COLL 123 |
| Yanjie Xu, Department of Chemical and Biological Engineering, University of Colorado at Boulder, UCB 0424, Boulder, CO 80309 and Douglas L. Gin, Dept. of Chemical Engineering, and Chemistry and Biochemistry, University of Colorado, Campus Box 424, Boulder, CO 80309-0424. |
| A new type of solid acid catalyst is formed by the self-assembly and copolymerization of two acidic lyotropic liquid crystals (LLCs), affording a columnar hexagonal polymer network with monodisperse nanochannels lined with sulfonic acid groups. The performance of this material as a heterogeneous catalyst was compared against that of two commercially available, amorphous sulfonic acid resins: Amberlyst-15 and Nafion NR50. Using the acid-catalyzed esterification of benzyl alcohol with hexanoic acid in dry toluene as a test reaction, it was found that the LLC acid resin displayed slightly lower overall reactivity compared to Amberlyst-15 and Nafion NR50 but an order of magnitude better selectivity for the desired ester product over dibenzyl ether side-product. Control experiments revealed that the higher product selectivity is not due to differences in relative acidity but due to the regular nanostructure present in the LLC acid resin, which affords a much more uniform local acid microenvironment. |
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Nanoscience and Nanotechnology
8:30 AM-11:45 AM, Monday, March 29, 2004 Marriott -- Grand Ballroom J, Oral
Division of Colloid and Surface Chemistry |