大豆种皮纳米纤维素水凝胶制备工艺优化及性能分析

Optimization of Preparation Process and Properties Analysis of Soy Hull Nanocellulose Hydrogel

采用Box-Behnken响应面法优化大豆种皮纳米纤维素水凝胶的最佳制备工艺,并表征其结构和性能。在单因素实验基础上,以纳米纤维素水凝胶的最大应力为考察指标,选取3因素3水平的响应面法优化制备工艺;采用傅里叶红外变换光谱、X射线衍射、扫描电子显微镜、紫外分光光度计等对其结构和性能进行表征。最佳纳米纤维素水凝胶的制备工艺为:凝胶温度191℃、冷冻时间102 h、无水CaCl_(2)浓度7%,在此条件下纳米纤维素水凝胶的最大应力的实际值为84.11 kPa,与预测值83.7 kPa相近。大豆种皮纳米纤维素/海藻酸钠/无水氯化钙(SCNFs/SA/CaCl_(2))水凝胶内部呈现均匀的三维网状结构,并且表现出良好的拉伸性(断裂伸长率220%)、良好的机械强度(83.97 kPa)、透光率(82%)和导电性(1.58 S/cm),并且水凝胶经过5次循环拉伸仍具有良好的机械强度,表现出良好的抗疲劳性,增加了水凝胶的使用寿命。本文为制备一种强韧、透明、导电和抗疲劳的纳米纤维素水凝胶提供了一种新的方法。

The preparation process of soy hull nanocellulose hydrogel was optimized by Box-Behnken response surface.The structure and properties of soy hull nanocellulose hydrogel were studied.On the basis of single factor experiment,the preparation process of soy hull nanocellulose hydrogel was optimized through response surface with three factors and three levels when the maximum stress was used as the index.The structure and properties of soy hull nanocellulose hydrogel were characterized by Fourier transform infrared spectroscopy,X ray polycrystalline diffractometer,scanning electron microscopy,UV spectrophotometer,etc.The optimal process parameters were as follows:gelling temperature 191℃,freezing time 102 h,CaCl_(2) concentration 7%.Under this condition,the actual maximum stress of soy hull nanocellulose hydrogel was 84.11 kPa,which was close to the predicted value of 83.7 kPa.The nanocellulose of soy hull/sodium alginate/CaCl_(2)(SCNFs/SA/CaCl_(2))hydrogel showed uniform 3D network structure,excellent tensile performance(elongation at break was 220%),mechanical strength(83.97 kPa),transmittance(82%),and electrical conductivity(1.58 S/cm).The SCNFs/SA/CaCl_(2) hydrogel also had excellent mechanical strength and fatigue resistance after five cycles of stretching,so the service life of hydrogel was increased.This study provides a new method for preparing a tough,transparent,conductive and fatigue-resistant nanocellulose hydrogel.