SGER: Microrheology of Liquid-Liquid Interfaces

Texas Tech University, Lubbock TX

Investigators

Abstract

PROPOSAL NO.: CTS-0624011 PRINCIPAL INVESTIGATORS: LENORE DAI INSTITUTION: TEXAS TECH UNIVERSITY SGER: MICRORHEOLOGY OF LIQUID-LIQUID INTERFACES The objective of this grant is to explore microrheology of liquid-liquid interfaces. Rheology is of critical importance in various natural and industrial processes. The rheology of liquid-liquid interfaces plays a critical role in interfacial self-assembly, membrane stability, emulsion stability, and lubrication. The PI has conducted proof-of-concept experiments and demonstrated the feasibility of doing single-particle microrheology at oil-water interfaces. However, the research remains exploratory and the methodology needs further validation. The following specific objectives are proposed: (1) evaluate the effect of potential specific interaction between the probe particle and the surrounding medium, (2) replace the oil-water interfaces with oil-oil interfaces where the two liquids have comparable viscosity, and (3) develop two-particle microrheology of liquid-liquid interfaces. The proposed work is anticipated to validate microrheology of liquid-liquid interfaces. Although initial proof-of-concept experiments were successful and promising, the intriguing preliminary results demonstrate the need for further investigation in order to validate microrheology of liquid-liquid interfaces. Although the nature of this investigation is exploratory and risky, the validation of microrheology at liquid-liquid interfaces will open new and important opportunities to the science and technology community. In addition, this research will serve as a standard for applying microrheology to other 2-D systems such as membranes, Langmuir-Blodgett films, etc. which exhibit complicated heterogeneity. There is urgency to establish such a standard otherwise the application of single-particle microrheology to 2-D complicated problems may lead to erroneous conclusions. The grant will support a graduate student to conduct advanced research and give the PI opportunities to incorporate a contemporary subject in an undergraduate class of Engineering Experimentation. In addition, the PI will participate the Teaching Training Institute program at the College of Engineering at Texas Tech and a science teacher from the O'Donnell High School, will work with the PI for 9 weeks in the summer of 2006.