壳聚糖基累托石改性复合薄膜的制备及抑菌性能研究

发布时间：2019-02-08 18:31

【摘要】：壳聚糖(CS)由于其来源广泛、储量丰富,且具有优异的成膜性能近几年来得到各个领域研究者的极大关注。壳聚糖具有良好生物相容性和易生物降解的优异性能,因此在关于壳聚糖可食用薄膜的研究方面具有极大的优势,其作为抑菌材料的报道也是屡见不鲜。但是,由于目的不同,壳聚糖单膜的抗菌能力达不到抑菌的要求,并且机械性能不是很高。这些缺陷限制了壳聚糖单膜的发展,因此本课题通过添加其它抗菌材料提高壳聚糖膜的抑菌性能。累托石(REC)是一种具有特殊结构的天然层状硅酸盐,由于其独特的片层结构,使得REC具有非常大的比表面积,进而获得相当的吸附性能以及协同增强能力。近年目前对于REC的研究主要是将聚合物和累托石通过溶液插层法制备插层复合材料,该材料具有两者的性能并且由于协同能力的存在都获得增强,该复合材料是一种无机纳米复合材料,且具有优良的性能和广泛的应用。醋酸纤维素(CA)是一种具有良好生物相容性、易生物降解性能的纤维素衍生物之一,近几年对于CA的研究大多出现在作为纤维素的替代材料并应用于纺织、医用等领域。随着材料学的发展,对于纳米材料的研究也是日益增多,静电纺丝技术作为一种新型制备纳米纤维的技术,已经被广泛应用于各种领域,而CA作为纤维素衍生物在制备纳米纤维材料上也得到了极大的关注。本研究的所涉及到的主要内容和结论如下:1.将天然抗菌剂溶菌酶(LY)与壳聚糖/累托石(REC)溶液共混,并通过流延法成膜,制备的壳聚糖复合膜通过扫描电镜观察了复合膜的形态变化和结构特征,结果发现复合膜随着累托石的加入形貌发生了极大的变化。X-射线衍射结果也表明复合膜中REC的层间距变大。热重分析也显示随着累托石的加入提高了复合膜的热稳定性。最后抑菌结果表示LY和REC的加入对于复合膜的抑菌性有了一定的增强。2.将壳聚糖分解为分子量更小的可水溶性的壳寡糖(COS),并配制不同浓度的COS溶液和COS/REC溶液,通过旋涂仪将所制组装到CA纳米纤维膜上,扫描电镜结果显示纤维的表面均匀覆盖着壳寡糖,随着浓度的增大覆盖面积随之增大,并且添加累托石之后,纤维表面壳寡糖呈现不均匀的颗粒分布。X-射线衍射结果也得出CA复合纳米纤维中REC的层间距变大的现象。水接触角结果显示膜的水接触角随着COS的组装有明显的减小,REC的加入使膜的吸水性更强。抑菌结果分析CA纳米复合膜的抗菌性能优异,符合在包装材料应用上的要求。
[Abstract]:Chitosan (CS) has attracted much attention in recent years because of its wide range of sources, abundant reserves and excellent film-forming properties. Chitosan has excellent biocompatibility and biodegradability, so it has great advantages in the research of chitosan edible film. However, because of the different aim, the antibacterial ability of chitosan monofilm is not up to the requirement of bacteriostasis, and the mechanical property is not very high. These defects limit the development of chitosan monomembrane. Therefore, the antimicrobial properties of chitosan membranes are improved by adding other antimicrobial materials. Rectorite (REC) is a kind of natural layered silicate with special structure. Because of its unique lamellar structure, REC has a very large specific surface area, which leads to considerable adsorption performance and synergistic enhancement ability. In recent years, the main research on REC is to prepare intercalated composite materials by solution intercalation method, which has the properties of both materials and has been enhanced due to the existence of synergistic ability. The composite is an inorganic nanocomposite with excellent properties and wide application. Cellulose acetate (CA) is one of the cellulose derivatives with good biocompatibility and biodegradability. In recent years, CA has been widely used as a substitute for cellulose and used in textile, medical and other fields. With the development of material science, the research of nano-materials is increasing day by day. As a new technology of preparing nanofibers, electrostatic spinning technology has been widely used in various fields. CA, as a cellulose derivative, has also attracted much attention in the preparation of nanofibers. The main contents and conclusions of this study are as follows: 1. The natural antimicrobial lysozyme (LY) was blended with chitosan / rectorite (REC) solution, and the chitosan composite membrane was prepared by casting method. The morphology and structural characteristics of the composite membrane were observed by scanning electron microscope. It was found that the morphology of the composite film changed greatly with the addition of rectorite. The results of X-ray diffraction also showed that the interlayer spacing of REC in the composite film increased. Thermogravimetric analysis also showed that the thermal stability of the composite film was improved with the addition of rectorite. Finally, the bacteriostatic results showed that the addition of LY and REC enhanced the bacteriostatic properties of the composite membrane. 2. 2. Chitosan was decomposed into water-soluble chitosan oligosaccharide (COS),) with lower molecular weight, and different concentrations of COS solution and COS/REC solution were prepared. The chitosan was assembled on CA nanofiber film by spin-coating apparatus. The SEM results showed that the fiber surface was uniformly covered with chitosan oligosaccharide, and the coverage area increased with the increase of concentration, and after adding rectorite, The distribution of chitosan oligosaccharides on the fiber surface was uneven, and the phenomenon of increasing the interlaminar spacing of REC in CA nanofibers was also obtained by X-ray diffraction. The results of water contact angle show that the water contact angle of the film decreases obviously with the assembly of COS, and the water absorption of the film is enhanced by the addition of REC. The bacteriostasis results showed that the CA nanocomposite membrane had excellent antibacterial properties and met the requirements of packaging materials.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2

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