聚多巴胺活化甲壳素功能材料的制备及应用

发布时间：2018-03-10 11:25

本文选题：甲壳素凝胶　切入点：甲壳素纳晶　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：甲壳素是海洋储量丰富的天然多糖,具有低毒、生物相容性、可降解以及高强度等优点,是构建新型生物材料的理想原料,具有非常重要的研究价值和应用前景。然而,低化学活性是制约甲壳素基生物材料发展的瓶颈,解决该问题的重要途径是对材料进行活化。本文利用聚多巴胺生物质材料对不同结构的甲壳素基材料进行生物活化,通过聚多巴胺在甲壳素材料表面的包覆来增加甲壳素材料的活性,如亲水性、还原性等性质。对活化的甲壳素材料在其表面进行二次修饰,以增加甲壳素的应用价值。首先,在Li OH/尿素体系下对甲壳素进行预处理,乙醇中再生制备出生物相容性好、力学性能优异的甲壳素气凝胶。利用多巴胺的自聚合作用在甲壳素凝胶表面包覆聚多巴胺,利用聚多巴胺的高反应活性及反应多样性的特点,在保留甲壳素自身优异性质的同时,解决其惰性表面的缺点。对包覆了PDA的甲壳素材料进行二次修饰,PDA能够吸附污水中的贵金属离子(如Au~(3+)、Ag+、Pt4+),将其还原成金属纳米颗粒。制备形成的甲壳素复合材料DCh48-Ag其杨氏模量达420.9MPa,比表面积为292.1m2/g,进行二次修饰过程中,气凝胶对银的负载量高达95.3mg/g。在催化降解有机染料过程中,复合凝胶体现出优异的催化性能,反应速率常数达4.0×10-5mol·L-1·min-1。利用复合凝胶的金属纳米颗粒,还研究了抗菌性实验及作为过滤膜初步进行过滤有机染料的研究等方面的应用。其次,通过硫酸水解法制备出甲壳素纳晶,对其进行改性及应用研究。通过硫酸水解甲壳素粉末中的无定型区制得甲壳素纳晶,调控硫酸的浓度和反应时间,来计算纳晶的产率和长径比。水解的最佳条件为30%的H2SO4,90°C反应6h产率及稳定性最高。利用上述方式对甲壳素纳晶进行活化并二次修饰,形成的载银甲壳素纳晶,通过简单的抽滤制备成纳滤膜研究了纳滤膜在催化有机染料、截留尺寸不同的纳米颗粒及选择性过滤不同金属离子等方面的应用。结果显示:银的负载量达57.2%,水通量达13400L·m-2·h-1·bar-1,能够成功截留3nm以上尺寸的纳米颗粒,对Au~(3+)的置换率高达90%以上。
[Abstract]:Chitin is a natural polysaccharide rich in marine reserves, with the advantages of low toxicity, biocompatibility, biodegradability and high strength. Chitin is an ideal raw material for the construction of new biomaterials, and has very important research value and application prospect. Low chemical activity is the bottleneck of the development of chitin based biomaterials, and the important way to solve this problem is to activate the materials. By coating polydopamine on the surface of chitin, the activity of chitin material, such as hydrophilicity and reductivity, is increased. The activated chitin material is modified twice on its surface to increase the application value of chitin. Chitin aerogels with good biocompatibility and excellent mechanical properties were prepared by pretreatment of chitin in Li OH/ urea system and regenerated in ethanol. Dopamine was coated on the surface of chitin gel by self-polymerization of dopamine. Taking advantage of the high reactive activity and diversity of polydopamine, the excellent properties of chitin itself were preserved at the same time. The second modification of chitin coated with PDA can adsorb precious metal ions (such as Au~(3 / Ag-Pt4) and reduce it to metal nanoparticles. The Young's modulus and specific surface area of DCh48-Ag were 420.9MPa and 292.1m2 / g respectively. The amount of silver loaded on aerogels was up to 95.3 mg / g. In the process of catalytic degradation of organic dyes, the composite gels showed excellent catalytic performance, and the reaction rate constant reached 4.0 脳 10 ~ (-5) mol 路L ~ (-1) 路min ~ (-1). The antimicrobial experiment and the application of filtering organic dyes as filtration membrane were also studied. Secondly, chitin nanocrystals were prepared by sulfuric acid hydrolysis. In order to control the concentration and reaction time of sulfuric acid, chitin nanocrystals were prepared by hydrolyzing the amorphous zone of chitin powder with sulfuric acid. To calculate the yield and aspect ratio of nanocrystalline, the optimum hydrolysis condition is that the yield and stability of H _ 2SO _ 4 / 90 掳C reaction at 30% are the highest for 6 h. The nanocrystalline supported on silver is formed by activating and modifying the nanocrystalline of chitin by the above methods. The preparation of nanofiltration membrane by simple filtration was used to study the catalytic effect of nanofiltration membrane on organic dyes. The results show that the silver loading is 57.2, the water flux is 13400L 路m-2 路h-1 路bar-1, and the replacement rate of Au~(3 is over 90%.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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