Liquid Metal Nanoparticles Physically Hybridized with Cellulose Nanocrystals Initiate and Toughen Hydrogels with Piezoionic Properties.
ACS Nano
; 18(11): 8038-8050, 2024 Mar 19.
Article
em En
| MEDLINE
| ID: mdl-38437220
ABSTRACT
Liquid metal (LM) particles can serve as initiators, functional fillers, and cross-linkers for hydrogels. Herein, we show that cellulose nanocrystals (CNCs) stabilize LM particles in aqueous solutions, such as those used to produce hydrogels. The CNC-coated LM particles initiate free-radical polymerization to form poly(acrylic acid) (PAA) hydrogel with exceptional propertiesâstretchability â¼2000%, excellent toughness â¼1.8 MJ/m3, mechanical resilience, and efficient self-healingârelative to cross-linked PAA networks polymerized using conventional molecular initiators. FTIR spectroscopy, rheology, and mechanical measurements suggest that physical bonds between PAA and both Ga3+ and LM-CNC particles contribute to the excellent mechanical properties. The gels are used to sense a wide range of strains, such as those associated with human motion, via changes in resistance through the gel. The sensitivity at low strains enables monitoring subtle physiological signals, such as pulse. Without significantly compromising the toughness, soaking the gels in salt solution brings about high ionic conductivity (3.8 S/m), enabling them to detect touch via piezoionic principles; the anions in the gel have higher mobility than cations, resulting in significant charge separation (current â¼30 µA, â¼10 µA/cm2) through the gel in response to touch. These attractive properties are promising for wearable sensors, energy harvesters, and self-powered ionic touch panels.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article