基于吸附质-分子探针的新型交联壳聚糖的吸附特性

研究了CCTS对低浓度游离酸的吸附特性,基于吸附质-分子探针电位法,考察了吸附剂活性中心数目、游离酸种类和温度对吸附行为的影响。结果表明,在30℃时,CCTS吸附游离酸的过程,遵循单分子层机理进行吸附。吸附剂―吸附质相互作用能U制约表观吸附速率常数K,K、U大小分别为2.519×10-2,4.084×10-2,9.398×10-2L/min和7.264,7.420,7.926 kJ/mol,两者存在线性相关性,呈逐渐增大趋势。K、U大小随着活性中心数目G的增加而增大。CCTS吸附游离酸为吸热过程,吸附表观活化能Ea为33.98 kJ/mol。3种类型游离酸K、U的大小顺序为:HClO4>HNO3>H2SO4,吸附分维数Dw分别为1.384、1.567、1.911,Dw值越大,导致表观吸附速率常数降低。

Adsorption Characteristics of a Newly-developed Cross-linked Chitosan:A Study Based on Adsorbate-molecular Probe

Cross-linked chitosan as a novel adsorbent material was studied.An experiment on adsorption of three kinds of low concentration free acid on cross-linked chitosan microspheres,which was prepared at the laboratory,was conducted by using the adsorbate-molecular probe-electric potentiometric method.The experiment showed that adsorption of free acids on the cross-linked chitosan followed the mechanism of monomolecular adsorption and was an endothermic process with the apparent adsorption activation energy of 33.98 kJ/mol.According to the experiment,there was a linear relationship between K(the apparent adsorption rate constant)and U(the adsorbent-adsorbate interaction energy constraint),and both K and U increased with the increase of G(the adsorbent activity center number).In addition,it was found the increased D(wthe adsorption fractal dimension)would lead to decreases of the apparent adsorption rate constant.