【摘要】 采用切线法测量聚丙烯中空纤维膜的静态接触角,考察实验条件如平衡时间、滴液体积以及环境温湿度对膜接触角的影响,根据相对标准偏差确定接触角测试条件.在此基础上,采用原子力显微镜进行膜表面形貌表征,测量并比较聚丙烯初生纤维和商品膜的接触角,分析表面粗糙度对膜疏水性能的影响.结果表明,当液滴体积小于0.1μL,避免了液滴重力对接触角的影响,环境温湿度和平衡时间是影响测量结果的主要因素.规则的微孔结构使膜表面粗糙度增大,形成毛细效应,有效阻止了液滴铺展和滑移,膜疏水性能显著提高.当液滴体积为0.04μL,环境温度为（20±2）℃,湿度为（25±4）%^65±4%,液滴平衡时间为15s,膜接触角为111.2°¹07.8°,相对标准偏差小于5%.更多还原

【Abstract】 Static contact angle of polypropylene hollow fiber membrane was measured by tangent fitting method.The effects such as droplet size,equilibrium time,environmental temperature and humidity on membrane contact angle were studied.According to relative standard deviation(RSD)of membrane contact angle,the optimal testing parameters were determined.Based on above results,atomic force microscopy was used to characterize membrane surface morphology.Through comparison the angle results of commercial membrane and as-spun fiber,the relevance between membrane roughness and membrane hydrophobic was analyzed as well.The results showed that in order to improve accuracy of testing method,the influence of droplet gravity was avoided when droplet size was less than 0.1μL.Droplet equilibrium time,environmental temperature and humidity were the main factors.Regular micro-porous structure increased membrane surface roughness and formed capillary effect,prevented the droplet spreading and sliding along the fiber axial effectively,so the membrane hydrophobic performance was improved significantly.The optimal testing parameters are listed as followed:droplet volume is 0.04μL, the environment temperature is 20 ℃±2 ℃,humidity is from 25%RH±4%RH to 65%RH±4%RH, droplet equilibration time is within 15seconds,RSD of membrane contact angle is less than 5%.更多还原