| Self-assembled Polymer Templates for the Fabrication of Well Ordered Hybrid Materials and Devices using Roll-to-Roll Platforms |
| Ordered polymer-inorganic hybrid materials are of interest in applications ranging from next generation lithography, to energy conversion and storage, to electronics and displays. Microphase segregated block copolymer melts are attractive candidates for templating nanostructured hybrids, composites, and device structures due their ability to spontaneously form periodic spherical, cylindrical, bicontinuous and lamellar morphologies at controllable length scales. Their deployment for these purposes in large scale applications, however, has been limited by the cost and scalability of the synthetic techniques necessary for the precise control of molecular parameters that are required to achieve well defined morphologies. Recently we have focused on low cost systems for self assembled materials that can be deployed on a roll-to-roll platform with the objective of extending polymer self assembly to low cost per function devices. Specifically we reported that nanostructured templates with sub-10 nm domains can be easily obtained through the blending of disordered polymer surfactants containing poly(ethylene oxide) (PEO) as the hydrophilic block with homopolymers including poly (acrylic acid) that selectively associate with the PEO block through hydrogen bonding. These inexpensive blends are strongly segregated, yielding well ordered domains. Moreover, the functionalities imparted by the homopolymers provide convenient handles for binding active materials such as nanoparticles.
We have now demonstrated that functional nanoparticles or non-polymeric additives that contain multiple hydrogen bonding sites at their periphery can likewise induce order in otherwise disordered surfactant melts. In comparison to polymeric additives, the nanoparticles and non-polymeric additives offer additional structural, chemical and functional flexibility. The principles employed in this additive-driven assembly technique are quite general and suggest a low cost, high volume strategy to produce ordered hybrids with spherical, cylindrical, or lamellar morphologies. The behavior of the template systems and their use for the fabrication of well ordered hybrid materials for energy and device applications will be discussed. --------------------------- Polymer Science and Engineering Department and Center for Hierarchical Manufacturing University of Massachusetts Amherst, USA 01003 watkins@polysci.umass.edu (413) 545-2569 |