活性碳纤维的表面改性及其对Ag^+的还原吸附  

Modification of Activated Carbon Fibers and Their Reduction/ Adsorption Capacities toward Ag + in Aqueous Solution

作　　者：陈水挟[1] 曾汉民[1] 刘立岸 陆耘[1] 

机构地区：[1]中山大学材料科学研究所聚合物复合材料及功能材料教育部开放研究实验室,广州510275

出　　处：《高技术通讯》1999年第8期29-34,共6页Chinese High Technology Letters

基　　金：863计划资助项目

摘　　要：研究了改性活性碳纤维的物理性质和表面化学性质， 并研究了这些改性后的活性碳纤维的结构及其对银离子的吸附特征。水蒸汽活化所得活性碳纤维分别经Ｈ２Ｏ２、ＫＭｎＯ４、ＨＮＯ３ 或ＮＨ３·Ｈ２Ｏ等多种无机试剂后处理。改性活性碳纤维的孔结构和表面积通过７７Ｋ氮吸附等温线进行表征； 表面化学性质用ＸＰＳ和ＩＲ进行表征。研究结果表明，与原活性碳纤维相比，改性活性碳纤维的比表面积和孔体积下降１０％ － ２０％ 左右。氧化改性较为剧烈的情况下（用浓硝酸处理）， 比表面积和孔体积约降低４０％ 。改性后活性碳纤维表面含氧量及含氧基团的种类与未改性处理的原活性碳纤维也有所区别。这些活性碳纤维对酸性条件下的Ａｇ＋ 的还原吸附量都不高。然而， 改性活性碳纤维对碱性条件下的Ａｇ（ＮＨ３）２＋ 的还原吸附量却大幅度提高，可达５５０ｍ ｇ Ａｇ／ｇ Ｃ以上。An activated carbon fiber obtained from sisal fiber activated with steam, SACF, was oxidized in aqueous solution with different inorganic oxidants. Oxidezed ACF(OACF) so obtained were characterized by N 2 adsorption at 77K, XPS and IR. It was shown that BET surface areas and total pore volumes of OACFs decreased 10-20% compared to those of virgin SACF. In severe condition ( oxidized with concentrated HNO 3) , BET surface areas and total pore volumes of OACFs decreased about 40%. The oxygen contents on the surface of OACFs also varied to some extent. The reduction - adsorption capacities of OACFs toward Ag + and Ag(NH 3) + 2 were studied. Although the reduction - adsorption amounts of Ag + at acidic condition on OACFs were fairly low, the reduction - adsorption capacities of OACFs toward Ag(NH 3) + 2 at basic condition on OACFs were improved to as high as 550 mg/g, which was near 3 times of the reduction - adsorption amount of Ag(NH 3) 2 + on virgin SACF. It was concluded that more “active sites” on OACFs contributing in the reduction of Ag(NH 3) 2 + were created through the modification of inorganic oxidants.

关 键 词：活性碳纤维 表面改性 还原 吸附 银 

分 类 号：TQ342.742[化学工程—化纤工业]