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Umaiyakunjaram R.,Tamil Nadu Pollution Control Board | Umaiyakunjaram R.,Anna University | Shanmugam P.,Central Leather Research Institute Council of Scientific and Industrial Research
Bioresource Technology | Year: 2016

This study deals with the treatment of high suspended solids raw tannery wastewater using flat sheet Submerged Anaerobic Membrane (0.4 μm) Bioreactor (SAMBR) acclimatized with hypersaline anaerobic seed sludge for recovering biogas. The treatability of SAMBR achieved higher CODremoval efficiency (90%) and biogas yield (0.160 L.g-1 CODremoved) coincided with high r2 values between permeate flux and TSS (0.95), biogas and COD removed (0.96). The acidification of hypersaline influent wastewater by biogas mixing with high CO2, achieved quadruplet benefit of gas liquid and solid separation, in-situ pH and NH3 control, in-situ CH4 enrichment, and prevention of membrane fouling. The initial high VFA became stable as time elapsed reveals the hydrolysing ability of particulate COD into soluble COD and into biogas, confirms the suitability of SAMBR for high suspended solids tannery wastewater. © 2016 Elsevier Ltd.


Indumathy R.,Central Leather Research Institute Council of Scientific and Industrial Research | Weyhermuller T.,Max Planck Institute for Chemistry | Nair B.U.,Central Leather Research Institute Council of Scientific and Industrial Research
Dalton Transactions | Year: 2010

Two new mixed ligand complexes of cobalt(iii) containing ancillary biimidazole ligands, [Co(phen)2H2biim](ClO 4)3·0.5(H7O3)(ClO 4) (1) and [Co(bpy)2H2biim](ClO 4)3·3H2O (2) have been synthesized and characterized by various spectroscopic and electrochemical techniques. Both complexes 1 and 2, have been characterized by the single crystal X-ray diffraction method. While cobalt complex 1 was found to crystallize in the triclinic system with the P1 space group, complex 2 was found to crystallize in the orthorhombic system with the Pbca space group. The unit cell packing of complex 1 shows the presence of a water cluster, which is buttressed by oxygen atoms present in the perchlorate anions and water with an average O⋯O bond distance of 2.41-2.86 Å. Interaction of these complexes with calf thymus DNA (CT-DNA) was investigated by electronic spectral titrations. The results suggest that complexes 1 and 2 bind to DNA through the groove via hydrogen bonding. This is due to the presence of -NH in the ancillary ligand biimidazole, which favors hydrogen bonding with DNA base pairs. The intrinsic DNA binding constant values for complexes 1 and 2 were found to be (5.18 ±0.23) × 104 M-1 and (1.26 ± 0.13) × 104 M-1 respectively. Groove binding of these complexes with DNA is further supported by viscosity measurements, thermal denaturation and circular dichroism studies. Among the two cobalt complexes, complex 1 possesses greater DNA binding strength due to the presence of the conjugated aromatic structure of the phen ligand which increases the hydrophobic interactions with DNA. DNA cleavage experiments using plasmid DNA pUC 18 show that these complexes exhibit efficient photonuclease activity in the presence of molecular oxygen. © 2010 The Royal Society of Chemistry.


Bakrudeen H.B.,Central Leather Research Institute Council of Scientific and Industrial Research | Tsibouklis J.,University of Portsmouth | Reddy B.S.R.,Central Leather Research Institute Council of Scientific and Industrial Research
Journal of Nanoparticle Research | Year: 2013

In the present study, to formulate captopril in a hierarchical porous structure of ZnO nanospheres by means of the soluble-starch-insertion method, state of drug carrier delivery toward oral route and the mode of delivery in suitable medium. Mesoporous ZnO nanospheres were synthesized by simple soluble-starch-insertion method, followed by loading of captopril using ultrasonic force. The materials were characterized by PXRD, SEM, FESEM, TEM, TGA, FT-IR, and BET analyses, and biocompatibility studies. Captopril-loaded porous ZnO nanospheres were evaluated as in vitro drug-release studies and its kinetic models. Crystallite plane arrangement, functional groups, materials morphology, and porosity of porous ZnO nanospheres were confirmed. Larger surface area and distribution in constrained pores on its surface make the nanospheres suitable for high drug loading of captopril. The ZnO nanocrystallites have given porous properties on the spherical surface leads to the drug adsorption. The loading and release studies (in vitro in simulated gastric and intestinal fluids) have shown that both were affected by the mesoporous nanospheres' surface properties of the ZnO materials and its biocompatibility has also been proved. Therefore, the in vitro experiments have indicated the considerable promise of mesoporous ZnO nanospheres, fabricated by the soluble-starch-insertion method acting as a biocompatible carrier for the controlled delivery of captopril in oral route of administration. Graphical Abstract: [Figure not available: see fulltext. Caption: Schematic representation of the protocol for the preparation of captopril-loaded mesoporous ZnO nanospheres ] © 2013 Springer Science+Business Media Dordrecht.


Sathyaraj G.,Central Leather Research Institute Council of Scientific and Industrial Research | Nair B.U.,Central Leather Research Institute Council of Scientific and Industrial Research
Inorganica Chimica Acta | Year: 2013

Two ruthenium(II) mixed ligand complexes [Ru(bpy)2(imiphen)] (PF6)2, 1 and [Ru(bpy)2(phimiphen)](PF 6)2, 2, where imiphen = 2-(1H-imidazol-2yl)-1H-imidazo[4, 5-F][1,10]phenanthroline and phimiphen = 2-(1H-benzimidazol-2yl)-1H-imidazo[4,5- F][1,10]phenanthroline have been synthesized and characterized using various spectroscopic techniques like ESI mass, electronic spectroscopy and fluorescence spectroscopy. Both these complexes exhibit unusual fluorescence spectra. Complexes 1 and 2 show emission maxima at 620 and 617 nm when excited at their MLCT band at 450 nm. The emission intensity has been found to depend on the nature of the solvent. Emission intensity of the aqueous solution of complexes 1 and 2 has been found to be 75-143% greater than the emission intensity of acetonitrile solution of these two complexes. This increase in the emission intensity in aqueous solution is accompanied by an increase in the lifetime of the excited state of the complex in aqueous solution. Emission intensity increase observed for these complexes is due to the involvement of the H 2O molecule in the hydrogen bonding with imidazole N-H of the ligand, making the ligand rigid. On the other hand, in acetonitrile medium because of lack of hydrogen bonding, the imidazole ring can have free rotation. © 2013 Published by Elsevier B.V.


Gnanasekaran D.,Central Leather Research Institute Council of Scientific and Industrial Research | Walter P.A.,Central Leather Research Institute Council of Scientific and Industrial Research | Reddy B.S.R.,Central Leather Research Institute Council of Scientific and Industrial Research
Polymer Engineering and Science | Year: 2013

A series of new hexafluoroisopropylidene, isopropylidene, carbonyl, and ether moieties substituted polyamides have been prepared from aromatic diamines and various moieties substituted aromatic dianhydrides. The synthesized polyamides were readily soluble in polar solvents such as N-methyl-2- pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethyl sulfoxide. These polyamides exhibited good thermal stability and high char yields. The chemical and physical properties of the newly prepared polyamide-polyhedral oligomeric silsequioxanes (PA-POSS) were compared in terms of their chemical structures and thermal properties. The morphological properties of the polymeric nanocomposites depend both on their chemical structure of dianhydride and the aggregation of POSS were investigated by scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Polyamides with bulky POSS and fluoro groups can effectively decrease dielectric constants. The dielectric constants of PA-POSS were found to be decreased from 3.75 to 3.29 by changing the substitution. These polyamides showed good thermal stability up to 353 °C for a 10 % weight loss. The fluorinated polyamides have relatively higher thermal stability than the polyamides without halogen because of high bond energy of C-F bond. The fiuorinated groups in the polymer backbone have played an important role in the improvement of dielectric performance of polymers. Copyright © 2012 Society of Plastics Engineers.


Murali R.,Central Leather Research Institute Council of Scientific and Industrial Research | Thanikaivelan P.,Central Leather Research Institute Council of Scientific and Industrial Research
RSC Advances | Year: 2016

Bionic collagen-poly(dialdehyde) locust bean gum based hybrid scaffolds synergistically combined with vascular endothelial growth factor were prepared to regenerate tissue formation for wound healing applications. The dialdehyde functionalities introduced in the locust bean gum were responsible for the improved collagen stability, biostability and immobilization of vascular endothelial growth factor in the hybrid scaffolds. In vitro Swiss 3T6 mouse fibroblast cell culture studies reveal that the prepared hybrid scaffolds have enhanced cell viability and infiltration. An in vivo wound healing study demonstrates that the collagen-poly(dialdehyde) locust bean gum-vascular endothelial growth factor hybrid scaffolds boost the level of fibroblast and neovascular content as well as collagen deposition; complete epithelialization occurs within 16 ± 0.9 days. The results show that the vascular endothelial growth factor immobilized hybrid scaffold induces chemotactic effects to promote rapid tissue regeneration and wound repair, thereby demonstrating its potential for burn wounds, chronic wounds and diabetic foot ulcer treatments. © The Royal Society of Chemistry 2016.


Cheirmadurai K.,Central Leather Research Institute Council of Scientific and Industrial Research | Biswas S.,Central Leather Research Institute Council of Scientific and Industrial Research | Murali R.,Central Leather Research Institute Council of Scientific and Industrial Research | Thanikaivelan P.,Central Leather Research Institute Council of Scientific and Industrial Research
RSC Advances | Year: 2014

We report large-scale biosynthesis of copper nanoparticles using an extract of henna leaves as reductant. Due to the substantial electrical conductivity of the calcined copper nanoparticles, we used them to prepare conductive nanobiocomposites utilizing collagen waste. We demonstrate that the nanobiocomposites, when inserted between batteries, illuminate a light emitting diode lamp. © the Partner Organisations 2014.


Nethaji S.,Central Leather Research Institute Council of Scientific and Industrial Research | Nethaji S.,Institute of Chemical Technology | Sivasamy A.,Central Leather Research Institute Council of Scientific and Industrial Research | Thennarasu G.,Central Leather Research Institute Council of Scientific and Industrial Research | Saravanan S.,Institute of Chemical Technology
Journal of Hazardous Materials | Year: 2010

In the present study, chemically prepared activated carbon derived from Borassus aethiopum flower was used as adsorbent. Batch adsorption studies were performed for the removal of Malachite Green (MG) from aqueous solutions by varying the parameters like initial solution pH, adsorbent dosage, initial MG concentration and temperature with three different particle sizes such as 100μm, 600μm and 1000μm. The zero point charge was 2.5 and the maximum adsorption occurred at the pH range from 6.0 to 8.0. Experimental data were analyzed by model equations such as Langmuir, Freundlich and Temkin isotherms and it was found that the Langmuir isotherm model best fitted the adsorption data. Thermodynamic parameters such as Δ G, Δ H and Δ S were also calculated for the adsorption processes. Adsorption rate constants were determined using pseudo first-order, pseudo second-order rate equations and also Elovich model and intraparticle diffusion models. The results clearly showed that the adsorption of MG onto PFAC followed pseudo second-order model and the adsorption was both by film diffusion and by intraparticle diffusion. © 2010 Elsevier B.V.


Wegene J.D.,Addis Ababa Institute of Technology | Thanikaivelan P.,Central Leather Research Institute Council of Scientific and Industrial Research
Industrial and Engineering Chemistry Research | Year: 2014

Leather is a unique consumer material possessing a variety of properties such as strength, viscoelasticity, flexibility, and longevity. However, the use of leather for smart product applications is a challenge since it is an electrically insulating material. Here, we report a simple method to produce conducting leathers using an in situ polymerization of pyrrole. The concentrations of pyrrole, ferric chloride, and anthraquinone sulfonic acid and the number of polymerization were optimized to produce maximum conductivity in the treated leathers. The coating of polypyrrole in the treated leathers was probed using Fourier transform infrared spectroscopy, X-ray diffraction, and electron microscopic analysis. We also show that the treated leathers are black through re flectance measurements, thereby suggesting that the use of toxic and expensive dyes can be avoided for coloration process. We further demonstrate that the treated leathers, with a maximum conductivity of 7.4 S/cm, can be used for making conductive gloves for operating touch-screen devices apart from other smart product applications. © 2014 American Chemical Society.


Ragothaman M.,Central Leather Research Institute Council of Scientific and Industrial Research | Palanisamy T.,Central Leather Research Institute Council of Scientific and Industrial Research | Kalirajan C.,Central Leather Research Institute Council of Scientific and Industrial Research
Carbohydrate Polymers | Year: 2014

Here we report the preparation of collagen-poly(dialdehyde) guar gum based hybrid functionalized scaffolds covalently immobilized with platelet derived growth factor - BB for tissue engineering applications. Poly(dialdehyde) guar gum was synthesized from selective oxidation of guar gum using sodium periodate. The synthesized poly(dialdehyde) guar gum not only promotes crosslinking of collagen but also immobilizes the platelet derived growth factor through imine bonds. The covalent crosslinking formed in collagen improves thermal, swelling and biodegradation properties of the hybrid scaffolds. The prepared hybrid scaffolds show 3D interconnected honeycomb porous structure when viewed under a microscope. The release of immobilized platelet derived growth factor was seen up to 13th day of incubation thereby proving its sustained delivery. The developed hybrid scaffold leads to a quantum increase in NIH 3T3 fibroblast cell density and proliferation thereby demonstrating its potential for tissue engineering applications. © 2014 Elsevier Ltd.

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