Polypropylene membrane surface modification by RAFT grafting polymerization and TiO2 photocatalysts immobilization for phenol decomposition in a photocatalytic membrane reactor

摘要

The main technical barriers that impede photocatalytic membrane reactor (PMR) commercialization remain on the post-recovery of the catalyst particles after water treatment. To overcome this problem, surface modification of polypropylene macroporous membrane was performed with the technique of photoinduced reversible addition-fragmentation chain transfer grafting polymerization of acrylic acid. Titanium oxide photocatalysts were introduced to the acrylic acid grafted membrane surface. Phenol decomposition was carried out under UV irradiation in a recycle batch photocatalytic membrane reactor. The normalized membrane flux reached 1.7 times that of the unmodified membrane for the PAAc modified membrane. Introducing TiO2 photocatalysts to the membrane surface reduced the normalized membrane flux slightly. For the PMR with a grafting degree of 12.9% (wt) of PAAc on the membrane surface, the corresponding decomposition percentage was 32.5% after 6 h UV light irradiation.