黄原胶-丙烯酰胺接枝共聚物吸附Cu(Ⅱ)的热力学、动力学性质（英文）  

Thermodynamics and Kinetics for Cu(Ⅱ) Adsorption by Graft Copolymer of Xanthan Gum and Acrylamide

作　　者：程磊[1] 程乐华[1] 王新运[1] 

机构地区：[1]巢湖学院化学与材料工程学院,安徽巢湖238000

出　　处：《材料科学与工程学报》2017年第4期553-558,581,共7页Journal of Materials Science and Engineering

基　　金：Education Committee of Anhui Province of China(KJ2016A503)

摘　　要：利用黄原胶-丙烯酰胺接枝共聚物(XG-g-AM)吸附溶液中的Cu(Ⅱ),通过静态吸附实验研究了吸附过程中的热力学和动力学性质,使用红外光谱仪和X射线衍射仪对XG-g-AM吸附Cu(Ⅱ)前后的分子结构进行了表征。研究结果表明:在298~318K温度范围内,吸附行为可同时用Freundlich等温式和Langmuir等温式进行描述,吸附为自发的、吸热的熵增加过程,温度升高有利于吸附。吸附过程符合伪二级动力学模型。XG-g-AM通过物理和配位吸附方式吸附Cu(Ⅱ),吸附Cu(Ⅱ)后,XG-g-AM的结晶结构被破坏,结晶度下降。Cu(Ⅱ)以非结晶态形式在XG-g-AM上聚集存在。Graft copolymer of xanthan gum and acrylamide （XG-g-AM） was used to adsorb Cu （Ⅱ） from aqueous solution. Thermodynamics and kinetic characteristics of the adsorption process were investigated based on the adsorption experiment. The molecular structures of XG-g-AM before and after adsorption were characterized by Fourier transform infrared spectroscopy （FT-IR） and X-ray diffraction （XRD）. The results show that the adsorption pattern of XG-g-AM for Cu （Ⅱ） fits with both the Langmiur and Freundlich adsorption isotherm equation within the temperature range of 298- 318K. Thermodynamic parameters, the change of free energy （AG）, enthalpy （AH） and entropy （AS）, indicate that the adsorption is a spontaneous, endothermic and entropy increase process. Moreover, temperature increase can benefit the adsorption. Kenetic experiments show that the adsorption process corresponds with pseudo-second order kinetic model. XG-g-AM adsorbs Cu （Ⅱ） by means of physical adsorption and coordination adsorption. The crystal structure of XG-g-AM was destroyed after adsorbing Cu （Ⅱ） and the crystallinity of XG-g-AM decreased. Cu （Ⅱ） congregate on XG-g-AM in the form of non crystalline state.

关 键 词：接枝共聚物 吸附 Cu(Ⅱ) 热力学 动力学 

分 类 号：O636.1[理学—高分子化学]