Transient electric birefringence of poly(sodium p-styrenesulfonate) solutions at very low field strengths†

摘要: Measurements of the electric birefringence were performed on dilute, aqueous solutions a poly(sodium p-styrenesulfonate). The concentrations chosen to be somewhat below and above critical concentration (c*) where, grounds theoretical considerations, rod-to-coil transition is expected occur. measurements conducted at very low field strengths E, viz. in order E = 104 V · m-1, using d. c. pulses as well 30 kHz a. pulses. When an applied, always negative shows monotonous rise decay. same holds true for provided polymer c*. However, when pulse strength applied solution which concentration, some strange features occur: At beginning negative, but then it reverses its sign approaches positive steady-state value. After cessation passes through maximum before decaying zero. whole curve looks like superposition two signals with opposite signs. These disappear higher strengths. On basis analysis field-strength dependence, tentatively concluded that other mechanisms besides rotational orientation molecules contribute birefringence. One such process could migration macroions giving flow