【作者】 郭元龙；

【导师】 许群；

【作者基本信息】 郑州大学 ， 材料学， 2013， 硕士

【摘要】 本文利用静电纺丝技术制备了PVA以及PVA/SWNTs和PVA/Ag复合纳米纤维。并研究了影响PVA纤维静电纺丝过程的各种参数。结果表明,外加电压的强度、高分子溶液的浓度、接收距离甚至是环境因素都会对纤维的形貌产生影响。把SWNTs通过简单的超声分散,加入到PVA溶液中,再通过纺丝过程制备出PVA/SWNTs复合纳米纤维。其中SWNTs的浓度对纤维的形貌有重要影响。由于PVA是高亲水性高分子,所以对PVA纤维交联处理使其具有抗溶解性是有很重要的意义。本文分别采用化学交联法和物理交联法对PVA纤维进行处理,结果表明物理交联可以很好的保持纤维的结构,并且使其有良好的抗溶解性。经热处理过的膜,利用银镜反应原理,在银氨溶液中浸泡后,再用水冲洗,然后再用葡萄糖还原,就可以制得中型纳米尺寸银粒子覆盖的PVA纤维膜。其中银氨溶液浓度、清洗次数都会对银粒子的尺寸有重要影响。如果重复在银氨溶液中浸泡和在葡萄糖溶液中还原的过程,就可以考察浸泡-还原次数对银粒子形貌的影响。除此之外,本文也尝试把硝酸银加入到纺丝液中,对纺丝液分别采取先纺丝后还原和先还原后纺丝的处理方式,来制备含较小尺寸银粒子的复合纳米纤维。最终,利用银氨溶液浸泡-还原处理得到的纤维膜成功制备出了银纤维。本文最后也考察了含银的复合纤维的抗菌作用,把以上制得的各种PVA/Ag复合纳米纤维膜放置在大肠杆菌固体培养基上,培养一段时间后发现含银的纤维膜确实有一定的抗菌作用。更多还原

【Abstract】 In this paper, the PVA, PVA/SWNTs and PVA/Ag nanofibers were prepared by electrospinning and the various parameters which could affect the electrospinning process were studied. The results show that voltage, polymer concentration, receiving distance and even environmental factors could impact on the fiber morphology. Before added to the PVA solution, the SWNTs were dispersed ultrasonically. Then the PVA/SWNTs nanofibers were produced by electrospinning. SWNTs concentration was important factor which could affect the fiber morphology. It is very important for crosslinking the PVA nanofibers because of the high hydrophilicity of PVA. There were two methods to crosslink nanofibers:chemical crosslinking method and physical crosslinking method. The result shows that the nanofibers could still maintain its structure after immersing in water by physical crosslinking method-the heat treated. Then the heat treated mats were soaked in Tollens, experiencing washing process, and reduced by glucose finally. Through varying washing times, Tollens concentration, and soaked-reduced times, we obtain the Ag midnanoparticles which coating degree and size are tunable. In addition to this, we tried to add AgNO3to PVA solution. The PVA/AgNO3nanofibers were prepared from a PVA/AgNO3aqueous solution by an electrospinning process. They were prepared into two types of PVA/AgNO3nanofibers:One was electrospun from PVA/AgN03aqueous solution and then the electrospun nanofibers were treated with UV radiation and heat; the other one was electrospun from PVA/AgNO3solution treated with UV radiation. Finally, calcination of the nanofibers which were soaked in Tollens and reduced by glucose produced smooth pure silver nanofibers. The antibacterial activities of various PVA/Ag and PVA/AgNO3nanofibers were examined against E.coli. It turned out that the Ag nanoparticles successfully inhibited the growth o f the bacteria.更多还原