Analysis of Factors Affecting the Gel Point of Methanol-Water-Sodium Stearate Mixed Gel

This study determined the gel point of methanol-water-sodium stearate mixed gels at various concentrations of water and gelling agent by monitoring turbidity changes during the sol-gel transition. The gel points determined by turbidity measurements were further validated by monitoring changes in electrical conductivity during the sol-gel process at various concentrations of water and gelling agent. Molecular dynamics simulations were also conducted to further corroborate the gel points determined experimentally. The turbidity test results showed that the gel point was 20°C for the 3% gelling mixture and 35°C for the 5% gelling mixture. Mixed gels with 10% water content and 3% gelling agent content have a gel spot of 33°C.The electrical conductivity tests revealed that the average gel points for mixed gels with different water contents were 16.75°C (0%), 25.1°C (5%), and 32.4°C (10%). The average gel points for different gelling agent contents were 16.75°C (3%), 23.55°C (4%), and 38.75°C(5%).According to the results, the gelling agent content can significantly affect the gel point of the mixed gel. The addition of water can also improve the gel point of the mixed gel. The diffusion coefficients of pure water molecules during the equilibrium process of 273K were used to determine the gel points of different water-containing gels, which were 314K (5%) and 318K (10%), respectively. By fitting the high and low temperature data of the diffusion coefficient, the gel points of the gelling mixture containing only gelling agent were 297.19K (3%), 303.18K (4%), and 309.91K (5%), respectively.