The hydrophilic-hydrophobic balance (HLB) of surfactants has a great influ-ence on surfactants. Among them, polyethylene glycol has an HLB value of 20 and is highly hydrophilic; oleic acid has an HLB value of 1, which is very lipophilic; and sodium dodecylbenzenesulfonate has an HLB value of 10.6 be-tween the two. This paper explores the use of these three surfactants with typi-cal HLB values to improve the performance of magnetorheological fluids, mainly to study its effect on the stability of magnetorheological fluids. Tests have shown that the use of lipophilic surfactants in oil-based magnetorheologi-cal fluids has better sedimentation stability than the use of hydrophilic surfac-tants.
Phulé, P.P., Mihalcin, M.P. and Genc, S. (1999) The Role of the Dispersedphase Remnant Magnetization on the Redispersibility of Magnetorheological Fluids. Journal of Materials Research, 14, 3037-3041. https://doi.org/10.1557/JMR.1999.0407
Shinoda, K. and Saito, H. (1969) The Stability of O/W Type Emulsions as Functions of Temperature and the HLB of Emulsifiers: The Emulsification by PIT-Method. Journal of Colloid & Interface Science, 30, 258-263. https://doi.org/10.1016/S0021-9797(69)80012-3