To make patterned nanostructures on surfaces, chemists first coat gold wafers with thiol molecules that stand head-first on the gold and form a dense carpet of upright chains. By scraping away the thiols using an instrument such as an atomic force microscope, researchers can position another molecule very precisely.
But how do the thiols themselves behave in different conditions? Guohua Yang and Gang-yu Liu used scanning tunneling microscopy to look at these self-assembling monolayers as they are heated. They found that as some thiols vaporize from the surface, the surface patterns change in distinct ways. They identified up to 15 different structural phases, some of them for the first time.
These studies shed light on the interaction between the thiol molecules and the gold surface and could be used for creating patterns of other molecules on the surface, Liu said.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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