Summary: High-interface materials like foams and emulsions are
ubiquitous in the world around us. For example, emulsions
find extensive use in drug delivery and in advanced (and
mundane) materials, and give both taste and texture to a fine
espresso. The simple act of breathing inflates and deflates
millions of alveoli and the stability, processing, and ultimate
performance of these systems depends crucially on the
properties of the interfaces. While centuries have been
devoted to the study of such equilibrium properties of
interfaces (e.g. surface tension), the dynamic properties (i.e.
the interfacial "rheology") have been more elusive: it is
difficult to measure the viscosity and elasticity of a
molecularly thin interface without getting swamped by the bulk
materials on either side.
Squires and collaborators in UCSB's Materials Research
Lab have developed a novel method for interfacial rheology.
This new and general technique will provide unprecedented
information about how interfaces behave, and how to better
design and control these materials.
High-interface materials like foams and emulsions are