diameters between 100 and 150 nm are formed through electrostatic interactions between charged polymer chains. Around equal mole fractions of the two polymers, the zeta potential of the particles reverses in sign and emulsions of oil-in-water (o/w) for a range of oils can be prepared which are the most stable to coalescence and creaming. The effects of PEC concentration and the oil : water ratio have been examined. All emulsions are o/w and stability is achieved by close-packed particle layers at drop interfaces and particle aggregation in the continuous phase. Increasing the salt concentration initially causes destabilisation of the aqueous particle dispersion due to particle aggregation followed by dissolution of particles at high concentrations; the corresponding emulsions change from being stable to completely unstable and are then re-stabilised due to adsorption of uncharged individual polymer molecules.
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Zhang, Jie, Gongwei Li, Yanping Cao, and Duoxia Xu. "The Improvement of Dispersion Stability and Bioaccessibility of Calcium Carbonate by Solid/Oil/Water (S/O/W) Emulsion." Foods 11, no. 24 (December 14, 2022): 4044. http://dx.doi.org/10.3390/foods11244044.
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Solid/oil/water (S/O/W) emulsion loaded with calcium carbonate (CaCO3) was constructed to raise the dispersion stability and bioaccessibility. In the presence or absence of sodium caseinate (NaCas), the particle size, Zeta-potential, physical stability, and apparent viscosity of stabilized S/O/W emulsions with different gelatin (GEL) concentrations (0.1~8.0 wt%) were compared. Combined with a confocal laser scanning microscope (CLSM), cryoscanning electron microscope (Cryo-SEM), and interfacial adsorption characteristics, the stabilization mechanism was analyzed. The bioavailability of CaCO3 was investigated in a simulated gastrointestinal tract (GIT) model. The S/O/W-emulsion droplets prepared by the NaCas–GEL composite have a smaller particle size, higher Zeta-potential, larger apparent viscosity, and better physical stability compared with GEL as a single emulsifier. CLSM results confirmed that CaCO3 powder was encapsulated in emulsion droplets. The Cryo-SEM results and interfacial adsorption characteristics analysis indicated that the NaCas–GEL binary composite could effectively reduce the interfacial tension, and the droplets form a denser three-dimensional network space structure with a shell–core structure which enhanced the stability of the system. GIT studies showed that the droplets presented higher CaCO3 bioaccessibility than the CaCO3 powder. This study enriched the theory of the S/O/W transfer system and provided theoretical support for the development of CaCO3 application in liquid food.
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Gavrielatos, I., R. Dabirian, R. Mohan, and O. Shoham. "Comparison of Nanoparticle and Surfactant Oil/Water-Emulsion Separation Kinetics." SPE Journal 24, no. 05 (May 14, 2019): 2182–94. http://dx.doi.org/10.2118/190114-pa.
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Summary Experimental observations, during oil–production operations, regarding the formation of oil/water emulsions stabilized by nanoparticles and surfactants, are presented. Similarities and differences between the two types of emulsions are discussed on the basis of acquired separation profiles, as well as respective fluid interfacial properties. A state–of–the–art portable dispersion–characterization rig (PDCR) was used to run the experiments, and a surveillance camera was deployed to monitor the emulsion separation kinetics. Commercial–grade mineral oil and distilled water were used as the test fluids. Silica nanoparticles of different wettabilities, as well as surfactants with different hydrophilic-lipophilic balance (HLB) values, were deployed to investigate commonalities/differences between the surfactant– and nanoparticle–stabilized emulsions under ambient–temperature and –pressure conditions. Separation profiles were analyzed, and similar behaviors between the corresponding surfactant and nanoparticle emulsions were observed for the 25%–water–cut case. For higher water cuts, however, the surfactant–stabilized emulsions were tighter than their nanoparticle counterparts, displaying much lower separation rates. In the most severe cases, the surfactants totally inhibited the oil–creaming process and oil remained trapped in the emulsion for several hours. Multiple emulsions (O/W/O) were observed in certain cases [for hydrophilic nanoparticles and lipophilic surfactants (Span® 80)]. On the basis of the aforementioned experimental observations, the presence of surfactants caused more–severe problems for the oil/water–separation process than did the presence of an equal concentration of nanoparticles. Pendant–drop measurements indicated that the surfactants significantly lowered the interfacial tension (IFT) between the oil and water, whereas the nanoparticles did not. Finally, a literature model was used to predict separation profiles for the oil/water dispersions and evaluated by comparing the predictions with the acquired experimental data. Current research sets the benchmark for more–thorough investigations aimed at providing guidelines for a more efficient operation of separators that handle surfactant– or nanoparticle–stabilized emulsions and a better understanding of the related phenomena.
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Giordano, Gabriela F., Leandro Y. Shiroma, Angelo L. Gobbi, Lauro T. Kubota, and Renato S. Lima. "Microemulsification-based method: analysis of ethanol in fermentation broth of sugar cane." Analytical Methods 7, no. 23 (2015): 10061–66. http://dx.doi.org/10.1039/c5ay02152a.
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Quintana, Somaris Elena, José María Franco, and Luis Garcia-Zapateiro. "PHYSICO-CHEMICAL AND BROMATOLOGICAL CHARACTERISTICS OF ARENCA AND RHEOLOGICAL PROPERTIES OF OIL-IN-WATER EMULSIONS CONTAINING ISOLATED PROTEIN." Ciência e Agrotecnologia 39, no. 6 (December 2015): 634–41. http://dx.doi.org/10.1590/s1413-70542015000600010.
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ABSTRACT The design, formulation and development of a new product or the improvement of a traditional product are dependent on the knowledge of the physicochemical, bromatological and rheological characteristics of that product. An important aspect of the study of food is complex dispersions such as emulsions. For preparation and formulation of emulsions, surfactants like protein are used to constitute a molecular barrier that helps emulsions to form and stabilizes dispersions. The aim of this work was to standardize an oil in water (O/W) food emulsion with Arencas (Triportheus magdalenae) isolated protein. For this procedure, a physicochemical and bromatological characterization of fish muscle has been done, in which a protein percentage of 17.85±0.12 has been achieved. This has allowed for the recovery of 72-90% of isolated protein to be used in food products such as salad dressing, mayonnaise, spreads, dressings and other products. Stable emulsions with adequate rheological and microstructural characteristics were prepared using 40% w/w palm oil and different concentrates of isolated protein from Arenca, between 2.5 and 3.5% w/w. Therefore, we have obtained an oil in water (O/W) food emulsion with isolated proteins from Arenca that presented non-Newtonian fluid type pseudoplasticity and homogeneous distribution of droplets.
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Xiao, Zuobing, Heqing Bao, Shuhan Jia, Yutian Bao, Yunwei Niu, and Xingran Kou. "Organic Hollow Mesoporous Silica as a Promising Sandalwood Essential Oil Carrier." Molecules 26, no. 9 (May 7, 2021): 2744. http://dx.doi.org/10.3390/molecules26092744.
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As film-forming agents, fillers and adsorbents, microplastics are often added to daily personal care products. Because of their chemical stability, they remain in the environment for thousands of years, endangering the safety of the environment and human health. Therefore, it is urgent to find an environmentally friendly substitute for microplastics. Using n-octyltrimethoxysilane (OTMS) and tetraethoxysilane (TEOS) as silicon sources, a novel, environmentally friendly, organic hollow mesoporous silica system is designed with a high loading capacity and excellent adsorption characteristics in this work. In our methodology, sandalwood essential oil (SEO) was successfully loaded into the nanoparticle cavities, and was involved in the formation of Pickering emulsion as well, with a content of up to 40% (w/w). The developed system was a stable carrier for the dispersion of SEO in water. This system can not only overcome the shortcomings of poor water solubility and volatility of sandalwood essential oil, but also act as a microplastic substitute with broad prospects in the cosmetics and personal care industry, laying a foundation for the preparation and applications of high loading capacity microcapsules in aqueous media.
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Nilsuwan, Krisana, Soottawat Benjakul, and Thummanoon Prodpran. "Effects of Soy Lecithin Levels and Microfluidization Conditions on Properties of Fish Gelatin-Based Film Incorporated with Palm Oil." International Journal of Food Engineering 12, no. 7 (September 1, 2016): 647–60. http://dx.doi.org/10.1515/ijfe-2016-0064.
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Abstract Properties of film-forming dispersion (FFD) and emulsion film incorporated with palm oil containing soy lecithin at 50 % and 75 % (w/w, based on palm oil) and emulsified with different microfluidization pressures (6.89, 13.79 and 20.68 MPa) and pass numbers (2 and 4) were investigated. Microfluidized FFD containing 50 % soy lecithin showed the smaller oil droplet size. The lower water vapor permeability with higher tensile strength and elongation at break were found for films from microfluidized FFD (p < 0.05). Films containing 50 % soy lecithin had higher light transmittance and lower b*- and ΔE*-values than those containing 75 % soy lecithin (p < 0.05). Smooth surface and compact cross-section were observed in films from microfluidized FFD. Film from microfluidized FFD containing 50 % soy lecithin showed higher thermal stability. Thus, the emulsion film with improved properties could be prepared from FFD using 50 % soy lecithin with the aid of microfluidization.
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Hapsari, Safrina, David Febrilliant Susanto, Hakun Wirawasista Aparamarta, Arief Widjaja, and Setiyo Gunawan. "Separation and Purification of Wax from Nyamplung (Calophyllum inophyllum) Seed Oil." Materials Science Forum 964 (July 2019): 1–6. http://dx.doi.org/10.4028/www.scientific.net/msf.964.1.
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Nyamplung (Calophyllum inophyllum) is a multi-functional plant which is spread widely over the coast of Indonesia. Its seed produces a high content of oil, but its utilization is still limited. It is because C. inophyllum seed oil contains toxic compounds. Therefore, C. inophyllum seed oil has been used as a biodiesel raw material for many years. It was reported that C. inophyllum seed oil contains wax, but its percentage remains unknown. Wax has been used in cosmetics, pharmaceuticals, foods, and coatings industries as oil binder, water repellent, scratch resistance, and dispersion medium. In this work, wax was separated from C. inophyllum seed oil by solvent crystallization with and without separating non-polar lipid fraction (NPLF) from crude oil. Non-polar lipid fraction was separated by batch-wise solvent extraction using petroleum ether to methanol mass ratio of 3:1 (w/w) for eight stages. After eight stages, non-polar lipid fraction was collected for further separation by solvent crystallization method. The ratios of non-polar lipid fraction to acetone were 1:10, 1:20, and 1:40 (w/v). Then, the isolated wax was analyzed by gas chromatography. It was found that wax (purity of 40% and yield of 0.35%) was successfully isolated by separating non-polar lipid fraction from crude oil (batch wise solvent extraction for eight stages) and followed by solvent crystallization (non-polar lipid fraction to acetone ratio of 1:40 (w/v)).
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Fraj, Jadranka, Lidija Petrovic, Jelena Milinkovic, Jaroslav Katona, Sandra Bucko, and Ljiljana Spasojevic. "Properties of water in oil emulsions (W/O) stabilized with mixtures of PGPR and polyglycerol fatty acid esters." Acta Periodica Technologica, no. 48 (2017): 95–107. http://dx.doi.org/10.2298/apt1748095f.
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Water in oil (W/O) emulsions are dispersed systems which have very wide application as a carriers in the food, pharmaceutical and cosmetic industry products. The main problem with practical application of such systems is their low stability. The emulsifiers used to stabilize this type of emulsions are with low hydrophilic-lipophilic balance values. The present work examines the possibility of the application of mixtures of lipophilic emulsifiers polyglycerol polyricinoleate (PGPR) and polyglycerol fatty acid esters for stabilization of W/O emulsions. First of all, the adsorption properties of the used emulsifiers were examined by tensiometic measurements. Based on these results, two emulsifiers PGPR and decaglycerol decaoleate (Caprol 10G10O) were selected for the preparation of the emulsions, as well as their mass ratios and total concentrations. The results of the investigation of the emulsions properties (dispersion analysis and sedimentation stability) showed that more stable emulsions can be obtained by decreasing the Caprol 10G10O mass ratio and increasing the total concentration of emulsifiers.
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Rubim, Alexandre Machado, Jaqueline Bandeira Rubenick, Eduarda Gregolin, Luciane Varini Laporta, Rosimar Leitenberg, and Clarice Madalena Bueno Rolim. "Amiodarone hydrochloride: enhancement of solubility and dissolution rate by solid dispersion technique." Brazilian Journal of Pharmaceutical Sciences 51, no. 4 (December 2015): 957–66. http://dx.doi.org/10.1590/s1984-82502015000400021.
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abstract Amiodarone HCl is an antiarrhythmic agent, which has low aqueous solubility and presents absorption problems. This study aimed to develop inclusion complexes containing hydrophilic carriers PEG 1500, 4000 and 6000 by fusion and kneading methods in order to evaluate the increase in solubility and dissolution rate of amiodarone HCl. The solid dispersion and physical mixtures were characterized by X-ray diffraction, FT-IR spectra, water solubility and dissolution profiles. Both methods and carriers increased the solubility of drug, however PEG 6000 enhanced the drug solubility in solid dispersion better than other carriers. Different media were evaluated for the solubility study, including distilled water, acid buffer pH 1.2, acetate buffer pH 4.5 and phosphate buffer pH 6.8 at 37 ºC. Based on the evaluation of the results obtained in the study phase solubility carriers PEG 4000 and PEG 6000 were selected for the preparation of the physical mixture and solid dispersion. All formulations were prepared at drug-carrier ratios of 1:1 to 1:10(w/w). The results of in vitro release studies indicated that the solid dispersion technique by fusion method in proportion of 1:10 (w/w) increased significantly the dissolution rate of the drug. X-ray diffraction studies showed reduced drug crystallinity in the solid dispersions. FT-IR demonstrated interactions between the drug and polymers.
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Nareswari, Tantri Liris, Erga Syafitri, and Okta Nurjannah. "Sunscreen lip balm stick formulation containing a combination of virgin coconut oil and crude palm oil." Pharmacy Reports 2, no. 2 (December 3, 2022): 48. http://dx.doi.org/10.51511/pr.48.
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Virgin coconut oil (VCO) and crude palm oil (CPO) are products of Indonesia’s natural wealth with significant antioxidant activity and potential as lip balm sticks to treat dry lips caused by sun exposure. This study aims to determine the formulation of lip balm stick preparations containing VCO and CPO that have sunscreen activity and acceptable physical characteristics. This study included the phases of testing, formulation of lip balm stick, sunscreen activity test, and evaluation of physical properties. The compositions were melted using a water bath, and the sunscreen’s efficacy was evaluated using UV-Vis spectrophotometry. VCO and CPO concentrations varied between 5%, 7.5%, 10%, 12.5%, and 15% (w/w). The F1 formula containing 5% VCO and 15% CPO (w/w) had the highest sun protection factor (SPF) value of 15.438. The evaluation of the formula activity test revealed that the higher the CPO content, the greater the sunscreen activity. Formula F1 has stable physical properties while stored at room temperature for 28 days. Formula F1 has a yellow color, chocolate scent, semi-solid consistency, homogeneous, 3.35 cm dispersion, 56 oC melting point, and 64-gram hardness. Formula F1 provides excellent sun protection and physical properties. It may be further evaluated as a lip balm stick sunscreen formulation for chapped lips.
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Guzmán, Eduardo, Laura Fernández-Peña, Lorenzo Rossi, Mathieu Bouvier, Francisco Ortega, and Ramón G. Rubio. "Nanoemulsions for the Encapsulation of Hydrophobic Actives." Cosmetics 8, no. 2 (June 1, 2021): 45. http://dx.doi.org/10.3390/cosmetics8020045.
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This work analyzes the dispersion of two highly hydrophobic actives, (9Z)-N-(1,3-dihydroxyoctadecan-2-yl)octadec-9-enamide (ceramidelike molecule) and 2,6-diamino-4-(piperidin-1-yl)pyrimidine 1-oxide (minoxidil), using oil-in-water nanoemulsions with the aim of preparing stable and safe aqueous-based formulations that can be exploited for enhancing the penetration of active compounds through cosmetic substrates. Stable nanoemulsions with a droplet size in the nanometric range (around 200 nm) and a negative surface charge were prepared. It was possible to prepare formulations containing up to 2 w/w% of ceramide-like molecules and more than 10 w/w% of minoxidil incorporated within the oil droplets. This emulsions evidenced a good long-term stability, without any apparent modification for several weeks. Despite the fact that this work is limited to optimize the incorporation of the actives within the nanoemulsion-like formulations, it demonstrated that nanoemulsions should be considered as a very promising tool for enhancing the distribution and availability of hydrophobic molecules with technological interest.
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Eitzen, Lars, Aki Sebastian Ruhl, and Martin Jekel. "Particle Size and Pre-Treatment Effects on Polystyrene Microplastic Settlement in Water: Implications for Environmental Behavior and Ecotoxicological Tests." Water 12, no. 12 (December 8, 2020): 3436. http://dx.doi.org/10.3390/w12123436.
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Microplastic (MP) particle dispersions used in many recent publications covering adsorption or toxicological studies are not characterized very well. The size distribution of polydisperse dispersions is highly dependent on the agglomeration processes and influences experimental outcomes. Therefore, pre-treatment is a prerequisite for reproducibility. In this study, manual/automated shaking and ultrasonic treatment as different mechanical dispersion techniques were applied for the dispersion of cryomilled polystyrene (PS). Particle numbers and size distribution of dispersions were analyzed by a light extinction particle counter and the dispersion efficiency (ED) as the ratio between calculated volume and theoretical volume of suspended particles was used to compare techniques. PS dispersions (20 mg/L) treated for 90 min in an ultrasonic bath (120 W, 35 kHz) were evenly dispersed with a particle concentration of 140,000 particles/mL and a high reproducibility (rel. SD = 2.1%, n = 6). Automated horizontal shaking for 754 h (250 rpm) reached similar particle numbers (122,000/mL) but with a lower reproducibility (rel. SD = 9.1%, n = 6). Manual shaking by hand dispersed the lowest number of particles (55,000/mL) and was therefore found to be unsuitable to counteract homo-agglomeration. ED was calculated as 127%, 104% and 69% for ultrasonic treatment, horizontal shaking and manual shaking, respectively, showing an overestimation of volume assuming spherical shaped particles.
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Lv, Yongli, Sheng Zhang, Yunshan Zhang, Hongyao Yin, and Yujun Feng. "Hydrophobically Associating Polyacrylamide “Water-in-Water” Emulsion Prepared by Aqueous Dispersion Polymerization: Synthesis, Characterization and Rheological Behavior." Molecules 28, no. 6 (March 16, 2023): 2698. http://dx.doi.org/10.3390/molecules28062698.
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The hydrophobically associating polyacrylamide (HAPAM) is an important kind of water-soluble polymer, which is widely used as a rheology modifier in many fields. However, HAPAM products prepared in a traditional method show disadvantages including poor water solubility and the need for hydrocarbon solvents and appropriate surfactants, which lead to environmental pollution and increased costs. To solve these problems, we reported a novel kind of HAPAM “water-in-water” (w/w) emulsion and its solution properties. In this work, a series of cationic hydrophobic monomers with different alkyl chain lengths were synthesized and characterized. Then, HAPAM w/w emulsions were prepared by the aqueous dispersion polymerization of acrylamide, 2-methylacryloylxyethyl trimethyl ammonium chloride and a hydrophobic monomer. All these emulsions can be stored more than 6 months, showing excellent stability. An optical microscopy observation showed that the particle morphology and the particle size of the HAPAM emulsion were more regular and bigger than the emulsion without the hydrophobic monomer. The solubility tests showed that such HAPAM w/w emulsions have excellent solubility, which took no more than 180 s to dilute and achieve a homogeneous and clear solution. The rheology measurements showed that the HAPAM association increases with a hydrophobe concentration or the length of hydrophobic alkyl chains, resulting in better shear and temperature resistances. The total reduced viscosity was 124.42 mPa·s for cw101, 69.81 mPa·s for cw6-1, 55.38 mPa·s for cw8-0.25, 48.95 mPa·s for cw12-0.25 and 28 mPa·s for cw16-0.25 when the temperature increased from 30 °C to 90 °C. The cw8-2.0 that contains a 2 mol% hydrophobe monomer has the lowest value at 19.12 mPa·s due to the best association. Based on the excellent stability, solubility and rheological properties, we believe that these HAPAM w/w emulsions could find widespread applications.
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Ye, Yinzhu, Yang Liu, Baoshan Guan, Yongda Tian, Liming Shao, Zhentao Yu, Zhihui Zeng, and Shichao Li. "Study on Performance Evaluation of Multifunctional Microgel System." Journal of Physics: Conference Series 2539, no. 1 (July 1, 2023): 012023. http://dx.doi.org/10.1088/1742-6596/2539/1/012023.
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Abstract Soft Microgel (SMG) used to enhance oilfield recovery is a kind of aqueous dispersion chemical agent system of microgel particles. It is usually used in medium and low permeability reservoirs and is generally not used for plugging large pores of reservoirs due to the limitation of particle size. To resolve the problem that SMG cannot effectively block large pores of the reservoir, the multi-functional system (SMG-w) can be synthesized by introducing inorganic components into SMG under special conditions. The main physical and chemical properties of SMG-w are carried out in the laboratory. The results of the study show that SMG-w has an excellent resistant ability to temperature and salinity. Besides, it can also decrease the interfacial tension of oil and water. What’s more, it can react with Ca2+ or Mg2+ in formation water from a large number of flocs in the high salinity reservoir, which can enhance physical and chemical properties of SMG-w and make it be applied in deep profile control of high permeability reservoirs with high temperature and high salinity.
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Fraj, Jadranka, Lidija Petrovic, Jelena Milinkovic-Budincic, Jaroslav Katona, Sandra Bucko, and Ljiljana Spasojevic. "Properties of double W/O/W emulsions containing vitamin C and E stabilized with gelatin/sodium caseinate complex." Journal of the Serbian Chemical Society 84, no. 12 (2019): 1427–38. http://dx.doi.org/10.2298/jsc190515075f.
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Double emulsions are complex liquid dispersion systems in which the droplets of one dispersed liquid are further dispersed in another liquid, producing W/O/W or O/W/O emulsions. W/O/W emulsions are the most studied systems because they have great potential application. However, despite all the advantages, that these systems offer, it is very difficult to obtain stable formulations, and this is the reason for their limited practical application. The use of biopolymers to stabilize double emulsions could give rise to pharmaceutical and food applications. Based on previous studies, appropriate concentrations of gelatin and sodium caseinate (NaCAS) were selected to investigate the possibility of stabilization of double W/O/W emulsions by this system, if they are present in the outer aqueous phase. The investigations showed that interactions between gelatin and NaCAS in the outer water phase, as well as the composition of the mixtures of lipohilic emulsifiers used for the primary W/O emulsions preparation, influences the droplets size and sedimentation stability of double emulsions. The most stable emulsions were obtained at a NaCAS concentration when an insoluble coacervate forms (0.5 mass %) and at concentrations higher then this, when soluble negatively charged complexes adsorb at the oil/water interface.
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Maulana, Riza, Henry Harto, and Tiara Dewi Salindri Pratama. "Formulation of Nifedipine–Polyvinyl Pyrrolidone (PVP) Solid Dispersion System and Intrinsic Dissolution Rate Evaluation." Pharmacon: Jurnal Farmasi Indonesia 19, no. 2 (December 31, 2022): 108–14. http://dx.doi.org/10.23917/pharmacon.v19i2.20545.
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Nifedipine is a drug that acts as an antihypertensive and anti-angina. Nifedipine is known as a drug with poor water solubility. This characteristic will affect the intrinsic dissolution rate so that it can affect the absorption process and reduce the amount of drug that reaches systemic circulation. One of the strategies to increase the intrinsic dissolution rate is developing nifedipine to solid dispersions form. This study aims to observe the intrinsic dissolution rate of nifedipine after it has been made into a solid dispersion. Four samples were prepared, including three solid dispersions of nifedipine-PVP K-30 and one sample of pure nifedipine. The results of the intrinsic dissolution tests are then interpreted through the intrinsic dissolution rate constant (G). The solid dispersions with concentration of nifedipine-PVP K-30 90%:10%; 75%:25%; 60%:40% (w/w), and pure nifedipine produced G values of 3.63; 9.33; 12.63; and 2.08 µg/mm2. min1, consecutively. It shows that the formulation of nifedipine-PVP K-30 solid dispersions has higher G values than pure nifedipine. In addition, increasing PVP K-30 concentration up to 40 % (w/w) can increase the intrinsic dissolution rate of the nifedipine-PVP K-30 solid dispersion system.
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Qiu, Jinghong, Hui Wang, Shihua Dong, Haibo Wang, Xu Cheng, and Zongliang Du. "Study on the preparation of PAM/MMT W/W emulsion and its application as a flocculant." RSC Advances 6, no. 10 (2016): 7908–13. http://dx.doi.org/10.1039/c5ra25546e.
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OMMT was first prepared by intercalation of AM into MMT, then the OMMT was added into the dispersion polymerization system of polyacrylamide/montmorillonite water in water (WPAMt) emulsion and gelatin was used as the stabilizer.
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Fischer, Ludger, Ernesto Mura, Geng Qiao, Poppy O’Neill, Silvan von Arx, Qi Li, and Yulong Ding. "HVDC Converter Cooling System with a Phase Change Dispersion." Fluids 6, no. 3 (March 12, 2021): 117. http://dx.doi.org/10.3390/fluids6030117.
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High voltage direct current converters require efficient cooling of thyristors via heat sinks. Currently, infrastructures use deionised water as a means of cooling the high voltage direct current converters; however, recent research has shown that other fluids have potential to offer more efficient cooling. Phase change dispersions are a new class of heat transfer fluids that employ the latent heat of phase change, thus offering isothermal cooling during melting. For cooling applications, the temperature increase during operation is thus lowered when using phase change dispersions (compared to water) and consequently, the heat sink and thyristors surface temperatures are reduced. In this investigation, a phase change dispersion with non-conductive components, high stability, high capacity and low viscosity has been developed and tested. An experimental setup of a real size heat sink has been installed and the heat transfer behaviour of both the formulated phase change dispersion and water have been investigated and a comparison has been presented. Using water as the heat transfer fluid, the temperature increase from inlet to outlet of the heat sink was 4 K and with the formulated phase change dispersion (at the same mass flow rate and heat input) the temperature increase was 2 K. The phase change dispersion caused a 50% reduction in the heat sink surface temperature. Furthermore, the global heat transfer coefficients obtained for the phase change dispersion were found to be independent of the heating input applied, unlike the trend found for water, additionally, the global heat transfer coefficients were found to be similar to those obtained for water at the same mass flow rates and reached a maximum value of 6100 W m2 K−1. Despite this, the pressure drops and viscosities obtained for the phase change dispersion were higher than for water. Overall, the current investigation demonstrates the ability of using a phase change dispersion as a cooling fluid for the cooling of electronic components, which thus far is limited to using air and water cooling and cannot reach the cooling capacity achieved by phase change dispersions.
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Bhide, Prashant, and Reeshwa Nachinolkar. "FORMULATION DEVELOPMENT AND CHARACTERISATION OF MECLIZINE HYDROCHLORIDE FAST DISSOLVING TABLETS USING SOLID DISPERSION TECHNIQUE." International Journal of Applied Pharmaceutics 10, no. 4 (July 7, 2018): 141. http://dx.doi.org/10.22159/ijap.2018v10i4.26493.
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Objective: The aim of the present investigation was to design and evaluate fast dissolving tablet (FDT) for the oral delivery containing solid dispersion of meclizine (MCZ) hydrochloride, an antiemetic drug.Methods: The solubility of meclizine was increased by preparing solid dispersions using mannitol as a carrier by fusion method. The prepared solid dispersion, was subjected for in vitro drug release, percent practical yield, drug content, infrared spectroscopy (IR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM). Optimized solid dispersion was incorporated to prepare fast dissolving tablets. Preformulation studies were carried out on tablet blends. The prepared solid dispersion, as well as pure drug fast dissolving tablets, was evaluated for drug content, weight variation, hardness, friability, in vitro drug release, wetting time, disintegration time, water absorption ratio, in vitro dispersion time.Results: Meclizine pure drug, solid dispersions formulations SD1, SD3 and SD5 showed 12.8, 31.68, 38.92 and 53.28% cumulative drug release in phosphate buffer pH 6.8 after 60 min, respectively. Thus faster dissolution rate was exhibited by the solid dispersion containing 1:5 (w/w) ratio of meclizine: mannitol. Percent cumulative drug release for control and solid dispersion tablets after 60 min in phosphate buffer pH 6.8 was 92.04 and 98.2% respectively. The release of drug meclizine from best formulation SD5 FDT was found to be faster than pure drug FDT.Conclusion: Fast dissolving tablet of optimized solid dispersion showed better in vitro dissolution result then FDT of pure drug at the end of one hour.
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Shi, Xiaorong, Xiaolin He, Xinqi Zhang, Haipeng Xu, Qian Wang, Binfei Li, Songyan Li, and Dongdong Liu. "Experimental Study on Chemical Recovery of Low-Permeability and Medium-Deep Heavy Oil Reservoir." Geofluids 2022 (November 10, 2022): 1–15. http://dx.doi.org/10.1155/2022/9366864.
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To improve the oil recovery of a block in the Wutonggou Formation of the Changji Oilfield, viscosity reducing and foaming agent was optimized to improve the development effect of the water flooding reservoir. The core flooding experiment and microscopic visual experiment were conducted to investigate the production characteristics and EOR mechanism of nitrogen foam flooding. The results show that the 0.5 wt% viscosity reducing and foaming agent DXY-03 was optimized. In the process of microscopic oil displacement by nitrogen foam, nitrogen foam continuously expands and spreads, improves oil displacement efficiency, and greatly improves oil recovery through emulsification and viscosity reduction, squeezing action, dragging action, and Jamin effect. The core flooding experiment shows that on the basis of the water flooding recovery rate of 20.3%, the nitrogen foam huff and puff is increased by 9.2%. The viscosity reducing and foaming agent flooding is increased by 7.8%, and the nitrogen foam flooding is increased by 12.9%. The main EOR mechanism of the viscosity reducing and foaming agent is that it can reduce the interfacial tension between oil and water and can promote heavy oil emulsification and dispersion, thereby forming an oil/water- (O/W-) type emulsion. The reduction in the viscosity of heavy oil makes crude oil easier to extract, realizing the synergistic viscosity reducing and efficiency enhancing effect of nitrogen and viscosity reducing and foaming agents. This study is helpful to provide reference for the development of low-permeability and high-viscosity medium-deep heavy oil reservoirs by chemical agents combined with cold production.
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Pichayakorn, Wiwat, Suchipha Wannaphatchaiyong, and Wanlapha Saisin. "Preparation Process and Properties of Crosslinked Gelatin Beads for Drug Loading." Advanced Materials Research 1060 (December 2014): 74–78. http://dx.doi.org/10.4028/www.scientific.net/amr.1060.74.
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This study aimed to develop the preparation process of stable gelatin beads for drug loading. Gelatin beads were prepared by either ionotropic gelation or emulsification techniques. Hardening of gelatin beads were done by both cooling and chemical treatments. For ionotropic gelation techniques, aqueous gelatin solution was continuously dropped into cool calcium chloride (CaCl2) or sodium tripolyphosphate (TPP) solution. However, the stable bead particles could not be formed. For emulsification techniques, water in oil (w/o) system was performed using aqueous gelatin solution as dispersed phase and cool soybean oil as dispersion medium, and glutaraldehyde (GAL) might also be used as chemical crosslinking agent. Gelatin type, amount of GAL, and crosslinking time slightly affected the characters of beads formation. Propranolol HCl could be loaded in gelatin beads.
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Long, Jian Xin, and Yong Jun Chen. "Synthesis and Characterization of TiO2 Nanoparticles Doped with Cu2+ by Microemulsion Method." Materials Science Forum 650 (May 2010): 23–27. http://dx.doi.org/10.4028/www.scientific.net/msf.650.23.
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Copper doped TiO2 nanoparticles were synthesized by hydrolysis of tetrabutyl titanate (Ti(OBu)4) and copper nitrate (Cu(NO3)2) in water-in-oil (W/O) microemulsions, consisting of water, Triton X-100, n-hexanol, cyclohexane and water. In this W/O system, Trinton X-100, n-hexanol and cyclohexane were used as surfactant, co-surfactant and organic solvent, respectively. The prepared nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). The results show that the Cu-doped TiO2 nanoparticles synthesized by this method have a good dispersion character and relatively small sizes of about 80 nm. The XRD results show that the calcination temperature greatly influences the crystallization transformation. When calcined below 550 °C, the prepared sample is composed of anatase structure. When the calcination temperature increases to 650 °C, rutile phase appears besides the anatase phase. While doping amount has little effects on crystal phase. FTIR analysis indicates that most of the contained water and the residual organic surfactants can be removed by calcination.
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Oliver-Ortega, Helena, Victor Vandemoortele, Alba Bala, Fernando Julian, José Alberto Méndez, and Francesc Xavier Espinach. "Nanoclay Effect into the Biodegradation and Processability of Poly(lactic acid) Nanocomposites for Food Packaging." Polymers 13, no. 16 (August 16, 2021): 2741. http://dx.doi.org/10.3390/polym13162741.
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One of the most promising expectations in the design of new materials for food packaging is focused on the development of biodegradable systems with improved barrier character. In this sense PLA reinforced with nanoclay is a potential alternative to the use of conventional oil-derivative polymers due to the synergetic effect of the biodegradable character of PLA and the barrier-induced effect derived from the dispersion of nanoparticles. In this work, composite materials based on PLA and reinforced with bentonite nanoparticles (up to 4% w/w) (NC) have been prepared to produce films with improved barrier character against water vapor transportation. Additionally, the biodegradable character of the composites depending on the crystallinity of the polymer and percentage of NC have been evaluated in the presence of an enzymatic active medium (proteinase K). Finally, a study of the capacity to film production of the composites has been performed to determine the viability of the proposals. The dispersion of the nanoparticles induced a tortuous pathway of water vapor crossing, reducing this diffusion by more than 22%. Moreover, the nanoclays materials were in all the cases acceptable for food packing in terms of migration. A migration lower than 1 mg/m2 was obtained in all the materials. Nonetheless, the presence of the nanoclays in decreased biodegradable capacity was observed. The time was enlarged to more than 15 days for the maximum content (4% w/w). On the other hand, the incorporation of NC does not avoid the processability of the material to obtain film-shaped processed materials.
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Liu, Fei, Yanling Wang, Xiaqing Li, Zhaoxiang Zhang, Xiaodong Dai, Xuewu Wang, Yanping Xin, et al. "The phase inversion mechanism of the pH-sensitive reversible invert emulsion from w/o to o/w." Open Physics 18, no. 1 (July 28, 2020): 380–90. http://dx.doi.org/10.1515/phys-2020-0112.
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AbstractAlteration in the environmental conditions will cause a reversed reaction between o/w emulsion and w/o emulsion that has similar advantages of different liquids form on the reversible invert emulsion. The reversible phase inversion of the emulsion has a benefit of dealing with drilling cutting, so the reversible invert emulsion also can be thought used as a drilling fluid. The phase inversion from w/o emulsion to o/w emulsion can be divided into three stages. They are w/o emulsion, w/o/w emulsion, and o/w emulsion. In the w/o emulsion stage, the structure appeared among water droplets when the percentage of the HCl solution (5%) was less than 0.375%. In the w/o/w emulsion stage, the structure among water droplets existed at the beginning of this stage; however, the internal phase and the external phase can interchange their positions during the process. In the third stage, the structures among droplets of the emulsion would be broken and the degree of the dispersion of the oil droplet in the emulsion would increase. The changes in the microstructure, conductivity, electrical stability, standing stability, and the viscosity of the emulsion, which have edified among droplets in the process from w/o emulsion to o/w emulsion, were studied. The result of the microstructure microscopic observation agrees with the result of the electrical stability and viscosity experiments. Moreover, the internal phase and the external phase can interchange positions during the process.
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Foley, John, and Catherine O'Connell. "Comparative emulsifying properties of sodium caseinate and whey protein isolate in 18% oil in aqueous systems." Journal of Dairy Research 57, no. 3 (August 1990): 377–91. http://dx.doi.org/10.1017/s0022029900027035.
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SummaryBoth whey protein isolate (WPI) and Na caseinate gave similar emulsion capacity-concentration profiles at pH 7. The emulsion capacity of aqueous solutions of WPI was relatively independent of pH while the values for caseinate fell in the isoelectric region. Saline (7·59 g/1) compared with aqueous solutions improved emulsion capacity, particularly above pH 7. At low concentration, WPI had greater emulsifying capacity and gave finer globule dispersion than sodium caseinate. Increase in emulsifier concentration, within a certain range, increased stability, improved dispersion and reduced capacity. Ethanol up to about 20% w/w improved the emulsion capacity of both proteins while at 50% the phases separated. Heat treatment (> 65 °C) of WPI solution before emulsion formation impaired capacity and stability. Heat treatment of preformed WPI emulsions did not have the same effect. Na caseinate and WPI each formed a thin continuous layer of relatively uniform thickness over the oil globule surfaces while denatured WPI appeared aggregated and relatively unevenly distributed at the oil-aqueous interface.
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Zaini, Erizal, Rahmi x. Rahmi Nofita, Salman, and Irna Kurniati. "KARAKTERISASI FISIKOKIMIA DAN LAJU DISOLUSI DISPERSI PADAT IBUPROFEN DENGAN PEMBAWA POLIETILENGLIKOL 6000." Jurnal Riset Kimia 4, no. 1 (February 11, 2015): 25. http://dx.doi.org/10.25077/jrk.v4i1.63.
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Solid dispersions of the antiinflamation drug ibuprofen and polyethylene glycol 6000 (PEG 6000) were prepared by the melting method in order to increase the dissolution rates of this poorly water-soluble compound. The temperature/composition phase diagram of binary system was analyzed by termal analysis hot-stage microscopy, showing an eutectic formation. Polarized light hot stage microscopy and X-ray-powder diffraction confirmed, that solid dispersion technique decrease the crystalliny of ibuprofen after melting and solidifying of a 4/6 (w/w) mixture of ibuprofen and polyethylene glycol 6000 respectively, which the results enhanced dissolution rates compared to the physical mixtures and ibuprofen intact. However, no such chemical interactions in the solid state were confirmed by FTIR spectra which showed the presence of ibuprofen crystalline in solid dispersion.
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Shaker, Dalia S., Rania A. H. Ishak, Amira Ghoneim, and Muaeid A. Elhuoni. "Nanoemulsion: A Review on Mechanisms for the Transdermal Delivery of Hydrophobic and Hydrophilic Drugs." Scientia Pharmaceutica 87, no. 3 (July 12, 2019): 17. http://dx.doi.org/10.3390/scipharm87030017.
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Nanoemulsions (NEs) are colloidal dispersions of two immiscible liquids, oil and water, in which one is dispersed in the other with the aid of a surfactant/co-surfactant mixture, either forming oil-in-water (o/w) or water-in-oil (w/o) nanodroplets systems, with droplets 20–200 nm in size. NEs are easy to prepare and upscale, and they show high variability in their components. They have proven to be very viable, non-invasive, and cost-effective nanocarriers for the enhanced transdermal delivery of a wide range of active compounds that tend to metabolize heavily or suffer from undesirable side effects when taken orally. In addition, the anti-microbial and anti-viral properties of NE components, leading to preservative-free formulations, make NE a very attractive approach for transdermal drug delivery. This review focuses on how NEs mechanistically deliver both lipophilic and hydrophilic drugs through skin layers to reach the blood stream, exerting the desired therapeutic effect. It highlights the mechanisms and strategies executed to effectively deliver drugs, both with o/w and w/o NE types, through the transdermal way. However, the mechanisms reported in the literature are highly diverse, to the extent that a definite mechanism is not conclusive.
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Noh, Gyubin, Taekwang Keum, Jo-Eun Seo, Jaewoong Choi, Bastola Rakesh, Lamichhane Shrawani, Byoungduck Park, Young Choi, and Sangkil Lee. "Development and Evaluation of a Water Soluble Fluorometholone Eye Drop Formulation Employing Polymeric Micelle." Pharmaceutics 10, no. 4 (October 28, 2018): 208. http://dx.doi.org/10.3390/pharmaceutics10040208.
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Low aqueous solubility of drug causes difficulties in preparation and inconvenience of administration. Polymeric micelles of fluorometholone (FML) using solid dispersion technique were prepared to develop an eye drop formulation with enhanced water solubility. Solid dispersions of FML were prepared at various FML:Soluplus® w/w ratios using solvent evaporation method. A physical mixture was also prepared. Physicochemical characterization was performed with various methods. Ex vivo porcine corneal permeation of polymeric micelle, physical mixture, and commercial product were compared. FML solid dispersion (1:15) showed the highest solubility, which was c.a. 169.6- and 15.3-fold higher than that of pure FML and physical mixture. Characterization showed that the crystalline form of FML changed to amorphous state and polymeric micelles were formed in round micelle. Flucon®, a commercial product of FML, showed significantly large particle size and high poly dispersity index. In contrast, FML polymeric micelle showed submicron size with uniform size distribution. Ex vivo porcine corneal permeation study showed that permeation by polymeric micelles was significantly higher than that by the commercial product and physical mixture. In addition, confocal laser scanning microscopic analysis supported the enhanced porcine corneal tissue permeation property of polymeric micelle. In conclusion, polymeric micelle prepared with solid dispersion using Soluplus® can be a potential nanomedicine for ocular delivery of poorly water-soluble FML.
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Zhang, Jie, Gongwei Li, Duoxia Xu, and Yanping Cao. "Stability, Microstructure, and Rheological Properties of CaCO3 S/O/W Calcium-Lipid Emulsions." Foods 10, no. 9 (September 18, 2021): 2216. http://dx.doi.org/10.3390/foods10092216.
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Calcium carbonate (CaCO3) is a commonly used fortified calcium, but poor suspension stability and easy precipitation seriously limited its food processing and products application. The formation of CaCO3 loaded microparticles based on the form of solid/oil/water (S/O/W) emulsion is a promising method to improve the dispersion stability of CaCO3 in liquid food. In this study, CaCO3, soybean oil, and sodium caseinate (NaCas) were used as the solid, oil, and W phase, respectively. The fabrication involved two steps: the S/O emulsion was prepared by adding CaCO3 into soybean oil by magnetic stirring and high-speed shearing, and then put the S/O crude emulsion into NaCas solution (W phase) to obtain S/O/W emulsion by high-speed blender. The particle size distribution, zeta potential, stability of the microsphere, infrared spectral analysis, and XRD of the S/O/W calcium-lipid microsphere were explored. The stability and rheological mechanism of S/O/W calcium-lipid emulsion were investigated by combining the microstructure, shear rheological, and microrheological properties. It was found that the emulsion particles have more uniform particle size distribution and no aggregation, and the stability of the emulsion was improved with increasing the content of NaCas. The mean square displacement (MSD) curve and solid-liquid equilibrium (SLB) value of S/O/W emulsion increased with the increase in NaCas concentration, and the viscosity behavior is dominant. The results of confocal laser microscopy (CLSM) and cryo-scanning electron microscopy (Cryo-SEM) showed that the three-dimensional network structure of S/O/W emulsions was more compact, and the embedding effect of calcium carbonate (CaCO3) was slightly improved with the increase in NaCas concentration. According to infrared spectrum and XDR analysis, the addition of CaCO3 into the emulsion system caused crystal structure distortion. This study provides a reference for solving the dispersibility of insoluble calcium salt in liquid food.
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Gibson, R. R., E. J. Cornel, O. M. Musa, A. Fernyhough, and S. P. Armes. "RAFT dispersion polymerisation of lauryl methacrylate in ethanol–water binary mixtures: synthesis of diblock copolymer vesicles with deformable membranes." Polymer Chemistry 11, no. 10 (2020): 1785–96. http://dx.doi.org/10.1039/c9py01768b.
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Diblock copolymer vesicles with deformable membranes are prepared via RAFT dispersion polymerisation of lauryl methacrylate in an 80 : 20 w/w ethanol–water mixture; visible light irradiation allows facile RAFT chain-end removal from these nano-objects.
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Kaushik, S., and Kamla Pathak. "DEVELOPMENT AND EVALUATION OF MONOLITHIC OSMOTIC TABLET OF KETOPROFEN: USING SOLID DISPERSION TECHNIQUE." International Journal of Pharmacy and Pharmaceutical Sciences 8, no. 12 (December 1, 2016): 41. http://dx.doi.org/10.22159/ijpps.2016v8i12.11437.
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<p><strong>Objective: </strong>The aim of the present study was to develop and evaluate the monolithic osmotic tablet (MOT) composed of the solid dispersion of ketoprofen (KETO), a poorly water-soluble drug. Solid dispersion technique is generally used for immediate release, as this maximizes the amount of drug absorbed. Sustained release may be obtained by combining solid dispersion technique with MOT so as to increase the therapy efficacy and patient compliance.</p><p><strong>Methods: </strong>Solid dispersion of KETO was prepared by using solvent melt method with polyethylene glycol (PEG) 6000, a hydrophilic carrier. The ratio of KETO to PEG 6000 were 1:1, 1:3 and 1:5 (%w/w). These solid dispersions were characterized by differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD) to ascertain whether there were any physicochemical interactions between drug and carrier.</p><p>The tablet core was prepared by using Polyox N80 (a suspending agent), sodium chloride (an osmotic agent), a solid dispersion consisting of PEG 6000 and KETO followed by a coating of cellulose acetate to make the monolithic osmotic tablet.</p><p><strong>Results: </strong>The results of DSC and PXRD indicated that the drug was in the amorphous state in solid dispersion when PEG 6000 was used as a carrier. The dissolution rate of the solid dispersion was much faster than those for the corresponding physical mixture and pure drug. The optimized MOT formulations were able to deliver KETO at the constant zero order release, above 95% <em>in vitro</em>, independent to environmental media and stirring rate. The release rate of KETO in the MOT is controlled by osmotic pressure, suspending agent and drug solubility in solid dispersion.</p><p><strong>Conclusion: </strong>The monolithic osmotic tablet containing solid dispersion has great potential in the controlled delivery of ketoprofen, a water-insoluble drug.</p><p><strong>Keywords: </strong>Ketoprofen, Monolithic osmotic tablet, Solid dispersion, Water insoluble</p>
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Schlappa, Stephanie, Lena Bressel, Oliver Reich, and Marvin Münzberg. "Advanced Particle Size Analysis in High-Solid-Content Polymer Dispersions Using Photon Density Wave Spectroscopy." Polymers 15, no. 15 (July 26, 2023): 3181. http://dx.doi.org/10.3390/polym15153181.
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High-solid-content polystyrene and polyvinyl acetate dispersions of polymer particles with a 50 nm to 500 nm mean particle diameter and 12–55% (w/w) solid content have been produced via emulsion polymerization and characterized regarding their optical and physical properties. Both systems have been analyzed with common particle-size-measuring techniques like dynamic light scattering (DLS) and static light scattering (SLS) and compared to inline particle size distribution (PSD) measurements via photon density wave (PDW) spectroscopy in undiluted samples. It is shown that particle size measurements of undiluted polystyrene dispersions are in good agreement between analysis methods. However, for polyvinyl acetate particles, size determination is challenging due to bound water in the produced polymer. For the first time, water-swelling factors were determined via an iterative approach of PDW spectroscopy error (Χ2) minimization. It is shown that water-swollen particles can be analyzed in high-solid-content solutions and their physical properties can be assumed to determine the refractive index, density, and volume fraction in dispersion. It was found that assumed water swelling improved the reduced scattering coefficient fit by PDW spectroscopy by up to ten times and particle size determination was refined and enabled. Particle size analysis of the water-swollen particles agreed well with offline-based state-of-the-art techniques.
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Kristiawan, Budi, Agung Tri Wijayanta, Wibawa Endra Juwana, and Shegi Wulandari. "ANALISA NUMERIK PENINGKATAN TRANSFER KALOR ALIRAN TURBULEN FLUIDA NANO TiO₂/AIR PADA CIRCULAR MINICHANNEL." Jurnal Rekayasa Mesin 13, no. 1 (June 22, 2022): 217–29. http://dx.doi.org/10.21776/ub.jrm.2022.013.01.21.
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Conventional heat transfer fluids such as water, ethylene glycol and oil are limited by their poor thermal properties therefore it is needed the advanced heat transfer fluids that be able to improve their thermal performance. Nanofluids is a colloidal dispersion of nano-sized particles which are a breakthrough of thermal system. This numerical study using the multi-phase mixture model method investigated the convective heat transfer of TiO2/water nanofluids flowing through a circular mini channel with a 1.09 mm diameter and 306 mm length under turbulent flow regime. TiO2 nanoparticles with a diameter of 21 nm were dispersed into water with volume concentrations of 1.0, 2.0, 3.5, and 5.0 vol.%. The Reynolds number was varied from 4000-20,000 and a constant heat flux of 6500 W/m2. The results showed that the addition of nanoparticles and the variation of the Reynolds number increased the convective heat transfer coefficient of TiO2/water nanofluid by 5.18%, 7.4%, 12.4%, and 14.3%, respectively, with increasing in nanoparticles concentrations.
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Horikawa, T., M. Katsura, T. Yokota, and S. Nakashima. "Effects of pore water distributions on P-wave velocity–water saturation relations in partially saturated sandstones." Geophysical Journal International 226, no. 3 (April 15, 2021): 1558–73. http://dx.doi.org/10.1093/gji/ggab143.
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SUMMARY We have developed a new method for introducing the effects of pore water distribution into the interpretation of P-wave velocity (VP) dispersion in a partially saturated rock. Pore water in an unsaturated rock is distributed as patches, and mesoscopic-scale wave-induced fluid flow (WIFF) from saturated patches to empty patches is known as a key mechanism for interpreting P-wave dispersion. Mesoscopic WIFF depends on permeability and the scale of the saturated patch, thus evaluating their influences is important for estimating the relationship between water saturation (${S_{\rm{w}}}$) and VP. The simplest and conventional law for simulating the ${S_{\rm{w}}} - {V_{{P}}}$ relation considering the mesoscopic WIFF is White's model, which describes the patch size changes proportional to the saturation. However, White's model assumes homogeneity in the size and distribution of pores, and does not consider the effects of pore water distribution in a partially saturated rock. In the rock, pore water is distributed heterogeneously according to the pore radius, causing non-linear changes in the permeability and size of the saturated patches against the water saturation. In this study, we modified White's model by introducing relative permeability and a new coefficient describing the nonlinear change of the patch size into the conventional version, and applied the modified model to better interpret our experimental ${S_{\rm{w}}} - {V_{{P}}}$ relations, which were measured by an ultrasonic technique at 200 and 500 kHz for two types of Berea sandstone samples with different permeabilities as their water saturation was decreased by evaporative drying. The relative permeabilities were determined by applying the Mualem–van Genuchten model into the capillary pressure curves from mercury intrusion porosimetry. Furthermore, we proposed a calculation method for the new coefficient using tortuosity, which corresponds to the pore water connection. The modified White's model could reproduce the experimental ${S_{\rm{w}}} - {V_{{P}}}$ relations better than other conventional models. Consequently, our modification, considering the effect of pore water distribution, would be useful for more quantitative interpretation of P-wave velocity and attenuation under coexisting multifluid conditions.