skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The influence of surfactants on the roughness of titania sol-gel films

Abstract

Substrate dipping in a composite sol-gel solution was used to prepare both smooth and rough thin films of titanium dioxide (TiO{sub 2}) on commercial fiberglass. The deposition of a composite film was done in a beaker using a solution of titanium (IV) isopropoxide as the sol-gel precursor and cetyltrimethyl ammonium bromide as the surfactant. In order to establish a correlation between experimental conditions and the titanium oxide produced, as well as the film quality, the calcined samples were characterized using Raman spectroscopy, UV-vis spectrophotometry, scanning electron microscopy and atomic force microscopy. One of the most important results is that a 61-nm TiO{sub 2} film was obtained with a short immersion of fiberglass into the sol-gel without surfactant. In other cases, the deposited film consisted of a titanium precursor gel encapsulating micelles of surfactant. The gel films were converted to only the anatase phase by calcining them at 500 deg. C. The resulting films were crystalline and exhibited a uniform surface topography. In the present paper, it was found that the TiO{sub 2} films prepared from the sol-gel with a surfactant showed a granular microstructure, and are composed of irregular particles between 1.5 and 3 {mu}m. Smooth TiO{sub 2} films couldmore » have useful optical and corrosion-protective properties and, on other hand, roughness on the TiO{sub 2} films can enhance the inherent photocatalytic activity.« less

Authors:
 [1];  [2];  [3];  [4];  [5]
  1. Departamento de Ingenieria Quimica y Bioquimica, Instituto Tecnologico de Aguascalientes, Av. A. Lopez Mateos Ote. No. 1801, Fracc. Bona Gens, Aguascalientes 20256 (Mexico). E-mail: jormeval@yahoo.com
  2. Centro de Investigaciones en Optica A.C., Loma del Bosque No. 115, Col. Lomas del Campestre, Leon, Gto. 37150 (Mexico). E-mail: cfraus@cio.mx
  3. Centro de Investigaciones en Optica A.C., Loma del Bosque No. 115, Col. Lomas del Campestre, Leon, Gto. 37150 (Mexico). E-mail: scalixto@cio.mx
  4. Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, Cd. Universitaria, Mexico, D.F. 04510 (Mexico). E-mail: croqcroqcroq@yahoo.com
  5. Universidad Autonoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco No. 186, Mexico, D.F. 09340 (Mexico). E-mail: lacv@xanum.uam.mx
Publication Date:
OSTI Identifier:
21003536
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 58; Journal Issue: 3; Other Information: DOI: 10.1016/j.matchar.2006.04.021; PII: S1044-5803(06)00122-7; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AMMONIUM COMPOUNDS; ATOMIC FORCE MICROSCOPY; BROMIDES; CORRELATIONS; CORROSION; FIBERGLASS; MICROSTRUCTURE; PHOTOCATALYSIS; RAMAN SPECTROSCOPY; ROUGHNESS; SCANNING ELECTRON MICROSCOPY; SOL-GEL PROCESS; SPECTROPHOTOMETRY; SUBSTRATES; SURFACTANTS; THIN FILMS; TITANIUM OXIDES; TOPOGRAPHY; ULTRAVIOLET SPECTRA

Citation Formats

Medina-Valtierra, Jorge, Frausto-Reyes, Claudio, Calixto, Sergio, Bosch, Pedro, and Hugo Lara, Victor. The influence of surfactants on the roughness of titania sol-gel films. United States: N. p., 2007. Web. doi:10.1016/j.matchar.2006.04.021.
Medina-Valtierra, Jorge, Frausto-Reyes, Claudio, Calixto, Sergio, Bosch, Pedro, & Hugo Lara, Victor. The influence of surfactants on the roughness of titania sol-gel films. United States. doi:10.1016/j.matchar.2006.04.021.
Medina-Valtierra, Jorge, Frausto-Reyes, Claudio, Calixto, Sergio, Bosch, Pedro, and Hugo Lara, Victor. Thu . "The influence of surfactants on the roughness of titania sol-gel films". United States. doi:10.1016/j.matchar.2006.04.021.
@article{osti_21003536,
title = {The influence of surfactants on the roughness of titania sol-gel films},
author = {Medina-Valtierra, Jorge and Frausto-Reyes, Claudio and Calixto, Sergio and Bosch, Pedro and Hugo Lara, Victor},
abstractNote = {Substrate dipping in a composite sol-gel solution was used to prepare both smooth and rough thin films of titanium dioxide (TiO{sub 2}) on commercial fiberglass. The deposition of a composite film was done in a beaker using a solution of titanium (IV) isopropoxide as the sol-gel precursor and cetyltrimethyl ammonium bromide as the surfactant. In order to establish a correlation between experimental conditions and the titanium oxide produced, as well as the film quality, the calcined samples were characterized using Raman spectroscopy, UV-vis spectrophotometry, scanning electron microscopy and atomic force microscopy. One of the most important results is that a 61-nm TiO{sub 2} film was obtained with a short immersion of fiberglass into the sol-gel without surfactant. In other cases, the deposited film consisted of a titanium precursor gel encapsulating micelles of surfactant. The gel films were converted to only the anatase phase by calcining them at 500 deg. C. The resulting films were crystalline and exhibited a uniform surface topography. In the present paper, it was found that the TiO{sub 2} films prepared from the sol-gel with a surfactant showed a granular microstructure, and are composed of irregular particles between 1.5 and 3 {mu}m. Smooth TiO{sub 2} films could have useful optical and corrosion-protective properties and, on other hand, roughness on the TiO{sub 2} films can enhance the inherent photocatalytic activity.},
doi = {10.1016/j.matchar.2006.04.021},
journal = {Materials Characterization},
number = 3,
volume = 58,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • Mesoporous titania-silica aerogels with highly dispersed titanium have been prepared by an alkoxide-sol-gel process with ensuing semicontinuous extraction using supercritical CO{sub 2}. An acidic hydrolysant was added to a solution of tetraisopropoxytitanium (IV) modified by acetylacetonate and tetramethoxysilicon (IV) in isopropanol. The resulting titania-silica gels were dried by different methods, including conventional drying, high-temperature supercritical drying, and extraction with supercritical CO{sub 2} (low-temperature aerogel). The influence of preparation parameters (the hydrolysis route, Ti-content, drying method, and calcination temperature) on the structural and chemical properties of the aero- and xerogels was studied by means of N{sub 2}-physisorption, X-ray diffraction, thermal analysis,more » and vibrational spectroscopy (FTIR, FTRaman). Prehydrolysis of the silicon alkoxide generally led to lower porosity, but did not influence the Si-O-Ti connectivity up to a calcination temperature of 1073 K. The conventionally dried xerogels contained titanium well-dispersed in the silica matrix and were predominantly microporous. High-temperature supercritical drying afforded meso- to macroporous aerogels with negligible microporosity, but undesired segregation of anatase. With the low-temperature aerogels, an increase in the nominal TiO{sub 2} content from 2 to 20 wt% resulted in lower microporosity, higher BET surface area (up to ca. 700 m{sup 2}/g), and a rise in the contribution of Si-O-Ti species. Concomitantly the Ti-O-Ti connectivity increased without any indication of long-range ordering from X-ray analysis. The low-temperature aerogel with 20 wt% TiO{sub 2} combined mesoporosity with high Ti dispersion and structural stability up to 873 K in air, properties desirable for epoxidation of olefins. 64 refs., 10 figs., 2 tabs.« less
  • A series of titania catalysts containing chromium, molybdenum as well as tungsten has been prepared by colloidal sol-gel route using metatitanic acid as the precursor. Structural characterization of the prepared catalysts was done with Energy dispersive X-ray analysis, X-ray diffraction, BET surface area and pore volume measurements. The influence of different transition metals like chromium, molybdenum and tungsten on the surface acidic properties of titania is investigated in detail. Two independent methods have been used to study the surface acidity of these catalyst systems: temperature programmed desorption of ammonia which is a measure of total acidity and thermodesorption studies usingmore » 2,6-dimethyl pyridine which is a measure of Bronsted acidity. Cumene cracking reaction is carried out over the prepared systems for further characterizing the acidity of the prepared catalysts. Remarkable enhancement in the surface acidity is observed after transition metal incorporation. The catalytic activity of the prepared catalysts was tested towards the dehydrogenation of cyclohexane.« less
  • No abstract prepared.
  • The microstructuring of titania based sol-gel films is investigated by direct writing with a continuous wave ultraviolet laser beam emitting at 244 nm. Depending on the exposure conditions, the films exhibit a volume expansion, a volume shrinkage, a self-shaped delamination, or are damaged. This paper is mainly focused on the regime where spontaneous local delamination occurs, which corresponds to a narrow range of laser irradiances and writing speeds. In this regime, self-organized round-shape micro-holes opened on the substrate are generated.