摘要
通过grafting-from法制备了聚酰胺-胺修饰的氧化石墨烯复合物(GO/PAMAMs),并用红外光谱(FTIR)、热重分析(TGA)和透射电子显微镜(TEM)进行了表征。考察了溶液pH、吸附时间、吸附温度、Cu(Ⅱ)初始质量浓度等因素对Cu(Ⅱ)在GO/PAMAMs上吸附过程的影响,并研究了GO/PAMAMs对铜离子的吸附动力学和热力学。研究结果表明,GO/PAMAMs对Cu(Ⅱ)的吸附过程符合Lagergren准二级动力学模型,主要为化学吸附。Langmuir和Freundlich等温模型均可以描述GO/PAMAMs对Cu(Ⅱ)的吸附行为,说明Cu(Ⅱ)在GO/PAMAMs上的吸附是单分子层吸附。自由能变(ΔG),焓变(ΔH)和熵变(ΔS)均大于0,说明GO/PAMAMs对Cu(Ⅱ)的吸附是吸热反应,非自发和熵增过程。
Graphene oxide （ GO grafting-from method, and then ） was modified by polyamide-amine the GO/PAMAMs were characterized dendrimers （ PAMAMs ） via a by means of Fourier transform infrared spectroscopy （ FTIR）, thermogravimetric analysis （ TGA ） and transmission electron microscopy （TEM）. The effects of the solution pH, the adsorption time and temperature and the initial concentration of Cu（ Ⅱ ） adsorption onto GO/PAMAMs were studied. The kinetics and thermodynamics of Cu（ Ⅱ ） adsorption were investigated with the Lagergren pseudo-first-order and pseudo-second-order kinetic model, and Langmuir and Freundlich isotherm models were applied to simulate the experimental data. The experimental data show that the adsorption process of Cu （ Ⅱ ） onto GO/PAMAMs can be described with the Lagrangian pseudo-second-order kinetic model, indicating that the adsorption process is mainly chemisorption. The experimental data of isotherm followed both the Langmuir isotherm model and the Freundlich model, which indicated that the adsorption was monolayer. The thermodynamic parameters of Gibbs free energy change （ AG）, enthalpy change （AH） and entropy change （AS） were calculated and found to be positive, indicating that the adsorption of Cu （ Ⅱ ） onto GO/PAMAMs was endothermic, non-spontaneous and entropy-producing.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2014年第8期998-1004,1023,共8页
Fine Chemicals
基金
国家自然科学基金项目(31360161)
湖南省自然科学基金项目(13JJ2030)~~
关键词
氧化石墨烯
聚酰胺
胺
吸附
动力学
热力学
水处理技术与环境保护
graphene oxide
polyamide-amine
adsorption
kinetics
thermodynamics
water treatment technology and environmental protection
