Characterizing the adsorption phenomenon that occurs at solid/liquid interfaces is an important subject not only in academia but also in industry. One of the instrumental analysis methods that can approach this subject is the quartz crystal microbalance with dissipation monitoring (QCM-D) technique. The QCM-D technique can estimate not only the mass of materials adsorbed at solid/liquid interfaces but also the viscoelasticity of the adsorbed film with high sensitivity and excellent time-resolution. Furthermore, the QCM-D technique can be used in a wide range of application fields, owing to its wide variety of materials coated on sensor surfaces and its capability of evaluating colored or turbid liquid samples. In this article, the basic principle of the QCM-D technique is explained and then some recent QCM-D results relevant to the fields of cleaning and tribology are reviewed.

While QCM-D has long been growing its major reputation as a powerful scientific instrument dedicated for the academic primary research, we see that in recent years it has been starting broad utilizations in the fields of industrial applied research as an analytical instrument providing practical “solutions” to their process issues. By introducing typical use cases we would like to show the true analytical capabilities of QCM-D contributing to various industrial applications.

I presented the results of my research on Behavior of High Concentrated α-gel made by Kneading Mixer at Annual Meeting of the Japan Oil Chemisits’ Society 2023. It showed α-gels with a large bilayer distance could be efficiently prepared by the process, structural analysis, but it has not been completed such as why the resulting gels were so transparent. This reports the structural analysis of Gel Network using new observation and analysis method. Also, this introduces a method for quantitatively measuring α-gel formation efficiency.