M. Selvaraj^ - Academia.edu (original) (raw)

Papers by M. Selvaraj^

Journal of Colloid and Interface Science, 2013

We prepared stable colloidal suspension graphene in aqueous medium by surface modification of gra... more We prepared stable colloidal suspension graphene in aqueous medium by surface modification of graphene with 4-benzenediazonium sulfonate. The sulfonate group on graphene surface interacts with water, exhibits well dispersibility and which prevents the aggregation even at neutral pH. This dispersion shows stability for three months and facile to produce films. Using such a modified graphene dispersion, transparent conductive film (TCF) has been fabricated on glass substrate by spin coating method. At appropriate concentration, the film exhibits an excellent optoelectrical property with resistivity of 1.1 kX with the transparency of 89% at the wavelength of 550 nm. Further, we also demonstrated the mechanical, thermal, and optoelectrical properties of prepared films.

Journal of Applied Polymer Science, 2013

ABSTRACT Microencapsule was incorporated into an interpenetrating polymer network and applied ove... more ABSTRACT Microencapsule was incorporated into an interpenetrating polymer network and applied over steel surface. A scratch was made on the coated surface and its self healing ability was studied using scanning vibrating electrode technique (SVET) and electrochemical impedance spectroscopy (EIS). Results of SVET studies show that the current density increases in the initial stage. After 24 h, the current density decreases, which indicating the formation of passive polymer film due to the diffusion of core polymer present in the microcapsules through the holidays. Increase in the resistance (107 Ω/cm2) of the self healing coating was observed after 24 h in EIS studies confirming the formation of the passive film. The results of the studies are discussed in this article. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012

The increasing commercial applications of nanoparticles have wide pertinent in the field of medic... more The increasing commercial applications of nanoparticles have wide pertinent in the field of medicine. Biological synthesis of Silver nanoparticles (AgNPs) are effective and environment friendly than chemical methods. In the present study, we demonstrated extracellular synthesis of AgNPs from Sargassum ilicifolium rapidly. The UV-Vis spectra of aqueous medium containing Ag + ions showed peak at 414 nm corresponding to the plasmon resonance of AgNPs. SEM and TEM analysis showed formation of welldispersed AgNPs in the range of 33-40 nm. Antibacterial activity against five clinical pathogens at various concentrations shows impediment in growth at various nanomolar concentrations. Further, the toxicity of biosynthesized AgNPs was tested against Artemia salina to evaluate the cytotoxic effect that displayed LD 50 value of 10nM/ml.

Synthetic Metals, 2008

This study deals with the preparation and characterization of polypyrrole (PPy) using ferric chlo... more This study deals with the preparation and characterization of polypyrrole (PPy) using ferric chloride and ammonium dichromate as oxidants and also with the addition of a common surfactant in aqueous solution. The combination of oxidant and surfactant in the ...

Progress in Organic Coatings, 2005

Polymer blends are used to protect mild steel structures from corrosive environment. Multi-coat p... more Polymer blends are used to protect mild steel structures from corrosive environment. Multi-coat protective coating systems are substituted by single coat polymer blend, which will protect the surface equally for long duration when compared to the multi-coat system. In ...

Progress in Organic Coatings, 2009

Corrosion of steel rebars in reinforced concrete constructions, particularly those located in mar... more Corrosion of steel rebars in reinforced concrete constructions, particularly those located in marine environments and industrially polluted areas is one of the major problems baffling the construction industry all over the world including India. A suitable protective coating to rebar is found to ...

Progress in Organic Coatings, 2005

Conversion coatings on metals enhance paint or lacquer adhesion and promote corrosion resistance.... more Conversion coatings on metals enhance paint or lacquer adhesion and promote corrosion resistance. Present study characterizes three different phosphate baths of zinc phosphate, calcium modified and manganese-modified formulations. It has been observed that manganese ...

Progress in Organic Coatings, 2008

Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts ... more Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts and similar equipments that are permanently or occasionally exposed to elevated temperatures. High-temperature coatings are generally based on silicone resin with ...

Progress in Organic Coatings, 2009

Progress in Organic Coatings, 1996

Thermal stability regimes of silicone based protective coatings have been examined by means of SE... more Thermal stability regimes of silicone based protective coatings have been examined by means of SEM and a.c. impedance techniques. It has been found that the coating has successfully passed the heat resistant test according to the ASTM specification D 2485. Analysis of these results obtained by the above-mentioned techniques reveals that an interesting correlation is found in conjunction with the heat resistive nature of the coating studied.

Journal of Molecular Biology, 2007

Peptidyl-tRNA hydrolase cleaves the ester bond between tRNA and the attached peptide in peptidyl-... more Peptidyl-tRNA hydrolase cleaves the ester bond between tRNA and the attached peptide in peptidyl-tRNA in order to avoid the toxicity resulting from its accumulation and to free the tRNA available for further rounds in protein synthesis. The structure of the enzyme from Mycobacterium tuberculosis has been determined in three crystal forms. This structure and the structure of the enzyme from Escherichia coli in its crystal differ substantially on account of the binding of the C terminus of the E. coli enzyme to the peptide-binding site of a neighboring molecule in the crystal. A detailed examination of this difference led to an elucidation of the plasticity of the binding site of the enzyme. The peptide-binding site of the enzyme is a cleft between the body of the molecule and a polypeptide stretch involving a loop and a helix. This stretch is in the open conformation when the enzyme is in the free state as in the crystals of M. tuberculosis peptidyl-tRNA hydrolase. Furthermore, there is no physical continuity between the tRNA and the peptide-binding sites. The molecule in the E. coli crystal mimics the peptide-bound enzyme molecule. The peptide stretch referred to earlier now closes on the bound peptide. Concurrently, a channel connecting the tRNA and the peptide-binding site opens primarily through the concerted movement of two residues. Thus, the crystal structure of M. tuberculosis peptidyl-tRNA hydrolase when compared with the crystal structure of the E. coli enzyme, leads to a model of structural changes associated with enzyme action on the basis of the plasticity of the molecule.

Anti-Corrosion Methods and Materials, 1997

The coating systems used to protect steel structures from corrosive environments are mainly multi... more The coating systems used to protect steel structures from corrosive environments are mainly multi-layer systems. They consist of an anti-corrosive primer layer, adherent undercoat layer followed by a barrier top coat layer and a weather resistant sealant coating system[1]. ...

Anti-Corrosion Methods and Materials, 1997

In recent years stainless steel flake pigmented coatings have been brought to the attention of pa... more In recent years stainless steel flake pigmented coatings have been brought to the attention of paint formulators. This metal, composed of iron, nickel and chromium, is known to resist most types of staining, tarnishing, oxidation and chemical attack. The stainless steel flake ...

Acta Crystallographica Section F Structural Biology and Crystallization Communications, 2012

Acta Crystallographica Section B Structural Science, 1986

Abstract The crystal structures of (1) L-arginine D-asparate, C6HIsN40~. C4H6NO4 [triclinic, P1, ... more Abstract The crystal structures of (1) L-arginine D-asparate, C6HIsN40~. C4H6NO4 [triclinic, P1, a= 5.239 (1), b= 9.544 (1), c= 14.064 (2) A, a= 85" 58 (1),/3= 88.73 (1),~/= 84.35 (1), Z= 2] and (2) L-arginine D-glutamate trihydrate, C6H15N40~-. CsHsNO4. 3H20 [monoclinic, ...

Journal of Nanoscience and Nanotechnology, 2015

A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic... more A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic method using calcined mesoporous KIT-6 with a diamine source, i.e., N-'[3-(tri methoxysilyl)- propyl]'ethylenediamine. The KIT-6 mesoporous silica used for N-KIT-6 was synthesized under weak acidic hydrothermal method using bitemplates, viz., Pluronic P123 and 1-butanol. The synthesized mesoporous materials, KIT-6 and N-KIT-6, have been characterized by the relevant instrumental techniques such as SAXS, N2 sorption isotherm, FT-IR, SEM, TEM and TGA to prove the standard mesoporous materials with the identification of diamine groups. The characterized mesoporous materials, KIT-6 and N-KIT-6, have been extensively used in the potential application of controlled drug delivery, where ibuprofen (IBU) employed as a model drug. The rate of IBU adsorption and release was monitored by UV vis-spectrometer. On the basis of the experimental results of controlled drug delivery system, the results of IBU adsorption and releasing rate in N-KIT-6 are higher than those of KIT-6 because of the higher hydrophobic nature as well as rich basic sites on the surface of inner pore wall silica.

Mesoporous silica molecular sieves MCM-41 containing zinc and aluminum ions (Zn-Al-MCM-41) with S... more Mesoporous silica molecular sieves MCM-41 containing zinc and aluminum ions (Zn-Al-MCM-41) with Si/(Zn+Al) ratio equal to 340 and 380 and only aluminum ions with Si/Al ratio equal to 93 and 104, respectively, were synthesized under hydrothermal conditions using cetyltrimethylammonium (CTMA+) surfactants as template in the absence of auxiliary organics. The mesoporous materials, viz. Zn-Al-MCM-41 and Al-MCM-41 were characterized using several

Journal of Nanoscience and Nanotechnology, 2014

Hard donor atoms (N and O) containing macrocyclic ligand was synthesized and further functionaliz... more Hard donor atoms (N and O) containing macrocyclic ligand was synthesized and further functionalized with mesoporous SBA-15 materials by chemical modification method. The modification was achieved by the immobilization of 3-chloropropyltriethoxysilane (CIPTES) onto mesoporous silica surface followed by post grafting route. The resulting material (Py-Cy-SBA-15) has been characterized by low angle X-ray diffraction (XRD), nitrogen adsorption-desorption isotherm, Fourier-transform infrared (FT-IR) spectroscopy, 29Si and 13C CP MAS NMR spectroscopic analyses, Thermogravimetric analysis (TGA) and elemental analysis. The long range orders of the materials were identified by transmission electron microscopy (TEM). The functionalized material was employed to the heavy metal ions adsorption from aqueous solution containing Cu2+, Co2+, Zn2+, Cd2+ and Cr2+. The prepared hybrid material showed high selectivity and adsorption capacity for Co2+ ion at pH 8.0.

RSC Adv., 2014

The incessant formation of chain-like IBN-4 mesoporous silica (ICMS-N) with long channels running... more The incessant formation of chain-like IBN-4 mesoporous silica (ICMS-N) with long channels running along the length of hexagonal rods have been directly achieved by the co-condensation of 3-aminopropyltriethoxysilane (APTES) and tetraethylorthosilicate as the silica source in the presence of Pluronic P123 and fluorocarbon (FC-4) surfactants as structure directing agents. The newly synthesized materials were successfully characterized using SAXS, N 2 -physisorption, FT-IR, XPS, 29 Si NMR, TEM, SEM and elemental analysis. TEM images confirmed the chain-like morphologies, whereas SEM studies showed that the synthesized ICMS-N particles possess length >10 mm. Moreover, the as-formed material was tested for the removal of oxyanions such as arsenate and chromate, and it exhibited the maximum adsorption capacity of 55 and 35 mg g À1 for ICMS-N15, respectively. The formation of quaternary species of amine on the surface of the ICMS-N enhanced the adsorption capacity towards arsenate and chromate under acidic pH and the adsorption isotherm fits with Langmuir monolayer adsorption. Naturally, existing anions such as nitrate, sulfate, phosphate and chlorides with 1 Â 10 À2 M have no significant effect on the adsorption of heavy metal ions; moreover, reusability tests were also carried out.

Journal of Colloid and Interface Science, 2013

We prepared stable colloidal suspension graphene in aqueous medium by surface modification of gra... more We prepared stable colloidal suspension graphene in aqueous medium by surface modification of graphene with 4-benzenediazonium sulfonate. The sulfonate group on graphene surface interacts with water, exhibits well dispersibility and which prevents the aggregation even at neutral pH. This dispersion shows stability for three months and facile to produce films. Using such a modified graphene dispersion, transparent conductive film (TCF) has been fabricated on glass substrate by spin coating method. At appropriate concentration, the film exhibits an excellent optoelectrical property with resistivity of 1.1 kX with the transparency of 89% at the wavelength of 550 nm. Further, we also demonstrated the mechanical, thermal, and optoelectrical properties of prepared films.

Journal of Applied Polymer Science, 2013

ABSTRACT Microencapsule was incorporated into an interpenetrating polymer network and applied ove... more ABSTRACT Microencapsule was incorporated into an interpenetrating polymer network and applied over steel surface. A scratch was made on the coated surface and its self healing ability was studied using scanning vibrating electrode technique (SVET) and electrochemical impedance spectroscopy (EIS). Results of SVET studies show that the current density increases in the initial stage. After 24 h, the current density decreases, which indicating the formation of passive polymer film due to the diffusion of core polymer present in the microcapsules through the holidays. Increase in the resistance (107 Ω/cm2) of the self healing coating was observed after 24 h in EIS studies confirming the formation of the passive film. The results of the studies are discussed in this article. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012

The increasing commercial applications of nanoparticles have wide pertinent in the field of medic... more The increasing commercial applications of nanoparticles have wide pertinent in the field of medicine. Biological synthesis of Silver nanoparticles (AgNPs) are effective and environment friendly than chemical methods. In the present study, we demonstrated extracellular synthesis of AgNPs from Sargassum ilicifolium rapidly. The UV-Vis spectra of aqueous medium containing Ag + ions showed peak at 414 nm corresponding to the plasmon resonance of AgNPs. SEM and TEM analysis showed formation of welldispersed AgNPs in the range of 33-40 nm. Antibacterial activity against five clinical pathogens at various concentrations shows impediment in growth at various nanomolar concentrations. Further, the toxicity of biosynthesized AgNPs was tested against Artemia salina to evaluate the cytotoxic effect that displayed LD 50 value of 10nM/ml.

Synthetic Metals, 2008

This study deals with the preparation and characterization of polypyrrole (PPy) using ferric chlo... more This study deals with the preparation and characterization of polypyrrole (PPy) using ferric chloride and ammonium dichromate as oxidants and also with the addition of a common surfactant in aqueous solution. The combination of oxidant and surfactant in the ...

Progress in Organic Coatings, 2005

Polymer blends are used to protect mild steel structures from corrosive environment. Multi-coat p... more Polymer blends are used to protect mild steel structures from corrosive environment. Multi-coat protective coating systems are substituted by single coat polymer blend, which will protect the surface equally for long duration when compared to the multi-coat system. In ...

Progress in Organic Coatings, 2009

Corrosion of steel rebars in reinforced concrete constructions, particularly those located in mar... more Corrosion of steel rebars in reinforced concrete constructions, particularly those located in marine environments and industrially polluted areas is one of the major problems baffling the construction industry all over the world including India. A suitable protective coating to rebar is found to ...

Progress in Organic Coatings, 2005

Conversion coatings on metals enhance paint or lacquer adhesion and promote corrosion resistance.... more Conversion coatings on metals enhance paint or lacquer adhesion and promote corrosion resistance. Present study characterizes three different phosphate baths of zinc phosphate, calcium modified and manganese-modified formulations. It has been observed that manganese ...

Progress in Organic Coatings, 2008

Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts ... more Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts and similar equipments that are permanently or occasionally exposed to elevated temperatures. High-temperature coatings are generally based on silicone resin with ...

Progress in Organic Coatings, 2009

Progress in Organic Coatings, 1996

Thermal stability regimes of silicone based protective coatings have been examined by means of SE... more Thermal stability regimes of silicone based protective coatings have been examined by means of SEM and a.c. impedance techniques. It has been found that the coating has successfully passed the heat resistant test according to the ASTM specification D 2485. Analysis of these results obtained by the above-mentioned techniques reveals that an interesting correlation is found in conjunction with the heat resistive nature of the coating studied.

Journal of Molecular Biology, 2007

Peptidyl-tRNA hydrolase cleaves the ester bond between tRNA and the attached peptide in peptidyl-... more Peptidyl-tRNA hydrolase cleaves the ester bond between tRNA and the attached peptide in peptidyl-tRNA in order to avoid the toxicity resulting from its accumulation and to free the tRNA available for further rounds in protein synthesis. The structure of the enzyme from Mycobacterium tuberculosis has been determined in three crystal forms. This structure and the structure of the enzyme from Escherichia coli in its crystal differ substantially on account of the binding of the C terminus of the E. coli enzyme to the peptide-binding site of a neighboring molecule in the crystal. A detailed examination of this difference led to an elucidation of the plasticity of the binding site of the enzyme. The peptide-binding site of the enzyme is a cleft between the body of the molecule and a polypeptide stretch involving a loop and a helix. This stretch is in the open conformation when the enzyme is in the free state as in the crystals of M. tuberculosis peptidyl-tRNA hydrolase. Furthermore, there is no physical continuity between the tRNA and the peptide-binding sites. The molecule in the E. coli crystal mimics the peptide-bound enzyme molecule. The peptide stretch referred to earlier now closes on the bound peptide. Concurrently, a channel connecting the tRNA and the peptide-binding site opens primarily through the concerted movement of two residues. Thus, the crystal structure of M. tuberculosis peptidyl-tRNA hydrolase when compared with the crystal structure of the E. coli enzyme, leads to a model of structural changes associated with enzyme action on the basis of the plasticity of the molecule.

Anti-Corrosion Methods and Materials, 1997

The coating systems used to protect steel structures from corrosive environments are mainly multi... more The coating systems used to protect steel structures from corrosive environments are mainly multi-layer systems. They consist of an anti-corrosive primer layer, adherent undercoat layer followed by a barrier top coat layer and a weather resistant sealant coating system[1]. ...

Anti-Corrosion Methods and Materials, 1997

In recent years stainless steel flake pigmented coatings have been brought to the attention of pa... more In recent years stainless steel flake pigmented coatings have been brought to the attention of paint formulators. This metal, composed of iron, nickel and chromium, is known to resist most types of staining, tarnishing, oxidation and chemical attack. The stainless steel flake ...

Acta Crystallographica Section F Structural Biology and Crystallization Communications, 2012

Acta Crystallographica Section B Structural Science, 1986

Abstract The crystal structures of (1) L-arginine D-asparate, C6HIsN40~. C4H6NO4 [triclinic, P1, ... more Abstract The crystal structures of (1) L-arginine D-asparate, C6HIsN40~. C4H6NO4 [triclinic, P1, a= 5.239 (1), b= 9.544 (1), c= 14.064 (2) A, a= 85" 58 (1),/3= 88.73 (1),~/= 84.35 (1), Z= 2] and (2) L-arginine D-glutamate trihydrate, C6H15N40~-. CsHsNO4. 3H20 [monoclinic, ...

Journal of Nanoscience and Nanotechnology, 2015

A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic... more A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic method using calcined mesoporous KIT-6 with a diamine source, i.e., N-'[3-(tri methoxysilyl)- propyl]'ethylenediamine. The KIT-6 mesoporous silica used for N-KIT-6 was synthesized under weak acidic hydrothermal method using bitemplates, viz., Pluronic P123 and 1-butanol. The synthesized mesoporous materials, KIT-6 and N-KIT-6, have been characterized by the relevant instrumental techniques such as SAXS, N2 sorption isotherm, FT-IR, SEM, TEM and TGA to prove the standard mesoporous materials with the identification of diamine groups. The characterized mesoporous materials, KIT-6 and N-KIT-6, have been extensively used in the potential application of controlled drug delivery, where ibuprofen (IBU) employed as a model drug. The rate of IBU adsorption and release was monitored by UV vis-spectrometer. On the basis of the experimental results of controlled drug delivery system, the results of IBU adsorption and releasing rate in N-KIT-6 are higher than those of KIT-6 because of the higher hydrophobic nature as well as rich basic sites on the surface of inner pore wall silica.

Mesoporous silica molecular sieves MCM-41 containing zinc and aluminum ions (Zn-Al-MCM-41) with S... more Mesoporous silica molecular sieves MCM-41 containing zinc and aluminum ions (Zn-Al-MCM-41) with Si/(Zn+Al) ratio equal to 340 and 380 and only aluminum ions with Si/Al ratio equal to 93 and 104, respectively, were synthesized under hydrothermal conditions using cetyltrimethylammonium (CTMA+) surfactants as template in the absence of auxiliary organics. The mesoporous materials, viz. Zn-Al-MCM-41 and Al-MCM-41 were characterized using several

Journal of Nanoscience and Nanotechnology, 2014

Hard donor atoms (N and O) containing macrocyclic ligand was synthesized and further functionaliz... more Hard donor atoms (N and O) containing macrocyclic ligand was synthesized and further functionalized with mesoporous SBA-15 materials by chemical modification method. The modification was achieved by the immobilization of 3-chloropropyltriethoxysilane (CIPTES) onto mesoporous silica surface followed by post grafting route. The resulting material (Py-Cy-SBA-15) has been characterized by low angle X-ray diffraction (XRD), nitrogen adsorption-desorption isotherm, Fourier-transform infrared (FT-IR) spectroscopy, 29Si and 13C CP MAS NMR spectroscopic analyses, Thermogravimetric analysis (TGA) and elemental analysis. The long range orders of the materials were identified by transmission electron microscopy (TEM). The functionalized material was employed to the heavy metal ions adsorption from aqueous solution containing Cu2+, Co2+, Zn2+, Cd2+ and Cr2+. The prepared hybrid material showed high selectivity and adsorption capacity for Co2+ ion at pH 8.0.

RSC Adv., 2014

The incessant formation of chain-like IBN-4 mesoporous silica (ICMS-N) with long channels running... more The incessant formation of chain-like IBN-4 mesoporous silica (ICMS-N) with long channels running along the length of hexagonal rods have been directly achieved by the co-condensation of 3-aminopropyltriethoxysilane (APTES) and tetraethylorthosilicate as the silica source in the presence of Pluronic P123 and fluorocarbon (FC-4) surfactants as structure directing agents. The newly synthesized materials were successfully characterized using SAXS, N 2 -physisorption, FT-IR, XPS, 29 Si NMR, TEM, SEM and elemental analysis. TEM images confirmed the chain-like morphologies, whereas SEM studies showed that the synthesized ICMS-N particles possess length >10 mm. Moreover, the as-formed material was tested for the removal of oxyanions such as arsenate and chromate, and it exhibited the maximum adsorption capacity of 55 and 35 mg g À1 for ICMS-N15, respectively. The formation of quaternary species of amine on the surface of the ICMS-N enhanced the adsorption capacity towards arsenate and chromate under acidic pH and the adsorption isotherm fits with Langmuir monolayer adsorption. Naturally, existing anions such as nitrate, sulfate, phosphate and chlorides with 1 Â 10 À2 M have no significant effect on the adsorption of heavy metal ions; moreover, reusability tests were also carried out.