【作者】 方旭；

【导师】 史向阳；

【作者基本信息】 东华大学 ， 生物化工， 2011， 硕士

【摘要】 纳米纤维材料作为新兴的纳米材料是纳米科学领域最前沿的研究领域,而高分子纳米纤维又是其中一个重要的研究方向之一,尤其是制备无机/有机高分子杂化材料因其具有的具备主体高分子和客体引入物双重性质更是得到了科学工作者广泛的关注,将在未来有着广泛的应用前景。因此,基于纳米纤维膜及含金属纳米颗粒复合纳米纤维膜材料的基本性能测试和研究成为目前开发复合纳米纤维材料最为迫切解决的问题之一。本文作者利用静电纺丝技术制备得到了含有丰富氨基的直径为490±83 nm的聚乙烯亚胺(polyethyleneimine, PEI)/聚乙烯醇(polyvinyl alcohol, PVA)纳米纤维,并以甲基蓝为模式污染物探讨了其在环境修复领域的应用。基于PEI/PVA纳米纤维膜为反应器制备了含直径为11.8±3.3 nm纳米金颗粒的复合纳米纤维膜,并对其热力学、机械性能及催化性能进行了测试和分析。主要工作包括以下4个部分：第一,水稳定性良好PEI/PVA纳米纤维膜的制备通过对影响静电纺丝工艺条件的因素如流速、电压、接收距离和浓度进行优化,通过扫描电镜观察得到了具有良好纤维形貌的纳米纤维。然后探讨了戊二醛溶液、热交联和戊二醛蒸汽交联等三种交联方法,筛选出可以制备良好纤维形貌的的戊二醛蒸汽交联方法。并用扫描电镜和傅里叶红外光谱表征其纤维物理化学性质的变化,并对交联前后纤维膜的机械性能做了测试。第二,水稳定性良好的PEI/PVA纳米纤维膜在环境修复中的应用以甲基蓝为模式污染物,研究PEI/PVA纳米纤维膜对甲基蓝的脱色效果。研究了PEI/PVA纳米纤维膜对甲基蓝的脱色效果,及PEI/PVA纳米纤维膜脱色的驱动力。并通过建立吸附等温线模型和吸附动力学方程纤维膜吸附甲基蓝的机理进行了初步的探讨。第三,含纳米金复合纳米纤维膜的制备以水稳定性良好的PEI/PVA纳米纤维膜为反应器。首先将纤维膜浸入氯金酸溶液中,使氯金酸根离子和PEI上的氨基通过静电相互作用结合到纤维膜上。然后通过原位还原的方法,制备得到含有纳米金颗粒直径为11.8±3.3 nm的复合纳米纤维膜。采用扫描电镜,透射电镜,X-射线能量分散谱,傅里叶红外光谱分析和热重分析等手段进行含纳米金复合纳米纤维的形貌、组分的表征。第四,含纳米金复合纤维膜催化性能测试将含金纳米纤维膜和含金流延膜在相同条件下进行催化性能的测试,研究表明：单位时间内含金纳米纤维的催化性能要远远高于含金流延膜。并且这种含金纳米复合纤维也展示出了良好可重复利用性和可回收性,3次催化实验仍然可以达到和第一次几乎完全一致的催化效果。另外,我们也对纤维膜的热力学性能进行了研究,在不同温度处理下,含金纤维膜形貌没有发生变化,纳米金也没有发生聚集。而且催化性能也和未做处理前保持一致,具有良好的热稳定性。更多还原

【Abstract】 The research of nanofibers is one of the most forefront research fields in nano science and technology, and research of macromolecule polymer nanofiber materials are also a important direction. Especially, the preparation of inorganic/organic polymer hybrid nanomaterials with the dual characteristics of the host polymer and guest incorporated object are receiving immense interest, they have broad applications in the future. Therefore, the basic research of nanofibrous-based membranes and metal nanoparticle-incorporated nanofibrous membrane has become necessary.In this present article, the polyethyleneine (PEI)/polyvinyl alcohol (PVA) nanofibers with a diameter of 490±83 nm were prepared using electrospinning techniques. And we select methyl blue, a common dye in the print and textile industry, as a model dye to investigate the water-stable nanofibrous membranes for environmental remediation applications. Based on the PEI/PVA nanofibers as a nanoreactor, we also fabricated the gold nanoparticle (AuNP)-containing nanofibrous membranes using in-situ reduction method for catalysis applications. The main content of this thesis include four parts:In the first section, we fabricated PEI/PVA nanofibers by electrospinning PEI and PVA mixture solution. The influence of the processing parameters such as flow rate, collection distance, voltage, and the polymer concentration on the morphology of the nanofibers was systematically investigated. In addition, different crosslinking methods including glutaradehyde solution, heat treatment and glutaradehyde vapor were employed to render the PEI/PVA nanofibrous membranes water stable. The formed PEI/PVA nanofibers with a smooth and uniform morphology before and after crosslinking were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and mechanical property testing. In the second section, the water stable PEI/PVA nanofibrous membrane was used for environmental remediation applications. We select methyl blue as a model contaminant to investigate the decoloration efficiency of the water stable PEI/PVA nanofibrous membranes, and preliminarily investigate the driving forces of the nanofibrous membranes to methyl blue. And the adsorption kinetics models and isotherms equations were established.The third section describes the fabrication of AuNP-incorporated composite nanofibrous membranes. The AuNPs with a diameter of 11.8±3.3 nm were synthesized and immobilized into the electrospun PEI/PVA nanofibrous membranes through in-situ reduction of the AuCl4- ions complexed with the water-stable PEI/PVA nanofibrous membranes. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, and thermal gravimetric analysis (TGA) were utilized to characterize the morphology and composition of the AuNP-containing nanofibers.In the fourth section, AuNP-containing nanofibrous membranes were used for catalysis applications. We investigated the catalysis activity of AuNP-containing nanofibrous membranes and cast films under the same conditions, the catalytic activity of the formed AuNP-containing hybrid nanofibrous mats was evaluated via the transformation of 4-nitrophenol to 4-aminophenol. It is demonstrated that the catalysis activity of AuNP-containing nanofibrous membranes is higher than the cast film. And the formed AuNP-immobilized PEI/PVA nanofibrous membranes can be easily handled and reused for at least 3 times with similar catalytic performance. In addition, we also investigate the effect of temperature on the catalytic activity of the AuNP containing composite nanofibrous membranes. Results show that the morphology and catalytic performance of the AuNP containing composite nanofibrous membranes did not change, the AuNP do not show aggregation after heat treatment at different temperatures. The AuNP-containing composite nanofibrous membranes have satisfactory thermal stability at different temperatures (80℃-150℃)更多还原