School of Electrics and Computer Engineering, Nanfang College, Guangzhou, Guangzhou, 510970, China.
College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping, 136000, China.
Macromol Rapid Commun. 2024 Jan;45(2):e2300467. doi: 10.1002/marc.202300467. Epub 2023 Oct 27.
Conductive polymer hydrogels are vital in strain sensors, yet achieving high resilience and toughness is a challenge. This study employs a prestretch method to engineer a tough conductive polymer hydrogel with sufficient resilience. Initially, a blend film of polyvinylalcohol (PVA) and ethylene-vinyl alcohol copolymer (EVOH) is prepared through solution casting, followed by a swelling process to form a PVA-EVOH hydrogel. This hydrogel, with PVA crystallites as crosslinking points, exhibits high toughness. The hydrogel is then immersed in pyrrole and ferric chloride solutions for in-situ polymerization of polypyrrole (PPy), creating a conductive PPy/PVA-EVOH hydrogel. Finally, a 200% prestretch is applied, breaking short chains within the network, eliminating energy dissipation at low strains. This results in a hydrogel with a 100% elastic deformation range, while maintaining high fracture toughness (1700 J m ). The prestretched PPy/PVA-EVOH hydrogel functions as a strain sensor with low hysteresis, providing consistent strain measurements during loading and unloading. This outperforms the non-prestretched sample, which shows inconsistent responses between stretching and releasing.
导电高分子水凝胶在应变传感器中至关重要，但要实现高弹性和韧性是一个挑战。本研究采用预拉伸方法来设计一种具有足够弹性的坚韧导电高分子水凝胶。首先，通过溶液浇铸制备聚乙烯醇（PVA）和乙烯-乙烯醇共聚物（EVOH）的共混膜，然后进行溶胀过程形成 PVA-EVOH 水凝胶。该水凝胶以 PVA 结晶为交联点，表现出高韧性。然后将水凝胶浸入吡咯和氯化铁溶液中进行原位聚合聚吡咯（PPy），形成导电 PPy/PVA-EVOH 水凝胶。最后，施加 200%的预拉伸，打破网络内的短链，消除低应变下的能量耗散。这导致水凝胶具有 100%的弹性变形范围，同时保持高断裂韧性（1700 J m ）。预拉伸的 PPy/PVA-EVOH 水凝胶作为应变传感器具有低滞后性，在加载和卸载过程中提供一致的应变测量。这优于未预拉伸的样品，后者在拉伸和释放之间表现出不一致的响应。
