Collaborative Research: Manufacturing of Polymer Nanofiber Arrays on Surfaces by Chemical Vapor Deposition into Liquid Crystal Templates

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This research grant establishes knowledge for a transformative new manufacturing process that has the potential to benefit a range of U.S. industries, creating new jobs and economic activity. Manufacturers of electronics, food packaging and medical devices currently coat their products with thin films of plastics that function as protective barriers using a process called chemical vapor deposition. The investigators supported by this research grant have discovered a new way to greatly expand the potential usefulness of chemical vapor deposition in manufacturing, using the process to fabricate surfaces covered with arrays of end-attached plastic nanofibers. Surfaces decorated with carpets of nanofibers exhibit properties that differ dramatically from continuous coatings, such as providing tunable optical or adhesive properties that might be used in energy-efficient and flexible displays or next generation robotics. This award supports fundamental research needed to understand how these nanofiber films form and how their surfaces are encoded with properties useful for electronics, food and medical device industries. The advances achieved during this research have the potential to be rapidly scaled into an industrially practiced nanotechnology, bringing economic prosperity and security. The grant also provides an outstanding opportunity for multidisciplinary training of the next generation manufacturing workforce.The approach to be investigated in this grant involves chemical vapor deposition of polymers into thin films of liquid crystals. Specifically, chemical vapor polymerization performed on surfaces coated with micrometer-thick films of liquid crystals leads to formation of organized assemblies of end-attached polymer nanofibers with unprecedented control over organization, size (length and width), surface chemistry, chirality, and shape (straight, bent or helical). In contrast to conventional liquid crystal-templated polymerizations, the monomer concentration in the liquid crystal phase remains low, as the monomers are formed in the vapor phase and then diffuse into the liquid crystal template. Accordingly, chemical vapor polymerization minimizes monomer-induced changes to the liquid crystal phase behavior and enables access to nanofiber arrays with precisely defined structures. Given the diverse range of liquid crystals available for use as templates for chemical vapor polymerization, this project has the potential to provide a paradigm-shifting approach for large-scale manufacturing of oriented nanofiber arrays with complex interfacial morphologies and chemistries.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.