Biography
Diptesh G Naik is pursuing his Doctoral degree under the guidance of Prof. Vishnu S Nadkarni at Goa University since 2012. He has completed his Master’s degree from Goa University, Goa in the year 2009 securing 3rd rank in Physical Chemistry. He has 2 publications in international journals and 1 Indian patent.
Abstract
In 1958, D A Young detected latent tracks in LiF crystal which lead to development of a new field solid state nuclear track detection (SSNTD) technique. After the invention, many materials like minerals, glasses, plastics, etc. were used as detectors in SSNTD application. For the first time, in 1966, K. Becker used phosphate glass as nuclear track detector. Barium phosphate BP-1 glass, LG-750 phosphate glass and various other sensitive phosphate glasses have been utilized as track detectors. Eventually, it was found that glass detectors showed poor radiation sensitivity as compared to many plastic detectors. Plastic materials like cellulose nitrate, bisphenol-A polycarbonate (lexan), poly (allyl diglycol carbonate) (CR-39), etc. were then used as track detectors. Out of which CR-39 was found out to be the best detector with high radiation sensitivity compared to all other detectors. Most of the reported polymeric track detectors have either -SO2-, -SO3-, -CO3- or - ONO2 linkage; there are no reports about the use of phosphate-carbamate containing polymers in track detection. Already, we have reported the application of poly triallyl phosphate PTAP and their copolymers with allyl diglycol carbonate (ADC) in international journal. At Goa University, we are involved in developing polymeric track detectors containing different radiation sensitive functionalities. Here, we report preparation of some novel polymeric track detectors having carbonate-phosphate; carbamate-phosphate linkages for their use in SSNTD. Poly (triallyl phosphate-co-pentaerythritol tetrakis allyl carbonate) i.e. poly (TAP-co-PETAC) and poly (triallyl phosphate-co-N-allyloxy diallyl carbamate) i.e. poly (TAP-co-NADAC) were prepared and successfully tested for SSNTD application. The alpha sensitivity as well as alpha track detection efficiency of the copolymers was compared with that of imported CR-39. It is observed that the alpha sensitivity of the copolymers was much better than that of CR-39.
Biography
Maria de los Angeles Vargas has completed her PhD from Mexico University and Post-doctoral studies from Institute of Technology Karlsruhe in Germany. She has a Lecturer position at the Higher Education Technology in Chemical Engineering Department, Mexico. She has published more than 16 papers in reputed journals and book chapters in NMR at 20 MHz: Possibilities and Challenges.
Abstract
The curing kinetics of UP nanocomposites prepared by incorporating different amounts of two kinds of organo-montmorillonite (organo-MMT): trimethyloctadecacylammonium chloride (TMOA) and aminopropyl-triethoxysilane (APTES) were studied by non-isothermal differential scanning calorimetry (DSC) experiments. Small angle X-ray scattering (SAXS) was used for measuring the d-spacings in the modified organo-clays, and no intercalation UP into these clays was observed for the nanocomposites. HRTEM images showed dispersed and agglomerated platelets in UP/APTES 2 and 10 wt.%. DSC analysis showed two peaks in UP resins and UP/organo-MMT, and a decrease in the exothermal peaks temperature (Tp1 and Tp2) for nanocomposites with the heating rate as compared with those of neat UP system; thus, the higher the heating rate, the higher the curing reaction rate. This effect was more clearly on the UP/MMT-APTES nanocomposites. The effective activation energies (Ea) were determined with the mode-free isoconversional Starik’s method. Sesták–Berggren model was chosen to simulate the reaction rate with a good match achieved. Thermal gravimetric analysis showed that the cured UP/APTES at high concentration were slightly more stable than UP and TMOA.