摘要
单宁酸(TA)作为一种典型的农林生物质多酚,具有抗菌、抗氧化、抗紫外、生物相容性好等优点。水凝胶是一种具有三维交联网络结构的湿软材料,但传统的水凝胶存在机械性能较差、不具备黏附性等问题,很大程度上限制了其应用。TA分子上的苯三酚和儿茶酚基团会以氢键、π-π相互作用、疏水相互作用等方式与聚合物形成物理交联,从而提升水凝胶的机械性能与黏附性。以甘氨酸(Gly)为原料合成聚合单体N-丙烯酰基-2-甘氨酸(ACG),引入TA作为物理交联剂,成功制备单宁酸增强聚甘氨酸水凝胶,并测试分析其力学、黏附、电导率以及应变传感性能。研究结果表明,TA的引入使水凝胶交联网络更加致密,其应力逐渐增大,韧性值、黏附能则是呈现先增大后减小的规律。当TA/ACG质量比为1∶100时,制备的单宁酸增强水凝胶综合性能最优,断裂拉伸应变达到162%,应力为196 kPa,韧性值为143 kJ/m^(3),电导率为1.48 mS/cm,对猪皮的黏附能达到17.68 kPa,且对不同基材具备黏附性能。因此,TA的引入有效增强了水凝胶网络,使其力学、黏附等性能均得到提升。将制备的单宁酸增强水凝胶组装成柔性电阻式传感器,该传感器对水凝胶的形变具有较好的灵敏度,实现了将手指、手肘等运动信号转变为稳定的电信号。本研究为开发绿色可持续、自黏附的生物基柔性电子传感器件提供了一种十分有前景的策略。
Polyphenols from agriculture and forestry biomass have received wide attention in the field of hydrogels due to their wide sources,low toxicity and environmentally friendly.As a typical polyphenol of agroforestry biomass,tannic acid(TA)has the advantages of antimicrobial,antioxidant,anti-ultraviolet,good biocompatibility,etc.Hydrogel is a wet and soft material with a three-dimensional cross-linked network structure.Due to their high-water content and biological tissue-like properties,hydrogels show great promise for applications in human motion sensing,soft robotics,biomedicine,and electronic skin.However,traditional hydrogels have low mechanical properties and non-adhesive properties,which largely limit their applications.Therefore,tannic acid is used to improve the properties of hydrogels for different applications.In the gel network,pyrogallol and catechol groups on the tannic acid molecules would form physical cross-links with the polymer using hydrogen bonding,π-πinteractions,hydrophobic interactions,etc.,thus enhancing its mechanical properties and functionality.The pyrogallol and catechol groups on the tannic acid also readily form hydrogen bonding interactions with the various materials,thus providing the hydrogel materials with adhesive properties.In this study,the author synthesized the polymeric monomer N-acryloyl-2-glycine(ACG)from glycine nature's simplest structured amino acid.By introducing tannic acid,phenolic hydroxyl groups formed hydrogen bonds with the carboxyl and imino groups on the polyglycine chain,creating physical cross-linking points and increasing the cross-linking density,and tannic acid-reinforced polyglycine hydrogels were successfully prepared.The mechanical performance,adhesive strength,electrical conductivity and strain sensing properties of the developed hydrogels were examined.The results showed that,after the introduction of tannic acid,the hydrogel crosslinking network became denser and its stress gradually increased,while the toughness and adhesion strength showed a pattern of first increasing and then decreasing.When the mass ratio of TA/ACG was 1∶100,the as-prepared hydrogel had great mechanical performance,reaching the fracture strain of 162%,tensile strength of 196 kPa,toughness of 143 kJ/m^(3),electrical conductivity of 1.48 mS/cm,and adhesive property(adhesion strength to porcine skin of 17.68 kPa).Besides,the hydrogel also had the good adhesive strength to different substrates(metal,silicone,wood,glass).Therefore,the introduction of tannic acid effectively enhanced the hydrogel network and improved its mechanical and adhesive properties.The prepared tannic acid-enhanced hydrogel was assembled into a flexible resistive sensor,which has good sensitivity to the deformation of the hydrogel and achieves the transformation of motion signals,such as fingers and elbows,into stable electrical signals.This study provides a promising strategy for fabricating a sustainable and self-adhesive bio-based flexible electronic sensor devices.
作者
吴启楠
康希彤
刘珍珍
刘焕生
赵喜阳
刘涛
王清文
WU Qinan;KANG Xitong;LIU Zhenzhen;LIU Huansheng;ZHAO Xiyang;LIU Tao;WANG Qingwen(Institute of Biomass Engineering,Key Laboratory of Energy Plants Resource and Utilization,Ministry of Agriculture and Rural Affairs,South China Agricultural University,Guangzhou 510642,China;Key Laboratory for Bio-based Materials and Energy of Ministry of Education,College of Materials and Energy,South China Agricultural University,Guangzhou 510642,China;College of Food Science,South China Agricultural University,Guangzhou 510642,China)
出处
《林业工程学报》
CSCD
北大核心
2024年第4期87-92,共6页
Journal of Forestry Engineering
基金
广东省自然科学基金(2023A1515012167)
国家自然科学基金(32001264)。
关键词
单宁酸
水凝胶
制备方法
机械性能
黏附性能
tannic acid
hydrogel
preparation method
mechanical property
adhesion property
