十二烷基苯磺酸钠对膜蒸馏过程膜润湿的研究

利用聚偏氟乙烯（PVDF）平板膜，以十二烷基苯磺酸钠(SDBS)的水溶液为介质，通过考察温度、原料质量分数以及是否加入NaCl等因素对跨膜通量的影响来研究膜润湿的过程。结果表明：膜蒸馏过程中膜润湿的进程与膜表面孔径的分布有关，表面活性剂分子由于表面扩散作用在部分润湿膜孔内爬伸的过程中，由于热侧气液界面处温度的降低导致的传质推动力降低占主要作用。当膜孔全润湿后，通量完全由膜两侧渗透压决定，脱盐率下降到较低水平。降低膜蒸馏的温度或降低SDBS含量均可以减缓膜蒸馏膜润湿的进程；加入NaCl导致溶液表面张力增大，也可以减缓膜润湿。

Study of membrane wetting in the process of membrane distillation of sodium dodecyl benzene sulfonate solution

The influence of membrane wetting in a membrane distillation process with sodium dodecyl benzene sulfonate(SDBS) as the feed solution has been investigated.A polyvinylidene fluoride(PVDF) membrane was used in the experiments.The influence of varying the operating conditions(feed temperature,feed mass fraction and adding NaCl) on the membrane distillation process was studied.The process of membrane wetting was found to be related to the distribution of the pore size of the membrane.During surfactant crawling within the partially wetted pores,the decrease in temperature at the gas-liquid interface resulted in a decrease in the driving force for mass transfer.After the membrane was completely wetted,the flux was determined by the osmotic pressure between the two sides of the membrane pore.At the same time,salt rejection decreased sharply.The process of membrane wetting can be delayed by reducing the temperature or the mass fraction of SDBS.Furthermore,the introduction of NaCl also delays the wetting process.