In-situ measurement of the formation process of poly(ethylene-co-vinyl alcohol) (EVAL) membran using an UTDR technique
Ultrasonic time-domain reflectometry (UTDR) technique was employed to visualize the kinetic behavior of poly(ethylene-co-vinyl alcohol) (EVAL) membrane formation. EVAL membranes were prepared by immersion-precipitation method in water/dimethyl sulfoxide (DMSO)/EVAL system. The results show that UTDR technique is able to recognize the acoustic response signals generated from the interface of nonsolvent and casting solution. The shift of the response signals in time-domain with formation time obtained by UTDR is associated with heat and mass transfer during the membrane formation. In coagulation bath, the ultrasonic velocity increased with an increase in DMSO concentration and temperature. On the other hand, the ultrasonic velocity decreased with an increase in DMSO concentration and temperature. The acoustic velocity as a function of DMSO concentration and temperature in coagulation was obtained. Finally the heat and mass transfer in both casting solution and membrane layer was calculated by the sound velocity obtained by UTDR. The average DMSO concentration and the temperature in coagulation bath increased from 0 to 1.67wt% and from 25 ℃ to 25.8 ℃ after 60s of immersion, respectively. Using this method, kinetic model of different systems could be predicted.
CAI Ying LI Jianxin GUO Yugao HUANG Dongwei ZHANG Yuzhong
The Key laboratory of Hollow Fiber Membrane Material and Processes, Ministry of Education, School School of Science, Tianjin Polytechnic University, Tianjin 300160, PR China
国际会议
2009 International Conference on Advanced Fibers and Polymer Materials(2009年先进纤维与聚合物材料国际学术会议)
上海
英文
750-753
2009-10-21（万方平台首次上网日期，不代表论文的发表时间）