气相生长碳纤维的表面改性及表征  

Surface Modification and Characterization of Vapor Grown Carbon Fibers

作　　者：黄玉安[1] 叶德举[1] 孙清[1] 张惠良[1] 沈俭一[1] 

机构地区：[1]南京大学化学系,南京210093

出　　处：《无机化学学报》2006年第3期403-410,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家科技部国际合作基金(No.2004DFB02900);江苏省科技厅高技术项目(No.BG2002019)资助。

摘　　要：用浓硝酸(65%￣68%)对气相生长碳纤维(VGCF)进行了不同时间的表面化学改性。X射线衍射(XRD)分析表明:改性使得VGCF的石墨晶型结构改变,其改变的程度随改性时间的延长而加深;BET比表面积(SBET)测试表明:改性后的VGCF的SBET有一定的变化,经120min长时间的改性处理后,SBET明显降低;傅立叶变换红外光谱(FTIR)测定得出:改性后VGCF表面上生长了不同类型的含氧基团,其总含量随改性时间的增大而增加;程序升温还原(TPR)得出:改性后VGCF表面上生成有2类以上的热稳定性不同的含氧基团,计算求得含氧基团的氧总含量为2mmol·g-1以上;NH3吸附微量量热测定得出:表面酸性基团的强度和含量随改性时间增加而增大;透射电子显微镜(TEM)结果表明:改性没有明显破坏VGCF的外观结构;吸油值(AOV)实验给出:改性后VGCF的AOV显著降低而亲水性增强;双液法接触角测试给出:改性后VGCF的表面能(SE)明显增大;偶联剂与VGCF作用的FTIR研究表明:改性后VGCF表面含氧基团和偶联剂发生反应,增强了偶联剂在VGCF表面上的结合强度。The surface chemical modification for the vapour grown carbon fibers （VGCF） produced with the catalytic dehydrogenation of hydrocarbon have been performed by concentrate nitric acid （65%-68%） for various times in order to extend the practical application in composite materials. The structure of VGCF has been char- acterized by XRD technique. The XRD results show that the graphite crystal structures of VGCF are transformed upon modification, and the extent of transformation is a function of modification time. The BET results indicate that through the modification the SBET of VGCF veries, and as the long modification time of 120 min is used, the SBET of VGCF decreases distinctly. The FTIR analyses illuminate that due to the modification the different functional oxygen-containing groups are grown on these surfaces of VGCF, and the total amount of the oxygen-containing groups increases with the modification time. In addition, the profiles of temperature programmed reduction （TPR） display that more than two kinds of oxygen-containing functional groups exist on the surfaces of VGCF and the total amount of oxygen for these oxygen-containing functional groups obtained is more than 2 mmol·g^-1. The microcalorimetric measurements of NH3 adsorption indicate that the strength and the amount of the functional groups of surface acids increase with the modification time. The transmission electron microscopy （TEM） shows during modification no damage is observed on these surfaces of the VGCF. The experiments of absorbed oil value （AOV） exhibite that the AOV decreases sharply whereas the hydrophilicity of VGCF increases. Double fluid method for the measurements of the contact angles shows that after modification the surface energy （SE） of VGCF increases apparently. The FTIR measurements of the modified VGCF treated with the titanate coupling agent indicate that the bonding abilities between modified fibers surface and coupling agent are enhanced.

关 键 词：气相生长碳纤维 改性 表面能 偶联剂 

分 类 号：O613.7[理学—无机化学]