银纳米材料的软模板法制备及其性能研究

发布时间：2018-04-24 08:34

本文选题：软模板法 + 制备　；参考：《西南大学》2015年硕士论文

【摘要】：纳米材料具有四大基本效应,即表面与界面效应、小尺寸效应、量子尺寸效应和宏观量子隧道效应。因而纳米材料与传统材料相比具有其独特的良好性能,而这些性能使其能够在很多领域都发挥着巨大作用,例如在催化、电学、光学、表面增强拉曼散射、生物医学及生物传感器等很多领域都具有广泛的应用潜力,这些独特的性能和应用又都与纳米粒子的形貌和尺寸紧密相关。因此,实现对纳米材料形貌可控地制备非常重要。虽然近年来新的制备方法和技术不断被开发出来,但是纳米材料的可控制备却依然十分困难,而且不够完善,还是目前纳米材料制备方面的重点和难点。因此,寻找新的合成方法来制备形貌和尺寸可控的纳米材料具有重要的意义和广阔的应用前景。此外,寻找无毒、环境友好、可再生试剂,开发绿色的制备方法也是目前研究的热点。本论文以银纳米粒子为研究对象,根据目前银纳米粒子的国内外研究现状,分别以丝胶和聚乙烯吡咯烷酮(PVP)为软模板制备出了银纳米材料。首先采用简便和绿色环保的方法制备了六角形银纳米片,研究了反应的影响因素,探索了生长机理及其抗菌性能；其次利用超声辅助法制备了银纳米球,研究了反应的影响因素,提出了可能的生长机制并探究了其对亚甲基蓝的催化降解性能。本论文创新点如下：1.采用化学还原法在室温下合成了六角形银纳米片。该方法中,银源为硝酸银,表面活性剂和软模板都为丝胶,还原剂为抗坏血酸。通过XRD, UV-vis, SEM, EDX, TEM等分析手段对制备的六角形银纳米片进行了表征。结果表明,制备的六角形银纳米片形貌均匀,平均粒径为200-300 nm,厚度为30nm。提出了六角形银纳米片的“表面活性剂导向生长”的生长机理,研究了反应时间、温度和丝胶的用量对产品形貌的影响,研究表明,反应时间、温度和丝胶的用量都可以改变产品的形貌。探究了六角形银纳米片对大肠杆菌和金黄色葡萄球菌抗菌活性,实验表明,制备的六角形银纳米片对大肠杆菌(革兰氏阴性)和金黄色葡萄球菌(革兰氏阳性)都具有良好的抗菌效果。2.采用超声辅助法在超声辅助的条件下制备出了银纳米球。该方法中,银源为银氨溶液,表面活性剂和软模板为PVP,还原剂为抗坏血酸。通过XRD, UV-vis, SEM, EDX等分析手段对制备的银纳米球进行了表征。结果表明,制备的银纳米球形貌均匀,分散性良好,平均粒径为300-400nm。提出了银纳米球的生长机理,超声波的空化作用的在银纳米球的形成过程中起着决定性的作用。研究了超声时间、PVP和氨水的用量对产品形貌的影响,研究表明,超声时间、PVP和氨水的用量都可以改变产品的形貌。探究了银纳米球对亚甲基蓝的催化降解活性,结果表明,制备的银纳米球对亚甲基蓝有明显的催化降解效果。
[Abstract]:The nanomaterials have four basic effects: surface and interface effect, small size effect, quantum size effect and macroscopic quantum tunneling effect. As a result, nanomaterials have unique good properties compared with conventional materials, and these properties enable them to play a significant role in many fields, such as catalysis, electricity, optics, surface enhanced Raman scattering. Many fields such as biomedicine and biosensor have wide application potential. These unique properties and applications are closely related to the morphology and size of nanoparticles. Therefore, it is very important to realize the controllable preparation of nano-materials. Although new preparation methods and techniques have been developed in recent years, the controllable preparation of nanomaterials is still very difficult and not perfect, which is still the focus and difficulty in the preparation of nanomaterials. Therefore, it is of great significance and wide application prospect to find a new synthesis method to prepare nano-materials with controllable morphology and size. In addition, the search for non-toxic, environmentally friendly, renewable reagent and the development of green preparation methods are also the focus of current research. In this thesis, silver nanoparticles were prepared by using sericin and polyvinylpyrrolidone polyvinyl pyrrolidone (PVP) as soft templates according to the research status of silver nanoparticles at home and abroad. At first, hexagonal silver nanoparticles were prepared by a simple and green method, the influencing factors of the reaction were studied, the growth mechanism and antibacterial properties were explored, and the silver nanospheres were prepared by ultrasonic assisted method. The influencing factors of the reaction were studied, the possible growth mechanism was proposed and the catalytic degradation of methylene blue was investigated. The innovation of this paper is as follows: 1. Hexagonal silver nanoparticles were synthesized by chemical reduction at room temperature. In this method, silver source is silver nitrate, surfactant and soft template are sericin, ascorbic acid is reducing agent. The hexagonal silver nanoparticles were characterized by XRD, UV-vis, SEM, EDX and TEM. The results show that the hexagonal silver nanoparticles have uniform morphology with an average diameter of 200-300 nm and a thickness of 30 nm. The growth mechanism of "surfactant oriented growth" of hexagonal silver nanoparticles was proposed. The effects of reaction time, temperature and dosage of sericin on the morphology of the product were studied. Both the temperature and the dosage of sericin can change the appearance of the product. The antibacterial activity of hexagonal silver nanoparticles against Escherichia coli and Staphylococcus aureus was investigated. The prepared hexagonal silver nanoparticles have good antimicrobial effect against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Silver nanospheres were prepared by ultrasonic assisted method. The silver source is silver ammonia solution, the surfactant and soft template are PVP, and the reducing agent is ascorbic acid. The silver nanospheres were characterized by XRD, UV-visS, SEM, EDX and so on. The results show that the silver nanoparticles have uniform morphology and good dispersion, and the average particle size is 300 ~ 400 nm. The growth mechanism of silver nanospheres is proposed. The cavitation of ultrasonic wave plays a decisive role in the formation of silver nanospheres. The effects of the amount of ultrasonic time PVP and ammonia water on the morphology of the product were studied. The results showed that the amount of ultrasonic time PVP and ammonia water could change the morphology of the product. The catalytic degradation activity of silver nanospheres for methylene blue was investigated. The results showed that the prepared silver nanospheres had obvious catalytic degradation effect on methylene blue.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O614.122

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