Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Large-scale adoption of biofuels is only feasible if biofuels are priced competitively with fossil fuels. In addition to reducing the cost of biofuel production itself, production of high-value co-products can off-set the operating costs of the biorefinery, especially if these co-products are derived from the waste stream. We have developed lignin-based nanotubes synthesized in a sacrificial template of commercially available alumina membranes. We covalently linked lignin to the inner walls of activated alumina membranes, then added layers of dehydrogenation polymer onto this base layer via a peroxidase-catalyzed reaction, and dissolved the membrane in dilute acid. By using phenolic monomers displaying different reactivities, we were able to change the thickness of the polymer layer deposited within the pores, resulting in the synthesis of nanotubes with a wall thickness of approximately 15 nm or nanowires with a nominal diameter of 200 nm. In contrast to carbon nanotubes based on the buckminsterfullerene structure, these novel nanotubes are flexible and can be bio-functionalized easily and specifically, as evidenced by in vitro assays with biotin and Concanavilin A. Together with their intrinsic optical properties due to the natural fluorescence of the lignin, which can also be varied as a function of their chemical composition, these lignin-based nanotubes are expected to enable a variety of new and high-value applications including as delivery systems that can be easily localized and imaged after uptake by living cells. Funding from the USDA-Biomass Research & Development Initiative project 2011-10006-303508 is gratefully acknowledged.