双改性Al_2O_3/PVDF杂化膜的制备和性能

Preparation and Performance of Modified Al_2O_3/PVDF Hybrid Membrane

分别利用乙烯基三甲氧基硅烷对Al_2O_3粒子进行了改性、KOH对聚偏氟乙烯(PVDF)进行了改性,并以改性后的产物为制膜材料,以过氧化苯甲酰(BPO)为引发剂,将改性纳米Al_2O_3粒子引入到改性PVDF中,通过热致相变法制备了双改性Al_2O_3/PVDF杂化膜。分别考察了硅烷偶联剂对Al_2O_3粒子粒径的影响,及不同碱浓度和碱处理时间对PVDF结构的影响,并对制备的双改性膜进行了性能测试。结果表明:当硅烷偶联剂的质量分数为33%(以体系总质量计,下同)时,Al_2O_3粒子的粒径从593.45 nm降为43.47 nm,在此基础上,当改性Al_2O_3粒子的质量分数为5%时,杂化膜的截留率为83.1%,水通量为621.5 L/(m2·h),膜的拉伸强度达到5.01MPa。改性纳米Al_2O_3粒子的引入,是杂化膜通量和力学强度提高的主要原因。

In order to improve hydrophilicity and mechanical properties of polyvinylidene fluoride（ PVDF） membrane,silane coupling agent（ ethenyl trimethoxysilane） and KOH were used to modify Al2O3 particles and PVDF,respectively. Then with benzoyl peroxide（ BPO） as the initiator,the modified Al2O3 particles were introduced into PVDF. Subsequently,the modified Al2O3/ PVDF hybrid membrane was prepared through thermal induced phase transition method. Meanwhile,the effect of silane coupling agent on Al2O3 particle size and the effects of alkali concentration and alkali treatment time on PVDF structure were investigated. Additionally,the properties of modified membrane were studied as well. As the results,when the mass fraction of silane coupling agent was 33%,the size of Al2O3 particles reduced to 43. 47 nm from 593. 45 nm. Accordingly,when the mass fraction of modified Al2O3 particles was 5%,the rejection and flux of the hybrid membrane were up to 83. 12% and 621. 5L /（ m2·h）,respectively. Moreover,the tensile strength of the hybrid membrane was 5. 01 MPa. The higher flux and excellent mechanical properties of the hybrid membrane are attributed to the introduction of modified Al2O3 particles.