M. Adhikari

Bio: M. Adhikari is an academic researcher. The author has contributed to research in topic(s): Isothermal process & Thermal decomposition. The author has an hindex of 1, co-authored 2 publication(s) receiving 3 citation(s).

Thermal Decomposition of Vermiculites: Kinetics of Dehydration and Dehydroxylation Processes

Abstract: The thermal decomposition reactions of some homoionic clay minerals, viz. vermiculite, in air in the temperature range 30°-1000°C by thermo-analytical methods are reported. The reaction kinetic of isothermal dehydration and dehydroxylation is found to obey first order reaction rate.

Studies on Mineralogical Properties of Vermiculites and Chlorites of Indian Origin

Abstract: Mineralogical characterizations of some Indian vermiculites and chlorites are reported. Significant differences in X-ray and thermal properties are observed. Such anomalies of the properties are presumably due to presence of mixed layer minerals and/or other contaminations.

Thermal behavior study of pristine and modified halloysite nanotubes

Abstract: Pristine halloysite nanotubes (HNTs) were studied by thermogravimetry (TG) up to 800 °C. Etching of alumina from inside the tube (causing a significant increase in tube lumen) was realized by treating the material with an acidic H2SO4 solution at 50 °C. Both materials were characterized by TG-FTIR techniques and their thermal behaviors were compared with that of kaolinite. The coupling of TG with FTIR enables to detect the gases evolved during the TG experiments, thus confirming that only pristine HNTs undergo dehydration with the loss of interlayer water molecules at around 245 °C, while dehydroxylation occurs in all these materials in close temperature ranges around 500 °C. TG runs at five different heating rates (2, 5, 10, 15 and 20 °C min−1), was carried out in the same experimental conditions used for the thermal analysis study with the aim to investigate dehydration and dehydroxylation kinetics using some isoconversional methods recommended by the ICTAC kinetic committee, and thermogravimetric data under a modulated rising temperature program. Finally, the results of the kinetic analysis were discussed and explained in terms of the strengths of the hydrogen bonds broken during these processes.

Thermal study of vermiculites and mica-vermiculite interstratifications

Abstract: Simultaneous DTA-TG has been carried out on a set of natural vermiculite samples. Based on their dehydration behaviour the samples can be divided in two groups: (a) those with DTA endothermic peak temperatures at 140°–150°C and 240°–270°C (pure vermiculties) and (b) those with peak temperatures at 95°–115°C (vermiculite with mica or mica-vermiculite interstratifications). The low temperature at which the endothermic effect in group (b) appears is discussed on the basis of dilution due to the inert layers of mica, differences in chemical composition, and lowering of interlamellar water bond energy.

Thermal Decomposition of Vermiculites: Kinetics of Dehydration and Dehydroxylation Processes

Abstract: The thermal decomposition reactions of some homoionic clay minerals, viz. vermiculite, in air in the temperature range 30°-1000°C by thermo-analytical methods are reported. The reaction kinetic of isothermal dehydration and dehydroxylation is found to obey first order reaction rate.