基于动态亚胺键结合的自粘附纳米纤维素-明胶离子传导凝胶的构建与性质

Construction and Properties of Self-adhesive Nanocellulolose-gelatin Ion Conduction Gels Based on Dynamic Imine Bond Binding

聚合物水凝胶通常具有优异的亲水性、粘附性、导电性等性能,可广泛应用于柔性传感、药物输送、环境等领域。针对天然高分子水凝胶存在的力学性能、导电性能等的不足,采用将含醛基的纳米纤维素与含氨基的明胶进行结合以形成动态亚胺键,并通过引入纳米蛭石形成的快速离子传输通道,以改善天然聚合物水凝胶的离子导电性。其次,采用物理共混方法将单宁酸引入到凝胶体系中,形成多重氢键网络,进一步提高凝胶的力学性能。同时,得益于单宁酸自身的儿茶酚结构能够与不同表面形成可逆非共价相互作用,从而赋予了凝胶优异的自粘附能力。结果表明:纳米纤维素-明胶离子传导凝胶的拉伸强度达到43.35kPa,应变提高了50倍,较未添加纳米蛭石凝胶提高了300%,弹性模量达到2870kPa,较未添加纳米蛭石凝胶提高了18倍,导电性能提高了92.4%,可作为柔性传感器用于人体运动监测,在智能可穿戴设备领域具有良好的应用潜力。

Polymer hydrogels usually have excellent hydrophilicity,adhesion,conductivity and other properties,which can be widely used in flexible sensing,drug delivery,environmental and other fields.In view of the shortcomings of natural polymer hydrogel in mechanical properties and electrical conductivity,the combination of nano cellulose containing aldehyde group and gelatin containing amino group was used to form dynamic imine bond,and the introduction of nano vermiculite to form a fast ion transport channel was used to improve the ionic conductivity of natural polymer hydrogel.Secondly,tannic acid was introduced into gel system by physical blending to form a multiple hydrogen bond network and further improve the mechanical properties of gel.At the same time,thanks to the catechol structure of tannic acid itself,it can form reversible non covalent interaction with different surfaces,thus giving gel excellent selfadhesion ability.The results showed that the tensile strength of nano cellulose gelatin ion conduction gel reached 43.35kPa,the strain increased by 50 times,the elastic modulus increased by 300%compared with the gel without nano vermiculite,the elastic modulus reached 2870kPa,and the conductivity increased by 92.4%compared with the gel without nano vermiculite.It can be used as a flexible sensor for human movement monitoring,and has good application potential in the field of intelligent wearable devices.