A Study on Particle Sedimentation Depression With Poly Vinyl Alcohol and Surfactant

The combination structure size in water of poly(vinyl alcohol) (PVA) and drag reducing surfactants has been performed in order to investigate the sedimentation depression effects on latent heat transportation systems found in the previous study. As surfactants, behenyltrimethylammonium chloride with 1.5 molar ratio of counter-ion suppliers, sodium salicylate, was used at the constant surfactant concentration of 2,000 ppm in water, while the concentration of PVA was changed from 0 to 2,000 ppm. The structure size of the combination was measured by a dynamic light scattering (DLS) system. From the results, DLS analysis indicated a large structure is formed by the interaction between PVA and surfactants. It was found that this structure becomes large with PVA concentration and the occupation volume of the structures expands widely in fluid. Thus, it was concluded that this large structure formation causes effective sedimentation depress on particles in latent heat systems.