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1.
J Hazard Mater ; 263 Pt 2: 501-16, 2013 Dec 15.
Article in English | MEDLINE | ID: mdl-24231314

ABSTRACT

Cyclodextrin-ionic liquid polymer (ßCD-BIMOTs-TDI) was firstly synthesized using functionalized ß-Cyclodextrin (CD) with 1-benzylimidazole (BIM) to form monofunctionalized CD (ßCD-BIMOTs) and was further polymerized using toluene diisocyanate (TDI) linker to form insoluble ßCD-BIMOTs-TDI. SEM characterization result shows that ßCD-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 ßCD-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 ßCD-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 ßCD-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 ßCD-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.


Subject(s)
Chlorophenols/analysis , Cyclodextrins/chemistry , Polymers/analysis , Water Pollutants, Chemical/analysis , Adsorption , Diffusion , Dose-Response Relationship, Drug , Hot Temperature , Hydrogen-Ion Concentration , Ionic Liquids , Ions , Kinetics , Models, Chemical , Polymers/chemistry , Spectroscopy, Fourier Transform Infrared , Thermodynamics , Water Purification/methods , X-Ray Diffraction
2.
Philos Trans R Soc Lond B Biol Sci ; 366(1582): 3210-24, 2011 Nov 27.
Article in English | MEDLINE | ID: mdl-22006963

ABSTRACT

We present results from the OP3 campaign in Sabah during 2008 that allow us to study the impact of local emission changes over Borneo on atmospheric composition at the regional and wider scale. OP3 constituent data provide an important constraint on model performance. Treatment of boundary layer processes is highlighted as an important area of model uncertainty. Model studies of land-use change confirm earlier work, indicating that further changes to intensive oil palm agriculture in South East Asia, and the tropics in general, could have important impacts on air quality, with the biggest factor being the concomitant changes in NO(x) emissions. With the model scenarios used here, local increases in ozone of around 50 per cent could occur. We also report measurements of short-lived brominated compounds around Sabah suggesting that oceanic (and, especially, coastal) emission sources dominate locally. The concentration of bromine in short-lived halocarbons measured at the surface during OP3 amounted to about 7 ppt, setting an upper limit on the amount of these species that can reach the lower stratosphere.


Subject(s)
Air Pollution/analysis , Arecaceae/chemistry , Atmosphere/chemistry , Trees/chemistry , Agriculture , Arecaceae/physiology , Atmosphere/analysis , Borneo , Bromine/chemistry , Butadienes/chemistry , Carbanilides/analysis , Carbanilides/chemistry , Computer Simulation , Formaldehyde/chemistry , Hemiterpenes/chemistry , Malaysia , Nitrogen Oxides/chemistry , Oxidation-Reduction , Ozone/chemistry , Pentanes/chemistry , Trees/physiology , Tropical Climate , Volatile Organic Compounds/chemistry
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