Directed Self Assembly of Triblock Terpolymer Films

Block copolymers are a class of polymeric materials whose molecules can come together when cast from solution to form intricate, regular three-dimensional internal structures called microdomains. These microdomains can have dimensions of a few nanometers (billionths of a meter) and above, and their geometry and chemistry can be controlled through the design of the block copolymer. Most work has focused on block copolymers with two types of microdomains, but this project examines the behavior of block copolymers in which three different types of microdomain are simultaneously present, producing a wide range of complex geometries. It investigates the conditions under which different arrangements of microdomains are formed in thin films of these materials, and it demonstrates their technological usefulness, in particular for semiconductor device manufacturing, where the microdomain patterns can be used to define features smaller than those available from conventional manufacturing processes. This may allow future scaling of devices to higher densities, producing cheaper and faster memories or microprocessors. Other applications include catalysis or filtration where surfaces are required with particular chemistry or porosity. The work will involve graduate and undergraduate students in an interdisciplinary environment combining experiment and theory. Outreach will include the creation of online learning materials, summer projects for teachers and community college students, and public activities at the Cambridge Science Festival.