Removal of 2,4-dichlorophenol using cyclodextrin-ionic liquid polymer as a macroporous material: characterization, adsorption isotherm, kinetic study, thermodynamics.
Cyclodextrin-ionic liquid polymer (βCD-BIMOTs-TDI) was firstly synthesized using functionalized β-Cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (βCD-BIMOTs) and was further polymerized using toluene diisocyanate (TDI) linker to form insoluble βCD-BIMOTs-TDI. SEM characterization result shows that βCD-BIMOTs-TDI exhibits macropore size while the BET result shows low surface area (1.254 m(2)g(-1)). The unique properties of the ILs allow us to produce materials with different morphologies. The adsorption isotherm and kinetics of 2,4-dichlorophenol (2,4-DCP) onto βCD-BIMOTs-TDI is studied. Freundlich isotherm and pseudo-second order kinetics are found to be the best to represent the data for 2,4-DCP adsorption on the βCD-BIMOTs-TDI. The presence of macropores decreases the mass transfer resistance and increases the adsorption process by reducing the diffusion distance. The change in entropy (ΔS°) and heat of adsorption (ΔH°) for 2,4-DCP on βCD-BIMOTs-TDI were estimated as -55.99 J/Kmol and -18.10 J/mol, respectively. The negative value of Gibbs free energy (ΔG°) indicates that the adsorption process is thermodynamically feasible, spontaneous and chemically controlled. Finally, the interactions between the cavity of βCD-BIMOTs and 2,4-DCP are investigated and the results shows that the inclusion of the complex formation and π-π interaction are the main processes involved in the adsorption process.
University of Malaya Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia; Advanced Medical & Dental Institute, University of Science Malaysia, No. 1-8 (Lot 8), Persiaran Seksyen 4/1, Bandar Putra Bertam, Kepala Batas, Pulau Pinang 13200, Malaysia.
Muggundha
M
Raoov
Sharifah
S
Mohamad
Mohd Radzi
MR
Abas
D000327:Adsorption; D002733:Chlorophenols / Q000032:analysis*; D003505:Cyclodextrins / Q000737:chemistry*; D004058:Diffusion; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids; D007477:Ions; D007700:Kinetics; D008956:Models, Chemical; D011108:Polymers / Q000032:analysis* / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction
D002733:Chlorophenols; D003505:Cyclodextrins; D052578:Ionic Liquids; D007477:Ions; D011108:Polymers; D014874:Water Pollutants, Chemical; C004762:2,4-dichlorophenol
Adsorption; Cyclodextrin; Ionic liquid; Phenol