Immobilization of dendrimers on Si-C linked carboxylic acid-terminated monolayers on silicon(111)

Bocking, T; Wong, ELS; James, M; Watson, JA; Brown, CL; Chilcott, TC; Barrow, KD; Coster, HGL

Immobilization of dendrimers on Si-C linked carboxylic acid-terminated monolayers on silicon(111)

Date

2006-12-05

Authors

Publisher

Elsevier

Abstract

Poly(amidoamine) dendrimers were attached to activated undecanoic acid monolayers, covalently linked to smooth silicon surfaces via Si-C bonds. The resulting ultra-thin dendrimer films were characterized by X-ray photoelectron spectroscopy (XPS), X-ray reflectometry (XR) and atomic force microscopy (AFM). XPS results suggested amide bond formation between the dendrimer and the surface carboxylic acid groups. XR yielded thicknesses of 10 angstrom for the alkyl region of the undecanoic acid monolayer and 12 A for the dendrimer layer, considerably smaller than the diameter of these spherical macromolecules in solution. This was consistent with AFM images showing collapsed dendrimers on the surface. It was concluded that the deformation arose from a large number of amine groups on the surface of each dendrimer reacting efficiently with the activated surface, whereby the dendrimers can deform to fill voids while spreading over the activated surface to form a homogeneous macromolecular layer. © 2006, Elsevier Ltd.

Keywords

Carboxylic acids, Silicon, Thin films, X-ray photoelectron spectroscopy, Surfaces, Atomic force microscopy

Citation

Bocking, T., Wong, E. L. S., James, M., Watson, J. A., Brown, C. L., Chilcott, T. C., Barrow, K. D., & Coster, H. G. L. (2006). Immobilization of dendrimers on Si-C linked carboxylic acid-terminated monolayers on silicon(111). Thin Solid Films, 515(4), 1857-1863. doi:10.1016/j.tsf.2006.07.017