Ruben G. Carbonell
 |
Frank Hawkins Kenan Distinguished Professor
B.S., Chemical Engineering, Manhattan College (1969) Ph.D., Chemical Engineering, Princeton University (1973) Areas of interest: Email: ruben@ncsu.edu |
Research |
Publications (2000-current) |
Our research group strives to understand how molecules in solution interact with interfaces, with specific applications to bio-separations, diagnostics and transport processes in compressible fluids.
The main thrust of the bio-separations and diagnostics efforts deals with the use of solid phase combinatorial peptide libraries to screen for small peptides that will bind specifically to bio-molecules such proteins, to viruses, and to bacteria. These small peptides exhibit great potential as ligands for large-scale affinity chromatography of therapeutic proteins to be obtained from complex mixtures such as human blood plasma, milk and fermentation broth. In addition, they can be used to develop robust sensing elements to detect low concentrations of analytes in medical diagnostics and process control applications. Peptides that can recognize and bind to viruses and bacteria can also play an important role in ensuring the safety of foods and drugs, since they can serve as the basis for novel viral clearance and anti-bacterial surfaces.
CO2-based technologies are being developed that will allow the replacement of hundreds of millions of pounds of organic and halogenated solvents and water that are used each year in chemical processes. Carbon dioxide in its liquid or supercritical phase is an inexpensive, safe, and environmentally benign solvent. It has a critical temperature that is close to room temperature and a relatively low critical pressure, allowing its use as a supercritical fluid in large-scale applications. Carbon dioxide is easy to separate from most solids and liquids so it can be recycled in chemical and manufacturing processes. Recently, novel surfactants have been developed which can enhance the solubility of a wide variety of compounds in carbon dioxide, thus widening its potential use as a solvent.
Our group has helped to develop novel coating processes that utilize both supercritical carbon dioxide and liquid carbon dioxide as the coating solvent. For example, we were the first to design and operate a liquid CO2-based spin coating process to form uniform films of photoresists on silicon wafers. This has made it possible to conceive of photolithography processes that use only carbon dioxide to both form and develop the photoresist. This would result in significant reductions in the use of organic solvents and water in microelectronics applications. Our students have developed novel dip coating processes utilizing liquid carbon dioxide as a solvent to create sub-micron thick films of lubricants and other materials on surfaces. In addition, we are currently studying the use of liquid and supercritical carbon dioxide for precision cleaning, to carry out extractions of solutes from fermentation broth, and to carry out enzymatic reactions. This are all challenging and interesting problems since they involve detailed knowledge of thermodynamics, heat and mass transfer and principles of colloid and interface science. All of our work is done in a collaborative, multi-institutional and multi-disciplinary environment with many industrial partners. This offers outstanding educational opportunities for our students to enhance their skills in written and oral communication and to obtain a better appreciation for the challenges encountered in commercializing new methods and applications.
