The innovation engine for new materials

David Guevel

David Guevel

University: 

University of California, Santa Barbara

Major: 

Physics

Site Abroad: 

Leibniz Institute for New Materials, Saarbruecken, Germany

Mentor(s): 

Jona Engel

Faculty Sponsor(s): 

Tobias Krauss

Project Title: 

Characterization of Polymer Drying Processes by Dynamic Light Scattering

Project Description: 

Industrial manufacturing processes often involve the application of a polymer coating, but it is difficult to tell when a coating is dry enough to continue the manufacturing process. If a method of analyzing the dryness of a coating can be simply implemented, the manufacturing process can be optimized and costs reduced; it is especially desirable for this method to leave the coating undisturbed. To test whether it is a viable way to measure the dryness of a coating, we used nanorod depolarized dynamic light scattering (NRDDLS) to observe the drying process of a thin droplet of an agarose solution. Using NRDDLS, the viscosity of a fluid can be measured by autocorrelating light scattering intensities and performing cumulant analysis. In a manufacturing setting, nanorods could be mixed into a coating and the dryness could be measured by simply illuminating the surface with a laser and measuring the scattered light. Gold nanorods were used because the translational and rotational movement within the drying polymer can be studied separately. Previous work suggests that there is a transition in agarose from liquid to solid characterized by an abrupt change from low to high viscosity; however, we extended the previous work by examining thin coatings.