Microporous hollow fiber membranes spun from PIM-1

New materials for separations are constantly being developed to improve upon the current state-of-the-art. One emerging class of materials that has garnered sustained interest are microporous polymer membranes. Polymers of intrinsic microporosity (PIMs) have highly rigid backbones that lead to a number of favorable properties, particularly for gas separation applications. Polymer of intrinsic microporosity 1 (PIM-1) is the prototypical microporous polymer that has been studied extensively due to its high gas permeabilities, good selectivities, and solution processability. Current research on PIMs has been exclusively performed on flat sheet membranes to understand fundamental membrane properties. To bridge the gap between development of new high performance polymers and industrially attractive technologies, more efficient membrane units need to be engineered. Hollow fiber membranes fulfill this need by combining large surface areas, excellent pressure resistance, and highly scalable fabrication in small volume, modular units. To date, only dilute PIM-1 containing hollow fiber membranes have been made, partly due to the somewhat unfavorable solubility properties of the polymer. This work is the first to demonstrate the fabrication of defect-free hollow fiber membranes derived purely from PIM-1. These membranes have been characterized for their separation performance under a variety of conditions and are in good agreement with their flat sheet analogs. More broadly, this work details a method of starting from synthesis of a non-commercially available polymer with limited solubility properties to spinning a hollow fiber membrane. The methods discussed could be expanded to fabricating hollow fiber membranes from other novel PIMs