COLL 101 |
| Heejoon Ahn1, Amol Chandekar1, Bongwoo Kang2, Changmo Sung2, and James E. Whitten1. (1) Department of Chemistry and Center for Advanced Materials, University of Massachusetts, Lowell, MA 01854, (2) Department of Chemical and Nuclear Engineering, University of Massachusetts, Lowell, One university ave, Lowell, MA 01854 |
| A series of gold nanoparticles stabilized by chemisorbed monolayers of thiophene-terminated alkanethiols, Th-(CH2)n-SH (Th=3-thiophene with n=2, 6, and 12), have been synthesized, and their films have been characterized by X-ray photoelectron spectroscopy, FT-IR, UV-vis, TEM, and AFM. TEM images show that the diameters of the particles are in the range of 2-7 nm. Electrical conductivity has been measured by coating the films onto interdigitated array (IDA) electrodes, and it is found to decrease as the number of methylene units increases. Vapor sensing properties have been examined by exposing the IDA electrode films to organic vapors. When the films are exposed to chloroform, toluene, hexane and ethanol vapors, the resistance of the films increases, and this effect is more pronounced for the longer alkanethiols. The vapor-induced decrease in conductivity is completely reversible, and implications of this work for fabricating a vapor-specific sensor will be discussed. |
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Symposium in Memory of Arthur W. Adamson
8:30 AM-11:50 AM, Monday, March 29, 2004 Marriott -- Orange County 4, Oral
Division of Colloid and Surface Chemistry |