We have investigated the chemical sensitivity of
nanoporous (NP) alumina-coated surface acoustic wave (SAW)
devices that have been surface-modified with polymeric
mediating films. The research in this dissertation covers
the refinement of the NP alumina coating, development of
dendrimer and/or polymer surface modifications, design of
composite ultrathin vapor-phase analyte gates, and
preparation of selectively permeable, polymeric films that
mediate analyte transport. Nanoporous alumina SAW devices were fabricated from planar Al SAW devices using an anodization process that yields a high-surface-area transduction platform. Refinement of the anodization process results in a homogeneously porous substrate capable of ~40 times the analyte sensitivity of conventional planar SAW devices. Attempts to directly impart selective gas-phase analyte permeation with monolayers of amine-terminated, poly(amidoamine) (PAMAM) dendrimer films were investigated with and without secondary functionalization. We also prepared and characterized pore-bridging
polymeric composite ultrathin films (~12 nm) of PAMAM
dendrimers and poly(maleic anhydride)-c-poly(methyl
vinylether) (Gantrez). Access to the underlying pores of
the NP alumina coating can be modulated through the
sequential deposition of the composite film. These
tailorable ultrathin films result in impermeable surface-
modifications which fully gate the analyte response without
filling the porous structure. Thin spin-cast films (40 nm) of polydimethylsiloxane (PDMS) were developed to simultaneously provide selective sorption and permeation characteristics towards vapor-phase analytes. The porous nature of the underlying alumina coating provides for this real-time evaluation of sorption and permeation. The results suggest that the thin films offer preferential sorption of non-polar organics and selective permeability towards water vapor.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/2202 |
| Date | 29 August 2005 |
| Creators | Perez, Gregory Paul |
| Contributors | Crooks, Richard M. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 6016999 bytes, electronic, application/pdf, born digital |
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