Quartz Crystal Microbalances for Microscale Thermogravimetric Analysis
Elisabeth Mansfield, Aparna Kar, Stephanie A. Hooker
A new method for analyzing the chemical purity and consistency of microscale samples is described using a quartz crystal microbalance (QCM) sensor platform. The QCM is used to monitor sub-picogram changes in the mass of a deposited thin film as a function of temperature, in a manner similar to a conventional thermogravimetric analyzer (TGA). Results correlated well with TGA for a wide range of representative materials, including organic compounds, ionic detergents, oxidizing and inert powders, carbon nantoubes, and various mixtures of these. In each case, the sample size was on the order of a few micrograms, compared to the need for several milligrams for conventional TGA analysis, illustrating the effectiveness of this approach for analysis of nanoparticles, thin films, and highly purified specimens.