scholarly journals TiO2–Polymer Nano–Composites by Sol–Gel

1995 ◽  
Vol 18 (1) ◽  
pp. 31-37 ◽  
Author(s):  
A. C. Pierre ◽  
G. Campet ◽  
S. D. Han ◽  
S. Y. Huang ◽  
E. Duguet ◽  
...  

Sol-gel processes make it possible to develop new hybrid electrolyte materials of the type ceramic-polymer, known as Nano-Crystallite-Insertion-Material (NCIM). They can be used in reversible alkali electrochemical cells after insertion with cations such as Li+. In the present study, TiO2-polyethylene oxide hybrid materials were synthesized from TiCl4and from Ti ethoxide. Their structure is analyzed in relation with the processing parameters. A primary evaluation of the nanoscale composite materials for reversible Li insertion was performed.

1994 ◽  
Vol 346 ◽  
Author(s):  
Reiner Kasemann ◽  
Helmut K. Schmidt ◽  
Elisabeth Wintrich

ABSTRACTA new type of sol-gel-based transparent inorganic-organic nano composites has been developed by increasing the inorganic phase dimension to values just below the point, where scattering can be neglected. For this purpose, nanosized boehmite particles ≤ 50 nm are homogeneously incorporated in a sol based on tetraethoxysilane and an epoxysilane. The nano-scale boehmite particles act as catalysts for the polymerization of the epoxy silane to polyethylene oxide, as proved by 13C NMR, and are linked to the matrix by Si-O-Al bridges, as proven by 27Al-NMR spectroscopy. The synthesized sols can be applied by standard coating techniques on transparent polymers and are cured thermally. The mechanical properties (scratch resistance, hardness) have been substantially improved compared to systems with molecular dimensions of the inorganic phase. The effect is attributed to the special structure of flexibly suspended nano-scale boehmite particles in an inorganic-organic network by a tailored interface.


1990 ◽  
Vol 180 ◽  
Author(s):  
J.M. Boulton ◽  
H.H. Fox ◽  
G.F. Neilson ◽  
D.R. Uhlmann

ABSTRACTSol-gel techniques are readily applicable to the preparation of Polycerams. These hybrid materials uniquely combine organic and inorganic functionalities at the molecular level. Polycerams have here been prepared from tetraethoxysilane and modified, functionalized polybutadiene, polyethylene oxide urethane and polyethyleneimine. The structures and physical characteristics of the materials are here in reported.


2020 ◽  
Vol 10 (18) ◽  
pp. 6594 ◽  
Author(s):  
Ioannis A. Kartsonakis ◽  
Costas A. Charitidis

In the present work, an assessment of the corrosion behavior of mild steel in the presence of an organic corrosion inhibitor loaded into hybrid composite materials is performed. Hybrid organic–inorganic nanocontainers based on cerium and titanium oxides were fabricated via a combination of radical polymerization together with the coprecipitation method and sol-gel technique. The corrosion inhibition role of these hybrid materials loaded with an inhibitor is considered. A set of characterization assays addressing morphology, composition and structural aspects of the exposed steels is illustrated, along with electrochemical evaluations. The results reveal enhanced stimuli responsive anticorrosion ability of the produced hybrid materials. Furthermore, upon corrosion, new compounds are formed onto the exposed areas of the treated metals. The conducted experiments shed light on the corrosion mechanisms for steel alloys as well as the actuation of the fabricated composite materials, paving the way for future developments in this area.


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‥


2020 ◽  
Vol 389 (1) ◽  
pp. 1900057
Author(s):  
Michelina Catauro ◽  
Elisabetta Tranquillo ◽  
Giovanni Dal Poggetto ◽  
Daniele Naviglio ◽  
Federico Barrino

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1586
Author(s):  
Michelina Catauro ◽  
Pavel Šiler ◽  
Jiří Másilko ◽  
Roberta Risoluti ◽  
Stefano Vecchio Ciprioti

The present study investigated the structure, morphology, thermal behavior, and bacterial growth analysis of novel three-component hybrid materials synthesized by the sol-gel method. The inorganic silica matrix was weakly bonded to the network of two organic components: a well-known polymer such as polyethylene glycol (PEG, average molar mass of about 4000 g/mol), and an antioxidant constituted by chlorogenic acid (CGA). In particular, a first series was made by a 50 wt% PEG-based (CGA-free) silica hybrid along with two 50 wt% PEG-based hybrids containing 10 and 20 wt% of CGA (denoted as SP50, SP50C10 and SP50C20, respectively). A second series contained a fixed amount of CGA (20 wt%) in silica-based hybrids: one was the PEG-free material (SC20) and the other two contained 12 and 50 wt% of PEG, respectively (SP12C20 and SP50C20, respectively), being the latter already included in the first series. The X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images of freshly prepared materials confirmed that all the materials were amorphous and homogeneous regardless of the content of PEG or CGA. The thermogravimetric (TG) analysis revealed a higher water content was adsorbed into the two component hybrids (SP50 and SC20) because of the availability of a larger number of H-bonds to be formed with water with respect to those of silica/PEG/CGA (SPC), where silica matrix was involved in these bonds with both organic components. Conversely, the PEG-rich materials (SP50C10 and SP50C20, both with 50 wt% of the polymer) retained a lower content of water. Decomposition of PEG and CGA occurred in almost the same temperature interval regardless of the content of each organic component. The antibacterial properties of the SiO2/PEG/CGA hybrid materials were studied in pellets using either Escherichia coli and Enterococcus faecalis, respectively. Excellent antibacterial activity was found against both bacteria regardless of the amount of polymer in the hybrids.


1994 ◽  
Vol 6 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Yoshitake Iyoku ◽  
Masa-aki Kakimoto ◽  
Yoshio Imai

Poly(methylsilsesquixoane) network (silicone)-polyimide hybrid materials were successfully prepared by the sol-gel reaction of methyltriethoxysilane (MTES). The ethoxysilyl group in MTES was hydrolyzed and polycondensed in the solution of the polyamic acid, derived from pyromellitic dianhydride and bis(4-aminophenyl)ether, in N,N-dimethyl-acetamide (DMAc). The hybrid films were obtained by casting the reaction mixture, followed by heating up to 300°C. The hybrid materials containing 0-60wt% of silicone afforded flexible films. The films containing less than 7 wt% silicone were yellow and transparent, whereas the films with higher silicone content were yellow and opaque. Silicone particles with a diameter of around 1-10 μm were observed in the fracture surface of the hybrid films by scanning electron microscopy. Although the tensile strength and tensile modulus of the films obtained decreased with increasing silicone content. the value of the elongation at break remained at 60% up to 30% silicone content.


2002 ◽  
Vol 748 ◽  
Author(s):  
C. L. Zhao ◽  
Z. H. Wang ◽  
W. Zhu ◽  
O. K. Tan ◽  
H. H. Hng

ABSTRACTLead zirconate titanate (PZT) films are promising for acoustic micro-devices applications because of their extremely high electromechanical coupling coefficients and excellent piezoelectric response. Thicker PZT films are crucial for these acoustic applications. A hybrid sol-gel technology has been developed as a new approach to realize simple and cost-effective fabrication of high quality PZT thick films. In this paper, PZT53/47 thick films with a thickness of 5–50 μm are successfully deposited on Pt-coated silicon wafer by using the hybrid sol-gel technology. The obtained PZT thick films are dense, crack-free, and have a nano-sized microstructure. The processing parameters of this technology have been evaluated. The microstructure of the film has been observed using field-emission scanning electron microscopy and the crystallization process has been monitored by the X-ray diffraction. The thick films thus made are good candidates for fabrication of piezoelectric diaphragm which will be an essential element of microspeaker and microphone arrays.


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