(2lm) Rapidly Ordered Block Copolymer Membranes with Tunable Pore Sizes for Wastewater Treatment

Research Interests: Block Copolymer Self-assembly, Polymer/Block copolymer membranes, Polymer/Block copolymer electrolytes, Neutron scattering, Atomic force microscopy

The present surface water resources will soon be insufficient to meet the needs of the next generations. Wastewater is now contaminated with oil and other organic compounds due to the rapid rise in oil and gas, petrochemical, pharmaceutical, and food processing industries. Membranes present an easy and energy-efficient solution for removing both particulates and oily matter from wastewater. Here we present a methodology to rapidly order block copolymer (BCP) thin films with well-defined through-thickness channels having minimal tortuosity. The technique involves casting diblock copolymer films from a binary solvent mixture blended with an active ionic plasticizer that has preferential interactions with one of the BCP domains. Due to the additive's selectivity and plasticization capability and the preferential solvation of BCP components in the solvent mixture, the film is fully ordered after the casting process. With careful selection of the casting environment, the surface interactions at the film-substrate interface can be neutralized to achieve a completely perpendicular domain morphology with variable domain sizes. The presence of fully vertical and tunable domains makes these films excellent candidates for membranes with high fluxes and tunable size cutoffs. These films are supported by commercial membranes like poly-ether-sulfone (PES) and treated to selectively crosslink one and etch the other block to open the pores. The film microstructure is characterized via atomic force microscopy and x-ray scattering. At the same time, the membrane performance is tested using a dead-end cell and UV-vis spectroscopy.