Microplastic-free, single-layered functional surface with localized liquid-discharging molecular channels for disposable hygiene products

Abstract

Conventional disposable absorbent hygiene products (DAHPs) currently represent a significant type of solid waste in landfills and are a substantial producer of fiber-based microplastics. In this work, a novel multifunctional cellulose nonwoven (CNW) is reported. The key structural design of this material was achieved by covalently grafting a naturally cycloheptatriene product namely hinokitiol and a silane covalent bridge, successfully transforming the original super hydrophilic substrate into a single-layered, multifunctional material with precisely designed liquid-discharging molecular channels and a tailored, sophisticated hydrophobic/hydrophilic distribution structure. This 3D structure perfectly mimics the conventional adhesive-bonded polyolefin/polyesters laminates comprising a top sheet and a liquid acquisition and distribution layer (ADL). The results of XPS and 1H NMR indicated the hinokitiol was successfully chemically bonded to the CNW surface. Compared with polyolefin or cotton substrates, the optimal CNW product (CNW-H-A-2) exhibits significantly improved long-term wearing comfort by minimizing the liquid strike-through time (by 26–27%), reducing wet-back amount (by 65–90%), and ensuring an outstanding air-permeability (3011 mm·s-1). Excellent antibacterial properties against Staphylococcus aureus (86.4%) and Escherichia coli (97.3%) were achieved due to the good preservation of the bioactive phenol groups of hinokitiol. Additionally, it can be completely enzymatically-degraded within 24 h. This strategy holds promise as a potential solution for mitigating fiber-based microplastics pollution of DAHPs.