Thermogravimetric Analysis (TGA) measures the amount and rate of change in the weight of a material as a function of temperature or time in a controlled atmosphere. Measurements are used primarily to determine the composition of materials and to predict their thermal stability at temperatures up to 1000°C. The technique can characterize materials that exhibit weight loss or gain due to decomposition, oxidation, or dehydration.
Differential scanning calorimetry (DSC) – versatile, reliable and most popular methods of thermal analysis. Instruments work on the principle of heat flow and have a three-dimensional symmetrical design with uniform heating. Highly sensitive calorimetric μ-sensors, a low time constant of devices provide a stable, reproducible baseline during prolonged and intensive use of the appliance. It is also possible to carry out measurements at high pressure, using mechanical coolers and external refrigerants – programmable cooling of the sample using compressed cold air or liquid nitrogen.
Simultaneous Thermal Analysis (STA) is the combination technique between DSC/DTA and TGA yields the simultaneous application of Thermogravimetric analysis (TGA) and Differential Scanning Calorimeter (DSC) to one and same sample in one instrument. STA can provide several benefits such as the test condition are perfectly identical for TGA and DSC signal (same atmosphere, heating rate, radiation effect, etc.), improved sample throughput, provide more comprehensive test result and it is the solution if you have limited amount of samples.
Thermomechanical Analysis (TMA) determines dimensional changes of solids, liquids or pasty materials as a function of temperature and/or time under a defined mechanical force. It is closely related to Dilatometry, which determines the length change of samples under negligible load. Many materials undergo changes of their thermomechanical properties during heating or cooling. For example, phase changes, sintering steps or softening can occur in addition to thermal expansion.
When heat is produced in a sample, isothermal calorimetry measures the heat flow. The sample is placed in an ampoule that is in contact with a heat flow sensor that is also in contact with a heat sink. When heat is produced or consumed by any process, a temperature gradient across the sensor is developed. This will generate a voltage, which is measured. The voltage is proportional to the heat flow across the sensor and to the rate of the process taking place in the sample ampoule.
Isothermal Titration Calorimetry (ITC) is a technique used in quantitative studies of a wide variety of biomolecular interactions. It works by directly measuring the heat that is either released or absorbed during a biomolecular binding event. ITC is the only technique that can simultaneously determine all binding parameters in a single experiment. Requiring no modification of binding partners, either with fluorescent tags or through immobilization, ITC measures the affinity of binding partners in their native states.
Vapor Sorption Analysis is a technique in which a sample is subjected to varying conditions of humidity and temperature, and the response of the sample is measured gravimetrically. Understanding the effects of water content on structure and properties is critical in the development, processing and end use of a broad spectrum of materials. The introduction of DVS fundamentally changed the field of gravimetric moisture sorption measurement, bringing outdated, time and labor intensive desiccator use into the modern world of cutting-edge instrumentation and overnight vapor sorption isotherms. DVS is a valued tool in laboratories all over the world from polymorphism and compound stability studies to bulk and surface adsorption effects of water and organic vapors.
Chemisorption refers to the chemical adsorption and desorption phenomena by which gas or vapor molecules bond to or are liberated from the solid surface of sample material. Temperature-programmed analyses are used to study chemisorption bonds under controlled conditions of varying thermal energy. Perhaps the most illustrative example of a temperature-controlled reaction study is the temperature-programmed desorption (TPD) analysis in which the temperature of the sample is increased until the thermal energy is sufficient to break the chemisorption bond.
The method of standard porometry is based on the principle of capillary equilibrium. When two partially saturated porous bodies are in contact, the system moves toward an equilibrium state where the capillary pressures of the liquid in both bodies are equal. SP exploits this phenomenon by placing the unknown sample in capillary contact with a standard sample. When the system is deemed to be in capillary equilibrium, the mass of each sample is determined.
