Nanostructured Doped Silica Films Application as Sensitive Layers for Chemical Sensors

The sensor behavior of nanostructured doped silica films produced by sol-gel way were examined. Hygroscopic substances and polyoxometalates were used as additives to make more significant sensitive characteristics of initial matrix. Factors that have effect on sol preparation and films forming were investigated. Adsorption activity of the sensitive films was studied and it was shown that the films had a highly developed surface with nano-size pores. Change of initial conditions of sol-gel process gives opportunity to influence on kinetics of gel formation and consequently, on structure and properties of final materials. The study showed that the conditions of the environment affected the sensors characteristics markedly, which can be improved by choosing of the right procedure of forming and treatment. Influence of type and additive substances quantity into doped films was discussed in the paper

Download Full-text

Crystallisation kinetics of hydroxyapatite thin films prepared by sol-gel process

Advances in Applied Ceramics ◽

10.1179/174367609x422144 ◽

2010 ◽

Vol 109 (6) ◽

pp. 313-317 ◽

Cited By ~ 6

Author(s):

H Najafi ◽

A Nemati ◽

Z Sadeghian

Keyword(s):

Thin Films ◽

Sol Gel ◽

Crystallisation Kinetics ◽

Sol Gel Process ◽

Kinetics Of

Download Full-text

Sol-gel process of non-linear optical silica films with organic chromophore as side chain

Journal of Materials Science ◽

10.1007/bf01152959 ◽

1996 ◽

Vol 31 (9) ◽

pp. 2443-2446 ◽

Cited By ~ 7

Author(s):

Po-Hou Sung ◽

Shao-Ling Wu ◽

Chien-Yang Lin

Keyword(s):

Sol Gel ◽

Side Chain ◽

Silica Films ◽

Sol Gel Process ◽

Non Linear ◽

Linear Optical ◽

Organic Chromophore

Download Full-text

Crystallization of nanosized titania particles prepared by the sol-gel process

Journal of Materials Research ◽

10.1557/jmr.1994.2102 ◽

1994 ◽

Vol 9 (8) ◽

pp. 2102-2108 ◽

Cited By ~ 96

Author(s):

E. Haro-Poniatowski ◽

R. Rodríguez-Talavera ◽

Heredia M. de la Cruz ◽

O. Cano-Corona ◽

R. Arroyo-Murillo

Keyword(s):

Particle Size ◽

Steady State ◽

Light Scattering ◽

Sol Gel ◽

X Ray ◽

Constant Size ◽

Size Profile ◽

Nanosized Titania ◽

Sol Gel Process ◽

Kinetics Of

Sols of titania were obtained by the sol-gel method and their size profile was followed by dynamical light scattering. In the early stages of the reaction an unstable behavior was detected. After this unstable regime the particle size reaches a steady state where the sols have a constant size while increasing in number. Once the sol concentration reaches its overlap value, the gelation regime takes place. For samples prepared in this way Raman spectra and x-ray diffractometry were used to characterize the kinetics of crystallization of the material.

Download Full-text

Textural characterization of porous silica films prepared by the sol–gel process

Surface and Colloid Science ◽

10.1007/b97091 ◽

2004 ◽

pp. 227-231

Author(s):

G. L. T. Nascimento ◽

L. M. Seara ◽

B. R. A. Neves ◽

N. D. S. Mohallem

Keyword(s):

Sol Gel ◽

Porous Silica ◽

Silica Films ◽

Textural Characterization ◽

Sol Gel Process

Download Full-text

Adsorption–desorption kinetics of silica coated on textile fabrics by the sol–gel process

Journal of Coatings Technology and Research ◽

10.1007/s11998-019-00281-8 ◽

2019 ◽

Vol 17 (2) ◽

pp. 371-380 ◽

Cited By ~ 1

Author(s):

Mohamed El messoudi ◽

Aicha Boukhriss ◽

Omar Cherkaoui ◽

M’hammed El kouali ◽

Said Gmouh

Keyword(s):

Sol Gel ◽

Desorption Kinetics ◽

Textile Fabrics ◽

Sol Gel Process ◽

Adsorption Desorption ◽

Kinetics Of

Download Full-text

Structural, Optical, and pH-Stimulus Response Properties of Cresol Red Immobilized Nanocomposite Silica Films Derived by a Sol–Gel Process Employing Different Synthetic Routes

Industrial & Engineering Chemistry Research ◽

10.1021/ie500846z ◽

2014 ◽

Vol 53 (49) ◽

pp. 18863-18872 ◽

Cited By ~ 5

Author(s):

Shobhit Singh Chauhan ◽

R. V. Jasra ◽

A. L. Sharma

Keyword(s):

Sol Gel ◽

Silica Films ◽

Response Properties ◽

Stimulus Response ◽

Sol Gel Process ◽

Synthetic Routes ◽

Cresol Red

Download Full-text

Characteristics and thermal decomposition kinetics of wood-SiO2 composites derived by the sol-gel process

Holzforschung ◽

10.1515/hf-2016-0126 ◽

2017 ◽

Vol 71 (3) ◽

pp. 233-240 ◽

Cited By ~ 12

Author(s):

Ke-Chang Hung ◽

Jyh-Horng Wu

Keyword(s):

Activation Energy ◽

Thermal Decomposition ◽

Apparent Activation Energy ◽

Sol Gel ◽

Weight Percent Gain ◽

Weight Percent ◽

Decomposition Kinetics ◽

Thermal Decomposition Kinetics ◽

Sol Gel Process ◽

Kinetics Of

Abstract Wood-SiO2 composites (WSiO2Cs) were prepared by means of the sol-gel process with methyltrimethoxysilane (MTMOS) as a reagent, and the physical properties, structure and thermal decomposition kinetics of the composites has been evaluated. The dimensional stability of the WSiO2Cs was better than that of unmodified wood, especially in terms of the weight percent gain (WPG), which achieved values up to 30%. The 29Si-NMR spectra show two different siloxane peaks (T2 and T3), which supports the theory about the formation of MTMOS network structures. Thermal decomposition experiments were also carried out in a TG analyzer under a nitrogen atmosphere. The apparent activation energy was determined according to the iso-conversional methods of Friedman, Flynn-Wall-Ozawa, modified Coats-Redfern, and Starink. The apparent activation energy between 10 and 70% conversion is 147–172, 170–291, 189–251, and 192–248 kJ mol−1 for wood and WSiO2Cs with WPGs of 10, 20, and 30%, respectively. However, the reaction order between 10 and 70% conversion calculated by the Avrami theory was 0.50–0.56, 0.35–0.45, 0.33–0.44, and 0.28–0.48. These results indicate that the dimensional and thermal stability of the wood could be effectively enhanced by MTMOS treatment.

Download Full-text

Study on the Dielectric Properties of Hybrid and Porous Polyimide-Silica Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.973 ◽

2008 ◽

Vol 47-50 ◽

pp. 973-976 ◽

Cited By ~ 1

Author(s):

Yi He Zhang ◽

Qing Song Su ◽

Li Yu ◽

Hong Zheng ◽

Hai Tao Huang ◽

...

Keyword(s):

Dielectric Constant ◽

Sol Gel ◽

Silica Particles ◽

Low Dielectric Constant ◽

Hybrid Films ◽

Porous Films ◽

Silica Films ◽

Low Dielectric ◽

Dimethyl Acetamide ◽

Sol Gel Process

A sol-gel process was used to prepare polyimide-silica hybrid films from the polyimide precursors and TEOS in N,N- dimethyl acetamide, then the hybrid film was treated with hydrofluoric acid to remove the dispersed silica particles, leaving pores with diameters between 80nm to 1µm, depending on the size of silica particles. The structure and dielectric constant of the hybrid and porous films were characterized by FTIR,SEM. The porous films displayed relatively low dielectric constant compared to the hybrid polyimide-silica films.

Download Full-text