Advanced functional polymer membranes

Poly(lactic acid) modifications

The use of light to mediate controlled radical polymerization has emerged as a powerful strategy for rational polymer synthesis and advanced materials fabrication. This review provides a comprehensive survey of photocontrolled, living radical polymerizations (photo-CRPs). From the perspective of mechanism, all known photo-CRPs are divided into either (1) intramolecular photochemical processes or (2) photoredox processes. Within these mechanistic regimes, a large number of methods are summarized and further classified into subcategories based on the specific reagents, catalysts, etc., involved. To provide a clear understanding of each subcategory, reaction mechanisms are discussed. In addition, applications of photo-CRP reported so far, which include surface fabrication, particle preparation, photoresponsive gel design, and continuous flow technology, are summarized. We hope this review will not only provide informative knowledge to researchers in this field but also stimulate new ideas and applications to further advance photocontrolled reactions.

http://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.5b00671

Light-Controlled Radical Polymerization: Mechanisms, Methods, and Applications

Polymer surface with graft chains

A novel sequential ultraviolet (UV)-induced living graft polymerization method has been designed and investigated to modify polymeric materials. This method consists of two steps. In the first step...

A Novel Sequential Photoinduced Living Graft Polymerization

Principal factors affecting sequential photoinduced graft polymerization

Using a novel photoinduced grafting method, hydrophobic polypropylene (PP) membranes were rendered hydrophilic by grafting monomers of poly(ethylene glycol 200) monomethacrylate (PEG200MA), dimethyl aminoethyl methacrylate (DMAEMA), or acrylic acid (AA), to produce a neutral, positive, or negative charge, respectively, on the membrane surface. Using both unmodified and modified PP membranes, as well as a hydrophilic cellulose acetate (CA) membrane, the effects of backpulsing and surface chemistries on membrane fouling were investigated for crossflow microfiltration of bentonite clay suspensions and crude oil emulsions. Without backpulsing, the permeate volumes collected over 60 min were not strongly dependent on membrane surface chemistry and morphology for the filtration of either clay or oil. With backpulsing, however, 5-fold and 6-fold permeate enhancements were obtained by backpulsing alone and by a combination of backpulsing and surface modification, respectively, for clay filtration. The recovered w...

Huimin Ma

Papers

A Novel Sequential Photoinduced Living Graft Polymerization

Principal factors affecting sequential photoinduced graft polymerization

Membrane surface modification and backpulsing for wastewater treatment