高强度水凝胶的制备及其热致驱动性能

Preparation of high-strength hydrogels and characterization of their thermally induced actuation properties

目的:受含羞草叶片运动循环机制的启发,本研究成功制备了一种高强度双层热响应型水凝胶,可在水、油甚至露天环境中发生驱动行为。方法:该水凝胶以聚(丙烯酰胺-丙烯酸)/纤维素纳米纤维(PPAM-AA/CNF)为底层,以聚(N-异丙基丙烯酰胺)/纤维素纳米纤维(PNIPAM/CNF)为顶层,构建的双层双网络结构有助于提高水凝胶驱动器的力学性能和驱动灵敏度。结果:PAM-AA/CNF+PNIPAM/CNF水凝胶拉伸强度和断裂伸长率分别为(427.00±0.02)kPa和(403.05±9.30)%。在进一步使用Fe^(3+)交联后,PAM-AA/CNF/Fe^(3+)+PNIPAM/CNF拉伸强度为1.9 MPa,与生物组织性能相当,且能够以每秒8.21度的高弯曲速度快速提起相当于自身质量80倍的重物。结论:所制备的双层水凝胶具有优良的力学性能和驱动能力,为智能型双层水凝胶在生物医学领域中的应用提供了新的思路。

Objective:Inspired by the movement cycle mechanism of Mimosa Mimosa leaves,this paper successfully prepared a high-strength double-layer heat-responsive hydrogel,which could drive in water,oil or even open air.Methods:The hydrogel was made of poly(acrylamide-acrylic acid)/cellulose nanofiber(PAM-AA/CNF)as the bottom layer and poly(N-isopropylacrylamide)/cellulose nanofiber(PNIPAM/CNF)as the top layer.The double-layer and double-network structure constructed was helpful to improve the mechanical properties and driving sensitivity of the hydrogel actuator.Results:The tensile strength and elongation at break of PAM-AA/CNF+PNIPAM/CNF hydrogel were(427.00±0.02)kPa and(403.05±9.30)%respectively.After further cross-linking with Fe^(3+),the tensile strength of PAM-AA/CNF/Fe^(3+)+PNIPAM/CNF was 1.9 MPa,which was equivalent to the biological tissue performance,and it could quickly lift the weight 80 times higher than its own weight at a high bending speed of 8.21(°/s).Conclusion:The prepared bilayer hydrogel had excellent mechanical properties and driving ability,which provided a new idea for the application of intelligent bilayer hydrogel in biomedical field.