Browsing by Author "Wanichapichart, P."

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Polysulfone/N-phthaloylchitosan novel composite membranes for salt rejection application
(2011) Padaki, M.; Isloor, A.M.; Wanichapichart, P.
N-phthaloylchitosan (CS) was synthesized by the reaction of chitosan with phthalic anhydride in dimethyl formamide. Different compositions of polysulfone (PSf) and N-phthaloylchitosan were used to prepare novel polysulfone/N-phthaloylchitosan (PSf/CS) composite membranes by phase inversion method. The composition ratios between the former and the latter were 80:20, 85:15, 90:10, and 95:5. Water flux results revealed that, PSf:CS 80:20 membrane is found to have greatest effective pore area while PSf:CS 95:05 membrane has the smallest value. The pore area is found to be larger with the increase in CS composition. In addition, its water swelling property increases with the increase of CS composition. Water flux results are in consistent with dielectric constant value. Use of known molecular weight of polyethylene glycol rejection study, revealed that, PSf:CS 95:05 membrane possessed the smallest pore size among these membranes. In conclusion, change of ratio between PSf and CS, considerably affects membrane pore size and hydrophilicity. For salt filtration, membrane PSf:CS 95:05 showed 93%, 76.11% and 70.12% rejection of MgSO4, Na2SO4, and NaCl, respectively. 2011 Elsevier B.V.
Polysulfone/N-phthaloylchitosan novel composite membranes for salt rejection application
(2011) Padaki, M.; Isloor, A.M.; Wanichapichart, P.
N-phthaloylchitosan (CS) was synthesized by the reaction of chitosan with phthalic anhydride in dimethyl formamide. Different compositions of polysulfone (PSf) and N-phthaloylchitosan were used to prepare novel polysulfone/N-phthaloylchitosan (PSf/CS) composite membranes by phase inversion method. The composition ratios between the former and the latter were 80:20, 85:15, 90:10, and 95:5. Water flux results revealed that, PSf:CS 80:20 membrane is found to have greatest effective pore area while PSf:CS 95:05 membrane has the smallest value. The pore area is found to be larger with the increase in CS composition. In addition, its water swelling property increases with the increase of CS composition. Water flux results are in consistent with dielectric constant value. Use of known molecular weight of polyethylene glycol rejection study, revealed that, PSf:CS 95:05 membrane possessed the smallest pore size among these membranes. In conclusion, change of ratio between PSf and CS, considerably affects membrane pore size and hydrophilicity. For salt filtration, membrane PSf:CS 95:05 showed 93%, 76.11% and 70.12% rejection of MgSO4, Na2SO4, and NaCl, respectively. © 2011 Elsevier B.V.
Preparation and characterization of sulfonated polysulfone and N-phthloyl chitosan blend composite cation-exchange membrane for desalination
(2012) Padaki, M.; Isloor, A.M.; Wanichapichart, P.; Ismail, A.F.
Sulfonated polysulfone (sPSf) was prepared and used as a polymer matrix for cation-exchange membranes (CEM). The sulfonation reaction was carried out at room temperature and the degree of sulfonation was calculated by titration method. Blend composite membranes were prepared using different ratios of sPSf and modified chitosan (CS). Membrane properties were studied in terms of water flux, water swelling ratio, molecular weight cut off (MWCO), ion-exchange capacity (IEC) and contact angle measurement. Charge on the membrane was confirmed by ionic diffusion potential (DP). It was observed that, DP increased with the increase in the concentration of sPSf. The membrane sPSf:CS 60:40 showed 1000Da MWCO, 14.6mV diffusion potential (DP) and 0.083mM/g of IEC. Similarly sPSf:CS 90:10 showed 10,000Da MWCO, 71.7mV diffusion potential (DP) and 0.176mM/g of IEC. Moreover, membrane sPSf:CS 60:40 showed 93%, 89% and 69% for MgSO 4, Na 2SO 4 and NaCl rejection respectively. 2012 Elsevier B.V.
Preparation and characterization of sulfonated polysulfone and N-phthloyl chitosan blend composite cation-exchange membrane for desalination
(2012) Padaki, M.; Isloor, A.M.; Wanichapichart, P.; A.F., A.F.
Sulfonated polysulfone (sPSf) was prepared and used as a polymer matrix for cation-exchange membranes (CEM). The sulfonation reaction was carried out at room temperature and the degree of sulfonation was calculated by titration method. Blend composite membranes were prepared using different ratios of sPSf and modified chitosan (CS). Membrane properties were studied in terms of water flux, water swelling ratio, molecular weight cut off (MWCO), ion-exchange capacity (IEC) and contact angle measurement. Charge on the membrane was confirmed by ionic diffusion potential (DP). It was observed that, DP increased with the increase in the concentration of sPSf. The membrane sPSf:CS 60:40 showed 1000Da MWCO, 14.6mV diffusion potential (DP) and 0.083mM/g of IEC. Similarly sPSf:CS 90:10 showed 10,000Da MWCO, 71.7mV diffusion potential (DP) and 0.176mM/g of IEC. Moreover, membrane sPSf:CS 60:40 showed 93%, 89% and 69% for MgSO 4, Na 2SO 4 and NaCl rejection respectively. © 2012 Elsevier B.V.
Synthesis and desalination performance of Ar+-N+ irradiated polysulfone based new NF membrane
(2011) Hegde, C.; Isloor, A.M.; Padaki, M.; Wanichapichart, P.; Liangdeng, Y.
In the last few years, membrane technology has gained more attention from polymer chemists throughout the globe. Nowadays, surface modification of membrane is very useful in biotechnology and food science. In the present investigation, we have synthesized polysulfone based composite nanofiltration (NF) membranes, and characterized these membranes by FT-IR, SEM and membrane performance studies. Surface plasma treatment was carried out by irradiation with argon and nitrogen beams in suitable conditions. It was observed that nitrogen beam caused surface roughness that was more severe than the Ar beam. After irradiation, water contact angle was slightly increased. For pure water permeability, flux increased linearly with the operating pressure. However, for the salt solution, the flux was decreased marginally and salt rejection increased after irradiation due to surface modification. The modification effect was characterized in terms of contact angle, AFM employed roughness measurement and dielectric property. It revealed that irradiated NF membranes showed higher salt rejection and lower flux as compared to the nonmodified membranes. Accordingly, the roughness of the membrane surface intensively affected the performance of RO membrane. 2010 Elsevier B.V.
Synthesis and desalination performance of Ar+-N+ irradiated polysulfone based new NF membrane
(2011) Hegde, C.; Isloor, A.M.; Padaki, M.; Wanichapichart, P.; Liangdeng, Y.
In the last few years, membrane technology has gained more attention from polymer chemists throughout the globe. Nowadays, surface modification of membrane is very useful in biotechnology and food science. In the present investigation, we have synthesized polysulfone based composite nanofiltration (NF) membranes, and characterized these membranes by FT-IR, SEM and membrane performance studies. Surface plasma treatment was carried out by irradiation with argon and nitrogen beams in suitable conditions. It was observed that nitrogen beam caused surface roughness that was more severe than the Ar beam. After irradiation, water contact angle was slightly increased. For pure water permeability, flux increased linearly with the operating pressure. However, for the salt solution, the flux was decreased marginally and salt rejection increased after irradiation due to surface modification. The modification effect was characterized in terms of contact angle, AFM employed roughness measurement and dielectric property. It revealed that irradiated NF membranes showed higher salt rejection and lower flux as compared to the nonmodified membranes. Accordingly, the roughness of the membrane surface intensively affected the performance of RO membrane. © 2010 Elsevier B.V.