title: The kinetic and thermodynamic sorption and stabilization of multiwalled carbon nanotubes in natural organic matter surrogate solutions: the effect of surrogate molecular weight.
abstract: Styrene sulfonate (SS) and polystyrene sulfonates (PSSs) were used as surrogates of natural organic matter to study the effect of molecular weight (from 206.2 to 70,000 Da) on their sorption by a multiwalled carbon nanotube (MWCNT) and an activated carbon (AC) and on their stabilization of MWCNT suspension. Results indicate that surface-diffusion through the liquid-sorbent boundary was the rate-controlling step of the kinetic sorption of both MWCNTs and AC, and surface-occupying and pore-filling mechanisms respectively dominated the thermodynamic sorption of MWCNTs and AC. Sorption rates and capacities of MWCNTs and AC in molecular concentration of SS and PSS decreased with increasing molecular weight. The PSSs but not SS facilitated the stabilization of MWCNT suspension because of the increased electrosteric repulsion. The PSSs with more monomers had greater capabilities to stabilize the MWCNT suspension, but the capabilities were comparable after being normalized by the total monomer number.
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China. Electronic address: lindaohui@zju.edu.cn.
authors.forename: Daohui
authors.initials: D
authors.lastname: Lin
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: wufengchang@vip.skleg.cn.
authors.forename: Fengchang
authors.initials: F
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D002606:Charcoal; D007700:Kinetics; D008956:Models, Chemical; D008970:Molecular Weight; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012996:Solutions; D013343:Styrenes / Q000737:chemistry; D013535:Suspensions; D013816:Thermodynamics
chemical_list: D037742:Nanotubes, Carbon; D011137:Polystyrenes; D012996:Solutions; D013343:Styrenes; D013535:Suspensions; D002606:Charcoal; C003321:polystyrene sulfonic acid
keywords: Activated carbon; Adsorption; Carbon nanotube; Polystyrene sulfonate; Suspension