Spectroelectrochemical Investigations of Cation-Insertion Reactions at Sol−Gel-Derived Nanostructured, Mesoporous Thin Films of Manganese Oxide†

Background: Silver nanosystems have attracted considerable attention for numerous applications in optoelectronics. The localized surface plasmon of silver nanoparticles embedded into mesoporous titania gives rise to an enhancement of local optical field in the vicinity of Ag nanoparticles which act as efficient light-trapping components, resulting in a visible wavelength-dependent photocurrent. Objective: In this paper, we synthetized patterned nanocomposites formed by titania mesoporous thin films loaded with alkanethiol functionalized Ag nanoparticles and we demonstrated that these stable and accessible nanostructures possess a photocurrent response. Method: Mesoporous thin films are created by combining sol-gel synthesis and template selfassembly. Based on a photolithography technique, silver nanoparticles were selectively photodeposited and then stabilized with octanethiols. Current vs. voltage curves with and without light were compared, where selective light wavelength measurements were achieved by using visible bandpass filters. The optofluidic behavior was evaluated by placing a drop of solutions on the mesoporous film. Results: We demonstrate photocurrent in these mesoporous thin film structures decorated with chemistabilized Ag nanoparticle-based conductive arrays, with significantly enhanced photocurrent peak at the plasmon resonant wavelength around 540 nm. Our findings offer a possibility to perform improved fluid detection with silver-mesoporous titania electronic devices. Conclusion: We showed that an optofluidic sensitive nanocomposite circuit consisting of alkanethiol- functionalized metal nanoparticles embedded in a mesoporous oxide thin film matrix can be produced.

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Capillary Stress in Microporous Thin Films

MRS Proceedings ◽

10.1557/proc-436-373 ◽

1996 ◽

Vol 436 ◽

Author(s):

J. Samuel ◽

A. J. Hurd ◽

C. J. Brinker ◽

L. J. Douglas Frink ◽

F. Van Swol

Keyword(s):

Thin Films ◽

Density Functional ◽

Sol Gel ◽

Vacuum System ◽

Relative Pressure ◽

A Value ◽

Capillary Stress ◽

Mesoporous Thin Films ◽

Order Of Magnitude ◽

Beam Bending

AbstractDevelopment of capillary stress in porous xerogels, although ubiquitous, has not been systematically studied. We have used the beam bending technique to measure stress isotherms of microporous thin films prepared by a sol-gel route. The thin films were prepared on deformablesilicon substrates which were then placed in a vacuum system. The automated measurement was carried out by monitoring the deflection of a laser reflected off the substrate while changing the overlying relative pressure of various solvents. The magnitude of the macroscopic bending stress was found to reach a value of 180 MPa at a relative pressure of methanol, P/Po = 0.001. The observed stress is determined by the pore size distribution and is an order of magnitude smaller in mesoporous thin films. Density Functional Theory (DFT) indicates that for the microporous materials, the stress at saturation is compressive and drops as the relative pressure is reduced.

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Sol-Gel Synthesis of TiO2 Mesoporous Thin Films on Silicon

Russian Journal of General Chemistry ◽

10.1134/s1070363218020263 ◽

2018 ◽

Vol 88 (2) ◽

pp. 345-346

Author(s):

V. S. Mironov ◽

T. N. Gasanov ◽

V. M. Smirnov

Keyword(s):

Thin Films ◽

Sol Gel ◽

Mesoporous Thin Films ◽

Sol Gel Synthesis

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Thermal Decomposition of Some Sol-Gel Precursors for Mesoporous TiO2-Based Thin Films for Chemorezistive Environmental Sensors

Revista de Chimie ◽

10.37358/rc.17.8.5748 ◽

2017 ◽

Vol 68 (8) ◽

pp. 1703-1707

Author(s):

Violeta Dediu ◽

Viorica Musat ◽

Bogdan Jurca ◽

Nicolae Ionut Cristea

Keyword(s):

Thin Films ◽

Thermal Decomposition ◽

Sol Gel ◽

Titanium Isopropoxide ◽

Mesoporous Tio2 ◽

Chemical Transformations ◽

Environmental Sensors ◽

Oxidative Decomposition ◽

Doped Tio2 ◽

Mesoporous Thin Films

This paper presents a comparative study on the thermal decomposition in air and FTIR analyses of complex sol-gel precursors used for the deposition of three titania based mesoporous thin films: TiO2, Nb-doped TiO2 and carbon nanotubes (MWCNT)-doped TiO2. The effect of doping with Nb or adding MWCNT on the thermal decomposition of titanium isopropoxide-based precursor and crystallization of TiO2 was investigated through thermogravimetric analysis (TGA), differential thermal analysis (DTA), and Fourier Transform Infrared (FTIR) data. TG-DTA results showed two main exothermic peaks were observed in all samples for the temperature range 280-300 oC and 429-444 oC, corresponding to isopropoxide oxidative decomposition and anatase crystallization. In case of Nb doped TiO2 an oxidative decomposition of Nb ethoxide appears at 198 �C. The acidified MWCNT are thermally stable up to 500�C. Doping TiO2 causes peaks shift to higher temperatures. Also, the effect of heating rate on thermal decomposition for precursors was studied. FTIR analyses were conducted on precursor systems thermally treated at different temperature to track the chemical transformations during the films formation.

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Surfactant Effect on the Synthesis of Mesoporous TiO2-SiO2 Coatings Using Sol-Gel Technology

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.762.263 ◽

2018 ◽

Vol 762 ◽

pp. 263-267

Author(s):

Margarita Karpe

Keyword(s):

Thin Films ◽

Sol Gel ◽

Mesoporous Structure ◽

Titanium Isopropoxide ◽

Water Contact ◽

Separation Membranes ◽

Mesoporous Thin Films ◽

Potential Applications ◽

Triblock Copolymer Surfactant ◽

Xrd Patterns

The aim of the research was to develop the area of mesoporous thin films of a binary TiO2–SiO2 system. Sol was synthesized from tetraethylorthosilicate as the silica source and titanium isopropoxide solution as the TiO2 source, while triblock copolymer surfactant (Pluronic F 127 (10% solution in water, (P))) was used as the mesostructure-directing agent. In this paper we present sol-gel obtained TiO2–SiO2 with a mesoporous structure. The effects of added titanium on the mesostructure and on the porosity are presented and discussed. Four different molar percentage ratios of Ti: Si were used for the synthesis of mixed TiO2–SiO2 mesoporous thin films on glass substrate. The mesoporous structure of thin films was characterized by X-ray diffraction (XRD) patterns, atomic force microscopy (AFM), scanning electron microscopy (SEM) and the water contact angle. These mesoporous TiO2–SiO2 thin films could have many potential applications in many areas such as separation membranes, catalysis, optics, and self-cleaning surfaces.

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Mesoporous Thin Films: An Example of Pore Engineered Material

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.391.109 ◽

2008 ◽

Vol 391 ◽

pp. 109-120 ◽

Cited By ~ 1

Author(s):

Plinio Innocenzi ◽

Galo Soler Illia

Keyword(s):

Thin Films ◽

Liquid Phase ◽

Supramolecular Chemistry ◽

Self Assembly ◽

Open Porosity ◽

Sol Gel ◽

Solvent Evaporation ◽

General Overview ◽

Mesoporous Thin Films

Self-assembly through supramolecular templates is an advanced process for preparing thin films with ordered mesostructure and tuned pore arrays; the overall process is a combination of sol-gel and supramolecular chemistry, while the organization is driven by solvent evaporation. Controlling of the process allows obtaining a nanomaterial whose ordered and open porosity can be exploited for applications in different fields. In the article we give a general overview of self-assembly during thin films deposition from a liquid phase and we present some possible fields of applications.

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The crystallization of thin-film ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122095 ◽

1992 ◽

Vol 50 (1) ◽

pp. 338-339

Author(s):

J.M. Schwartz ◽

L.F. Francis ◽

L.D. Schmidt ◽

P.S. Schabes-Retchkiman

Keyword(s):

Thin Films ◽

Grain Size ◽

Sol Gel ◽

Processing Route ◽

Small Areas ◽

Ceramic Thin Films ◽

Complex Shapes ◽

Sol Gel Process ◽

Ceramic Precursors ◽

Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

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