Thermogravimetric analysis

About: Thermogravimetric analysis is a(n) research topic. Over the lifetime, 37248 publication(s) have been published within this topic receiving 862144 citation(s). The topic is also known as: thermal gravimetric analysis & TGA.

A New Method of Analyzing Thermogravimetric Data

Abstract: A new method of obtaining the kinetic parameters from thermogravimetric curves has been proposed. The method is simple and applicable to reactions which can not be analyzed by other methods. The effect of the heating rate on thermogravimetric curves has been elucidated, and the master curve of the experimental curves at different heating rates has been derived. The applications of the method to the pyrolyses of calcium oxalate and nylon 6 have been shown ; the results are in good agreement with the reported values. The applicability of the method to other types of thermal analyses has been discussed, and the method of the conversion of the data to other conditions of temperature change has been suggested. From these discussions, the definition of the thermal stability of materials has been criticized.

The characterization of activated carbons with oxygen and nitrogen surface groups

Abstract: The physicochemical properties and the surface chemical structure of the carbon materials obtained by the modification of the commercial activated carbon D43/1 (Carbo-Tech, Essen, Germany) were studied. The previously de-ashed activated carbon was subjected to the following modification procedures: high-temperature treatment (1000 K) under vacuum; oxidation with conc, nitric acid; and ammonia-treatment of annealed and oxidised carbons at high temperatures. The porous structure and the surface area of the five different carbon samples obtained were estimated by means of mercury porosimetry and from low-temperature nitrogen adsorption data. The thermogravimetric analysis and the quantitative determination of surface functional groups by selective neutralisation of bases and pH-metric titration were carried out. FTIR spectra (transmission) and X-ray photoelectron spectra (Cls, Ols and Nls) were obtained for all the carbon samples and compared with one another. The changes in the porosity and the chemical properties of the carbon surface caused by the modification were analysed. Some possible surface functional species, their structure and surface state are discussed.