Surface and Interface Control on Photochemically Initiated Immobilization
Surface and interface properties are important in controlling the yield and efficiency of the photochemically initiated immobilization. Using a silane-functionalized perfluorophenylazide (PFPA-silane) as the photoactive crosslinker, the immobilization of polymers was studied by adjusting the density of the surface azido groups. Dilution of the photolinker resulted in a gradual decrease in the density of surface azido groups as well as the thickness of the immobilized film. When a non-photoactive silane was added to PFPA-silane, the film thickness decreased more rapidly, indicating that the additive competed with PFPA-silane and effectively reduced the density of the surface azido groups. The effect of surface topography was studied by adding a non-photoactive silane with either a shorter (n-propyltrimethoxysilane (PTMS)) or a longer spacer (n-octadecyltrimethoxysilane (ODTMS)). In most cases the long chain ODTMS shielded the surface azido groups resulting in more rapid decrease in film thickness as compared to PTMS treated under the same conditions. As the density of the surface azido groups decreased, the immobilized polymer changed from smooth films to patched structures, and eventually single polymer molecules.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 894837
- Report Number(s):
- PNNL-SA-51562; 20494; KP1303000; TRN: US200702%%378
- Journal Information:
- Journal of the American Chemical Society, 128(43):14067 (6 pages), Journal Name: Journal of the American Chemical Society, 128(43):14067 (6 pages)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Speciation of uranium in surface-modified, hydrothermally treated, (UO{sub 2}){sup 2+}-exchanged smectite clays
Photochemical Reactions of Poly(4-vinylphenol) Thin Films