Interfacial Selective Study on the Gelation Behavior of AqueousMethylcellulose Solution via a Quartz Crystal Microbalance

:it is important to understand the interfacial structureand physical properties of a polymer material to improve itsfunction. In this study, we used a quartz crystal microbalance(QCM) and neutron reflectivity (NR) measurements to evaluate theviscoelasticity and structure of an aqueous methylcellulose solutionnear the gold interface. The apparent shear modulus, which wascalculated from the complex frequency, was used to assess gelationbehavior. The apparent shear modulus determined via the QCMsuggested high-frequency rheological properties that reflected therelaxation of skeletal stretching and rotational motion of polymersegments, as well as cooperative motion of the various functionalgroups. The gelation temperature was found to be lowered at theinterface in comparison with that of the bulk. It is suggested that theQCM can evaluate the shear modulus accompanying the gelation near the interface. The interfacial segregation on the gold substratecaused by the surface free energy and long-range van der Waals interaction was observed from NR measurements.

Automated summary

Understanding the interfacial structure and physical properties of polymer materials is crucial for enhancing their functionality. This study utilized QCM and NR measurements to assess the viscoelasticity and structure of an aqueous methylcellulose solution near the gold interface. QCM provided information about the shear modulus accompanying gelation, while NR revealed interfacial segregation on the gold substrate.