Papers by Keyword: Emulsion

Abstract: One of the emerging alternatives to surfactants in crude oil dehydration is the application of nanoparticles. This review aims to assess the recent progress in the application of nanoparticles for the chemical demulsification of water-in-oil and to provide knowledge gaps for future research. This review covers the nanomodification of commercial demulsifiers and the demulsification performance of magnetic and nonmagnetic nanoparticles, along with their possible mechanisms and factors that affect their dehydration efficiency. The addition of nanoparticles improves the dehydration performance of commercial demulsifiers by improving their wettability and interfacial activity. The advantage of magnetic nanoparticles is their rapid response to a magnetic field, which allows them to be recoverable. For nonmagnetic nanoparticles, their advantage is their environmental friendliness, biocompatibility, and cost-effectiveness. Nanoparticles were able to dehydrate emulsions by modifying the interfacial properties and possibly through adsorption of asphaltenes. Factors such as dosage, temperature, pH, salinity, water content, surfactant concentration; and nanoparticle wettability, and surface chemistry significantly affect the demulsification performance. The application of nanoparticles as demulsifiers is still on a laboratory scale. However, studies on toxicity and proper handling may increase interest for field application. Studies are encouraged on the exact mechanism on the reduction of interfacial tension.

Abstract: The leaf extract from Tithonia diversifolia is recognized for its ability to deter feeding in various Lepidoptera insect pests, including the larvae of Crocidolomia pavonana. Presently, transformation efforts from conventional formulations into nano-based formulations for biopesticides exhibit enhanced effectiveness and efficiency. Utilizing a low-energy process, an inversion emulsion facilitates the dispersion of the extract suspension in an organic solvent into a water-immiscible solvent using a suitable surfactant. The forming nano-size droplets in water (t1, t2, t3, t4) are influenced by the ratio of surfactant and organic suspension (Water: Tween 80: Organic suspension). The emulsification method successfully formulated T. diversifolia leaf extract, into dispersed nano-size and submicron suspensions in water. The t3 formula exhibits the smallest nano-size dispersed in water (D=23.6 ± 39.6 nm; polydispersity index IP=0.702) and enhanced wettability, evident in the lower contact angle of the droplet on the cabbage leaf surface (49.4°) compare with the control group. The Phytochemicals confirmed by IR-spectra analysis identified the phenols, alkaloids, and steroids constituents of leaf extract, which are known to have antifeedant properties. The enhanced antifeedant properties of T. diversifolia nanosuspension against C. pavonana third-instar larvae demonstrated by the antifeedant test results showing that t3 is the most successful deterrent larvae feeding activity compared to the control (P<0.05), due to the highest total antifeedant coefficient (74.27%) in a category medium antifeedant activity, while the non-emulsification displayed the lowest antifeedant coefficient (25.36%) in a category as low antifeedant activity. T. diversifolia leaf extract with a nano-based formula succeeded resulting in dispersed nano-size and submicron suspension in aqueous media, thereby reducing surface tension and enhancing wettability on the leaf surface during application. The improved dispersion of antifeedant nanosuspension on the leaf surface results in more effective delivery to target insects.

Abstract: The paper deals with highly stable emulsions. It is concentrated on de-emulsification of crude oil. In the petroleum industry, de-emulsification is an important and urgent task that is typically required for the treatment of crude oil. This work, suggests method using coupling device integrated centrifuge with chemical to strengthen the de-emulsification efficiency. A number of de-emulsification runs were conducted to determine how centrifuge and chemical components affected the effectiveness of de-emulsifying crude oil and the separation of water, Different types of de-emulsifiers the (ethylene glycol, choline chloride and ethyl cellulose), were used with different concentration of de-emulsifiers, de-emulsification time in centrifuge and centrifugal speed. Also studied at the same time. Studies on the de-emulsification of crude oil were conducted at room temperature. As the concentration of de-emulsifiers was increased, crude oil's de-emulsification efficiency rose , centrifuge time and centrifugal speed ,with de-emulsifier type effect on de- emulsification ,which reached maximum (85.9%,84.4% and 74.07%) at rate 4% of ethylene glycol, choline chloride and ethyl cellulose respectively ,at 60 min and 4000 rpm . This method provides higher water separation from crude oil emulsion and quicker method.

Abstract: Hydroxypropyl methylcellulose/Shellac-based Composite (HPMC/Sh composite) is produced from oil/water emulsion. The emulsifiers are necessarily used to stabilize and enhance the dispersion of this emulsion. This study conducted the experiments to evaluate effects of saturated fatty acids of lauric acid (LA), stearic acid (SA) and unsaturated fatty acid of oleic acid (OA) to the sensory, mechanical properties and microstructure of the HPMC/Sh emulsion. In which, the saturated fatty acids were used in mixtures with the ratios of shellac : emulsifier at 20 : 1, 10 : 1, and 5 : 1. On the other hand, the unsaturated fatty acid was used in mixtures with the ratio of shellac : emulsifier at 1 : 5, 1 : 10, and 1 : 20. The emulsifiers increased the dispersion and effective interaction of the polymers causing the emulsion formation become more stable and finer particle size. In addition, the films had smooth surfaces without unfractured, flexible and elastic.

Abstract: The existing methods of confering hydrophobic properties to various building materials are considered. Obtaining special, including hydrophobic, properties of water-emulsion paints is a very relevant task. Previously, a method was developed for producing an emulsion of a polysiloxane stabilized with polyvinyl alcohol. The paper describes the possibility of using a hydrophobisating emulsion of polyhydrosiloxane as a functional additive for an acrylic water-dispersion paint. This emulsion is capable of forming coatings on dense and porous surfaces with an adjustable contact angle up to 105 °. The use of this emulsion, with its sufficient coalescence for volumetric hydrophobization of coatings, makes it possible to obtain a high contact angle on the surface. In the paper, it was assumed that the partial introduction of small amounts (up to 10 %) of a hydrophobizing emulsion into water-dispersion paints would allow achieving the contact angle of wetting for similar coatings consisting exclusively of emulsion. It is shown that the introduction of small amounts of a hydrophobizing emulsion with an auxiliary coalescing action of ethylene glycol makes it possible to impart hydrophobic properties to the surface of the resulting coating. When the optimum concentration of ethylene glycol in the coating is reached, dissolution and transport (yield) of polysiloxane to the surface is ensured. The research carried out made it possible to develop a paint composition with a hydrophobizing emulsion with a contact wetting angle of about 100 °, which ensured the hydrophobicity of the previously hydrophilic coating of a water-dispersion acrylic paint.

Abstract: Electrospinning is considered a promising technology for encapsulating and loading various drugs into nanofibers. Metoprolol tartrate (MPT), hydrophilic therapy, was used as model drug. Metoprolol tartrate was loaded into poly(ɛ-caprolactone) (PCL) via blend and emulsion electospinning. The preparation processes, morphology, chemical structure thermal properties were evaluated. FESEM showed that emulsion electospinning produce larger fiber diameters(301.775nm) when compared to fibers produced by blend electrospinning(112.463, 249.34)nm, the PCL/ span 80 and MPT-PCL by emulsion method which have high fiber diameter than pure PCL and MPT-PCL by blend method and the Tm of pure PCL nanofibers and all drug loaded scaffolds are around 60°C from DSC test, water contact angle to pure PCL electrospun mats hydrophobic character (126.2°), while PCL/span 80, and PCL-drug nanofiber mats showed hydrophilic character. Our study demonstrated the possibility of using electrospinning with a promising good potential toward sustained and controlled drug delivery system.

Abstract: This study aimed to develop sunscreen emulsion from natural sunscreening agents, titanium dioxide and Aloe vera gel extract that have good sun protection efficacy. The effects of formulation variables i.e., particle size and amount of titanium dioxide, amount of Aloe vera gel extract (spray dried powder) and combination of sunscreening agents (titanium dioxide and Aloe vera gel extract) on physical properties and sun protection efficacy (e.g., SPF, UVA/UVB ratio, critical wavelength) of sunscreen products were evaluated. The results showed that the smaller particle size of titanium dioxide improved the sun protection efficacy and increased the UVB absorption edge of the products. SPF of the formulations could be ranked as Nanofine TiO₂ (particle size 25–30 nm) > Kingruti T-01 TiO₂ (particle size 200 nm) > Pigment TiO₂ (particle size < 45,000 nm) and UVA/UVB ratio and critical wavelength of the formulations could be arranged in order as follows: Nanofine TiO₂ < Kingruti T-01 TiO₂ < Pigment TiO₂. Increasing amount of titanium dioxide from 5 to 15 %w/w increased significantly viscosity and SPF of formulations. Aloe vera gel extract itself did not significantly affect SPF, however, combination of Aloe vera gel extract and titanium dioxide seemed to have synergistic effect on sun protection efficacy and decreased viscosity of the formulation. According to the results, the good sunscreen formulation consisted of 15 %w/w Nanofine TiO₂, 5 %w/w Aloe vera gel spray dried powder in emulsion base because it was broad spectrum sunscreen and showed high SPF (27.53±1.92), high UVA/UVB ratio with critical wavelength higher than 370 nm.

Abstract: Smart polymers have been one of the most popularly studied materials owing to their capability to alter physio-chemical behaviour upon exposure to specific external stimuli. The biocompatible thermally responsive poly (N-isopropylacrylamide), PNIPAm shows reversible transition between hydrophilic-hydrophobic characteristics at the vicinity of human physiological temperature has great potential to propel the development of smart tissue engineering scaffold and drug delivery. However, the limited availability and its high cost have dampened the extent of research on this polymer. To address these challenges, the current work demonstrates an economical lab-scale polymerization of crosslinked PNIPAm and the optimised parameters to produce mono-dispersed polymer hydrogel particles were investigated. Characterisation of the synthesized PNIPAm polymer revealed particle size polydispersity index of 0.215, indicative of distribution within the mono-dispersed range, with average hydrodynamic diameter of 346.3 nm. Zeta-potential of the synthesized PNIPAm was found to be -20.6 mV, suggesting an incipient instability in terms of colloidal coagulation. Viscosity of the synthesized PNIPAm (4 wt% concentration in methanol) was 28.6 cP. Thermal gravimetric analysis (TGA) indicated the thermal degradation of main chain PNIPAm fell in the range of 340 to 480°C.

Abstract: In view of the serious emulsification existing in Changqing condensate gas emulsion, the unclear oil-water interface and the poor application effect of demulsifier used in the field, it is urgent to study an efficient demulsifier. In this paper, PM and XP-1221 two kinds of demulsifiers are used to solve the emulsification problem. The PM demulsifier was compounded with XP-1221 chemical demulsifier to solve the emulsification problem of Changqing condensate. The effect of temperature and demulsifier concentration on demulsification performance was studied by bottle test method. The results showed that XP-1221 and PM could be effectively combined. The demulsification efficiency was high and the dehydrated water was clear. Studies have shown that XP-1221 has a good synergistic effect with PM. The suitable ratio of the composite demulsifier is 1:1, and the demulsifier effect of the demulsifier can meet the requirements of the oil field demulsifier. The composite demulsifier can meet the requirements of current oilfield demulsifiers.

Abstract: The following investigation was carried out with the objective of characterizing a concrete added with an emulsion based on reused polystyrene. The tests that were carried out for this characterization are: compression resistance, resistivity and ultrasonic pulse speed, in addition to the proper characterization of the stone material. A control mixture was also made and one in which a fluidiser is added in order to compare the results of these mixtures against the results of the concrete added with emulsion. The proportions of the emulsion are 1% and 4% because in the setting times [1], made in previous research results in that 1% is the beginning of setting and 4% the end of it. Values greater than 4% exceed the time allowed in the NMX-C-177-1997 ONNCCE standard.