【作者】 杨华忠；

【导师】 史铁钧；

【作者基本信息】 合肥工业大学 ， 材料学， 2006， 硕士

【摘要】 溶胶凝胶方法一般是金属醇盐在酸或碱的催化条件下水解缩合制备高纯度材料的一种方法。电纺法是聚合物溶液或熔体借助高压静电作用进行喷射拉伸而获得超细或纳米级纤维的一种纺丝方法。本文结合溶胶凝胶法与电纺法,以正硅酸乙酯（TEOS）为原料,制备出主链为Si-O-Si的聚合物电纺纤维,这种纤维在复合材料、膜材料、试剂或药物载体等方面具有广泛的应用前景。 首先,以TEOS为原料,采用溶胶凝胶法制备了硅溶胶,研究了溶胶体系中H₂O、盐酸的含量和不同溶剂对其电纺性能及分散形态的影响。SEM结果表明,当H₂O/TEOS的摩尔比为1～2时,电纺纤维连续且表面光滑,当H₂O/TEOS的摩尔比为4时,形成堆积在一起的圆形颗粒;当HCl/TEOS的摩尔比为0.01～0.1时,随着HCl的增加,电纺纤维相互粘结,形成交叉的网状结构;用四氢呋喃和丙酮作溶剂电纺,形成了珠节较多的纤维,用乙醇则电纺形成完全没有珠节的长纤维。 其次,在以上研究的基础上用电纺法制备出直径为300～500nm、具有一定柔韧性的二氧化硅电纺纤维。经室温干燥和1200℃高温烧结后分别用场发射扫描电镜（SEM）、X射线衍射（XRD）、红外光谱法（FTIR）、热重分析法（TG）表征。结果表明二氧化硅电纺纤维连续、表面光滑平整;纤维结构中仍存在少量未水解的烷氧基团,在低温下易转变成二氧化硅无机纤维;经高温烧结后仍保持连续长纤维的形状,且由无定形结构转变为微晶结构。 最后,采用溶胶凝胶法和电纺法制备了PDMS/SiO₂电纺纤维,纤维连续、直径均匀、表面光滑平整,形成了一块完整的纤维毡。并用SEM、FTIR、TG研究了纤维的形态、结构和热性能。结果表明PDMS通过两端羟基与TEOS发生了缩合;电纺纤维具有良好的耐高温性能,并且随着PDMS含量的增加,纤维直径变粗。更多还原

【Abstract】 The sol-gel method is a promising technique for obtaining pure materials by hydrolysis and condensation of metal alkoxide under acid or alkali catalyzed condition. Electrospinning is a fiber spinning technique to prepare polymer fibers sized in diameter ranging from nanometer to micrometer. Si-O-Si polymer superfine fibers were prepared by sol-gel and electrospinning methods using tetraethyl orthosilicate （TEOS） as a starting material. These materials will display good application future in compounds, membrane materials, reagent or medicine carriers and so on.Firstly, the silica sol was prepared by a sol-gel method using TEOS as a starting material. Effects of acetic acid, water, and solvents on the spinnability and morphologies of electrospun fibers were investigated. The morphologies of fibers were observed by SEM. When the molar ratio of H₂O/TEOS was 1², electrospun fibers were smooth and continual. While the ratio was up to 4, circular pellets were gained. When the molar ratio of HC1/TEOS was 0.01 ⁰.1, fibers became mutual cementation, and formed intercross network structure with increase of HCl content. Using THF, acetone or ethyl alcohol as solvent, the sols were spinnalbe. With THF or acetone solvent, the electrospun fibers had numerous beads, but with ethyl alcohol as solvent, the fibers were continual and long without any beads.Secondly, silica fibers sized 300⁵00nm in diameters were prepared using electrospinning methods which are flexible and foldable. After dried at room temperature or calcined at 1200℃, the fibers were further characterized by SEM, XRD, FTIR, and TGA respectively. The results show that the silica glass fibers are continuous and generally uniform. Moreover, the fibers with few unhydrolyzed alkoxyl（OC₂H₅） groups could change into inorganic silicon dioxide （SiO₂） in low temperature. After calcined at 1200℃, the amorphous silica fibers were changed into continuous microcrystalline silica fibers.Finally, PDMS/SiO₂ hybrid fibers were prepared by sol-gel and electrospinning methods. The morphologies, components and thermal properties ofthe fibers were characterized by SEM, FTIR, TG respectively. The results indicated that the hydroxyl groups of polydimethylsiloxane （PDMS） and TEOS could be condensed. The hybrid materials had excellent stability at high temperature and the fibers diameter increased with the increase of PDMS content.更多还原