Phase Separation in Sol-Gel Systems of Organic-Inorganic Hybrids

2006 ◽  
Vol 45 ◽  
pp. 759-768
Author(s):  
Kazuki Nakanishi ◽  
Kazuyoshi Kanamori
Keyword(s):  
Phase Separation ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Surface Hydrophobicity ◽  
The Other ◽  
Inorganic Hybrid ◽  
Surface Hydrophilicity ◽  
Other Hand ◽  
Sol Gel Process ◽  
Polymerization Induced Phase Separation

Organic-inorganic hybrid monoliths with well-defined macropores and/or mesopores have been synthesized by a sol-gel process accompanied by polymerization-induced phase separation. Using aklyltrialkoxysilanes and alkylene-bridged alkoxysilanes, two different categories of organo-siloxane networks have been characterized in view of macroporoisity based on phase separation as well as mesoporosity based on supramolecular templating by surfactants. The alkyl-terminated polysiloxane network exhibited substantial surface hydrophobicity together with the mechanical flexibility. On the other hand, the alkylene-bridged network behaved much more similarly to those prepared from tetraalkoxysilanes with regard to surface hydrophilicity, mechanical rigidness and mesopore-forming ability. Supramolecular templating of mesopores embedded in the gel skeletons comprising well-defined macroporous network has proven to give wide variety of hierarchically designed macro-mesoporous organic-inorganic hybrid materials.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

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‥

Study on acrylic resin/titania organic–inorganic hybrid materials prepared by the sol–gel process

Polymer ◽  
2004 ◽  
Vol 45 (9) ◽  
pp. 2967-2976 ◽  
Author(s):  
Mingna Xiong ◽  
Bo You ◽  
Shuxue Zhou ◽  
Limin Wu
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Acrylic Resin ◽  
Inorganic Hybrid ◽  
Sol Gel Process

Preparation and characterization of organic-inorganic hybrid materials incorporating diphosphino moieties. Study of the accessibility of the phosphorus atoms included into the material

2000 ◽  
Vol 78 (11) ◽  
pp. 1519-1525 ◽  
Author(s):  
Jean-Philippe Bezombes ◽  
Claude Chuit ◽  
Robert JP Corriu ◽  
Catherine Reyé
Keyword(s):  
Solid State ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Inorganic Hybrid ◽  
Sol Gel Process ◽  
Inorganic Network

The hydrolysis-polycondensation by the sol-gel process of the aromatic diphosphines (X3SiC6H4)2PC6H4P(C6H4SiX3)2, which are rigid molecules bearing four hydrolysable SiX3 groups (X = OiPr, H), leads to new organic-inorganic hybrid materials, characterized by solid state 13C, 29Si, and 31P NMR spectroscopies. The accessibility of the phosphorus centres incorporated into the xerogel obtained from the diphosphine with X = OiPr has been studied. All the phosphorus atoms reacted quantitatively with H2O2, S8, and CH3I but only 20% with the more bulky reagent W(CO)5·THF. This result is explained by the rigidity of the inorganic network resulting from the high number of hydrolysable Si-OiPr groups in the precursor.Key words : Diphosphines, sol-gel process, xerogels, solid 31P NMR.

Hybrid materials based on the reaction of polyorganophosphazenes and SiO2 precursors

1996 ◽  
Vol 11 (8) ◽  
pp. 2029-2034 ◽  
Author(s):  
M. Guglielmi ◽  
G. Brusatin ◽  
G. Facchin ◽  
M. Gleria
Keyword(s):  
Phase Separation ◽  
Hybrid Materials ◽  
Sol Gel ◽  
Organic Polymer ◽  
Experimental Conditions ◽  
Covalent Bonds ◽  
Soluble Polymers ◽  
Sol Gel Process ◽  
Free Hydroxyl ◽  
Polymeric Solid

New molecular composite materials can be prepared based on an inorganic oxide network and an organic polymer. The polymeric component generally requires low process temperatures, due to the presence of the organic backbone or side groups. A sol-gel process therefore is suitable for synthesizing the inorganic component by dissolving soluble polymers into sol-gel precursor solutions in order to obtain ceramic and polymeric solid phases. In this work polyorganophosphazenes were used because they have many technologically interesting properties (chemical, optical, electrical, mechanical). The methods to obtain covalent bonds between polymer and inorganic network and to obtain homogeneous, transparent hybrid materials without phase separation were studied. It was possible to avoid phase separation by preparing phosphazenes containing free hydroxyl functions and by adequately choosing the experimental conditions.

scholarly journals Hierarchically Structured Porous Spinels via an Epoxide-Mediated Sol–Gel Process Accompanied by Polymerization-Induced Phase Separation

ACS Omega ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 1201-1212 ◽  
Author(s):  
Jan Herwig ◽  
Juliane Titus ◽  
Jens Kullmann ◽  
Nicole Wilde ◽  
Thomas Hahn ◽  
...  
Keyword(s):  
Phase Separation ◽  
Sol Gel ◽  
Sol Gel Process ◽  
Polymerization Induced Phase Separation

Synthesis and Intermolecularly Mediated Assembly of Organic Pigment in Hybrid Coating Films

1998 ◽  
Vol 519 ◽  
Author(s):  
Y. Yan ◽  
Z. Duan ◽  
D.-G. Chen ◽  
S. Ray Chaudhuri
Keyword(s):  
Sol Gel ◽  
Hybrid Coating ◽  
Hypsochromic Shift ◽  
Hybrid Films ◽  
Coating Films ◽  
Organic Pigment ◽  
Inorganic Hybrid ◽  
Matrix Interactions ◽  
Sol Gel Process

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.

The preparation of poly(methylsilsesquioxane) network-polyimide hybrid materials by the sol-gel process and their properties

1994 ◽  
Vol 6 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Yoshitake Iyoku ◽  
Masa-aki Kakimoto ◽  
Yoshio Imai
Keyword(s):  
Hybrid Materials ◽  
Sol Gel ◽  
Tensile Modulus ◽  
Hybrid Films ◽  
Elongation At Break ◽  
Dimethyl Acetamide ◽  
Flexible Films ◽  
Sol Gel Process ◽  
Heating Up ◽  
Silicone Content

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.

Preparation of Macroprous C12A7 Mayenite Monoliths via a Sol-Gel Process with Nitrates as Precursors

2018 ◽  
Vol 768 ◽  
pp. 211-217 ◽  
Author(s):  
Rui Wang ◽  
Yu Kun Sun ◽  
Bao Jia Qi Jiang ◽  
Hui Yang ◽  
Xing Zhong Guo
Keyword(s):  
Heat Treatment ◽  
Phase Separation ◽  
Binary System ◽  
Propylene Oxide ◽  
Crystalline Phase ◽  
Sol Gel ◽  
Single Crystalline ◽  
Sol Gel Process

Macroporous Ca12Al14O33(C12A7) mayenite monoliths have been successfully prepared via a sol-gel process in the presence of propylene oxide (PO) and poly (ethyleneoxide) (PEO). Gelation of CaO-Al2O3binary system with nitrates salts as additional precursors is accelerated by PO as an acid scavenger, while PEO works as a phase separation inducer to mediate the phase separation of the system. Appropriate PO and PEO amounts allow the formation of monolithic xerogel with interconnected macropores and co-continuous skeletons. The resultant dried gels are amorphous and the single crystalline phase Ca12Al14O33mayenite forms after heat-treatment at 1100 °C in air, while the macrostructure is preserved with a porosity as high as 78% and smoother and denser skeletons.

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