聚丙烯微孔膜的表面矿化修饰及其亲水性能

摘要

In order to improve the surface hydrophilicity of microporous polypropylene membrane (MPPM), a facile and effective method was developed to hydrophilize the surface of MPPM using CaCO3 mineral. This was achieved by dopamine oxypolymerization and alternate soaking mineralization (ASM). The resulted membranes were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), environmental scanning electron microscopy (ESEM), energy dispersive X-ray spectroscopy (EDX) and water contact angle. The influences of mineralization conditions, such as solution concentration, number of ASM and polydopamine-coating degree on CaCO3-based mineralization degree were investigated. The results confirmed that CaCO3 mineral was dispersed uniformly on the surface of MPPM. Due to intrinsic wettability of CaCO3 mineral, the mineralized membranes were superhydrophilic, and showed excellent water permeability with high pure water flux (up to 6450 L·m−2·h−1) and low membrane permeation resistance. Under the drive of external pressure of 0.01MPa, water could permeate through the mineralized membranes. The separation ability of the mineralized membrane for oil/water emulsion was also investigated. The mineralized membranes could separate a range of oil/water emulsions effectively with high water flux (>1800 L·m−2·h−1), and could be easily cleaned by water, showing attractive potential for practical oil/water emulsion separation.%为了改善聚丙烯微孔膜（MPPM）的表面亲水性，通过组合多巴胺氧化聚合和交替浸渍矿化修饰技术，在MPPM表面构建了均匀的CaCO3矿物层，实现了利用CaCO3矿物对膜表面进行亲水化修饰的目的。采用FTIR、XPS、ESEM、EDX 和水接触角对矿化膜表面进行了相应的表征。考察了溶液浓度、浸渍循环次数及聚多巴胺涂覆率等对CaCO3矿化率的影响。结果证实，CaCO3矿物均匀地负载在MPPM表面，膜的亲水性因CaCO3固有的润湿性而明显改善。纯水通量测试结果表明，矿化膜具有强的水渗透能力，纯水通量大（高达6450 L·m−2·h−1），渗透阻力小，施加0.01 MPa的外压，水即可透过膜。油水乳液分离研究发现，矿化膜能有效地分离一定范围的油水乳液，水通量大（＞1800 L·m−2·h−1），且膜容易用水清洗，展现出理想的油水乳液分离应用前景。