Prasanta Kumar Sinha

Central Glass and Ceramics Research Institute | CGCRI · Material Characterisation Division

Processing of commercial bioactive glasses in the form of scaffolds, fibers and coatings on metal implants is a major challenge due to their high crystallization tendency leading to loss of many desirable functionalities relevant to bone tissue engineering applications. In this context, this work focuses on developing borosilicate bioactive glasses...

In this report, we have systematically evaluated the role of boron in regulating the degradation, apatite formation and antibacterial properties of bioactive glasses by substituting SiO2 with B2O3 in S53P4 based glass composition. The structural analysis of the glasses has been carried out using neutron diffraction and Raman spectroscopic technique...

Oxide‐bonded porous SiC ceramic filter supports were prepared using SiC powder (d50=212 μm), Al2O3 and clay as bond forming additives and graphite as pore‐former following reaction bonding of powder compacts at 1400°C in air. Reaction bonding characteristics, phase composition, porosity, pore size, mechanical strength and microstructure of porous S...

Zn1-xMgxO / Cu2O / Ag solar cells were fabricated upon fluorine doped tin oxide coated soda lime glass substrate with varying percentage of Mg mol% doping in zinc oxide (ZnO) layer. Short circuit current density & open circuit voltages of the fabricated cells were investigated. Optimum doping with Mg improved the transparency of ZnO layer which hel...

The present work focuses on the synthesis and structural elucidation of fluoride containing bioactive glasses in the system (in mol%) given by (53.86) SiO2 – (22.65) Na2O – (21.77-x) CaO – (1.72) P2O5 – x CaF2, where, x = 0, 5.44, 10.885 and 16.33. The role of the incorporated fluoride and its distribution within the glass were interpreted and anal...

Thin films of ZnO nanorods (ZnO NRs) and CdS coated ZnO nanorods (ZnO NRs/CdS) core shell structures have been prepared for comparison study. ZnO NRs were fabricated on to fluorine doped tin oxide (FTO) coated soda lime glass (SLG) substrate by a two step chemical routes viz. spin coating and electrochemical deposition. CdS layer on the surfaces of...

The present work elucidates about the structure of bioactive glasses having chemical compositions expressed as (mol %) (50.0-x) SiO2 - x B2O3 - 9.3 Na2O - 37 CaO - 3.7 P2O5, where x = 0.0, 12.5, 25 and 37.5, and establishes a correlation between the structure and thermal stability. The structural modifications in the parent boron free glass (B0) wi...

Iron impurity in raw material remains a major challenge in producing colourless glass. In this investigation, we report microwave (MW) heating capable of altering Fe-redox ratio (Fe2+/∑Fe) enabling preparation of colourless phosphate glass. The effect of Sn concentration in retention of Fe[II] in glass melted in MW was compared with conventional gl...

Chronic osteomyelitis, a bone infection caused by bacteria, requires extensive parenteral treatments. With an aim to develop bioactive glass with antibacterial properties to resist such infections, bioactive glasses with bismuth oxide as the dopant in various amounts up to 8 wt% were prepared. X-ray diffraction patterns and Fourier-transform infrar...

Mesoporous alumina (MA) was prepared via the sol–gel process at 40 °C/48 h followed by calcinations at 550 °C/5 h, in the absence of organic acids and in the presence of malic, tartaric, and citric acids (sample IDs: A-550, AM-550, AT-550, and AC-550, respectively). For fluoride ion adsorption on MA, the effects of different parameters such as cont...

Glass comprising B2O3-Al2O3-Na2O-ZnO with doping iron metal powder has been melted at 1200 °C under microwave heating. The identical batch was melted in resistive heating. UV–Vis-NIR spectroscopy has been employed to determine the ferrous ion intensity in glass within 1000–1200 nm wavelength and recorded spectra for both the glasses indicate higher...

In the present study, Fe-doped barium borosilicate glass has been melted at 1250 degrees C under microwave heating. The iron redox ratio (Fe2+/total Fe) in the glass is investigated by two spectrophotometric methods. A novel decomposition technique has been optimized to measure the ferrous oxidation state in glass. Ferrozine was chosen as a specifi...

Iron doped phosphate glasses containing P2O5-MgO-ZnO-B2O3-Al2O3 were melted using conventional resistance heating and microwave heating in air and under reducing atmosphere. All the glasses were characterised by UV-Vis-NIR spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis and wet colorimetry analysis. Mössbauer spectroscopy revealed...

We report tuning of thickness of polymeric bi-layers, deposited by Electrostatic Self Assembly on the surface of a Long Period Fiber Grating to obtain optimum sensitivity with varying pH of polyelectrolyte for immunoassay experiments.

In this work we propose a five-layer model of a long period grating. The model redefines LPG sensitivity and accurately interprets bio-molecular interaction that occurs on the LPG surface. Experimental results are compared with theory.

We report tuning of thickness of polymeric bi-layers, deposited by Electrostatic Self Assembly on the surface of a Long Period Fiber Grating to obtain optimum sensitivity with varying pH of polyelectrolyte for immunoassay experiments.

In this work we propose a five-layer model of a long period grating. The model redefines LPG sensitivity and accurately interprets bio-molecular interaction that occurs on the LPG surface. Experimental results are compared with theory.

For detecting bio-molecular interaction using long period grating (LPG) we believe that a quantitative data concerning sensitivity for addition of layers on the surface and subsequently to optimize the same appears to be more usefull than defining LPG sensitivity for a surrounding refractive index change in bulk form. For the first time, to the bes...

A simple and reliable analytical method was developed using inductively coupled plasma atomic emission spectrometry (ICP-AES) for rapid simultaneous determination of aluminium, barium and potassium as host materials in neodymium doped phosphate laser glass. The method has been developed by checking the spectral interferences for the optimal line se...

Simple, rapid and accurate spectrophotometric method is presented for the determination of arsenic in water. The method is based on the preconccntration of arsenomolybdate on polyurethane foam followed by its elution in acetone and formation of ion association complex of arsenomolybdate with Rhodamine B. The absorbance of the complex is measured at...

A simple, rapid and reliable analytical procedure has been developed for the determination of transition elements such as Fe, Cu and Cr in neodymium doped phosphate laser glass samples using inductively coupled plasma-atomic emis- sion spectrometry (ICP-AES). The ICP-AES method has been developed and was optimized through several parameters such as...

Heavy metals like lead and cadmium were found to leach out from food contact surface of opal glass dinnerware when treated with five food acids as a leaching solution. The leachates used were: acetic acid, tartaric acid, citric acid, lactic acid and ascorbic acid at three different concentrations 2%, 4%, and 8% (v/v). At room temperature, duration...

Raman study of CN-stretching mode of acrylonitrile and ring-breathing mode of 2Cl-phenol was made in the binary mixture of (acrylonitrile + 2Cl-phenol) at different molar ratios of the two components. Raman spectra were recorded in the different spectral regions, 990–1070 cm−1 and 2170–2300 cm−1. Ring-breathing mode of 2Cl-phenol exhibited two comp...

Reaction of four phenolate ligands, viz. N-(2-hydroxyphenyl)salicylaldimine (H2L1), 2,2′-dihydroxyazobenzene (H 2L2), N-(2-carboxyphenyl)salicylaldimine (H 2L3) and 2-carboxy-2′-hydroxy-5′- methylazobenzene (H2L4) (abbreviated in general as H 2L, where H stands for the acidic protons), has been carried out with [Ru(trpy)Cl3] (trpy = 2,2′,2″-terpyri...

FT-Raman and FT-infrared spectra of pyridine-2-carboxylic acid (picolinic acid) and its corresponding trans-diaquabis(picolinato)zinc(II) dihydrate complex were recorded. Density functional theory was used in order to calculate the optimized geometries and harmonic vibrational wavenumbers of the coordination compound and its isolated ligand. The ca...

Reaction of three phenolate ligands, viz. 2,4,6-tribromophenol (HL1, where H stands for the phenolic proton), 2-nitrophenol (HL2) and 2,4,6-trinitrophenol (HL3O), with [Ru(PPh3)3Cl2] in a 2:1 molar ratio in the presence of a base gives complexes of type [Ru(PPh3)2(L)2] (L=L1, L2 and L3). The 2,4,6-tribromophenolate ligand (L1) binds to ruthenium as...

Reaction of phenols containing a second donor site linked to the ortho- position [viz. 2,4,6-tribromophenol (HL1), 2-nitropllenol (HL2) and 2,4,6- trinitrophenol-(HL3)] with [Ru(bpy)2Cl2] in the presence of a base has afforded complexes of the type [Ru(bpy)2(L)]+ (where L stands for the deprotonated ligands), which have been isolated as perchlorate...

Seven complexes of the type [RuIII(PPh3)2(L)Cl2] (where L = 8-quinolinolate, 4-methyl-2-(phenylazo) phenolate and salicylal-diminate anion) have been synthesized by the reaction of [Ru(PPh3)3Cl2] with HL. These complexes are one-electron paramagnetic and show rhombic ESR spectra in 1:1 dichloromethanetoluene at 77 K. In CH2Cl2 solution, these compl...

Some ruthenium(II) complexes of type [Ru11 (trpy) (L)Cl] [trey = 2,2′: 6′,2″-terpyridine ; L = salicylaldiminate and 2-(arylazo)phenolate anion] have been synthesized and characterized. The complexes are diamagnetic (low-spin d6, S = 0) and show intense metal-to-ligand charge transfer transitions in the visible region. Cyclic voltammetry of these c...