DMREF: Rapid Design and Engineering of Materials Systems for Nanomanufacturing via Directed Self-Assembly

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Block copolymers are a special form of polymer made by simply joining two different types of polymer chains together. These interesting materials naturally exhibit complex nanostructured morphologies and have potential uses in a wide range of applications including organic solar cells, water purification filters, fuel cells for power production, and semiconductor device fabrication. This nanostructured morphology is the result of the different types of polymer chains in the copolymer trying to separate from one another much like oil and water do not like to mix, a process referred to as phase separation. To be useful in many applications, these block copolymers must be used as thin films and the location and orientation of the different polymer phases must be carefully controlled. Current understanding of such materials and processes is limited, which makes designing and using these fascinating nanostructured materials difficult. The goal of this project is to develop a set of design tools and methodologies that will allow for the rapid design of block copolymers and interfacial coatings that can enable production of highly ordered nanostructured organic materials. The general approach to be used will combine detailed molecular modeling tools with carefully selected experimental studies to form a material and process design loop that can result in significantly faster material design cycles than are currently possible. Directed self-assembly (DSA) methods offer the possibility to use the interaction of a block copolymer thin film with heterogeneous patterned interfaces to guide assembly of the block copolymer microphases into desired orientations with long range order. Current efforts in the field rely on time consuming and expensive experimental studies to identify materials and processing conditions that can achieve ordered nanometer scale structures. Furthermore, most work thus far has focused on poly(styrene)-b-poly(methyl methacrylate) block copolymers in which both polymer blocks exhibit very similar properties. In general, there is interest in block copolymers that possess blocks with very different properties, contain useful functional properties, and which can achieve smaller phase separated domain sizes. In this project, new block copolymers that can achieve much smaller feature sizes and which possess useful functional properties will be developed. In addition, a new meso-scale molecular dynamics model that can accurately reproduce the properties and behavior of realistic block copolymers will be coupled to detailed experimental studies to develop well parameterized models for these new block copolymer systems. This modeling capability will form the core of a new rapid methodology for designing the interfacial guiding layers required to produce ordered films using DSA with these new polymers. These models will be used to explore and map the behavior and process windows for such systems so that DSA manufacturing processes can be rapidly developed.