Dkm College For Women

Vellore, India

Dkm College For Women

Vellore, India
SEARCH FILTERS
Time filter
Source Type

Ashwini R.,Thiruvalluvar University | Vijayanand S.,Thiruvalluvar University | Hemapriya J.,DKM College for Women
Current Microbiology | Year: 2017

Haloarchaea are known for its adaptation in extreme saline environment. Halophilic archaea produces carotenoid pigments and proton pumps to protect them from extremes of salinity. Bacteriorhodopsin (bR) is a light-driven proton pump that resides in the membrane of haloarchaea Halobacterium salinarum. The photocycle of Bacteriorhodopsin passes through several states from K to O, finally liberating ATP for host’s survival. Extensive studies on Bacteriorhodopsin photocycle has provided in depth knowledge on their sequential mechanism of converting solar energy into chemical energy inside the cell. This ability of Bacteriorhodopsin to harvest sunlight has now been experimented to exploit the unexplored and extensively available solar energy in various biotechnological applications. Currently, bacteriorhodopsin finds its importance in dye-sensitized solar cell (DSSC), logic gates (integrated circuits, IC’s), optical switching, optical memories, storage devices (random access memory, RAM), biosensors, electronic sensors and optical microcavities. This review deals with the optical and electrical applications of the purple pigment Bacteriorhodopsin. © 2017, Springer Science+Business Media New York.


Vijayalakshmi K.,DKM College for Women | Gomathi T.,DKM College for Women | Sudha P.N.,DKM College for Women
Der Pharmacia Lettre | Year: 2014

The main aim of the present study was to synthesize and characterize the nanochitosan /sodium alginate/ microcrystalline cellulose beads in 2:8:1 ratio using the calcium chloride as the ionic crosslinking agent. Initially the steam explosion method was utilized to extract the microcrystalline cellulose from the banana fiber and the nanochitosan was synthesized from chitosan by utilizing the ionotropic gelation method. The characterization of the modified fibers and synthesized bead was done using the FT-IR, XRD, DSC, TGA and SEM studies. The chemical modification occurred during the steam explosion and the physical and chemical interaction in the bead formation was evidenced from the FT-IR results. The XRD pattern elucidates the increase in crystallinity of the fourth stage fiber when compared to first stage fiber and the decrease in crystallinity in case of the bead. The thermal stability of the prepared samples was identified from the TGA and DSC studies. The observed SEM results clearly indicate that the prepared bead has a spherical morphology and the rough surface which will be suitable for the adsorption process. The results were investigated.


Gopal Reddi M.R.,Bharathiar University | Gomathi T.,Dkm College For Women | Sudha P.N.,Dkm College For Women
Der Pharmacia Lettre | Year: 2014

In the present study, chemical modification of chitosan was carried out by graft copolymerization of ethylene dimethacrylate monomer onto chitosan-g-Maleic anhydride. The polymerization reaction was initiated by Ceric Ammonium Nitrate, Nitric acid redox system. Graft copolymer was prepared by varying parameters such as monomer concentration, initiator concentration and temperature. The chemical structure and physical properties of prepared Chitosan-g-MA-g-ethylene dimethacrylate copolymer were carried out by various analytical techniques such as Fourier transform resonance spectroscopy (FT-IR), X-ray diffraction (XRD) and Thermo gravimetric analysis (TGA). Grafting was confirmed by FTIR. X-ray diffraction showed changes in crystallinity pattern. Slightly different mechanisms in side chain substitution for these polymers were envisaged. The thermal properties of prepared graft copolymer were obtained by TGA thermal studies. The total effect of monomer concentration, initiator concentration and temperature on grafting percentage were investigated and discussed.


Mubashirunnisa A.,Manonmaniam Sundaranar University | Vijayalakshmi K.,DKM College for Women | Gomathi T.,DKM College for Women | Sudha P.N.,DKM College for Women
Der Pharmacia Lettre | Year: 2012

Natural fiber reinforced composites have attracted the attention of research community mainly because they are turning out to be an alternative solution to the ever depleting petroleum sources. Various natural fibres such as jute, sisal, palm, coir and banana are used as reinforcements. In this paper, banana fibres and glass fibers have been used as reinforcement. The aim of this present study was to develop a polymer made up of banana/glass fiber reinforced nanochitosan composites. The nanochitosan was prepared using polyphosphoric acid and composites of nanochitosan were prepared with short fibers of banana and glass in the presence of crosslinking agent glutaraldehyde. The prepared glass and banana fiber reinforced nanocomposites were characterized using different analytical tools such as FT-IR, XRD, TGA and DSC. The FT-IR studies reveal the formation of nanocomposites. The observed results of TGA and DSC show that the addition of glutaraldehyde along with the nanosized chitosan has increased the thermal stability. The XRD results indicate the change in crystallinity of nanocomposites.


Hajeeth T.,Sathyabama University | Vijayalakshmi K.,DKM College for Women | Gomathi T.,DKM College for Women | Sudha P.N.,DKM College for Women
International Journal of Biological Macromolecules | Year: 2013

The extraction of cellulose from sisal fiber was done initially using the steam explosion method. The batch adsorption studies were conducted using the cellulose extracted from the sisal fiber and cellulose-g-acrylic acid as an adsorbent for the removal of Cu(II) and Ni(II) metal ions from aqueous solution. The effect of sorbent amount, agitation period and pH of solution that influence sorption capacity were investigated. From the observed results, it was evident that the adsorption of metal ions increases with the increase in contact time and adsorbent dosage. The optimum pH was found to be 5.0 for the removal of copper(II) and nickel(II) for both the extracted cellulose and cellulose-g-acrylic acid copolymer. The adsorption data were modeled using Langmuir and Freundlich isotherms. The experimental results of the Langmuir, Freundlich isotherms revealed that the adsorption of Cu(II) and nickel(II) ion onto cellulose extracted from the sisal fiber and cellulose-g-acrylic acid copolymer was found to fit well with Freundlich isotherm. The kinetics studies show that the adsorption follows the pseudo-second-order kinetics. From the above results, it was concluded that the cellulose-g-acrylic acid copolymer was found to be an efficient adsorbent. © 2013 Elsevier B.V.


Shankar P.,Sathyabama University | Gomathi T.,DKM College for Women | Vijayalakshmi K.,DKM College for Women | Sudha P.N.,DKM College for Women
International Journal of Biological Macromolecules | Year: 2014

The graft copolymerization of acrylonitrile onto cross linked chitosan was carried out using ceric ammonium nitrate as an initiator. The prepared cross linked chitosan- g-acrylonitrile copolymer was characterized using FT-IR and XRD studies. The adsorption behavior of chromium(VI), copper(II) and nickel(II) ions from aqueous solution onto cross linked chitosan graft acrylonitrile copolymer was investigated through batch method. The efficiency of the adsorbent was identified from the varying the contact time, adsorbent dose and pH. The results evident that the adsorption of metal ions increases with the increase of shaking time and metal ion concentration. An optimum pH was found to be 5.0 for both Cr(VI) and Cu(II), whereas the optimum pH is 5.5 for the adsorption of Ni(II) onto cross linked chitosan- g-acrylonitrile copolymer. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isothermal data could be well interpreted by the Freundlich model. The kinetic experimental data properly correlated with the second-order kinetic model. From the above results it was concluded that the cross linked chitosan graft acrylonitrile copolymer was found to be the efficient adsorbent for removing the heavy metals under optimum conditions. © 2014 Elsevier B.V.


Bhargavi V.L.N.,Sri Venkateswara College of Engineering | Sudha P.N.,DKM College for Women
International Journal of ChemTech Research | Year: 2015

The focus of the present research work is on the monitoring of heavy metal pollution in water and soils of Ranipet, Tamil nadu India. The physico-chemical characteristics and heavy metals like Chromium and Cadmium were analysed for two polluted water and soil samples collected from Bharathi nagar (I) and Tandalam (II) villages of Ranipet surroundings. The soil sample of Tandalam was chosen for the remediation studies, due to its high levels of pollution. Electrokinetic remediation of Tandalam soil was carried at 50 V. The electrokinetic cell was sectioned into four compartments and analysed for the concentrations of Chromium and Cadmium. After electrokinetic remediation, the heavy metal contaminants get concentrated in different sections according to their charges and the soil in the four compartments of the electrokinetic cell was subjected to phytoremediation with Indian mustard (Brassica juncea) seeds. The efficiency of Brassica juncea was proved in remediating the heavy metals Chromium and Cadmium from the polluted soils. © 2015, Sphinx Knowledge House. All rights reserved.


Jayakumar S.,Bharathiar University | Gomathi T.,DKM College for Women | Sudha P.N.,DKM College for Women
International Journal of Biological Macromolecules | Year: 2013

The removal of Pb (II) ions from aqueous solution by crosslinked (glutaraldehyde-chitosan/Nylon6/Polyurethane foam) and non crosslinked (chitosan/Nylon6/Polyurethane foam) blends has been investigated. Chitosan solution was blended with Nylon6 and Polyurethane foam in the ratio of 2:1:1 with and without crosslinking agent (glutaraldehyde), in order to obtain sorbents that are insoluble in aqueous acidic and basic solution. Batch adsorption studies were performed as a function of pH, contact time and adsorbent dose. The optimum pH required for maximum adsorption of lead was found to be 5. The equilibrium adsorption data has been tested for the Langmuir, Freundlich and Temkin isotherms. The data were suitable to Freundlich isotherm model for both the blends. The kinetic parameters of the adsorption process were estimated using the pseudo-first and pseudo-second order models. These data indicated that the adsorption process followed the pseudo-first-order kinetics. © 2013 Elsevier B.V..


Saravanan D.,Tamil University | Hemalatha R.,Tamil University | Sudha P.N.,DKM College for Women
Der Pharma Chemica | Year: 2011

Mixing of two or more polymers to produce blends is a well established strategy for achieving specific combination of physical properties. Polymer blend films of chitin and bentonite were prepared from homogeneous solutions in trichloroacetic acid at various ratios of chitin and bentonite. The cross linking agent glutaraldehyde was incorporated into the polymer blends to improve the properties such as surface hardness, stiffness, resistance to temperature and solvent attack. FTIR study revealed that there is intermolecular molecular hydrogen bonding interaction between the two polymer components. XRD studies shows that the films to exhibit an amorphous character. Glass transition temperature and the crystallization of the polymer blends were investigated on the basis of studies differential scanning calorimetry (DSC). By TGA and DTG experiments, enhancement in the thermal stability of polymer blend in presence of cross linking agent (glutaraldehyde) was found out. Adsorption of Cu (II) and Cr (VI) on chitin was studied by the Longmuir and Freundlich method. The influence of dosage of adsorbent, contact time & pH were experimentally verified. The results revealed that the adsorption of Cu (II) and Cr (VI) on chitin is spontaneous, endothermic and favorable. This blended polymer was used as an adsorbent in dye effluent treatment.


Sivakami M.S.,Mills College | Gomathi T.,DKM College for Women | Venkatesan J.,Pukyong National University | Jeong H.-S.,Pukyong National University | And 3 more authors.
International Journal of Biological Macromolecules | Year: 2013

Chitosan nanorod with minimum particle size of <100. nm was prepared by crosslinking low molecular weight chitosan with polyanion sodium tripolyphosphate and physicochemically characterized (FT-IR, XRD, SEM, AFM, TGA and DSC) for waste water treatment. Its sorption capacity and sorption isotherms for chromium (Cr) were studied. The effect of initial concentration of Cr ions, sorbent amount, agitation period and pH of solution that influence sorption capacity were also investigated. It was found that nanochitosan in the solid state was rod shaped which could sorb Cr (VI) to Cr (III) ions effectively. Based on the Langmuir, the Freundlich and the Temkin sorption isotherms, the sorption capacity of chitosan nanoparticles is very high and the adsorbent favors multilayer adsorption. The kinetics studies show that the adsorption follows the pseudo-second-order kinetics, which infers the transformation of Cr (VI) to Cr (III). From the results it was concluded that nanochitosan is an excellent material as a biosorbent for Cr removal from water. © 2013 Elsevier B.V.

Loading Dkm College For Women collaborators
Loading Dkm College For Women collaborators