The electrorheological (ER) fluids are composed of polarizable particle dispersed in insulating fluid. The ER particles and ER fluids are one of the smart materials which can switch their shear viscosity under an electric field. Thus, the ER fluids have been highlighted in industrial fields such as clutches, shock absorbers, damping devices, gripping devices, human muscle stimulators, and so on thanks to their controllable viscosity and rapid response time.<br/>In order to use the ER fluids in industrial fields, the ER particles have to meet some conditions such as low cost, dispersion stability, high yield stress, high shear stress, etc. Nowadays, some materials such as the graphene oxides, natural polymers, conductive polymers and dielectric inorganics, have been researched to meet the conditions. However, the estimation of the ER behavior prior to actual use is hard. Because, the ER behavior of the ER particles is affected by various parameter, such as shape uniformity of the particles, size of the particles, functional groups of the particle surface, particle concentration in suspension, dipole moment of the particles, chemical reaction between the particles, operation temperature of the ER fluid, etc.<br/>In this work, we have studied the interrelation between functional groups and the ER behavior to offer the effective strategy for estimation the ER behaviors before actual use. We used the polyacrylonitrile (PAN) spherical homopolymer particle as a base material, because the PAN has nitrile groups only, which can be easily substituted to other functional groups by chemical reaction. Aminated PAN and Sulfonated PAN particles were prepared to determine the amine and sulfonate group-induced ER behavior, and other parameters such as concentration, shape, size, operation temperature were controlled.<br/>As a result, we can know that the ER behavior of ER fluid can be controlled by substitution of functional group of the ER particles, and the sulfonate group is a better functional group than amine group to improve the ER effect.

Effect of surface functional groups on electric stimuli-responsive behavior of polyacrylonitrile dispersed colloid

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.