Hong Kong Polytechnic University, Hong Kong

Title: Self-adaptive polymeric membrane with adjustable water vapor permeability


Jin-lian Hu has obtained her PhD from University of Manchester Institute of Science and Technology, and now is the Professor of Hong Kong Polytechnic University. Before appointed as a Professor at the University, she has Founded the Shape Memory Textile Centre in 2003. Her research fields include shape memory materials and textiles. She and her research group have invented the world’s first cellulose-based shape memory fabric, and registered about 50 patents in the US, China and other countries. She has published several books/book chapters, and more than 250 research articles. There are more than 25 PhD students and about 35 Postdoctoral fellows studied/studying under her supervision in the Shape Memory Polymer and smart textiles areas alone


Many natural materials demonstrate adaptive abilities to keenly respond upon triggering of a suitable external stimulus. Nowadays, self-adaptive breathable polymeric membrane (SBPM) is becoming a fundamental material in various advanced applications such as protective garments/shoes, chemical/medical equipment, sophisticated electronics, and construction materials. SMPM usually introduces in the garment for the enhancing the comfort to the wearer body in extreme environmental conditions. In this context, a series of segmented shape memory polyurethanes (SMPU) was synthesis by adjusting the molecular weight of macroglycol, hard to soft ratio, and incorporation of carbon dot (highly oxygenating groups containing nanoparticles) in different weight % to obtain the suitable SBPM. SMPU showed good self-adaptive WVP by changing the free volume in their soft-segments upon triggering of a stimulus, especially heat. It is found that the mobility of soft segment is low below its transition temperature (Ttrans) and SMPU acts as an insulator. It helps to maintain the warmth and moisten skin along with a low WVP. When the used temperature is above the Ttrans, the soft segment of SMPU converts ‘active’ and increase the free volume in SMPU. This aids the transportation of more water vapor to retain the body dry and comfortable. The moisture level is also a very crucial factor which governs the comfort of clothing in addition to heat, as people can sweat both in high and low temperatures during a high degree of workload. The outcome polymeric membrane showed strong potential for textiles and packaging industrials, especially for sports wears, wound dressing and food storage, where moderate RH range is essential for human health.