Entropic control in green chemistry and materials design*
John C. Warner
Center for Green Chemistry, University of Massachusetts Lowell,One University Avenue, Lowell, MA 01854, USA
Abstract: The traditional construction of materials is usually driven by classical synthetic transformations involving the making and breaking of covalent bonds. These processes often require high-energy input and highly reactive and hazardous materials. In natural systems, one typically encounters synthetic control schemes that are based on entropic forces rather than these human-designed enthalpic manipulations. In natural processes, phase changes and triggered mixing are often employed to direct systems toward or away from equilibrium conditions. The recognition of these "natural tendencies" allows one to design processes that have reduced toxicological and environmental impact. Results in noncovalent derivatization (NCD) and bioinspired photopolymers that illustrate this shift toward entropic control are described.
Keywords: green chemistry; phase diagrams; entropy; photopolymers; thymine.
*Paper based on a presentation at the Second International Symposium on Green/Sustainable Chemistry, 10-13 January 2006, Delhi, India. Other presentations are published in this issue, pp. 1971-2050.