Non-technical: Amphiphilic molecules consist of water loving and oil loving components that are permanently linked to each other, thus frustrating bulk separation. When added to water these molecules self-assemble into membranes, thin flexible sheets with remarkable properties that play an essential role in biology, physics, and material science. It is commonly believed that the antagonistic nature of the amphiphilic molecules is an essential requirement for membrane assembly. In this proposal PI will study a fundamentally different method for assembly of colloidal based membrane-like materials. Assembly of the novel colloidal membranes takes place in a simple mixture of chemically homogeneous filamentous viruses, which have the shape of billiard cues, and polymers, which resemble billiard balls. Besides providing fundamental insight into universal aspects of all membrane-like materials, results will also describe a new and easily scalable process for assembly of rod-like nanoparticles into novel nanostructures that could act as efficient photovoltaic devices. The PI's research and education plans are seamlessly joined together through their mutual emphasis on visualization techniques and an interdisciplinary approach to science. Specifically, the PI will continue to build upon existing successful collaborations with The Discovery Museum in Action, in order to organize biannual visits to the museum for hands-on demonstrations of various concepts in optical microscopy and materials science. The PI will also extend connections with the local elementary and middle schools by participating in Science Fairs, by organizing class visits, and hosting students in his laboratory. Finally, the PI will continue to provide opportunities to undergraduate students to pursue research projects and will continue to build upon existing local and national connections in order to recruit students form groups that are underrepresented in STEM fields.
Colloidal membranes are comprised from a one-rod-length thick liquid-like monolayer of aligned rods that is held together by the osmotic pressure of the enveloping polymer solution. The goal of this proposal is to elucidate the fundamental laws that govern the assembly processes of colloidal membranes and to use colloidal membranes as a basis for engineering of a new generation of spatially heterogeneous, shape-changing functional materials. The PI will first use colloidal membranes as a robust platform for assembly of well-defined mesoscopic clusters and macroscopic 2D materials with predetermined heterogeneities. In parallel, the PI will devise new methods to measure the mechanical properties of colloidal membranes, and use this knowledge to engineer shape-changing 3D materials. Colloidal membranes are interesting in their own right as they offer a unique opportunity to organize complex 2D materials on micron scales. Furthermore, although distinct on molecular scales, the continuum deformations of colloidal monolayers and lipid bilayers are described by the same free energy expressions. Thus they provide a unique opportunity to gain insight into universal membrane processes that are mainly determined by the fundamental symmetries of the system.
