Multi-sensing dye-doped electrospun polystyrene microfiber mats

Abstract

In this study, multi-sensing dye-doped electrospun polystyrene microfiber mats were developed. The individual fibers are composed of an inexpensive commodity polymer (atactic polystyrene; aPS) doped with a gas-sensitive dye (bromocresol green; BCG). The fiber mats exhibited outstanding quasi-static direct electromechanical properties, which were enhanced by increasing the doping ratio of BCG. This improvement was attributed to an increase in the real charge density stored in the fiber mats and a decrease in their secant modulus of elasticity. The increase in charge density with increasing BCG doping ratios was attributed to the enhanced conductivity of the electrospinning solution; the decrease in secant modulus was attributed to the decrease in fiber diameter and density of the fiber mats. The BCG-doped aPS fiber mats demonstrated distinguishable color changes even under a low concentration of ventilating ammonia gas (1 ppm). Additionally, the degree of color change increased with an increase in ammonia gas concentration. The proposed multi-sensing microfiber mats can facilitate the development of wearable, lightweight multi-sensors with flexibility and breathability, which, for example, ensure the safety of workers at risk of exposure to harmful gases.