Termogravimetriás

Termogravimetria is an analytical technique used to measure the change in mass of a sample as a function of temperature or time in a controlled atmosphere. It is a subset of thermal analysis, where other techniques like differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) measure other physical properties as a function of temperature. In thermogravimetry, the sample is placed on a high-precision balance and heated or cooled at a programmed rate. The resulting data is a thermogravimetric curve, which plots mass versus temperature or time.

The mass changes observed in a thermogravimetric analysis can be attributed to several phenomena. These include decomposition, desorption, oxidation, reduction, and the loss or gain of water or other volatile components. By analyzing the shape, temperature range, and magnitude of these mass changes, researchers can gain valuable information about the thermal stability of materials, reaction kinetics, composition, and purity.

Thermogravimetric analysis is widely applied in various fields. In materials science, it is used to study the degradation of polymers, ceramics, and composites, as well as to determine the composition of inorganic materials. In pharmaceuticals, it can be employed to assess the drying process of active pharmaceutical ingredients and excipients. The petrochemical industry uses TGA to analyze the thermal decomposition of fuels and lubricants. Other applications include the analysis of catalysts, foods, and environmental samples. The specific atmosphere used during the analysis, such as inert (e.g., nitrogen, argon) or reactive (e.g., air, oxygen), significantly influences the observed results and provides further insights into the material's behavior.