Liquid crystal‐forming aqueous hydroxypropyl cellulose solutions: Effects of surfactants on the turbidity and shear viscosity

Abstract

AbstractThe effects of type and concentration of surfactant on the turbidity and viscometric behavior for dilute and concentrated aqueous hydroxypropyl cellulose (HPC) solutions were examined. Two anionic surfactants, sodium dodecyl benzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS), caused the cloud point of the dilute system to increase, but a nonionic and two cationic surfactants did not do so markedly. The transmittance for the dilute system increased with surfactant. The transmittance and viscometric behavior for the concentrated system were strongly dependent on the phase of the system: In the single‐phase (isotropic and anisotropic), the transmittance and viscosity increased with SDBS, but, in the biphasic region, the behaviors were not as simple. An attempt was made to explain the transmittance and viscometric behavior in the single‐phase on the basis of the change in apparent molecular weight and in order of HPC molecules. The phase transformation appeared to become less sensitive to temperature with SDBS. © 1993 John Wiley & Sons, Inc.