Faculty Publications
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Item Membrane technology—a promising approach for metal ion extraction(Elsevier, 2024) Antony, N.; Vijesh, A.M.; Isloor, A.M.Metal ion extraction using ion exchange membranes (IEM) receives much attention as it can find a solution to environmental problems to reduce emissions of heavy metals from wastewater contaminated with industrial effluents. Among the various IEM available, cation exchange membranes are widely used by researchers due to its enhanced ability to hold the metal ion and retain them in the organic phase. This review book chapter emphasizes the extraction of metal ions, specifically about the studies carried out in the field of iron, zinc, and copper metal ions using IEM. © 2024 Elsevier Inc. All rights reserved.Item Advances of membrane technology in wastewater treatment(Elsevier, 2024) Deepthi, P.V.; Viji, K.; Vijesh, A.M.; Isloor, A.M.; Kumar, V.Pure water scarcity is becoming a real threat to the modern world. Rapid growth in the textile, paper, and printing industries has caused the production of large quantities of dye effluents, and they must be treated before passing to the water bodies or lands to minimize pollution and environmental impacts. Polymeric membrane-based filtration has been established as an optimal and greener approach for removing hazardous dyes from polluted water. Superior thermal, chemical, and mechanical properties and convenient modifiability made polysulfone (PSF), polyethersulfone (PES), and polyphenylsulfone (PPSU) ideal for the production of membranes for the treatment of dye effluents from industries. This chapter emphasizes the recent developments in modified PSF, PES, and PPSU membranes and their dye rejection properties. © 2025 Elsevier Inc. All rights reserved.Item Nonporous polymeric membranes for biohydrogen purification(Elsevier, 2025) Mendonca, N.R.; Isloor, A.M.; A.F., A.F.Biohydrogen generated from biomass is a clean form of hydrogen. The dark fermentation process for the generation of biohydrogen gives a mixture of H2 and CO2 from which biohydrogen needs to be purified. From the available methods for biohydrogen purification, membrane technology is the most viable since it is less energy-intensive and can be combined easily with other processes. Both polymeric as well as inorganic membranes are employed in gas separation processes. Of these, nonporous polymeric membranes are economically viable and are hence used in large-scale gas separations. The use of nonporous polymeric membranes, composed of polymers like polybenzimidazole, polyimide, and polysulfone, for biohydrogen purification is an ongoing area of research which can help to generate hydrogen for use in hydrogen fuel cells, hence reducing the dependence on fossil fuels which pollute the environment. © 2026 Elsevier Inc. All rights reserved.Item Stimulus response experiments are conducted in four different rectangular columns having two and three spout cells. A pink-coloured polymer material is used as bed material with ambient air as the spouting fluid. A pulse input of dark blue colour polymer material is used as the stimulus, when the column is operating under steady flow conditions, and the response measured. A mathematical model 'plug flow-mixed flow in series' is used to fit the experimental data and the model parameters are evaluated.(Can Soc for Chem Eng, Mixing behaviour of solids in multiple spouted beds) Saidutta, M.B.; Murthy, D.V.R.2000Item Studies on nonlinear optical parameters of bis-chalcone derivatives doped polymer(Elsevier BV, 2006) Shettigar, S.; Chandrasekharan, K.; Umesh, G.; Sarojini, B.K.; Narayana, B.Two bis-chalcone derivatives, 1,5-[di(4-methoxyphenyl)]penta-1,4-dien-3-one and 1,5-[di(4-chlorophenyl)]penta-1,4-dien-3-one were synthesized. Their SHG conversion efficiencies are reported to be 6.0 and 5.0 times that of urea and hyper polarizabilities are 9.9×10-30 and 10.2×10-30 esu, respectively. The third-order nonlinear optical properties in PMMA matrix were studied by Z-scan technique using 7 ns laser pulses at 532 nm. The nonlinear refractive index ?, nonlinear absorption coefficient ?, magnitude of effective third order susceptibility ?(3) and the coupling factor ? have been investigated. The values obtained are of the order of 10-14 cm2/W, 1.2 cm/GW, 10-14 esu and 0.2, respectively, which are comparable with the values obtained in stilbazoleum like dyes. The experimental investigation also shows that they are very interesting optical limiting materials and their optical limiting behaviour is mainly due to two photon absorption phenomenon. © 2006 Elsevier Ltd. All rights reserved.Item Biodegradability of PMMA blends with some cellulose derivatives(2006) Bhat, D.K.; Muthu, M.S.High polymer blends of Polymethyl methacrylate (PMMA) with cellulose acetate (CA) and Cellulose acetate phthalate (CAP) of varying blend compositions have been prepared to study their biodegradation behavior and blend miscibility. Films of PMMA-CA, and PMMA-CAP blends have been prepared by solution casting using Acetone and Dimethyl formamide(DMF) as solvents respectively. Biodegradability of these blends has been studied by four different methods namely, soil burial test, enzymatic degradation, and degradation in phosphate buffer and activated sludge degradation followed by water absorption tests to support the degradation studies. Degradation analysis was done by weight loss method. The results of all the tests showed sufficient biodegradability of these blends. Degradability increased with the increase in CA and CAP content in the blend compositions. The miscibility of PMMA-CA and PMMA-CAP blends have been studied by solution viscometric and ultrasonic methods. The results obtained reveal that PMMA forms miscible blends with either CA or CAP in the entire composition range. Miscibility of the blends may be due to the formation of hydrogen bond between the carbonyl group of PMMA and the free hydroxyl group of CA and CAP. © Springer Science+Business Media, Inc. 2006.Item Continuous phenol removal using Nocardia hydrocarbonoxydans in spouted bed contactor: Shock load study(2009) Dabhade, M.A.; Saidutta, M.B.; Murthy, D.V.R.Shock load studies are essential to investigate the suitability of biocontactors in degradation of pollutants. In the present work, the degradation of phenol by immobilized Nocardia hydrocarbonoxydans in a spouted bed contactor was conducted. Granular activated carbon (GAC) and polymer beads were tested for the immobilization of cells of N. hydrocarbonoxydans-NCIM 2386. Initially, batch immobilization study was conducted to know the quantity of immobilized microorganisms per gram of solids and then the immobilized solids were used in the spouted bed contactor for phenol degradation. Also, the shock loading of phenol and hydraulic shock load test was performed to check the stability of operation. The immobilized Nocardia cells sustained the shock load and hydraulic load of phenol. Increase of influent phenol concentration and dilution rates increased the steady state effluent phenol concentration. Almost 95% degradation at maximum phenol loading of 0.73 gL-1h-1 was achieved. GAC has more attached biomass weight compared to polymer beads. © 2009 Academic Journals.Item 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.Item Wave steepness and relative width: Influence on transmission coefficient of horizontal interlaced, multilayered, moored floating pipe breakwater with five layers(2011) Rajappa, S.; Hegde, A.V.; Rao, S.; Channegowda, V.This paper presents the results of a series of physical model scale experiments conducted to determine the transmission characteristics of a horizontal interlaced, multilayered, moored floating pipe breakwater. The studies are conducted on physical breakwater models having five layers of PVC pipes. The wave steepness (H i/gT 2, where H i is incident wave height, g is acceleration due to gravity, and T is time period) was varied between 0.063 and 0.849, relative width (W/L, where W is width of breakwater and L is the wavelength) was varied between 0.4 and 2.65, and relative spacing (S/D, where S is horizontal centre to centre spacing of pipes and D is the diameter of pipes) was set equal to 2. The transmitted wave height is measured, and the gathered data are analyzed by plotting nondimensional graphs depicting the variation of K t (transmission coefficient) with Hi/gT 2 for values of d/W (d is depth of water) and of K t with W/L for values of H i /d. It is observed that K t decreases as H i /gT 2 increases for the range of d/W between 0.082 and 0.139. It is also observed that K t decreases with an increase in W/L values for the range of H i /d from 0.06 to 0.40. The maximum wave attenuation achieved with the present breakwater configuration is 78%.Item Synthesis and characterization of thiophene and fluorene based donor-acceptor conjugated polymer containing 1,3,4-oxadiazole units for light-emitting diodes(2012) Murali, M.G.; Naveen, P.; Udayakumar, U.; Yadav, V.; Srivastava, R.A new donor-acceptor (D-A) conjugated polymer (PDTOF) containing 3,4-didodecyloxythiophene, fluorene and 1,3,4-oxadiazole units is synthesized by using Wittig reaction methodology. The synthesized polymer is characterized by 1H NMR, FTIR, GPC, and elemental analysis. The optical energy band gap of the polymer is found to be 2.42 eV as calculated from the onset absorption edge. The electrochemical studies of PDTOF reveal that, the HOMO and LUMO energy levels of the polymer are -5.45 eV and -3.58 eV, respectively. The polymer is thermally stable up to 320 °C. Polymer light-emitting diode devices are fabricated with a configuration of ITO/PEDOT: PSS/PDTOF/Al using PDTOF as the emissive layer. The electroluminescence (EL) spectrum of the device showed green emission with CIE coordinate values (0.34, 0.47). By current density-voltage characteristics, threshold voltage of the PLED device is found to be 6.5 V. © 2011 Elsevier Ltd. All rights reserved.