磷酸活化棕榈纤维的制备与结构表征

Preparation and characterization of windmill palm fiber activated by phosphoric acid

为高值化利用棕榈纤维,在不同活化温度下以磷酸为活化剂制备棕榈活性碳纤维,通过扫描电镜、氮气吸附-脱附、压汞法和亚甲基蓝吸附法对其孔隙结构和吸附性能表征,结果表明:(1)随着活化温度升高,棕榈纤维表面受活化剂侵蚀而引起组织结构破坏,产率逐渐降低;(2)随着活化温度升高,活性碳纤维中孔含量减少,有利于微孔的产生,导致比表面积的增加;随着活化温度继续增加,部分微孔扩大为中孔,引起中孔增多;(3)棕榈纤维的亚甲基蓝吸附能力较活化处理前有明显提高,并与活性碳纤维中孔含量变化呈正相关。

Activated carbon fibers（ACFs）were prepared by chemical activation of windmill palm（WP）fibers with phosphoric acid at different temperatures,promoting the high value utilization of WP fibers.The effects of temperature,in terms of porous texture and adsorption property,were identified through the use of scanning electron microscopy,nitrogen adsorption-desorption,mercury intrusion porosimetry and methylene blue adsorption.Results indicated that 1）the ACFs prepared at relatively high temperatures presented more collapsed surfaces,and lower yields because of the violent reaction during the activation process.2）with increasing temperature,the Vmesoof ACFs gradually increased,which contributed to the generation of micropores,leading to the increase of SBET;at higher activation temperatures,part of existing micropores were widened into mesopores,leading to the decrease of Vmeso.3）it was also found that methylene blue adsorption of WP fibers were highly increased after the activation treatments,and the variations of MB adsorption for ACFs showed patterns similar to their Vmesovalues.