Conference Papers
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Item Investigation of the photoalignment effect of 1, 3, 4-oxadiazoles bearing 2-fluoro-4-methoxy phenyl moiety(2010) Alla, R.A.; Hegde, G.; Isloor, A.M.; Chandrakantha, B.; Shetty, P.; Komitov, L.A new series of 1,3,4-oxadiazole derivatives containing 2-fluoro-4-methoxy moiety were synthesized by refluxing mixture of acid hydrazide 3 with different aromatic carboxylic acid in phosphorous oxychloride. Photoalignment studies were performed on these materials indicating that the position of fluorine plays vital role in promoting planar alignment either parallel or perpendicular to the light polarization direction. © 2010 ITE and SID.Item Blue light emitting materials for organic light emitting diodes: Experimental and simulation study(2012) Ulla, H.; Garudachari, B.; Satyanarayan, M.N.; Umesh, G.; Isloor, A.M.Novel blue light-emitting materials were designed by the substitution at the 4-position of 1,8-naphthalimide with electron-donating phenoxy group. The effect of molecular structure on the photophysical, electronic structure properties of the derivatives was explored by UV-visible absorption spectroscopy, photoluminescence spectroscopy, cyclic voltammetry and quantum chemical calculations. Both UV-visible absorption and emission spectra of derivatives indicate that the emission is in blue region. Electrochemical studies of the molecules revealed that they have low-lying energy levels of the lowest unoccupied molecular orbital (LUMO) and energy levels of the highest occupied molecular orbital (HOMO) indicating that the derivatives possess good electron-transporting or hole-blocking properties. To further reveal the electronic structure and the optical properties, the structural and electronic properties of the synthesized derivatives were calculated. These results indicate that molecules may offer potential as dopants as well as non-doping light-emitting materials with good electron injection capabilities for fabrication of blue organic light-emitting diodes. © 2012 IEEE.Item Blue light emitting naphthalimides for organic light emitting diodes(2013) Ulla, H.; Garudachar, B.; Satyanarayan, M.N.; Umesh, G.; Isloor, A.M.The photophysical, electrochemical, surface morphology and thermal properties of two novel blue lightemitting materials were studied. Results indicate that the molecules offer potential as non-doping light-emitting materials with good electron injection capabilities for fabrication of blue organic light-emitting diodes. © 2013 American Institute of Physics.Item Compressive and swelling behavior of cuttlebone derived hydroxyapatite loaded PVA hydrogel implants for articular cartilage(American Institute of Physics Inc. subs@aip.org, 2018) Kumar, B.Y.S.; Mohan Kumar, G.C.; Isloor, A.M.Developing a novel antibacterial, nontoxic and biocompatible hydrogel with superior physio mechanical properties is still becoming a challenge. Herein, we synthesize hydroxyapatite (HA) powder from cuttlefish bone and prepare a series of stiff, tough, high strength, biocompatible hydrogel reinforced with HA by integrating glutaraldehyde into PVA/HA. Powder was characterized by SEM and XRD. Compressive strength and swelling properties are studied and compare the results with the properties of healthy natural articular cartilage. © 2018 Author(s).Item Viscoelastic behavior of HAp reinforced polyvinyl alcohol composite hydrogel for tissue engineered articular cartilages(American Institute of Physics Inc. subs@aip.org, 2019) Kumar, B.Y.S.; Isloor, A.M.; Mohan Kumar, G.C.Polyvinyl alcohol (PVA) hydrogels have desirable characteristics for use as a soft tissue substitute. However, their low mechanical strength and biocompatibility hinder the wide range of biomedical application. Herein, hydroxyapatite blended PVA/HAp composite hydrogel was developed by freeze-thawing and annealing method. The microstructure and rheological properties such as storage and loss modulus are investigated. Samples showed a porous structure with interconnected porosity and HAp distributed uniformly in a PVA matrix. Further, the composite hydrogel showed favorable viscoelastic properties and is suitable for artificial articular cartilage replacement. © 2018 Author(s).Item Fabrication of eggshell derived hydroxyapatite polymer composite membrane for efficient removal of thorium ions from aqueous solutions(Elsevier Ltd, 2020) Ravindran, C.; Anitha, A.; Kunhikrishnan Maniath, J.; Isloor, A.M.A novel eggshell-derived hydroxyapatite polymer composite membrane was fabricated to explore its efficiency in the elimination of Th(IV) metal ions from water bodies. Membrane fabrication was carried out by two stage process in which, at first hydroxyapatite (Hap) was derived from eggshell and the minerals thus obtained were used as filler in Poly vinyl alcohol (PVA) - Poly vinyl pyrrolidone (PVP) based polymer membrane. Structural and morphological studies of PVA-PVP-Hap membrane were carried out by analyzing Fourier transform IR spectra (FTIR), X-Ray diffraction spectra (XRD), Scanning electron microscope-energy dispersive X-ray images (SEM-EDX) etc. Water uptake capacity and ion exchange capacity were determined for membrane characterization. Optimization studies were performed for the elimination of Th(IV) metal from polluted water. Regeneration studies also proved that the membrane can be used upto 4 cycles of operation with less than 5% loss in performance using ethanol as eluent for the desorption of this pollutant from the membrane. © 2020 Elsevier Ltd.Item Fabrication of PPSU/PANI hollow fiber membranes for humic acid removal(Elsevier Ltd, 2020) Vijesh, A.M.; Arathi Krishnan, P.V.; Isloor, A.M.; Shyma, P.C.Membrane based separation has proved its efficiency over other traditional techniques of water purification. Hollow fiber (HF) membranes are more ideal compared to other types of membranes due to their high surface area, enhanced mechanical property and easy handling. Significant research had been done in this area, still the abundant scope of membrane technology has motivated many scientists to further explore the field. The current work is an attempt to study the efficiency of nanomaterials in polymeric membranes. This paper is focused on incorporating polyaniline (PANI) based nanocomposites into the polymer membranes and to study the properties and performance of the prepared nanocomposite membranes. Polyphenylsulfone (PPSU) and polyvinylpyrrolidone (PVP) are the main polymer and pore forming agent used in this study respectively. The dope solution was prepared by blending PPSU and PVP with PANI in different compositions. New PPSU composite HF membranes were fabricated using wet-jet phase inversion technique. The properties and performance of the membranes were analyzed by cross sectional morphology, water uptake capacity, permeation properties and antifouling ability. The self-cleaning capacity of the membranes was determined by evaluating the flux recovery ratio. The water purification efficiency of the membranes was evaluated in terms of humic acid rejection studies. Polyphenylsulfone containing 0.5 wt% of polyaniline exhibited maximum rejection of 99% for humic acid. © 2020 Elsevier Ltd. All rights reserved.Item Structure and rheology of chitosan-nanohydroxyapatite composite hydrogel for soft tissue regeneration(American Institute of Physics Inc. subs@aip.org, 2020) Kumar, B.Y.S.; Isloor, A.M.; Periasamy, K.; Kumar, G.C.M.Chitosan (CS) hydrogels show desirable characteristics to use a soft tissue implants due to its biocompatibility, biodegradability and antimicrobial characteristics. However, the structural stability hinders its application in vivo. In the present work nanohydroxyapatite (HAp) was reinforced with chitosan hydrogel and to develop chitosan-hydroxyapatite (CS-HAp) composite hydrogel. The nanohydroxyapatite modifies the hydrogel network by promoting the secondary hydrogen bonds thereby enhances the mechanical stiffness. The elastic modulus could reach 10 kPa which is necessary for the proposed application. Overall, chitosan-hydroxyapatite composite hydrogels are the promising implant materials for next-generation soft tissue regeneration. © 2020 Author(s).