为了制备较高膨胀容积的膨胀石墨,研究了以50目、80目天然石墨为原料,以高锰酸钾为氧化剂,硫酸做插层剂,用化学氧化法制备膨胀石墨时,氧化剂、插层剂的用量以及酸浓度等因素对膨胀石墨膨胀容积的影响;测定了膨胀温度对膨胀容积的影响。...为了制备较高膨胀容积的膨胀石墨,研究了以50目、80目天然石墨为原料,以高锰酸钾为氧化剂,硫酸做插层剂,用化学氧化法制备膨胀石墨时,氧化剂、插层剂的用量以及酸浓度等因素对膨胀石墨膨胀容积的影响;测定了膨胀温度对膨胀容积的影响。通过正交实验,确定获得最大膨胀容积的最佳实验条件。实验结果表明:50目原料石墨的最佳条件为硫酸与原料石墨的液∶固=5∶1,KMn O4∶C=0.15∶1,硫酸浓度为50%(均为质量比),室温下反应时间为30 min,所得产品的膨胀容积为370 m L/g;80目原料石墨的最佳条件为硫酸与原料石墨的液:固=1.5∶1,KMn O4∶C=0.18∶1,硫酸浓度为73%(均为质量比),室温下反应时间为40 min,所得产品的膨胀容积为280 m L/g。原料石墨及可膨胀石墨的X-射线及电子能谱分析,证实了硫酸插层反应的成功性,两种原料制得可膨胀石墨的最佳膨胀温度均为900℃。展开更多
Expansion graphite (EG) processing of an expanded volume of 400 mL/g was prepared with 50 mesh crude graphite after chemical oxidation intercalation of potassium permanganate and vitriol, and its adsorption kinetics a...Expansion graphite (EG) processing of an expanded volume of 400 mL/g was prepared with 50 mesh crude graphite after chemical oxidation intercalation of potassium permanganate and vitriol, and its adsorption kinetics and thermodynamics characteristics for xylenol orange (XO) was investigated. In thermodynamic study, adsorption isotherm and free energy change (⊿G°) were detected and calculated, respectively. Influence of ionic strength on adsorbance was investigated. Kinetic studies were carried out with a series of XO concentration under different temperatures, and the data were simulated with pseudo first-order and second-order kinetic model, respectively. Results illustrate: adsorption of EG for XO is a spontaneous process, and adsorption isotherm is type II;equilibrium adsorbance increases with the increase of ionic strength. Kinetic studies show that the kinetic data can be delineated by pseudo second-order kinetic model. Initial adsorption rate increases with the increase of temperature. Adsorption activation energy is less than 20 kJ/mol;physical adsorption is the major mode of the overall adsorption process.展开更多
文摘为了制备较高膨胀容积的膨胀石墨,研究了以50目、80目天然石墨为原料,以高锰酸钾为氧化剂,硫酸做插层剂,用化学氧化法制备膨胀石墨时,氧化剂、插层剂的用量以及酸浓度等因素对膨胀石墨膨胀容积的影响;测定了膨胀温度对膨胀容积的影响。通过正交实验,确定获得最大膨胀容积的最佳实验条件。实验结果表明:50目原料石墨的最佳条件为硫酸与原料石墨的液∶固=5∶1,KMn O4∶C=0.15∶1,硫酸浓度为50%(均为质量比),室温下反应时间为30 min,所得产品的膨胀容积为370 m L/g;80目原料石墨的最佳条件为硫酸与原料石墨的液:固=1.5∶1,KMn O4∶C=0.18∶1,硫酸浓度为73%(均为质量比),室温下反应时间为40 min,所得产品的膨胀容积为280 m L/g。原料石墨及可膨胀石墨的X-射线及电子能谱分析,证实了硫酸插层反应的成功性,两种原料制得可膨胀石墨的最佳膨胀温度均为900℃。
文摘Expansion graphite (EG) processing of an expanded volume of 400 mL/g was prepared with 50 mesh crude graphite after chemical oxidation intercalation of potassium permanganate and vitriol, and its adsorption kinetics and thermodynamics characteristics for xylenol orange (XO) was investigated. In thermodynamic study, adsorption isotherm and free energy change (⊿G°) were detected and calculated, respectively. Influence of ionic strength on adsorbance was investigated. Kinetic studies were carried out with a series of XO concentration under different temperatures, and the data were simulated with pseudo first-order and second-order kinetic model, respectively. Results illustrate: adsorption of EG for XO is a spontaneous process, and adsorption isotherm is type II;equilibrium adsorbance increases with the increase of ionic strength. Kinetic studies show that the kinetic data can be delineated by pseudo second-order kinetic model. Initial adsorption rate increases with the increase of temperature. Adsorption activation energy is less than 20 kJ/mol;physical adsorption is the major mode of the overall adsorption process.
