【作者】 刘瑞来；

【导师】 刘海清；

【作者基本信息】 福建师范大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 静电纺丝技术是一种简单且实用的制备连续纳米纤维的方法。纳米纤维具有优良的力学性能、大的比表面积和长径比,因而被广泛应用于催化剂、气体传感、增强材料、组织工程支架材料、光电材料等领域。本论文采用静电纺丝技术制备复合纳米纤维,研究内容主要包括以下三个方面：（1）通过静电纺丝方法制备了直径为85-200 nm TiO₂/ZnO复合纳米纤维。在0.1mol/L NaOH水溶液中水解TiO₂/ZnAc/CA复合纳米纤维,使其转化为TiO₂/Zn（OH）2/纤维素复合纳米纤维。分别在500和700℃下煅烧TiO₂/Zn（OH）2/纤维素复合纳米纤维而得到TiO₂/ZnO复合纳米纤维。实验结果表明：在TiO₂中加入一定量的ZnO后,生成了新的ZnTiO3晶相,使其提高了对光的利用率。当ZnO的加入量为15.76 wt%且在500℃下煅烧时,光催化活性最强。TiO₂/ZnO复合纳米纤维对罗丹明B和苯酚的降解率达到100%和85%。（2）通过静电纺丝技术制备了孔径小于15nm的多孔ZnO/SnO₂复合纳米纤维。透射电镜表明：多孔纤维是由许多纳米尺寸的颗粒组成,且这些纳米颗粒随着煅烧温度的升高,颗粒逐渐变大。实验结果表明：多孔ZnO/SnO₂复合纳米纤维的催化活性与比表面积、光利用率和光生电子/空穴对的分离效率有关。当Zn:Sn摩尔比为2：1且在500℃下煅烧5h,光催化活性达到最大值。最后提出了电荷分离和光催化反应机理。（3）通过静电纺丝技术制备了一系列组分比例不同的聚氨酯（PU）/聚碳酸酯（PC）复合纳米纤维。实验结果表明：纤维结构和形态受到二元混合物组成比例的影响。PU/PC复合纳米纤维综合了PU和PC各自的优点。PC纳米纤维较脆容易断裂。但随着PU/PC复合组分中PU含量的增加,PU组分不仅促进了PC的纺丝,而且改善了PU/PC纳米纤维膜的力学性能。然而加入一定量的PC有效的改善了PU的热稳定性。主要是因为PU上的羰基和PC上的酰胺基形成氢键,有助于改善其在界面上的相容性。在一系列组分比例不同的PU/PC纳米纤维膜中,PU/PC（70/30）展示了优异的拉伸强度（9.60 MPa）和杨氏模量（55 Mpa）。用丙酮洗涤选择性去除PC组分后,剩余PU组分仍保持纤维形貌。但是,剩余的PU纤维变得不规则且表面含有很多凹槽。纺丝溶液和纺丝过程中的相分离导致PU/PC复合纳米纤维为海-岛结构。更多还原

【Abstract】 Electrospinning is a simple and versatile technique for generating continuous nanofibers. Nanofiber possesses features of excellent mechanical property, very high specific surface area and aspect ratios, which assure its promising applications in various areas, such as catalysts, gas sensing, reinforcing materials, tissue engineering scaffolds, and photoelectric materials. This thesis research work includes the following aspects:（1） TiO₂/ZnO composite nanofibers with diameter in the range of 85-200 nm were fabricated via the electrospinning technique. After treated with 0.1 mol/L NaOH solution, TiO₂/ZnAc/CA composite nanofibers were transformed into Ti02/Zn（OH）2/cellulose composite nanofibers. TiO₂/ZnO composite nanofibers were obtained by calcinating the hydrolyzed composite fibers at 500 and 700℃for 5h. With the blending of ZnO into TiO₂, a new crystallite ZnTiO3 was formed in addition to the ZnO and TiO₂ crystallites, and the ultraviolet light absorption efficiency was enhanced according to the UV-vis diffuse reflectance spectroscopy （DRS）. Almost 100% Rhodamine B （RhB） and 85% phenol were decomposed in the presence of TiO₂/ZnO composite nanofibers under mild conditions. The results demonstrated that the blending of ZnO in the composite nanofibers increased the photocatalytic efficiency, whereas the optimum ZnO content was 15.76 wt% to reach the most efficient photocatalytic activity.（2） The mesoporous ZnO/SnO₂ composite nanofibers with pore size less than 15 nm were prepared via the electrospinning technique. Transmission electron microscopy （TEM） images showed that the mesoporous ZnO/SnO₂ composite nanofibers were composed of grain-like nanoparticles. The nanoparticles size increased with the increasing of the calcination temperature from 500℃to 900℃. Moreover, the crystal phases, grain sizes, and band gap energy of the mesoporous ZnO/SnO₂ composite nanofibers were influenced by the molar ratio of Zn:Sn and the calcination temperatures. It was found that the photocatalytic activity of the mesoporous ZnO/SnO₂ composite nanofibers was dependant on their surface areas, light utilization efficiency, and the separation of photogenerated electron/hole pairs. The maximum photocatalytic activity was shown for composite nanofibers with the molar ratio of Zn:Sn=2:1 and calcination at 500℃for 5 h. A mechanism of the charge separation and photocatalytic reaction for the mesoporous ZnO/SnO₂ composite nanofibers was also presented.（3） Sea-island polyurethane （PU）/polycarbonate （PC） composite nanofibers were obtained through electrospinning of partially miscible PU and PC in 3:7 （v/v） N,N-dimethylformamide （DMF） and tetrahydrofuran （THF） mixture solvent. The structures and morphologies of the nanofibers were influenced by composition ratio in the binary mixtures. The pure PC nanofiber was brittle and easy to break. With increasing the PU content in the PU/PC composite nanofibers, PU component not only facilitated the electrospinning of PC, but improved the mechanical properties of PU/PC nanofibrous mats. In a series of nanofibrous mats with varied PU/PC composition ratios, PU/PC 70/30 showed excellent tensile strength of 9.60 Mpa and Young’s modulus of 55 Mpa. After selective removal of PC component in PU/PC composite nanofibers by washing with acetone, the residual PU maintained fiber morphology. However, the residual PU nanofiber became irregular and contained elongated indents and ridges along the fiber surface. PU/PC composite fibers showed sea-island nanofiber structure due to phase separation in the spinning solution and in the course of electrospinning.更多还原