Tunable Morphology of Porous Polymers via Polymerization‒Induced Microphase Separation

Abstract

Nanoporous polymers are useful materials for applications in separations, catalysis, and templating. The ability to synthesize nanoporous polymers with a good control over pore size and chemistry is highly desirable. This dissertation investigates routes to tuning the morphology and pore wall chemistry of nanoporous polymers produced via polymerization-induced microphase separation (PIMS) of a growing block polymer. The PIMS processes is a facile route to synthesizing a bicontinuous microphase-separated block polymer. Selective etching of one of the blocks renders the material mesoporous (pore size 2 – 50 nm). Chapter 1 gives an overview of this process, as well as an analogous process, polymerization-induced phase separation (PIPS), which is frequently used to produce macroporous polymers (pore size > 50 nm) via phase separation of a nonreactive component. Chapter 2 describes the experimental synthetic and characterization techniques that are relevant to nanoporous polymers. Chapter 3 describes the production of a hierarchically porous polymer, which has two discrete pore sizes, by combining the PIMS and PIPS processes. Importantly, a high degree of control over porosity is attained. Chapter 4 explores this idea more thoroughly, and shows how sample composition can be used to transition from a morphology that is controlled by PIMS to one that is controlled by PIPS. Chapter 5 focusses on PIMS, and demonstrates a new approach to the preparation of disordered tricontinuous polymers with two different pore wall functionalities.