Molecular dynamics simulation was used to calculate the self-diffusion coefficients of ginger bioactive compounds (6-gingerol and 6-shogaol) in subcritical water with the presence of ethanol as an entrainer (0-10 mol%) at temperatures from 373.15 to 453.15 K. The all-atom optimised-potentials (OPLS/AA) were employed for the ginger bioactive compounds and ethanol. The extended simple point charge (SPC/E) model was adopted for water molecules. The self-diffusion coefficients increase from 1.00 × 10 −9 to 2.70 × 10 −9 m 2 /s with increasing temperature from 353.15 to 453.15 K. The self-diffusion coefficients also increase from 1.71 × 10 −9 to 3.00 × 10 −9 m 2 /s with increasing percentage of ethanol from 0 to 10 mol% at 413.15 K. The radial distribution functions between the ginger bioactive compounds and subcritical water (solvent) illustrate a weak interaction between the ginger bioactive compounds and solvent. The interaction increases with addition of ethanol as entrainer.
An emulsion is defined as a phase containing two immiscible liquids consisting of water and oil. In the oil and gas industry, the presence of emulsions results in high costs for pumping equipment, reduced performance and increased corrosion rates in pipelines and other equipment. Numerous studies have been conducted for crude oil emulsions, but are still lacking for emulsions present in base oil. Therefore, the research focuses on characterising the emulsified base oil by comparing the physical and thermophysical properties of the emulsified base oil with and without a formulated surfactant and using the base oil as a control sample to observe the stabilisation of the samples. Physical properties include material composition, particle size and distribution, density, viscosity and shear stress; thermophysical properties include thermal stability. Samples were prepared using a homogeniser (2 hours) followed by ultrasonic treatment (2 hours) with 10 mL of water and 190 mL of base oil at room temperature. About 10 mL of the formulated surfactant was added to characterise the emulsified base oil with surfactant. The samples were further analysed for molecular compounds, particle distribution, physical properties (density and viscosity) and thermal stability using DSC and TGA. The results showed that the emulsified base oil with formulated surfactant has higher viscosity and lower density than the emulsified base oil without formulated surfactant.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.