Soft and flexible polyvinyl alcohol/pullulan aerogels with fast and high water absorption capacity for facial mask substrates

Abstract

Facial mask substrates commonly used in skincare are often considered unhealthy and environmentally unfriendly due to their composition of premoistened nonwovens containing various preservatives. This study aims to address this issue by developing a preservative-free degradable aerogel made from polyvinyl alcohol (PVA)/pullulan (PUL) using a unidirectional freeze-drying method. The aerogels had ordered three-dimensional porous structures and exhibited desirable mechanical properties. They were soft and flexible in both dry and wet states, and their Young's moduli were comparable to that of human skin. The aerogels had high porosity, ranging from 93.0 % to 95.1 %, and exhibited a high water absorption rate and water absorption capacity (ranging from 7.5 g/g to 10.1 g/g). After 30 min of water evaporation, the aerogels showed excellent moisture retention, ranging from 88 % to 93 %. Additionally, the PVA/PUL aerogel efficiently loaded and released active ingredients, such as rapidly releasing ascorbic acid (> 90 % within 30 min). These findings suggest that the PVA/PUL aerogel has potential as a material for facial mask substrates.