We are interested in the development of surfactants derived from hemicellulosic biomass, as they are potential components in pharmaceuticals, personal care products and other detergents. Such surfactants should exhibit low toxicity in mammalian cells. In this study we synthesized a series of alkyl or fluoroalkyl β-xylopyranosides from azides and an alkyne using the copper-catalyzed azide-alkyne (CuAAC) “Click” reaction in 4 steps from xylose. The purified products were evaluated for both their surfactant properties, and for their biocompatibility. Unlike other carbohydrate-based surfactants, liquid-crystalline behavior was not observed by differential scanning calorimetry. The triazole-containing β-xylopyranosides with short (6 carbons) and long (>12 carbons) chains exhibited no toxicity at concentrations ranging from 1 to 1000 μM. Triazole-containing β-xylopyranosides with 8, 10 or 12 carbons caused toxicity via apoptosis, with CC50 values ranging from 26-890 μM. The two longest chain compounds did form stable monolayers at the air-water interface over a range of temperatures, although a brief transition to an unstable monolayer was observed.

The National Science Foundation (NSF) has supported an undergraduate curriculum reform project in chemical engineering with an overall objective of developing a web-based educational resource for teaching and learning. One aspect of this project involves the development of Interlinked Curriculum Components (ICCs). These are web-based learning sites that aim to strengthen student knowledge in the fundamental subjects that span all chemical engineering courses, and to broaden their exposure to emerging technologies and non-traditional applications.This paper describes the development of an ICC that is focused on microprocess technology. This is a key emerging technology in chemical engineering that has applications ranging from discovery research of new catalysts and materials to small-scale manufacturing of high value-added products, toxic reagents, explosives, and other chemicals where point-of-use is preferred over a largescale centralized manufacturing plant. The ICC module design follows a standardized protocol that includes five major sub-components: (1) pre-testing to quantitatively assess existing student knowledge on the module topic; (2) a set of topic notes so that students can perform a self-paced online review of the required subject matter; (3) examples that provide illustrations of various problems; (4) a series of exercises and problems having increasing complexity that allow the effect of various model equation set-ups and the effect of various model parameters to be studied in a conversational type of mode with graphical output; and (5) post-testing for quantitative assessment of student knowledge progression for validation of the desired modules outcomes.The examples, exercises and problems mentioned above employ a software tool called COMSOL Multiphysics as the numerical engine to simulate various microprocess system components involving fluid flow, heat transfer, and species transport, such as micro-scale fluidics and fluid micro mixers, micro heat exchangers, and micro reactors. A library of various models was also created so that students can readily explore the effect of various model parameters on the physical system without worrying focusing on details of the numerical solution. This approach allows them to focus on developing better insight and understanding of the system physics, which helps to reinforce the fundamentals that are taught in required courses on fluid mechanics, heat transfer, and mass transfer. To provide a more direct connection between the model equations and the calculated results, a user interface was also created that provides either a 2-D and 3-D visualization of the model simulations where the effect of various model parameters can be explored. Complex chemical engineering problems that are typically omitted in undergraduate training can now be readily studied and provide new opportunities for student learning.

Before being appointed to this position in January 2006, he was a Senior Research Associate in the DuPont Company's Central Research and Development Department in Wilmington, Delaware with more than 25 years of experience in chemical sciences and engineering. His research interests include multiphase reaction engineering, transport phenomena, and reaction system modeling. He is a member of American Institute of Chemical Engineers, Sigma Xi, and the Society for Industrial and Applied Mathematics. He served as chair of the AIChE Catalysis and Reaction Division in 2005.