Publication Date

2011

Document Type

Honors Thesis

Department

Chemistry

Keywords

Silicon-Surfaces, Surface chemistry, Alkenes, Radicals (Chemistry), Silicon, Si(100), Nanotopeography, Alkene radical addition

Abstract

Incorporating nanopatterned surfaces into biofilm nucleation studies would expand knowledge of the parameters that control biofilm absorption. However, there is evidence that traditional methods of silanizing surfaces in preparation for protein adsorption corrupt the surface topography. Radical alkene addition provides an alternate method to replace hydride termination with hydrocarbon chains. This reaction proceeds on nanopatterned surfaces to produce substrates with only marginally less alkyl termination coverage than the same reaction performed on smooth surfaces, although intermediately roughened surfaces prove much less organically reactive and more prone to oxidation than either the roughest or the smoothest surfaces. A majority of the possible reactive sites on the surface undergo reaction within the first five minutes of reflux. Substrates that experience less organic functionalization experience a greater degreee of oxidation, though oxidation cannot be said to operate in direct competition with organic functionalization due to the majority of oxidation occurring underneath areas of alkyl functionalization. At lower temperatures, the all surfaces undergo less organic functionalization than similar surfaces at high reflux temperatures, and rough surfaces experience a greater percentage of organic functionalization than smooth surfaces. Although surfaces undergo a lesser degree of organic functionalization at lower temperatures, it appears that functionalized portions of the surface exhibit a similar degree of homogeneity as the tightly packed, maximally functionalized surface produced by high reflux temperatures. At lower temperatures oxidation increases drastically, and hydride termination left over after reaction decreases very slightly. Future work will involve confirming and explaining these trends through more extensive IR studies of surfaces functionalized at low to intermediate reflux temperatures. AFM imagining studies will reveal any differences in organic coverage that arise from selective functionalization of different portions of the nanotopography.

Language

English

Comments

63 p. : ill. Honors project-Smith College, Northampton, Mass., 2011. Includes bibliographical references (p. 61-63)

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