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

Title: Pore orientation effects on the kinetics of mesostructure loss in surfactant templated titania thin films

Journal Article · · Physical Chemistry Chemical Physics. PCCP
DOI:https://doi.org/10.1039/c5cp05178a· OSTI ID:1248735
 [1];  [1];  [1];  [2];  [1];  [3];  [1]
  1. Univ. of Kentucky, Lexington, KY (United States). Dept. of Chemical & Materials Engineering
  2. Argonne National Lab. (ANL), Argonne, IL (United States).Chemical Sciences and Engineering Division
  3. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

The mesostructure loss kinetics are measured as a function of the orientation of micelles in 2D hexagonal close packed (HCP) columnar mesostructured titania thin films using in situ grazing incidence small angle x-ray scattering (GISAXS). Complementary supporting information is provided by ex situ scanning electron microscopy. Pluronic surfactant P123 acts as the template to synthesize HCP structured titania thin films. When the glass substrates are modified with crosslinked P123, the micelles of the HCP mesophase align orthogonal to the films, whereas a mix of parallel and orthogonal alignment is found on unmodified glass. The rate of mesostructure loss of orthogonally oriented (o-HCP) thin films (~60 nm thickness) prepared on modified substrate is consistently found to be less by a factor of 2.5 ± 0.35 than that measured for mixed orientation HCP films on unmodified substrates. The activation energy for mesostructure loss is only slightly greater for films on modified glass (155 ± 25 kJ/mol-1) than on unmodified (128 kJ/mol-1), which implies that the rate difference stems a greater activation entropy for mesostructure loss in o-HCP titania films. Nearly perfect orthogonal orientation of micelles on modified surfaces contributes to the lower rate of mesostructure loss by supporting the anisotropic stresses that develop within the films during annealing due to continuous curing, sintering and crystallization into the anatase phase during high temperature calcination (>450 °C). Because the film thickness dictates the propagation of orientation throughout the films and the degree of confinement, thicker (~250 nm) films cast onto P123-modified substrates have a much lower activation energy for mesostructure loss (89 ± 27 kJ/mol-1) due to the mix of orientations found in the films. Thus, in conclusion, this kinetic study shows that thin P123- templated o-HCP titania films are not only better able to achieve good orthogonal alignment of 3 the mesophase relative to thicker films or films on unmodified substrates, but that alignment of the mesophase in the films stabilizes the mesophase against thermally-induced mesostructure loss.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-06CH11357; FG02-07-ER46375; IIA-1355438
OSTI ID:
1248735
Journal Information:
Physical Chemistry Chemical Physics. PCCP, Vol. 18, Issue 4; ISSN 1463-9076
Publisher:
Royal Society of ChemistryCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

References (56)

Highly Porous TiO 2 Anatase Optical Thin Films with Cubic Mesostructure Stabilized at 700 °C journal December 2003
The AVRAMI equation in polymer crystallization journal January 1963
A review of growth mechanism, structure and crystallinity of anodized TiO2 nanotubes journal December 2013
Perspective on the Influence of Interactions Between Hard and Soft Templates and Precursors on Morphology of Hierarchically Structured Porous Materials journal September 2013
Synthesis and Characterization of Mesostructured Titania-Based Materials through Evaporation-Induced Self-Assembly journal February 2002
Tuning the Mesopore Size of Titania Thin Films Using a Polymeric Swelling Agent journal May 2011
Pyrolysis, Crystallization, and Sintering of Mesostructured Titania Thin Films Assessed by in Situ Thermal Ellipsometry journal June 2008
N2/Ar plasma induced doping of ordered mesoporous TiO2 thin films for visible light active photocatalysis journal January 2016
Organized Mesoporous TiO 2 Films Exhibiting Greatly Enhanced Performance in Dye-Sensitized Solar Cells journal September 2005
Highly Organized Mesoporous Titania Thin Films Showing Mono-Oriented 2D Hexagonal Channels journal July 2001
Thermally Stable Two-Dimensional Hexagonal Mesoporous Nanocrystalline Anatase, Meso-nc-TiO2: Bulk and Crack-Free Thin Film Morphologies journal April 2004
General Predictive Syntheses of Cubic, Hexagonal, and Lamellar Silica and Titania Mesostructured Thin Films § journal August 2002
Surfactant-Directed Synthesis of Mesoporous Titania with Nanocrystalline Anatase Walls and Remarkable Thermal Stability journal March 2004
Silver-modified titanium dioxide thin films for efficient photodegradation of methyl orange journal May 2003
Synthesis and properties of photosensitive polyimide–nanocrystalline titania optical thin films journal October 2009
Highly-ordered mesoporous titania thin films prepared via surfactant assembly on conductive indium–tin-oxide/glass substrate and its optical properties journal April 2010
The dedicated high-resolution grazing-incidence X-ray scattering beamline 8-ID-E at the Advanced Photon Source journal June 2012
Synthesis of Surfactant-Templated Silica Films with Orthogonally Aligned Hexagonal Mesophase journal March 2005
End-Group Functionalization of Poly(3-hexylthiophene) as an Efficient Route to Photosensitize Nanocrystalline TiO 2 Films for Photovoltaic Applications journal May 2011
Titania nanocomposite thin films with enhanced photovoltaic efficiency: Effects of Ti-alkoxide sol and compact layer journal January 2012
Sol–gel preparation of titania multilayer membrane for photocatalytic applications journal July 2009
Hierarchically Porous Titania Thin Film Prepared by Controlled Phase Separation and Surfactant Templating journal August 2011
Fabrication and characterization of nanostructured titania films with integrated function from inorganic–organic hybrid materials journal January 2012
Titania and tungsten doped titania thin films on glass; active photocatalysts journal January 2003
Tuning the mesopore structure of 3D hexagonal thin films using butanol as a co-solvent journal February 2012
Controlling Morphological Parameters of Anodized Titania Nanotubes for Optimized Solar Energy Applications journal October 2012
Generalized Coating Route to Silica and Titania Films with Orthogonally Tilted Cylindrical Nanopore Arrays journal November 2006
Generalized syntheses of large-pore mesoporous metal oxides with semicrystalline frameworks journal November 1998
Nanostructured Hybrid Solar Cells Based on Self-Assembled Mesoporous Titania Thin Films journal December 2006
Calculation of the Avrami parameters for heterogeneous solid state reactions using a modification of the Kissinger method journal April 1978
Hierarchically Structured One-Dimensional TiO 2 for Protein Immobilization, Direct Electrochemistry, and Mediator-Free Glucose Sensing journal August 2011
Mesophase Ordering of TiO 2 Film with High Surface Area and Strong Light Harvesting for Dye-Sensitized Solar Cell journal June 2010
In Situ GISAXS Investigation of Low-Temperature Aging in Oriented Surfactant-Mesostructured Titania Thin Films journal September 2015
Mesoporous titania photocatalysts: preparation, characterization and reaction mechanisms journal January 2011
The True Structure of Hexagonal Mesophase-Templated Silica Films As Revealed by X-ray Scattering:  Effects of Thermal Treatments and of Nanoparticle Seeding journal June 2000
Continuous formation of supported cubic and hexagonal mesoporous films by sol–gel dip-coating journal September 1997
Highly Crystalline Cubic Mesoporous TiO 2 with 10-nm Pore Diameter Made with a New Block Copolymer Template journal July 2004
Fabrication, modification, and biomedical applications of anodized TiO 2 nanotube arrays journal January 2014
Interpretation of the nonisothermal crystallization kinetics of polypropylene using a power law nucleation rate function journal May 1997
Effects of crystallinity and grain size on photocatalytic activity of titania films journal September 2007
Pore architecture affects photocatalytic activity of periodic mesoporous nanocrystalline anatase thin films journal January 2007
Preparation of Mesoporous Titania Thin Films with Remarkably High Thermal Stability journal March 2005
Large-pore mesoporous nanocrystalline titania thin films synthesized through evaporation-induced self-assembly journal November 2005
In-Situ X-ray Diffraction Study of the Crystallization Kinetics of Mesoporous Titania Films journal August 2004
GIXSGUI : a MATLAB toolbox for grazing-incidence X-ray scattering data visualization and reduction, and indexing of buried three-dimensional periodic nanostructured films journal April 2015
Vertically oriented hexagonal mesoporous films formed through nanometre-scale epitaxy journal September 2008
Mesostructured self-assembled titania films for photovoltaic applications journal January 2006
The avrami index and the fractal dimension in vegetable oil crystallization journal September 2002
Controlled Formation of Highly Organized Mesoporous Titania Thin Films:  From Mesostructured Hybrids to Mesoporous Nanoanatase TiO 2 journal August 2003
Tuning the wall thickness and pore orientation in mesoporous titania films prepared with low-temperature aging journal August 2011
Highly Efficient Dye-Sensitized Solar Cells with a Titania Thin-Film Electrode Composed of a Network Structure of Single-Crystal-like TiO 2 Nanowires Made by the “Oriented Attachment” Mechanism journal November 2004
Synthesis of mesoporous titanium dioxide by soft template based approach: characterization and application in dye-sensitized solar cells
  • Gajjela, Satyanarayana Reddy; Ananthanarayanan, Krishnamoorthy; Yap, Christopher
  • Energy & Environmental Science, Vol. 3, Issue 6 https://doi.org/10.1039/b921360k
journal January 2010
High sensitivity and fast response hydrogen sensors based on electrochemically etched porous titania thin films journal May 2006
Mesoporous titania: From synthesis to application journal August 2012
In-Situ GISAXS Investigation of Pore Orientation Effects on the Thermal Transformation Mechanism in Mesoporous Titania Thin Films journal December 2013
Block copolymer-templated synthesis of highly organized mesoporous TiO2-based films and their photoelectrochemical applications journal June 2011

Cited By (1)