本文選題：甲殼素凝膠　切入點：甲殼素納晶　出處：《青島科技大學》2017年碩士論文　論文類型：學位論文

【摘要】：甲殼素是海洋儲量豐富的天然多糖,具有低毒、生物相容性、可降解以及高強度等優(yōu)點,是構(gòu)建新型生物材料的理想原料,具有非常重要的研究價值和應(yīng)用前景。然而,低化學活性是制約甲殼素基生物材料發(fā)展的瓶頸,解決該問題的重要途徑是對材料進行活化。本文利用聚多巴胺生物質(zhì)材料對不同結(jié)構(gòu)的甲殼素基材料進行生物活化,通過聚多巴胺在甲殼素材料表面的包覆來增加甲殼素材料的活性,如親水性、還原性等性質(zhì)。對活化的甲殼素材料在其表面進行二次修飾,以增加甲殼素的應(yīng)用價值。首先,在Li OH/尿素體系下對甲殼素進行預(yù)處理,乙醇中再生制備出生物相容性好、力學性能優(yōu)異的甲殼素氣凝膠。利用多巴胺的自聚合作用在甲殼素凝膠表面包覆聚多巴胺,利用聚多巴胺的高反應(yīng)活性及反應(yīng)多樣性的特點,在保留甲殼素自身優(yōu)異性質(zhì)的同時,解決其惰性表面的缺點。對包覆了PDA的甲殼素材料進行二次修飾,PDA能夠吸附污水中的貴金屬離子(如Au~(3+)、Ag+、Pt4+),將其還原成金屬納米顆粒。制備形成的甲殼素復合材料DCh48-Ag其楊氏模量達420.9MPa,比表面積為292.1m2/g,進行二次修飾過程中,氣凝膠對銀的負載量高達95.3mg/g。在催化降解有機染料過程中,復合凝膠體現(xiàn)出優(yōu)異的催化性能,反應(yīng)速率常數(shù)達4.0×10-5mol·L-1·min-1。利用復合凝膠的金屬納米顆粒,還研究了抗菌性實驗及作為過濾膜初步進行過濾有機染料的研究等方面的應(yīng)用。其次,通過硫酸水解法制備出甲殼素納晶,對其進行改性及應(yīng)用研究。通過硫酸水解甲殼素粉末中的無定型區(qū)制得甲殼素納晶,調(diào)控硫酸的濃度和反應(yīng)時間,來計算納晶的產(chǎn)率和長徑比。水解的最佳條件為30%的H2SO4,90°C反應(yīng)6h產(chǎn)率及穩(wěn)定性最高。利用上述方式對甲殼素納晶進行活化并二次修飾,形成的載銀甲殼素納晶,通過簡單的抽濾制備成納濾膜研究了納濾膜在催化有機染料、截留尺寸不同的納米顆粒及選擇性過濾不同金屬離子等方面的應(yīng)用。結(jié)果顯示:銀的負載量達57.2%,水通量達13400L·m-2·h-1·bar-1,能夠成功截留3nm以上尺寸的納米顆粒,對Au~(3+)的置換率高達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 擄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%.
【學位授予單位】：青島科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TB34

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