Pirzada Tahira, Arvidson Sara A, Saquing Carl D, Shah S Sakhawat, Khan Saad A
Department of Chemistry, Quaid-i-Azam University , Islamabad 44000, Pakistan.
Langmuir. 2014 Dec 30;30(51):15504-13. doi: 10.1021/la503290n. Epub 2014 Dec 17.
A controlled sol-gel synthesis incorporated with electrospinning is employed to produce polyacrylonitrile-silica (PAN-silica) fibers. Hybrid fibers are obtained with varying amounts of silica precursor (TEOS in DMF catalyzed by HCl) and PAN. Solution viscosity, conductivity, and surface tension are found to relate strongly to the electrospinnability of PAN-silica solutions. TGA and DSC analyses of the hybrids indicate strong intermolecular interactions, possibly between the -OH group of silica and -CN of PAN. Thermal stabilization of the hybrids at 280 °C followed by carbonization at 800 °C transforms fibers to carbon-silica hybrid nanofibers with smooth morphology and diameter ranging from 400 to 700 nm. FTIR analysis of the fibers confirms the presence of silica in the as-spun as well as the carbonized material, where the extent of carbonization is also estimated by confirming the presence of -C═C and -C═O peaks in the carbonized hybrids. The graphitic character of the carbon-silica fibers is confirmed through Raman studies, and the role of silica in the disorder of the carbon structure is discussed.
采用一种结合静电纺丝的可控溶胶-凝胶合成法来制备聚丙烯腈-二氧化硅（PAN-二氧化硅）纤维。通过改变二氧化硅前驱体（在HCl催化下于DMF中的TEOS）和PAN的用量来获得杂化纤维。发现溶液粘度、电导率和表面张力与PAN-二氧化硅溶液的可静电纺性密切相关。对杂化材料的热重分析（TGA）和差示扫描量热分析（DSC）表明存在强烈的分子间相互作用，可能是二氧化硅的-OH基团与PAN的-CN之间的相互作用。将杂化材料在280℃下进行热稳定化处理，然后在800℃下碳化，可将纤维转变为具有光滑形态且直径在400至700nm之间的碳-二氧化硅杂化纳米纤维。对纤维的傅里叶变换红外光谱（FTIR）分析证实了在初纺材料以及碳化材料中均存在二氧化硅，同时通过确认碳化杂化材料中-C═C和-C═O峰的存在来估计碳化程度。通过拉曼研究证实了碳-二氧化硅纤维的石墨化特性，并讨论了二氧化硅在碳结构无序化中的作用。
