Coupling polymeric systems to nonlinear dynamics offers opportunities to create materials with tailored morphology and functionality via pattern forming processes. Examples include periodic striations from traveling fronts in thermal polymerization, coalescence of polymer films during dewetting, oscillatory gels, and phase separation. Here, we present a fundamentally new mechanism to organize polymeric materials that couples photopolymerization to the nonlinear dynamics of optical fields. In a new process of optical auto-acceleration, a positive feedback mechanism emerges between photopolymerization and transmitted light intensity, whereby a mutual, dynamic interaction emerges between optical field distribution and the underlying morphology of the polymer medium. The input light undergoes Modulation Instability – dividing into a multitude of microscale “self-trapped” beams, which are nonlinear waveforms characterized by divergence-free propagation. As a result, these nonlinear waveforms inscribe permanent microstructure consisting of microscopic “channels” in the polymer. This coupling between optical nonlinearity and morphology evolution will be demonstrated in polyfunctional acrylate systems, polymer blends, as well as polymer-solvent mixtures. As a demonstration of the potential of this new process and the material properties, their application towards creating light-collecting encapsulants for solar cells will be discussed. Harnessing nonlinear optical pattern formation to direct the organization of polymeric materials opens opportunities for studying the fascinating complexity of nonlinear systems, while creating advanced microstructures that can serve functional roles in a broad range of applications.
Dr. Ian Hosein is an Assistant Professor in the Department of Biomedical and Chemical Engineering at Syracuse University. He completed his graduate studies at Cornell University in the Department of Materials Science and Engineering. Dr. Hosein then completed post-doctoral positions at the University of Waterloo and McMaster University, Canada. At Syracuse University, Dr. Hosein leads an group of graduate, undergraduate, and high school students to create materials-based solutions to address global issues on energy, the environment, and sustainability. The group combines materials processing techniques with smart polymer chemistry to create highly organized polymeric materials tailored with enhanced optical, electronic, and chemical functionality. Dr. Hosein is a winner of the ACS Petroleum Research Fund Doctoral New Investigator Grant, National Science Foundation Early CAREER award, and the 3M Non-Tenured Faculty Award.