Abstract

Titanium alkoxide (titanicone) thin films were coated on large quantities of sub-micron sized silica particles at 100 °C using molecular layer deposition (MLD) in a fluidized bed reactor. Titanium tetrachloride and ethylene glycol were used as precursors. The content of titanium on the particles increased linearly as the number of MLD coating cycles increased. The conformity of the films, with a thickness of ~12 nm, was verified using TEM for silica particles coated with 50 cycles of titanicone. The composition of the titan cone films was confirmed using energy dispersive X-ray spectrometry. Porous titanium oxide films were formed for the particles coated with 50 cycles of titanicone MLD by oxidation in air at 400 °C or by decomposition of the organic components of the titanicone films in the presence of water. The thicknesses of the films were reduced from ~12 nm to ~8 nm after oxidation in air at 400 °C for 1 hr. The effect of aging on the titanicone films was studied at different lengths of aging time in the presence of water. A greatly increased surface area of 48.8 m2 g-1 was obtained for the particles exposed to water for 24 hr., compared to the as-deposited 50 cycles of titanicone coated sample with a surface area of 7.7 m2 g-1. The decomposition of titanicone films, after exposure to water vapor for various lengths of time, was studied using Fourier transform infrared spectroscopy.

Department(s)

Chemical and Biochemical Engineering

Comments

National Science Foundation, Grant 1402122

Keywords and Phrases

Fluidized bed reactor; Molecular layer deposition (MLD); Porous film; Titanium alkoxide (titanicone); Titanium oxide (titania); Ultra-thin

International Standard Serial Number (ISSN)

0272-8842

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 Elsevier, All rights reserved.

Publication Date

01 Mar 2015

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