Reversible Hydration Composite Films for Evaporative Perspiration Control and Heat Stress Management

Small. 2022 Apr;18(14):e2107636. doi: 10.1002/smll.202107636. Epub 2022 Feb 20.

Abstract

Donning of personal protective equipment (PPE) in the healthcare sector has been intensified by the on-going COVID-19 pandemic around the globe. While extensive PPE provides protection, it typically limits moisture permeability and severely hinders the sweat evaporation process, resulting in greater heat stress on the personnel. Herein, a zinc-poly(vinyl alcohol) (Zn-PVA) composite film is fabricated by embedding a super-hygroscopic zinc-ethanolamine complex (Zn-complex) in the PVA matrix. By attaching the Zn-PVA composite film, the relative humidity (RH) inside the protective suit decreases from 91.0% to 48.2%. The reduced RH level, in turn, enhances evaporative cooling, hence bringing down the heat index from 64.6 to 40.0 °C at an air temperature of 35 °C, remarkably lowering the likelihood of heat stroke. The American Society for Testing and Materials tests conducted on a sweating manikin have also proven that the Zn-PVA composite films can significantly reduce the evaporative resistance of the protective suit by 90%. The low material cost, facile fabrication process, and reusability allow the Zn-PVA composition films to be readily available for healthcare workers worldwide. This application can be further extended to other occupations that are facing severe thermal discomfort and heat stress.

Keywords: composite films; evaporative cooling; heat stress; hygroscopic materials; moisture sorbing; perspiration control; thermal management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / prevention & control
  • Heat-Shock Response
  • Hot Temperature
  • Humans
  • Pandemics
  • Sweat
  • Sweating*
  • Zinc

Substances

  • Zinc