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Water Emulsions (water + emulsion)
Selected AbstractsA Physical Method of Fabricating Hollow Polymer Spheres Directly from Oil/Water Emulsions of Solutions of Polymers,MACROMOLECULAR RAPID COMMUNICATIONS, Issue 18 2004Young Baek Kim Abstract Summary: A new physical method of fabricating hollow spheres from different polymers has been developed. In this method, emulsions were prepared by mixing organic solutions of polystyrene, poly(D,L -lactide- co -glycolide) (PLGA), and bacterial poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV), water, and surfactants. The evaporation of solvents at room temperature caused a phase separation that eventually yielded hollow spheres. Molecular weights, concentrations of polymers, and the natures of surfactant and solvent were important aspects of hollow sphere formation and structure. A mechanism for the formation of hollow spheres is proposed based on observations made using an optical microscope equipped with a digital camcorder and using scanning electron microscopy images of hollow spheres obtained under different conditions. A scanning electron microscopy image of a broken smaller hollow sphere prepared using a 7 wt.-% polystyrene solution (diameter of the sphere ,10 micrometers). [source] Evidence for oil-induced oxidative stress to larvae of the lightbrown apple moth, Epiphyas postvittana Walker (Lepidoptera: Tortricidae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2002Peter D Taverner Abstract For the purpose of understanding better the mode of action of alkanes on insects, the relationship between mortality, weight loss in oxygen enriched atmospheres and dietary antioxidants was examined using an alkane, C15 Ampol CPD and a spray oil, C23 DC-Tron NR, on lightbrown apple moth, Epiphyas postvittana Walker, (LBAM). The results showed that the surfactant blend used in CPD was an insignificant contributor to the overall toxicity of dilute oil/water emulsions. Higher weight loss occurred in CPD-dipped larvae than C23 DC-Tron NR-dipped larvae, which suggests that alkanes disrupt tracheal waxes and render insects more prone to desiccation. High levels of oxygen increased the toxicity of CPD to LBAM larvae. In addition, dietary supplements of anti-oxidant, ,-tocopherol, fed to LBAM larvae were successful in reducing the toxicity of CPD. These results suggest that the alkane may contribute to oxidative injury. The potential role of oil-induced oxidative stress in acute and chronic toxicity in insects is discussed. © 2002 Society of Chemical Industry [source] Determination of cosmetic ingredients causing extrusion-coated and adhesive joint multilayer packaging delaminationPACKAGING TECHNOLOGY AND SCIENCE, Issue 7 2009Álvaro Garrido-López Abstract In order to study the effect of several compounds on packaging stability, different cosmetic ingredients at two concentration levels were added to a NeoPCL® (Acofarma, Terrassa, Spain) water emulsion, and the preparations packed in sachets and stored at 40°C during 3 months. After that, the packaging was subjected to a T-peel test and headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) analysis. The HS-SPME-GC-MS analyses were performed using a 75,,m carboxen polydimethylsiloxane fibre to check for the presence of the studied analytes in the inner layers. The study revealed that the presence of a phenyl and a hydroxyl group in the compound structure lead to an important loss of adhesion between packaging layers joined by an adhesive. The interaction between the cosmetic ingredient and the adhesive was proposed as the main cause of the loss of adhesion. However, extrusion-coating packaging was more susceptible to delamination, particularly with the volatile compounds. Copyright © 2009 John Wiley & Sons, Ltd. [source] Water-repellent finishing of cotton fabrics by ultraviolet curingJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2008F. Ferrero Abstract Cotton fabrics were water-repellent-finished by radical ultraviolet curing of silicone and urethane acrylates with different formulations. The fabrics were impregnated with undiluted resins and with toluene solutions or water emulsions. Moreover, cationic ultraviolet-curable systems were also investigated, such as an epoxy-functional polysiloxane and mixtures of an epoxy resin with hydroxyl-containing silicone additives. The gel content and polymerization yield were considered for the ultraviolet-curing process evaluation. Water-resistance properties were determined in terms of the contact angle, wettability, moisture adsorption, and water vapor permeability measurements, whereas the morphology and surface composition of treated fabrics were examined with scanning electron microscopy and energy-dispersive X-ray analysis. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Effects of sand and process water pH on toluene diluted heavy oil in water emulsions in turbulent flowAICHE JOURNAL, Issue 1 2009Chandra W. Angle Abstract The presence of sand in heavy oil production is known to enhance oil recovery. Sand can also be detrimental depending on the properties of the sand,water interface. In this process, the water soluble material interacts with both sand and oil droplets and affects emulsion stability. The formation and stability of heavy oil-in-water emulsions during turbulent flow using batch process stirred-tank mixing of oil, sand, and water were investigated at three pH. Size distributions were measured by laser diffraction. High-speed video photomicrography was used to observe the process during mixing. Results showed that the presence of sand enhanced formation of stable, fine emulsion at basic pH 8.5. When the pH of the water was reduced below 6.5 both sand and droplets surface properties changed, the emulsions became less stable and coalescence was apparent. The sand grains acted as coalescers at low pH and enhanced breakage at high pH. © Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources, 2008 AIChE J, 2009 [source] Organic coated solids in athabasca bitumen: Characterization and process implicationsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2000Farid Bensebaa Abstract Bitumen, separated from oil sands by the hot water extraction process, contains ultra-fine (< 200 nm), inorganic solids (BS). Surfaces of BS particles are coated with toluene insoluble organic matter (TIOM). This organic material is polar and aromatic with contributions from both humic and asphaltene-like components. Although the surfaces of BS particles are dominated by TIOM, the coverage is patchy rather than continuous. As a result, these solids are capable of stabilizing fine water emulsions in the bitumen phase. The nature of the organic matter on the surfaces of the particles is such that it has a high propensity to form coke. Therefore, these particles can also play a role in fouling on equipment and catalysts. Le bitume séparé des sables pétrolifères par le procédé d'extraction à air chaud, contient des solides inorganiques (BS) ultrafins (<200 mm). Les surfaces des particules BS sont recouvertes de matière organique insoluble au toluène (TIOM). Cette matière organique est polaire et aromatique avec des contributions provenant de composants humiques et proches de l'asphaltène. Bien que les surfaces des particules BS soient dominées par le TIOM, le revêtement est irrégulier plutôt que continu. Par conséquent, ces solides sont capables de stabiliser des émulsions aqueuses fines dans la phase du bitume. La nature de la matière organique sur les surfaces des particules est telle qu'elle a une forte propension à former du coke. Ces particules peuvent donc jouer un rôle dans l'encrassement des équipements et des catalyseurs. [source] | |||||||||||||