The kinetics of adsorption and parameters of equilibrium adsorption of Methylene Blue（MB）on hybrid laponite-multi-walled carbon nanotube（NT）particles in aqueous suspensions were determined.The laponite platelets w...The kinetics of adsorption and parameters of equilibrium adsorption of Methylene Blue（MB）on hybrid laponite-multi-walled carbon nanotube（NT）particles in aqueous suspensions were determined.The laponite platelets were used in order to facilitate disaggregation of NTs in aqueous suspensions and enhance the adsorption capacity of hybrid particles for MB.Experiments were performed at room temperature（298 K）,and the laponite/NT ratio（Xl）was varied in the range of 0–0.5.For elucidation of the mechanism of MB adsorption on hybrid particles,the electrical conductivity of the system as well as the electrokinetic potential of laponite-NT hybrid particles were measured.Three different stages in the kinetics of adsorption of MB on the surface of NTs or hybrid laponite-NT particles were discovered to be a fast initial stage Ⅰ（adsorption time t=0–10 min）,a slower intermediate stage Ⅱ（up to t=120 min）and a long-lasting final stage Ⅲ（up to t=24 hr）.The presence of these stages was explained accounting for different types of interactions between MB and adsorbent particles,as well as for the changes in the structure of aggregates of NT particles and the long-range processes of restructuring of laponite platelets on the surface of NTs.The analysis of experimental data on specific surface area versus the value of Xl evidenced in favor of the model with linear contacts between rigid laponite platelets and NTs.It was also concluded that electrostatic interactions control the first stage of adsorption at low MB concentrations.展开更多
基金supported by National Academy Science of Ukraine(No.43/15H)
文摘The kinetics of adsorption and parameters of equilibrium adsorption of Methylene Blue（MB）on hybrid laponite-multi-walled carbon nanotube（NT）particles in aqueous suspensions were determined.The laponite platelets were used in order to facilitate disaggregation of NTs in aqueous suspensions and enhance the adsorption capacity of hybrid particles for MB.Experiments were performed at room temperature（298 K）,and the laponite/NT ratio（Xl）was varied in the range of 0–0.5.For elucidation of the mechanism of MB adsorption on hybrid particles,the electrical conductivity of the system as well as the electrokinetic potential of laponite-NT hybrid particles were measured.Three different stages in the kinetics of adsorption of MB on the surface of NTs or hybrid laponite-NT particles were discovered to be a fast initial stage Ⅰ（adsorption time t=0–10 min）,a slower intermediate stage Ⅱ（up to t=120 min）and a long-lasting final stage Ⅲ（up to t=24 hr）.The presence of these stages was explained accounting for different types of interactions between MB and adsorbent particles,as well as for the changes in the structure of aggregates of NT particles and the long-range processes of restructuring of laponite platelets on the surface of NTs.The analysis of experimental data on specific surface area versus the value of Xl evidenced in favor of the model with linear contacts between rigid laponite platelets and NTs.It was also concluded that electrostatic interactions control the first stage of adsorption at low MB concentrations.
