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摘要：利用实验室中保存的纳豆芽孢杆菌，以大豆为原料，固体发酵制成γ聚谷氨酸，通过等点沉淀法和有机溶剂结合的方法沉淀提纯聚谷氨酸，再通过冷冻干燥能够得到较纯净的γ-聚谷氨酸结晶。在不添加任何化学试剂的前提下，将γ-聚谷氨酸与聚乙烯醇进行反应，反复冻融3次后冷冻干燥，制得pH敏感型水凝胶。研究水凝胶在不同pH的缓冲溶液中的溶胀性、溶胀动力学，保水性，以及水凝胶的机械性能。结果表明，水凝胶在pH=7.4条件下溶胀率最大，随着pH的上升和下降，溶胀率都会变小，显示出了水凝胶的pH敏感响应能力。水凝胶的组分对溶胀速率变化趋势及达到溶胀平衡所需的时间影响不大， 各组分水凝胶样品都会首先经历一个快速的溶胀过程，然后溶胀速率逐渐减小，在30min后达到溶胀平衡。并且随着γ-PGA量的增加，水凝胶的平衡溶胀率有所减小，但保水性增强。同时对不同配比的水凝胶进行了机械性能的研究。
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毕业论文关键词： γ-聚谷氨酸；水凝胶；固体发酵；溶胀动力学；机械性能
Preparation and characterization of poly glutamic acid/ polyvinyl alcohol hydrogel
Abstract：Use the Bacillus natto preserved in the laboratory, using soybean as raw material, made of solid fermentation of γ-poly glutamic acid, through methods such as point precipitation method and organic solvent precipitation and purification with poly glutamic acid, and then get the pure γ-poly glutamic acid crystallization by freeze drying can. In the premise of not adding any chemical reagent, the γ-poly glutamic acid and polyvinyl alcohol to react, repeated freezing and thawing 3 times after freeze drying, preparation of pH sensitive hydrogel. Swelling, swelling kinetics of the hydrogels in different pH buffer solution in, water retention, and the mechanical properties of hydrogel.The results show that, under the condition of pH=7.4 hydrogel swelling was the biggest, along with the pH rise and fall, swelling rate will become smaller, showing the response ability of pH sensitive hydrogel. Hydrogel composition has little effect on the swelling rate and change trend of time to reach the equilibrium swelling state required, each water gel samples are the first to experience a rapid swelling process, then the swelling rate decreased gradually and reached equilibrium swelling after 30min. And with the increase in γ-PGA amount, the equilibrium swelling ratio of hydrogel decreased, but increased water retention. At the same time with different proportion of hydrogels were studied mechanical properties.
KeyWords： γ-PGA；Hydrogels；Solid state fermentation；Swelling kinetics；Mechanical properties
目录
1 绪论 - 1 -
1.1 γ-聚谷氨酸的性质 - 1 -
1.1.1 吸水特性 - 1 -
1.1.2 生物降解性 - 1 -
1.1.3 γ-PGA的水解特性 - 1 -
1.2 γ-聚谷氨酸研究国内外研究现状概述 - 1 -
1.2.1 γ-聚谷氨酸的简介 - 1 -
1.2.2 γ-聚谷氨酸的研究现状 - 2 -
1.3 聚谷氨酸水凝胶的简介 - 3 -
1.3.1 聚谷氨酸水凝胶的结构与性质 - 3 -
1.3.2 聚谷氨酸水凝胶的应用 - 3 -
1.4 水凝胶的研究进展 - 4 -
1.5 国内外水凝胶发展概况 - 5 -
1.5.1 国内水凝胶研究概况 - 5 -
1.5.2 国外水凝胶研究概况 - 5 -
2 实验方法 - 5 -
2.1 实验材料 - 5 -
2.2 实验菌种 - 5 -
2.3 实验仪器 - 5 -
2.4 γ-聚谷氨酸制备方法 - 5 -