Stable, Microfabricated Thin Layer Chromatography Plates without Volume Distortion on Patterned, Carbon and Al2O3-Primed Carbon Nanotube Forests
In a recent report (Song, J.; et al., Advanced Functional Materials 2011, 21, 1132-1139) some of us described the fabrication of thin layer chromatography (TLC) plates from patterned carbon nanotube (CNT) forests, which were directly infiltrated/coated with silicon by low pressure chemical vapor deposition (LPCVD) of silicon using SiH4. Following infiltration, the nanotubes were removed from the assemblies and the silicon simultaneously converted to SiO2 in a high temperature oxidation step. However, while straightforward, this process had some shortcomings, not the least of which was some distortion of the lithographically patterned features during the volume expansion that accompanied oxidation. Herein we overcome theis issue and also take substantial steps forward in the microfabrication of TLC plates by showing: (i) A new method for creating an adhesion promotion layer on CNT forests by depositing a few nanometers of carbon followed by atomic layer deposition (ALD) of Al2O3. This method for appears to be new, and X-ray photoelectron spectroscopy confirms the expected presence of oxygen after carbon deposition. ALD of Al2O3 alone and in combination with the carbon on patterned CNT forests was also explored as an adhesion promotion layer for CNT forest infiltration. (ii) Rapid, conformal deposition of an inorganic material that does not require subsequent oxidation: fast pseudo-ALD growth of SiO2 via alumina catalyzed deposition of tris(tert-butoxy)silanol onto the carbon/Al2O3-primed CNT forests. (iii) Faithful reproduction of the features in the masks used to microfabricate the TLC plates (M-TLC) this advance springs from the previous two points. (iv) A bonded (amino) phase on a CNT-templated microfabricated TLC plate. (v) Fast, highly efficient (125,000 - 225,000 N/m) separations of fluorescent dyes on M-TLC plates. (vi) Extensive characterization of our new materials by TEM, SEM, EDAX, DRIFT, and XPS. (vii) A substantially lower process temperature for the removal of the CNT scaffold as a result of the (already oxidized) materials used in this study.
- 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:
- 1050794
- Report Number(s):
- PNNL-SA-87886; 34739; KP1704020; TRN: US201218%%1563
- Journal Information:
- Journal of Chromatography A, Vol. 1257
- Country of Publication:
- United States
- Language:
- English
Similar Records
Conformal High-K Dielectric Coating of Suspended Single-Walled Carbon Nanotubes by Atomic Layer Deposition
Al2O3 e-Beam Evaporated onto Silicon (100)/SiO2, by XPS
Related Subjects
ALUMINIUM OXIDES
CARBON
CHEMICAL VAPOR DEPOSITION
DEPOSITION
LAYERS
MATERIALS
NANOTUBES
OXIDATION
PLATES
SILICON
TEMPERATURE RANGE 0400-1000 K
THIN-LAYER CHROMATOGRAPHY
VOLUME
X-RAY PHOTOELECTRON SPECTROSCOPY
atomic layer deposition
thin layer chromatography
CVD of carbon
template carbon
Environmental Molecular Sciences Laboratory