Characterization of the Dynamic Behavior of Particle Contact Angle at an Oil/Water Interface

Texas Tech University, Lubbock TX

Investigators

Abstract

CBET - 1604398 PI: Snoeyink, Craig Immiscible liquid drops that are coated with small colloidal particles are known as colloidosomes. They are used in a variety of technological applications, including drug delivery, tissue engineering, and food preservation. Water colloidosomes in air are used in gas sensing and as ball bearings. The goal of this project is to develop a new experimental technique to determine how the contact angles between the surfaces of the particles and the interface influence the dynamics of the interface and the overall behavior of the colloidosomes. The results will be useful to practitioners to design better and more robust colloidsomes for use in biomedical, sensing, and consumer products. The project will provide opportunities for students, especially those from underrepresented groups, to participate in the research, and the researchers will develop a class in soft matter for a summer camp for grade five through eleven girls. Three-dimensional particle locating Bessel Beam microscopy will be built into an interfacial rheometer to allow real-time monitoring of the three-dimensional position of colloidal particles at an interface under highly controlled interfacial deformations including steady and oscillatory shear. Images obtained from the microscope will be analyzed to determine the position and orientation of nonspherical particles with twenty nanometer resolution. The effects of particle shape, interfacial microstructure, and interfacial flow on the contact angle distribution and particle dynamics will be determined. This method represents a significant improvement over current contact angle measurement techniques, because it will provide real-time data on the locations and orientations of densely packed particles under well-controlled interface deformations.