Indentation stress relaxation of sol–gel-derived organic/inorganic hybrid coating

2005 ◽  
Vol 53 (16) ◽  
pp. 4455-4462 ◽  
Author(s):  
M SAKAI ◽  
M SASAKI ◽  
A MATSUDA
1998 ◽  
Vol 519 ◽  
Author(s):  
Y. Yan ◽  
Z. Duan ◽  
D.-G. Chen ◽  
S. Ray Chaudhuri

AbstractThe insoluble, strongly hydrogen bonded organic pigment of 3,6-bis-(4-chlorphenyl)-l,4- diketopyrrolo [3,4-c] pyrrole was transiently blocked by adding carbamate groups, and consequently incorporated into organic-inorganic hybrid matrices by a sol-gel process. The homo- (pigment-pigment) and hetero-intermolecular (pigment-matrix) interactions were found to control both the assembly and dispersion of pigment molecules in the hybrid coating films. A weaker interaction between matrices and pigment molecules results in aggregation of the carbamate pigment in the methyl-silicate films. A stronger interaction forms a homogenous dispersion and coloration of the phenyl-silicate films. The as-prepared methyl- and phenylsilicate films doped with the organic pigment were distinguished by a morphology change and a blue (hypsochromic) shift in absorption from 550 to 460 nm. Thermal treatment can remove the carbamate groups and in-situ form the organic pigment in the hybrid films.


Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 72 ◽  
Author(s):  
Simona Ortelli ◽  
Anna Luisa Costa

Organic–inorganic hybrid (ceramer) coatings were synthesized and deposited on the polyester nonwoven fabrics through the sol–gel process. This promoted the formation of an insulating barrier that was able to enhance the thermal stability and the hydrophobicity of fabrics. The hybrid phase is made of an organic network arising from different alkoxysilane precursors (trimethoxymethylalkoxysilane (TMEOS), 3-aminopropyl-trimethoxyalkoxysilane (APTMS), and tetraethylorthosilicate (TEOS)) and inorganic phase made of titanium dioxide TiO2 nanoparticles (NPs) and, in some cases, coated by P-based compound. The characterization of hybrid phase at liquid (size distribution and zeta potential of dispersed nanoparticles), dried state (crystalline phase, thermogravimetric (TGA), and Fourier transform infrared spectroscopic (FTIR) analyses), and on deposited coatings (contact angle, burn-out tests) aimed to find a correlation between the physicochemical properties of ceramer and functional performances of coated fabrics (thermal stability and hydrophobicity). The results showed that all ceramer formulations were able to improve the char formation after burn-out, in particular the highest thermal stability was obtained in the presence of TMEOS precursor and TiO2 NPs coated by P-based compound, which also provided the highest hydrophobicity. In conclusion, we presented an environmentally friendly and easily scalable process for the preparation of ceramer formulations capable of being formed into transparent, thermal-resistant, and hydrophobic fabric coatings, whose functions are extremely challenging for the textile market.


RSC Advances ◽  
2020 ◽  
Vol 10 (27) ◽  
pp. 15881-15887
Author(s):  
Xuyang Luo ◽  
Fei Gao ◽  
Fengbiao Chen ◽  
Qian Cheng ◽  
Jinze Zhao ◽  
...  

A novel coating material was synthesized in one-step comprising two reactions (an amine–acetoacetate reaction and an in situ sol–gel technique).


2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥


Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3265 ◽  
Author(s):  
Li ◽  
Li ◽  
Li ◽  
Guan ◽  
Zheng ◽  
...  

A new synthesis method for organic–inorganic hybrid Poly(vinylidene fluoride)-SiO2 cation-change membranes (CEMs) is proposed. This method involves mixing tetraethyl orthosilicate (TEOS) and 3-mercapto-propyl-triethoxy-silane (MPTES) into a polyvinylidene fluoride (PVDF) sol-gel solution. The resulting slurry was used to prepare films, which were immersed in 0.01 M HCl, which caused hydrolysis and polycondensation between the MPTES and TEOS. The resulting Si-O-Si polymers chains intertwined and/or penetrated the PVDF skeleton, significantly improving the mechanical strength of the resulting hybrid PVDF-SiO2 CEMs. The -SH functional groups of MPTES oxidized to-SO3H, which contributed to the excellent permeability of these CEMs. The surface morphology, hybrid structure, oxidative stability, and physicochemical properties (IEC, water uptake, membrane resistance, membrane potential, transport number, and selective permittivity) of the CEMs obtained in this work were characterized using scanning electron microscope and Fourier transform infrared spectroscopy, as well as electrochemical testing. Tests to analyze the oxidative stability, water uptake, membrane potential, and selective permeability were also performed. Our organic–inorganic hybrid PVDF-SiO2 CEMs demonstrated higher oxidative stability and lower resistance than commercial Ionsep-HC-C membranes with a hydrocarbon structure. Thus, the synthesis method described in this work is very promising for the production of very efficient CEMs. In addition, the physical and electrochemical properties of the PVDF-SiO2 CEMs are comparable to the Ionsep-HC-C membranes. The electrolysis of the concentrated CoCl2 solution performed using PVDF-SiO2-6 and Ionsep-HC-C CEMs showed that at the same current density, Co2+ production, and current efficiency of the PVDF-SiO2-6 CEM membrane were slightly higher than those obtained using the Ionsep-HC-C membrane. Therefore, our novel membrane might be suitable for the recovery of cobalt from concentrated CoCl2 solutions.


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