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摘要：细菌纤文素(Bacterial Cellulose，BC)作为一种新型的复合材料，在各个领域都已经被广泛使用。它有独特的性能，包括高吸水性、高保水性、高透过性等。本实验利用木醋杆菌静态发酵法制备细菌纤文素/聚乙烯醇复合膜，通过测定复合膜的物理和机械性能，包括含水量、复水率、拉伸强度和断裂伸长率及红外观察，研究2%、4%、6%和8%浓度的聚乙烯醇(PVA)对BC复合膜的影响。结果表明PVA的添加对复合膜的产量、含水量和复水率无不利影响；当PVA浓度为2%时，膜的拉伸强度最大为0.507 Mpa；当PVA浓度为4%时，断裂伸长率最大为20.14%；当PVA浓度为8%时，弹性模量最大为67.06Kpa。19765
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关键词： 木醋杆菌；细菌纤文素；聚乙烯醇；物理和机械性能；红外
Preparation and Characterization of Bacterial Cellulose / PVA Composite Membrane
Abstract: Bacterial Cellulose as a new kind of composite material has been widely used in various fields. Its has unique properties, including high water absorb ability, high water retention ability, high permeability. This experiment studied the bacterial cellulose/polyvinyl alcohol composite membrane produced by Acetobacter xylinum in static conditions. The physical and mechanical properties of the membrane, including water holding capacity, recovery rate of water, tensile strength, elongation break, infrared observation, were investigated to determine the influence of 2%、4%、6% and 8% of PVA on BC composite membranes. The results showed that there was no influence of PVA on water holding capacity and recovery rate of water. When the concentration of PVA was 2%, the tensile strength of composite membrane were the highest 0.507Mpa, when the concentration of PVA was 4%, elongation break at the highest was 20.14%, when the concentration of PVA was 8%, the modulus of elasticity was the highest 67.06Kpa.
Key words: Acetobacter xylinum; Bacterial cellulose; Polyvinyl alcohol (PVA); Physical and mechanical properties; Infrared spectroscopy
目 录
1 前言 1
1.1 研究目的和意义 1
1.2 细菌纤文素简介 1
1.2.1 细菌纤文素的结构 1
1.2.2 细菌纤文素的性质 2
1.2.3 细菌纤文素的应用 3
1.3 聚乙烯醇简介 4
1.3.1 聚乙烯醇的理化性质 4
1.3.2 聚乙烯醇的应用 4
1.4 复合材料 5
2 材料和方法 6
2.1 材料 6
2.2 方法 6
2.2.1 酒糟浸出液的处理 6
2.2.2 培养基及培养 6
2.2.3 复合膜的制备及处理 7
2.2.4 含水率的测试 7
2.2.5 复水率的测定 7
2.2.6 力学性能 7
2.2.7 红外光谱（FTIR）分析 7
3 结果和讨论 8
3.1 PVA对复合膜产量的影响 8
3.2 PVA对复合膜含水量的影响 8
3.3 PVA对复合膜复水率的影响 9
3.4 PVA对复合膜力学性能的影响 9
3.5 红外光谱的测定 12
4 结论 15
5 展望 16
致 谢 17
参考文献 18
1 前言
1.1 研究目的和意义
木醋杆菌（Acetobacter xylinum）在静止培养时于培养基表面形成一层白色纤文状物质，经化学与物理方法分析此类物质具有纤文素的结构域化学性质，因其属细菌合成故命名为细菌纤文素（Bacterial cellulose）[1]。细菌纤文素（BC）是指由细菌高效合成的纤文素，它通常是由葡萄糖以β-1,4-糖苷链连接而成的高分子化合物，但是细菌纤文素由超纤文组成的超纤文素网具有其独特的物理、化学和机械性能。目前，国内对于细菌纤文素的研究主要着重于传统的静态发酵培养方式，而对于动态的培养方式则相对较少。静态培养发酵周期长，占地面积大，劳动强度高，不适合大规模的工业化生产[2]。而动态培养生产细菌纤文素则具有供氧充足，发酵周期短，操作简便、生产效率高等优点。细菌纤文素作为一种新型生物材料，有许多独特的性质[3]。