Polyacrylonitrile (PAN)-based Membranes for Dehumidification and Oxygen Enrichment
Air quality is fundamental to people’s well-being. Dehumidification (or the removal of excess moisture from the air) creates a more comfortable living environment. For businesses like restaurants, it can also help keep perishable inventory fresh for longer periods of time. With increasing consumer and commercial interest in air quality, the global dehumidifier market reached US$2.13 billion in 2014 and is expected to maintain momentum moving forward. At the same time, demand for oxygen-enriched air (or air that has a higher oxygen content) is also growing. With versatile applications in healthcare, combustion, water treatment and more, the global market for oxygen-enriched air has been forecast to reach US$1.3 billion by 2025 at a CAGR of 8.4% from 2017 to 2025.
Both dehumidification and oxygen enrichment can be achieved with membrane technology but those available in the market today tend to require labour, energy or cost intensive/inefficient processes. We have invented a high-performance hollow-fibre membrane from a composite of two commonly-used materials (PDMS and PAN) to circumvent these challenges and create new opportunities.
The material selection, fabrication method and performance of a membrane are related. Industries primarily use polydimethylsiloxane (PDMS) as the membrane material for gas separation because it is one of the most permeable polymers. To achieve effective and economical separation, membranes need to be fabricated with a thin selective layer over a substrate (or support) material. The conventional method of solution coating, however, results in a thick selective layer, leading to a significant loss of gas permeance and therefore performance. While there are common workarounds to this issue, they are either labour, energy or cost intensive/ineffective.
Instead, we have developed a modified PDMS that can be used to form an extremely thin selective layer onto a low cost, commonly available PAN substrate. This results in a high-performance composite membrane with superior gas permeance that eliminates the issues arising from the solution coating process and removes the need for inefficient workarounds.