The Modern Thermogravimetric Approach to the Compositional Analysis of Materials

摘要: Thermogravimetry (TG) is an analytical technique that monitors the mass of a substance as it is subjected to a controlled temperature program. TG is the modern day frontier of the much older and well-established technique of gravimetry. Although many compositional analyses may be performed by conventional gravimetry, thermogravimetry offers a more rapid method because of the smaller sample size and faster heating rates. Thus, special instrumentation requirements are imposed on the more modern, rapid, and automated thermogravimetric method. Many commercial TG systems are available. The major difference in these are in the furnace (size, design, and positioning with respect to the furnace tube and sample specimen), degree of computerization, direction of purge gas flow (horizontal or vertical) with respect to the sample specimen, and microbalance type and sensitivity. Recent years have brought computerization of data handling as well as many of the hardware components of the technique. This paper will present and discuss the role of the basic components of a thermogravimetric apparatus in performing compositional analysis. Some of the aspects of computerization of the technique will be included.