Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
11 results
Search Results
Item Synthesis, characterization and nonlinear optical properties of 2-[(E)-2-(4-ethoxyphenyl)ethenyl]-1-methylquinolinium 4-substitutedbenzenesulfonate compounds(2010) Ruanwas, P.; Kobkeatthawin, T.; Chantrapromma, S.; Fun, H.-K.; Philip, R.; Smijesh, N.; Padaki, M.; Isloor, A.M.In the present investigation, 2-[(E)-2-(4-ethoxyphenyl)ethenyl]-1-methylquinolinium 4-substituted benzenesulfonate (X = CH3 (1), X = OCH3 (2), X = Cl (3), X = Br (4)) have been synthesized and characterized by 1H NMR, UV-Vis and FT-IR spectroscopy methods. In addition compound 3 was also characterized by single crystal X-ray diffraction (XRD) and found that it crystallized out in the monoclinic space group P21 with cell parameters, a = 9.8072(9) Å, b = 6.4848(5) Å, c = 19.4405(16) Å, ? = 90°, ? = 103.421(5)°, ? = 90°, z = 2 and V = 1202.61(17) Å3. The nonlinear optical absorption of the samples has been studied at 532 nm using 5 ns laser pulses, employing the open-aperture z-scan technique. It is found that some of the samples are potential candidates for optical limiting applications. © 2009 Elsevier B.V. All rights reserved.Item New CPS-PPEES blend membranes for CaCl2 and NaCl rejection(Techno Press technop2@chollian.net, 2012) Hegde, C.; Isloor, A.M.; Padaki, M.; A.F., A.F.; Lau, L.W.Carboxylated polysulfone (CPS), poly (1,4-phenylene ether ethersulfone) (PPEES), membranes were prepared and used for the separation of NaCl and CaCl2 in efficient way with less energy consumption. In this work, nanofiltration and reverse osmosis membranes were employed to the salt rejection behavior of the different salt solutions. The influence of applied pressure (1-12 bar), on the membrane performance was assessed. In CM series of membranes, CM1 showed maximum of 97% water uptake and 36% water swelling, whereas, CM4 showed 75% water uptake and 28% water swelling. In RCM series, RCM1 showed 85% water uptake and 32% water swelling whereas, in RCM4 it was 68% for water uptake and 20% for water swelling. Conclusively reverse osmosis membranes gave better rejection whereas nanofiltration membrane showed enhanced flux. CM1 showed 58% of rejection with 12L/(m2h) flux and RCM1 showed 55% of rejection with 15L/(m2h) flux for 0.1wt.% NaCl solution. Whereas, in 0.1wt.% CaCl22 solution, membrane CM11 showed 78% of rejection with 12L/(m2h) flux and RCM1 showed 63% rejection with flux of 9L/(m2h).Item Synthesis and characterization of schiff base metal complexes and reactivity studies with malemide epoxy resin(Korean Chemical Society sunlee@kcsnet.or.kr, 2012) Lakshmi, B.; Shivananda, K.N.; Prakash, G.A.; Isloor, A.M.; Mahendra, K.N.A novel malemide epoxy containing Co(II), Ni(II) and Cu(II) ions have been synthesized by curing malemide epoxy resin (MIEB-13) and Co(II), Ni(II) and Cu(II) complexes of macrocyclic bis-hydrazone Schiff base. The Schiff base was synthesized by reacting 1,4-dicarbnyl phenyl dihydrazide with 2,6-diformyl-4-methyl phenol. The Schiff base and its Co(II), Ni(II) and Cu(II) complexes have been characterized by elemental analyses, spectral (IR, 1H NMR, UV-vis., FAB mass, ESR), thermal and magnetic data. The curing reaction of maleimide epoxy compound with metal complexes was studied as curing agents. The stability of cured samples was studied by thermo-gravimetric analyses and which have excellent chemical (acid/alkali/solvent) and water absorption resistance. Further, the scanning electron microscopy (SEM) and definitional scanning colorimetric (DSC) techniques were confirmed the phase homogeneity of the cured systems.Item Antifouling and performance enhancement of polysulfone ultrafiltration membranes using CaCO3 nanoparticles(2013) Nair, A.K.; Isloor, A.M.; Kumar, R.; A.F., A.F.Calcium carbonate nanoparticles were synthesized from calcium nitrate via chemical precipitation method. The nanoparticles were characterized using scanning electron microscope (SEM), Attenuated total reflectance infra red (ATR-IR) spectrum and by X-ray diffraction (XRD). These nanoparticles were used as additive for polysulfone (PSf) ultrafiltration membrane along with polyethylene glycol (PEG) as pore forming agent. The PSf hybrid membranes were characterized by ATR-IR, XRD, and SEM studies. ATR-IR and XRD results indicated the successful incorporation of the nanoparticles in the membranes. Cross sectional images of the membranes along with the elemental mapping of calcium on the membrane surface were assessed using SEM. Hydrophilicity of the membranes was evaluated in terms of contact angle measurements. The permeability of the membranes was determined by measuring the pure water flux (PWF). Membranes were also subjected to antifouling studies using bovine serum albumin (BSA) as the standard protein for rejection. The membranes showed better permeability and antifouling property with the increased addition of CaCO3 nanoparticles. © 2013 Elsevier B.V.Item Synthesis and characterization of novel water soluble derivative of Chitosan as an additive for polysulfone ultrafiltration membrane(2013) Kumar, R.; Isloor, A.M.; A.F., A.F.; Matsuura, T.A novel water soluble Chitosan derivative N-propylphosphonic Chitosan (NPPCS) having a terminal phosphonic acid group was synthesized by reacting Chitosan with Hydroxybenzotriazole (HOBt) and propylphosphonic anhydride (T3P)® via one pot reaction. The novel derivative was characterized by 1H NMR, Attenuated Total Reflectance Infra Red (ATR-IR) spectroscopy and XRD. Due to insolubility of NPPCS in organic solvents, a new process was demonstrated for blending of NPPCS with Polysulfone. The proper blending of NPPCS with Polysulfone was confirmed by ATR-IR spectroscopy. The improved hydrophilicity of PSf/NPPCS membranes was confirmed by contact angle measurement. The permeation studies showed increased flux of PSf/NPPCS membranes as compared to the pristine Polysulfone membrane. The antifouling property of PSf/NPPCS membrane was determined by Bovine Serum Albumin (BSA) protein rejection studies. The membranes showed the enhanced antifouling property as compared to pristine Polysulfone membranes with a maximum of 74% flux recovery ratio (FRR) value. © 2013 Elsevier B.V.Item 1,3,4-Trisubstituted pyrazole bearing a 4-(chromen-2-one) thiazole: Synthesis, characterization and its biological studies(Royal Society of Chemistry, 2015) Harikrishna, N.; Isloor, A.M.; Kulal, K.; AlObaid, A.; Fun, H.-K.A new series 3-{2-[N?-(1,3-disubstituted-1H-pyrazol-4-yl-methylene)-hydrazino]-thiazol-4-yl}-chromen-2-one (10a-l) was synthesized by a multi-step reaction. All the synthesized compounds were characterized by IR, NMR, and mass spectral studies, followed by elemental analysis. The newly synthesized thiazole compounds were screened for their in vitro antibacterial and antifungal studies against various microorganisms. Antimicrobial studies carried out by the well diffusion method, showed a very good zone of inhibition for both bacteria (at a range of 20-50 mm diameter) and fungi (at a range of 10-30 mm diameter). Minimum Inhibitory Concentration (MIC) required for the 100% inhibition of bacteria and fungi was found to be as low as 15.6 ?g ml-1 for a few of the synthesized compounds. © The Royal Society of Chemistry 2015.Item Synthesis and in vitro biological evaluation of new pyrazole chalcones and heterocyclic diamides as potential anticancer agents(Elsevier B.V., 2015) Sankappa Rai, U.; Isloor, A.M.; Shetty, P.; Pai, K.S.R.; Fun, H.-K.Synthesis and characterization of new heterocyclic pyrazole chalcones (4a-. e) and diamide (6a-. e) derivatives are described. Pyrazole chalcones were synthesized by the reaction of pyrazole aldehydes and suitable aromatic ketones. Diamides were synthesized by the reaction of phthalic acid and amines. Newly synthesized compounds were characterized by spectral studies and their biological activity was assessed in vitro using MCF-7 (human breast adenocarcinoma) and HeLa (human cervical tumor cells) cell lines. Few of the synthesized molecules inhibited the growth of the human breast cancer cell lines and human cervical tumor cell lines at low micromolar to nanomolar concentrations. © 2014 King Saud University.Item Antibiofouling hollow-fiber membranes for dye rejection by embedding chitosan and silver-loaded chitosan nanoparticles(Springer Verlag, 2019) Kolangare, I.M.; Isloor, A.M.; Zulhairun, Z.A.; Kulal, A.; A.F., A.F.; Siddique, I.; Asiri, A.M.The removal of toxic dyes from the wastewater and industrial effluents is a major environmental challenge. Various techniques have been employed for the removal of dyes, including the application of nano-sized adsorbents, nanocomposite membranes and photodegradation. Membrane filtration is an alterntive but suffers from drawbacks such as fouling. Here we present a simple approach for the development of antibiofouling membranes based on chitosan. The application of chitosan-based nanoparticles as additives for wastewater treatment is poorly explored. The chitosan and silver-loaded chitosan nanoparticles were synthesized by ionic gelation method and incorporated to fabricate hollow-fiber membranes by dry–wet spinning technique. The prepared membranes were characterized by morphological study, permeability test, antibiofouling study and dye rejection study. The nanocomposite hollow-fiber membranes displayed superior performance than their pristine form. The incorporation of 0.30 weight percent of the chitosan and silver-loaded chitosan nanoparticles into the hollow-fiber membranes enhanced the antifouling property with flux recovery ratio of 81.21 and 86.13%, respectively. The dye rejection results showed maximum rejection of 89.27 and 86.04% for Reactive Black 5 and Reactive Orange 16, respectively. Hence, it can be concluded that hollow-fiber membranes with silver-loaded chitosan nanoparticles are pertinent in developing antibiofouling membranes for the treatment of industrial dye effluents. © 2018, Springer Nature Switzerland AG.Item Integration of Zwitterionic Polymer Nanoparticles in Interfacial Polymerization for Ion Separation(American Chemical Society, 2020) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Bavarian, M.; Nejati, S.A thin-film nanocomposite (TFN) membrane was developed by integrating zwitterionic polymeric nanoparticles into the active layer of the membranes. High surface area zwitterionic polymeric nanoparticles (370 m2/g) were developed through distillation-precipitation polymerization (DPP). Sodium 4-vinylbenzenesulfonate (SVBS) was used as the monomer and N,N?-methylenebis(acrylamide) (MBAAm) utilized as the cross-linking agent. l-cysteine (l-Cys) was tethered to these matrices through thiol-ene reaction. The as-synthesized zwitterionic P(MBAAm-co-SVBS)@l-Cys nanoparticles were dispersed into the organic solution of trimesoyl chloride (TMC) to be integrated into the polyamide (PA) selective layer of thin film nanofiltration membranes. The PA layer was synthesized by interfacial polymerization through the reaction of 2% (w/v) of piperazine (PIP) in the aqueous phase and 0.15% (w/v) of the TMC solution. The fabricated TFN membranes exhibited pure water permeability (Jw) of 11.4 L/m2h bar and salt rejection value of 97.6% and 16.9%, for sodium sulfate and sodium chloride, respectively. The fabricated membranes demonstrated metal ion removal efficiencies of 99.48% and 95.67% for Pb2+ and Cd2+ ions, respectively. © © 2020 American Chemical Society.Item Tuning the surface properties of Fe3O4 by zwitterionic sulfobetaine: application to antifouling and dye removal membrane(Springer, 2020) Gnani Peer Mohamed, G.P.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; Farnood, R.In this paper, zwitterionic polysulfobetaine@Fe3O4 (PSBMA@Fe3O4) nanoparticles were synthesized via covalent grafting and free radical polymerization and characterized. The PSBMA@Fe3O4 noparticles had a zeta potential of ? 36 mV (pH 6.3), which guaranteed the high colloidal stability. The as-synthesized nanoparticles were employed as a nanofiller to prepare superior antifouling polysulfone hybrid hollow fiber membranes. The FM-2 membrane exhibited the maximum pure water permeability of 61.1 L/m2 h bar with humic acid (HA) removal efficiency of 98%. The fouling resistance was evaluated using HA as a foulant, and the results suggested that the FM-2 membrane had less amount of HA adsorption with flux recovery ratio of 88.4%. Furthermore, the FM-2 membrane was demonstrated the reactive black-5 and reactive orange-16 removal of above 99% and 84% without much reduction in the dye solution permeability. © 2020, Islamic Azad University (IAU).