Faculty Publications
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Item Carbon-based nanocomposite membranes for water and wastewater purification(Elsevier, 2018) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Yuliwati, E.; A.F., A.F.The carbon-based nanocomposite membranes are developing core technology for water and wastewater purification. These materials are broadly used in the fabrication of ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO) and evolving forward osmosis (FO) nanocomposite membranes as an additive. In this chapter, performance enhancement of nanocomposite membranes using carbon nanotubes (CNTs) and graphene oxide (GO), especially in the field of desalination, dye removal, oil/water separation and natural organic matter removal, is discussed. © 2019 Elsevier Inc. All rights reserved..Item A review on RO membrane technology: Developments and challenges(Elsevier B.V., 2015) Shenvi, S.S.; Isloor, A.M.; A.F., A.F.Reverse osmosis (RO) based desalination is one of the most important and widely recognized technologies for production of fresh water from saline water. Since its conception and initiation, a significant development has been witnessed in this technology w.r.t. materials, synthesis techniques, modification and modules over the last few decades. The working of a RO plant inclusive of the pretreatment and post-treatment procedures has been briefly discussed in the article. The main objective of this review is to highlight the historical milestones achieved in RO technology in terms of membrane performance, the developments seen over the last few years and the challenges perceived. The material properties of the membrane dominate the performance of a RO process. The emergence of nano-technology and biomimetic RO membranes as the futuristic tools is capable of revolutionizing the entire RO process. Hence the development of nano-structured membranes involving thin film nano-composite membranes, carbon-nanotube membranes and aquaporin-based membranes has been focussed in detail. The problems associated with a RO process such as scaling, brine disposal and boron removal are briefed and the measures adopted to address the same have been discussed. © 2014 Elsevier B.V.Item Synthesis, characterization and desalination study of novel PSAB and mPSAB blend membranes with Polysulfone (PSf)(2012) Padaki, M.; Isloor, A.M.; A.F., A.F.; Abdullah, M.S.The present paper describes the synthesis of poly sulphonyl amino benzamide (PSAB) and methyalated poly sulphonyl amino benzamide (mPSAB) polymer, using terephthalic acid chloride and substituted 4-amino-1-benzensulphonmide in N-methyl-. 2-pyrrolidone. Polymers were characterized by FT-IR, NMR and GPC. Polysulfone composite membranes were prepared using these novel poymers by DIPS (Diffusion Induced Phase Seperation) method. These composite membranes are useful for water purification with special emphasis on sea water desalination. Newly prepared membranes were studied for salt rejection, water flux, molecular weight cut off by PEG solution, effect of the pH on water swelling and salt rejection and flux decline was also studied. 30 to 70% of the salt rejection was observed in all membranes. Effect of the dilution on salt rejection was studied using different concentration of NaCl solution varying from 1000. ppm to 3500. ppm. All the membranes showed 80% rejection for PEG having 1000. Da molecular weight. Contact angle and water swelling was measured to determine hydrophilicity of the membrane. Water swelling and salt rejection in different pH was also studied. © 2012 Elsevier B.V.Item 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.Item Synthesis, characterization and desalination study of composite NF membranes of novel Poly[(4-aminophenyl)sulfonyl]butanediamide (PASB) and methyalated Poly[(4-aminophenyl)sulfonyl]butanediamide (mPASB) with Polysulfone (PSf)(2013) Padaki, M.; Isloor, A.M.; Kumar, R.; A.F., A.F.; Matsuura, T.In the present investigation, Poly [(4-aminophenyl)sulfonyl]butanediamide (PASB) and methylated Poly[(4-aminophenyl)sulfonyl] butanediamide (mPASB) polymers were synthesized, using succinyl chloride and substituted 4-amino-1-benzenesulphonamide. Polysulfone composite membranes were prepared by blending these novel polymers by Diffusion Induced Phase Separation (DIPS) method. The performance of the membrane was studied in terms of salt rejection, water flux and molecular weight cutoff. The prepared membranes were hydrophilic in nature, which was confirmed by water uptake studies and contact angle measurement. All the membranes showed 1000. Da molecular weight cutoff. A maximum NaCl rejection of 52% was observed in some of the membranes. The effect of feed NaCl concentration on the NaCl rejection was also studied. The resistance of the membranes in a wide pH range was studied by water uptake measurement. Antifouling properties of the membranes were also performed using Bovine Serum Albumin (BSA) solution. © 2012 Elsevier B.V.Item Studies on copper coated polysulfone/modified poly isobutylene alt-maleic anhydride blend membrane and its antibiofouling property(2013) Isloor, A.M.; Ganesh, B.M.; Isloor, S.; A.F., A.F.; Nagaraj, H.S.; Pattabi, M.As nanofiltration is gaining more and more importance in the field of desalination, one has to address the many obstacles in order to achieve effective/efficient filtration. One such issue is biofouling and microbial attack to the membrane. This paper describes about the study on copper coating onto the membrane surface as biofouling protective layer. This is an attempt to come up with a new approach for desalination and an antimicrobial membrane. The work indicates that, the copper coated membrane can resist the possible microbial attack to some extent while maintaining good salt rejection and appreciable flux. SEM and EDX studies had shown the distribution of copper on the membrane surface. The copper coated membrane had shown the maximum salt rejection of about 96% for 3500ppm NaCl solution and also it had shown the pure water flux of 36Lm-2h-1. © 2012 Elsevier B.V.Item Permeation, Antifouling and desalination performance of TiO2 nanotube incorporated PSf/CS blend membranes(2013) Kumar, R.; Isloor, A.M.; A.F., A.F.; Abdul Rashid, S.A.; Ahmed, A.A.Polysulfone (PSf) and chitosan (CS) blend membranes were prepared by incorporating titanium dioxide nanotubes (TiO2NT) in different compositions. The proper blending of PSf and CS in the PSf/CS/TiO2 membranes was confirmed by ATR-IR spectroscopy. The influence of nanotubes on morphology of membranes was investigated by Field Emission Scanning Electron Microscopy (FESEM). The effect of nanotubes on hydrophilicity of the membranes was studied by water swelling and contact angle measurements. The distribution of TiO2NT on the membrane surface was determined by Transmission Electron Microscope (TEM) analysis. The permeation property of PSf/CS/TiO2NT membranes was carried out by measuring the time dependent pure water flux (PWF). Bovine serum albumin (BSA) protein rejection studies were performed to know the antifouling properties. The rheological percolation threshold of PSf/CS/TiO2NT solutions was measured by viscosity studies. The nanotubes incorporated PSf/CS membranes showed enhanced permeation and antifouling properties compared to PSf/CS and nascent PSf ultrafiltration membranes. Membranes prepared well above rheological percolation threshold showed drastic reduction in pore size and acted as nanofiltration (NF) membranes. © 2013 Elsevier B.V.Item Modification of PSf/PIAM membrane for improved desalination applications using Chitosan coagulation media(2013) Kumar, R.; A.F., A.F.; Kassim, M.A.; Isloor, A.M.Polysulfone (PSf)/poly (isobutylene-alt-maleic anhydride) (PIAM) nanofiltration membranes were modified by changing the coagulation bath with various concentrations of glutaraldehyde cross-linked Chitosan solutions. Further the membranes were treated with 0.1N NaOH solution in order to achieve the hydrolysis of PIAM. The morphological changes of the membranes were determined using scanning electron microscope. The blending of PSf/PIAM membrane, the incorporation of Chitosan (CS) molecules in membrane matrix and the hydrolysis of PIAM in the membrane upon alkali treatment were studied by Attenuated Total Reflectance Infra Red (ATR-IR) spectroscopy. The hydrophilicity of modified membranes was measured using the contact angle analyzer. The pressure and time dependent pure water flux of modified PSf/PIAM/CS membranes were measured and compared with PSf/PIAM membranes (after alkali treatment). The antifouling property of membranes was determined using Bovine Serum Albumin (BSA) protein rejection studies. The modified membranes showed improved hydrophilicity and reduced pore size. The order of rejection of membranes for various electrolytes was Na2SO4>MgSO4>NaCl at minimum pressure of 0.2MPa TMP. The antifouling property of modified membranes increased with an increase in the composition of Chitosan in coagulation bath and membrane M-0.8 showed a maximum fouling resistance ratio of 74%. © 2013 Elsevier B.V.Item Improved desalination by polyamide membranes containing hydrophilic glutamine and glycine(Springer Science and Business Media Deutschland GmbH, 2019) Kolangare, I.M.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; A.F., A.F.Water desalination and recycling of wastewater is a key challenge to meet water shortage issues. Thin film composite polyamide membranes are widely used for desalination; however, their low permeability due to a poor hydrophilicity is a major drawback. Here, we designed novel thin film composite membranes having good hydrophilicity, permeability, and stability without compromising solute rejection. We improved the membrane hydrophilicity by incorporation of hydrophilic additives, such as glycine and l-glutamine, into the polyamide layer. Hence polyamide-based flat sheet membranes were fabricated via interfacial polymerization of m-phenylenediamine and trimesoyl chloride and then were coated over a polysulfone/sulfonated polyphenylsulfone (85:15) support. Polyamide membranes were then characterized and tested for desalination. Results show that the ridge and valley structure observed by scanning electron microscopy confirms the formation of the polyamide layer on membrane surface. The performance reached the highest pure water flux of 36.23 Lm?2 h?1 and flux recovery ratio of 89.18% for membranes with 2 wt% of l-glutamine. Incorporation of 2 wt% l-glutamine induced a high permeate flux and a maximum rejection of 87.87% for MgSO4, 83.50% for Na2SO4 and 60.77% for NaCl solutions. Overall, the polyamide nanofiltration membrane with hydrophilic groups displayed superior antifouling property and can be used as a potential candidate for desalination. © 2018, Springer Nature Switzerland AG.