Hydrophobic Thin Films from Sol–Gel Processing: A Critical Review

Fabrication of hydrophobic thin films from a liquid phase is a hot topic with critical technological issues. Interest in the production of hydrophobic surfaces is growing steadily due to their wide applications in several industrial fields. Thin films from liquid phases can be deposited on different types of surfaces using a wide variety of techniques, while the design of the precursor solution offers the possibility of fine-tuning the properties of the hydrophobic coating layers. A general trend is the design of multifunctional films, which have different properties besides being hydrophobic. In the present review, we have described the synthesis through sol–gel processing of hydrophobic films enlightening the main achievements obtained in the field.

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PREPARATION AND STRUCTURE CHARACTERIZATION OF BiFeO3-SrBi2Nb2O9 THIN FILMS ON SILICON BY SOL-GEL PROCESSING

International Journal of Modern Physics B ◽

10.1142/s0217979202015601 ◽

2002 ◽

Vol 16 (28n29) ◽

pp. 4455-4459

Author(s):

HAOSHUANG GU ◽

WANQIANG CAO ◽

JUNMIN XUE ◽

JOHN WANG

Keyword(s):

Thin Films ◽

Sol Gel ◽

Precursor Solution ◽

Monomethyl Ether ◽

Structure Characterization ◽

Layered Perovskite ◽

Heat Treated ◽

Average Grain Size ◽

Gel Processing

A new system 0.1 BiFeO 3-0.9 SrBi 2 Nb 2 O 9 thin films have been successfully prepared by an ethanolamine-modified sol-gel technique. The precursor solution was synthesized from compounds, Bi(NO 3)3· 5H 2 O , Sr(NO 3)2, Fe(NO 3)3· 9H 2 O and Nb(OC 2 H 5)5 in solution ethylene glycol monomethyl ether. The thin films were deposited on Si single crystal by spinning coating, and heat-treated at temperatures ranging from 400°C to 700°C. Crystallization of thin films occurred at about 500 ~ 600°C and the films exhibit a pure phase of layered perovskite ferroelectric structure. The grain of films is well distributed and the average grain size of the film is about 100nm.

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Synthesis and Microstructure of Barium Bismuth Titanate Thin Films Using a Sol-Gel Technique

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.845 ◽

2007 ◽

Vol 280-283 ◽

pp. 845-848

Author(s):

Dan Xie ◽

Wei Pan ◽

Tian Ling Ren ◽

Li Tian Liu

Keyword(s):

Thin Films ◽

Bismuth Titanate ◽

Ph Value ◽

Sol Gel ◽

Precursor Solution ◽

Layered Perovskite ◽

Layered Perovskite Structure ◽

Gel Technique ◽

Gel Processing ◽

Barium Bismuth

The preparation and the microstructure of BaBi4Ti4O15 (BBT) thin films were reported in the paper. BBT thin films were fabricated on silicon substrate using a modified Sol-Gel technique. A key issue of Sol-Gel processing is the chemical reaction and mechanism of precursor solution, which governs the crystallization and characteristics of the final oxide layer. Ethanolamine is an effective complexation reagent of Bi3+, which could moderate the acidity of precursor. When pH value is about 3.5, the stable and uniform BBT precursor solution could be obtained. The Bi-layered perovskite structure of BBT forms at 750°C. The morphology of the grains in BBT thin films is spheroidal and the grain size is about 120nm.

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Fabrication of Sr2Nb2O7 thin films by sol-gel processing

Journal of Materials Research ◽

10.1557/jmr.1995.0704 ◽

1995 ◽

Vol 10 (3) ◽

pp. 704-707 ◽

Cited By ~ 15

Author(s):

Alamanda V. Prasadarao ◽

Ulagaraj Selvaraj ◽

Sridhar Komarnenici

Keyword(s):

Thin Films ◽

Perovskite Phase ◽

Sol Gel ◽

Precursor Solution ◽

Si Substrates ◽

Niobium Ethoxide ◽

First Time ◽

Gel Processing ◽

Room Temperature Dielectric Constant ◽

Sem Microstructure

Sol-gel Sr2Nb2O7 thin films were deposited on Si(100) and Pt-coated Si substrates for the first time by spin-coating. The Sr2Nb2O7 precursor solution was prepared from strontium metal dissolved in 2-methoxyethanol, acetylacetone, and niobium ethoxide. The formation of phase pure Sr2Nb2O7 occurred via an intermediate perovskite phase of composition close to Sr0.82NbO3. Crack-free Sr2Nb2O7 films of ∼0.4 μm thickness were deposited on these substrates using a single-coating followed by heat treatment at 850 °C for 12 h. SEM microstructure and thin film XRD results indicated the deposition of a grain-oriented film on the Pt-coated Si substrate. The room temperature dielectric constant and the loss values of the film measured at 10 kHz are 45 and 0.045, respectively.

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Preparation of Pb(Zr,Ti)O3 thin films by sol gel processing: Electrical, optical, and electro‐optic properties

Journal of Applied Physics ◽

10.1063/1.341613 ◽

1988 ◽

Vol 64 (5) ◽

pp. 2717-2724 ◽

Cited By ~ 493

Author(s):

Guanghua Yi ◽

Zheng Wu ◽

Michael Sayer

Keyword(s):

Thin Films ◽

Sol Gel ◽

Electro Optic ◽

Gel Processing

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Sol-gel synthesis of textured lanthanum titanate thin films

Journal of Materials Research ◽

10.1557/jmr.2003.0046 ◽

2003 ◽

Vol 18 (2) ◽

pp. 357-362 ◽

Cited By ~ 12

Author(s):

Mary M. Sandstrom ◽

Paul Fuierer

Keyword(s):

Thin Films ◽

Sol Gel ◽

Precursor Solution ◽

Solution Concentration ◽

Optical Measurements ◽

Layered Perovskite ◽

Orientation Factor ◽

Anisotropic Structures ◽

Sol Gel Films ◽

Sol Gel Synthesis

Control over crystallographic orientation in thin films is important, particularly with highly anisotropic structures. Because of its ferroelectric nature, the layered perovskite La2Ti2O7 has interesting piezoelectric and electrooptic properties that may be exploited when films are highly textured. Sol-gel films with an orientation factor of greater than 95% were fabricated without relying on epitaxial (lattice-matching) growth from the substrate. Film orientation and crystallization were confirmed by x-ray diffraction, scanning electron microscopy, atomic force microscopy, and optical measurements. The particle sizes in all precursor solutions were measured by dynamic light scattering experiments. Experimental results indicate that film orientation is a function of precursor solution concentration, size of the molecular clusters in the solution, and film thickness.

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Structure and electrical properties of CuAlO2 thin films derived by sol–gel processing

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-010-0193-9 ◽

2010 ◽

Vol 22 (6) ◽

pp. 666-671 ◽

Cited By ~ 3

Author(s):

Si-Jia Liu ◽

Hua Wang ◽

Ji-Wen Xu ◽

Ming-Fang Ren ◽

Ling Yang ◽

...

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Sol Gel ◽

Gel Processing

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Phase transition and piezoelectricity of sol–gel-processed Sm-doped BiFeO3 thin films on Pt(111)/Ti/SiO2/Si substrates

Journal of Materials Chemistry C ◽

10.1039/c4tc02886d ◽

2015 ◽

Vol 3 (9) ◽

pp. 2115-2122 ◽

Cited By ~ 43

Author(s):

Wei Sun ◽

Jing-Feng Li ◽

Qi Yu ◽

Li-Qian Cheng

Keyword(s):

Thin Films ◽

Phase Transition ◽

Sol Gel ◽

Orthorhombic Phase ◽

High Quality ◽

Si Substrates ◽

Bifeo3 Thin Films ◽

Gel Processing

We prepared high-quality Bi1−xSmxFeO3 films on Pt(111)/Ti/SiO2/Si substrates by sol–gel processing and found rhombohedral–orthorhombic phase transition with enhanced piezoelectricity.

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