In the last 10-20 years Polymers of Intrinsic Microporosity (PIMs) have attracted significant scientific interest directed towards potential applications as membranes, catalysts or absorbers. PIMs showcase an extreme among a class of glassy polymers by being able to form very highly microporous, yet solution-processable films. In particular in membrane technology, the large amounts of interconnected microporosity (or excess free volume) have enabled materials with unprecedented permeabilities and selectivities for the separated fluids.
To make practical industrial membranes the material needs to combine excellent intrinsic properties with the ability to form very thin, defect-free selective layers, often in a sub 100 nm range. This is necessary to assure very low transport resistance leading to high process efficiency. In this thickness range polymers are known to exhibit finite size effects, also known as nano-confinement effects, and their important properties, such as glass transition temperature, physical aging rates, swelling or penetrant diffusion can be affected.
In this contribution we will discuss the behavior of ultra-thin PIMs films of various chemical structures in contact with fluids. In particular, we will show how the large microporosities dictate the sorptive and swelling behavior of PIMs which is crucial for their viability as high-end membranes. The presented results are outcome of a joint project of KAUST and DWI Leibniz Institute in Aachen (Germany).
Level 0, between bld. 4 and 5
11:30 - 12:00