Cold Zone Annealing for Directed Assembly of Multicomponent Block Copolymer Thin Films

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TECHNICAL SUMMARY:Cold zone annealing is a novel technique that utilizes a dynamic thermal gradient to orient block copolymer thin films. The thermal gradient in this technique can be shallow (CZA), sharp (CZA-S), or coupled with a shear force (CZA-SS). This proposal examines multicomponent block copolymer films as an important class of functional nanostructured films to understand and address key scientific issues in CZA induced ordering of complex BCP systems from a fundamental perspective: 1) What synergistic or disruptive effect does the presence of multicomponents have on the order of BCP thin film systems undergoing directed assembly? 2) How does nanoparticle location in the domains affect ordering? 3) How should the nanoparticle be treated conceptually? Our approach entails exploiting the non-monotonic molecular coupling between CZA and CZA-S dynamic parameters for parallel and vertical orientation of multicomponent BCP systems, notably where additives and nanoparticles can have very different coupling dynamics with CZA than the BCP. CZA-SS will be used to break the symmetry of multicomponent BCP ordering, with the possibility of different dynamic coupling to different components. By zone annealing the multicomponent BCP films at continuous different sweep rates, radially and tangentially with CZA-R in angular co-ordinates, and serial and parallel solvo-thermal methods (CZA-SVA), we will leverage high-throughput character and fast processing to order and align multicomponent BCP films at the molecular level in different and versatile ways. NON-TECHNICAL SUMMARY:Next-generation advanced manufacturing requires innovations in continuous production techniques that are applicable to dynamic processing methods such as roll-to-roll (R2R) manufacturing rather than batch processing. This research will address this issue through the development of such a dynamic R2R compatible method, known as zone-refinement, for thermally processing multifunctional polymeric films and coatings to exhibit anisotropic properties. Once heated the microstructure of polymers can be altered to increase properties such as strength, rigidity, porosity, crystallinity, refractive index, or dielectric strength. This project will seek to understand the complexities associated with producing highly ordered multicomponent and hybrid/nanocomposite polymeric films using the zone refinement method, with an eye towards demonstrating continuous and scalable R2R manufacturing with a high degree of versatility in handling diverse polymeric materials used by industry. This project will also provide training to graduate students in an interdisciplinary area of block copolymer processing and functional hybrid materials, with detailed knowledge development of nanoparticles. The co-PI will mentor STEM and local high-school students in his laboratory. High-school students will also be recruited by each of the PI and co-PI to work on this project.