Ji Liwen, Saquing Carl, Khan Saad A, Zhang Xiangwu
Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695-8301, USA.
Nanotechnology. 2008 Feb 27;19(8):085605. doi: 10.1088/0957-4484/19/8/085605. Epub 2008 Feb 1.
In this study, polyacrylonitrile (PAN) composite nanofibers containing different amounts of silica nanoparticulates have been obtained via electrospinning. The surface morphology, thermal properties and crystal structure of PAN/silica nanofibers are characterized using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, wide-angle x-ray diffraction (WAXD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The results indicate that the addition of silica nanoparticulates affects the structure and properties of the nanofibers. In addition to PAN/silica composite nanofibers, porous PAN nanofibers have been prepared by selective removal of the silica component from PAN/silica composite nanofibers using hydrofluoric (HF) acid. ATR-FTIR and thermal gravimetric analysis (TGA) experiments validate the removal of silica nanoparticulates by HF acid, whereas SEM and TEM results reveal that the porous nanofibers obtained from composite fibers with higher silica contents exhibited more nonuniform surface morphology. The Brunauer-Emmett-Teller (BET) surface area of porous PAN nanofibers made from PAN/silica (5 wt%) composite precursors is higher than that of pure nonporous PAN nanofibers.
在本研究中，通过静电纺丝制备了含有不同量二氧化硅纳米颗粒的聚丙烯腈（PAN）复合纳米纤维。采用衰减全反射傅里叶变换红外（ATR-FTIR）光谱、广角X射线衍射（WAXD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和差示扫描量热法（DSC）对PAN/二氧化硅纳米纤维的表面形态、热性能和晶体结构进行了表征。结果表明，二氧化硅纳米颗粒的添加会影响纳米纤维的结构和性能。除了PAN/二氧化硅复合纳米纤维外，还通过使用氢氟酸（HF）从PAN/二氧化硅复合纳米纤维中选择性去除二氧化硅成分制备了多孔PAN纳米纤维。ATR-FTIR和热重分析（TGA）实验验证了HF酸对二氧化硅纳米颗粒的去除效果，而SEM和TEM结果表明，由二氧化硅含量较高的复合纤维制备的多孔纳米纤维表现出更不均匀的表面形态。由PAN/二氧化硅（5 wt%）复合前驱体制备的多孔PAN纳米纤维的比表面积高于纯无孔PAN纳米纤维。
