Amphiphilic copolymers comprising a hydrophobic backbone with polar zwitterionic side groups are inclined to microphase separation due to molecular dissimilarity between the constituents, which stimulates interesting self-assembly in bulk. The drive for microphase separation is further enhanced in comb-shaped copolymers with this combination of constituents because of the architectural distinction between the backbone and zwitterionic side chains. We developed selective thin films whose morphology and function arise from the self-assembled nanostructure of the zwitterionic comb copolymer. First, we established a correlation between polymer chemistry, film preparation method, self-assembled domain size, and thin film morphology. To achieve that, we synthesized a series of zwitterionic comb copolymers with varying zwitterionic side chain frequency and length, and applied each of these copolymers as a thin film on glass substrate using different deposition methods. Upon examining the resulting self-assembled nanostructures, we employed for thin film composite development the zwitterionic comb copolymer that led to a continuous nanoporous network, which is intriguing for water transport applications. We applied this copolymer by non-solvent induced phase separation as a thin selective layer on a porous support to attain a mechanically strong thin film composite. Hierarchical features including 17 ± 5 nm spherical micelles along with larger nanopores of 85 ± 45 nm arose from the self-assembly of the copolymer in this bilayer system. In addition, we could govern the domain size simply by using zwitterionic homopolymer additive. The films proved ionic strength responsive permeation in ultrafiltration range with a pore density as high as 10<sup>13</sup> pores/m<sup>2</sup>.

Porous thin films with hierarchical structures formed by self-assembly of zwitterionic comb copolymers

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.