N. Rajeswara Rao; T. Venkatappa Rao; S.V.S. Ramana Reddy; B. Sanjeeva Rao
Abstract
Thermal, morphological and antioxidant properties of lignin irradiated with electron beam (EB) of doses 30, 60 and 90 kGy have been investigated by Electron spin resonance (ESR), Fourier transform infrared spectroscopy, Differential scanning calorimetry, Scanning electron microscope and Spectrophotometer ...
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Thermal, morphological and antioxidant properties of lignin irradiated with electron beam (EB) of doses 30, 60 and 90 kGy have been investigated by Electron spin resonance (ESR), Fourier transform infrared spectroscopy, Differential scanning calorimetry, Scanning electron microscope and Spectrophotometer techniques. ESR studies confirm the presence of poly-conjugated radicals in unirradiated lignin; whereas irradiated lignin posses both poly-conjugated and peroxy radicals. The peroxy radicals decay near the glass transition point on thermal heating while poly-conjugated radicals are stable even up to a temperature of 450K. Presence of conjugated structures is confirmed by the presence of 1604 cm -1 absorption band whose concentration increases following radiation dose. Up to a radiation dose of 60 kGy the fall in glass transition temperature (Tg) is very slow, while at 90 kGy Tg decreased abruptly. The decrease in Tg is assigned to be due to intermolecular chain interactions or plasticization effect. Granular structure of lignin is found to be effected by EB irradiation. Cracks were generated on lignin granules on EB irradiation. Due to increase in poly-conjugation, amorphous nature and granular cracks the antioxidant property is observed to increase. The current research trends in lignin materials include modification of lignin, fabrication of biodegradable thermoset/thermoplastic and use of lignin as stabilizers and dispersants.
Umesh Kumar Parida; S. K. Biswal; B.K. Bindhani
Abstract
Gold nanoparticles (AuNPs) have found widespread applications in life sciences. Gold nanoparticles are of interest because of the unique properties which can be incorporated into cancer therapy applications, biosensor materials, composite fibers, cryogenic superconducting materials, cosmetic products, ...
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Gold nanoparticles (AuNPs) have found widespread applications in life sciences. Gold nanoparticles are of interest because of the unique properties which can be incorporated into cancer therapy applications, biosensor materials, composite fibers, cryogenic superconducting materials, cosmetic products, and electronic components. In the present research program, cost effective and environment friendly gold nanoparticles were synthesized using red grape pomace (GPM) ethanolic extract as a reducing agent and a capping agent. The nanoparticles were characterized using UV-visble, XRD, TEM and DLS methods. The absorption peak at 554 nm was found to be broadening with increase in time indicating the polydispersity nature of the nanoparticles. The XRD results suggested that the crystallization of the bioorganic phase occurs on the surface of the gold nanoparticles or vice versa. The TEM image showed relatively spherical shape nanoparticles. We also Purified anti-OMP85 antibody were successfully conjugated on 13 ± 34 nm gold nanoparticles by an electrostatic adsorption method.