(4bt) Design of Advanced Organic Materials: Block Copolymers and Photoresists

Modern materials require modern, interdisciplinary approaches to their design and development.  This is especially true of highly functional materials such as organic electronics and photoresists.  Design space can be very broad, yet the property specifications can be very narrow.  This means that large amounts of time and effort can be spent investigating materials that will eventually fail to meet specifications in the end. An improved alternative to this is the development of predictive models and heuristics which can rapidly shrink design space to improve the likelihood of success when experimentally investigating these materials. This is a daunting task even at the level of simply predicting the bulk properties of a material, but unfortunately in many emerging applications (e.g. organic electronics) the manner in which the material is processed and used can strongly affect its physicochemical properties. Thus, intelligent material design must have both structure-property relations, but also processing-property relations. My Ph.D. and Post-Doctoral work has led to the development of a number of design and simulation tools for the rational design of block copolymers, photoresists, and organic electronics.  In the realm of structure-property relations, models have been developed that successfully predict the glass transition temperature of organic glasses and the full range of dissolution properties of small molecule photoresists including intrinsic solubility and dissolution rate.  Further work has been done to develop design heuristics for high χ block copolymers and for directly photodefinable guiding layers for directed self assembly of block copolymers. Investigating the processing effects required the development of sophisticated simulation tools due to the multiple variables at play in processing beyond just the material’s intrinsic properties.  On-lattice kinetic Monte Carlo simulations were developed to investigate photoresist design strategies and the effect of additives on the patterning process in order to improve material performance.  Off-lattice molecular dynamics simulations of block copolymers were developed to better understand their use in directed self-assembly.  These simulations are especially useful to investigate the advantages and disadvantages of potential design schemes that are time and cost intensive to investigate experimentally such as the use of block copolymer or homopolymer blending to obtain a specified domain size and the use of tri-block, quad-block, and higher multiplicity block copolymers.  These structure-property and processing-property relations have already been used to develop improved experimental photoresists and high χ block copolymers. Similar approaches could be used for the design of any number of advanced organic materials.