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Eremenko, B. V.; Bezugla, Tetiana; Savitskaya, A. N.; Malysheva, M. L.; Kozlov, Ivan; Bogodist, L. G.

doi:10.1023/a:1016673605744

Cited by 18 publications

(15 citation statements)

References 7 publications

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“…[1][2][3][4][5][6][7][8][9]. Immobilization of water-soluble polymers onto a surface of fumed silica (or other hydrophilic metal oxides having surface hydroxyls) from aqueous media can cause substantial diminution of the dispersivity and the specific surface area (by half) of the dried powder materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. This effect is rather negative because it leads to a reduction of the adsorption capacity, the particle mobility in liquid media and negative changes of other characteristics.…”

Section: Introductionmentioning

confidence: 99%

Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

Гунько

Воронин

Носач

et al. 2006

Applied Surface Science

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Section: Introductionmentioning

confidence: 99%

Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

Гунько

Воронин

Носач

et al. 2006

Applied Surface Science

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“…The coagula tion threshold values were studied from the sedimenta tion stability of the anatase obtained by TiCl 4 hydrolysis on heating. 18 The parallel determination of the electroki netic potential and isoelectric point (IEP) showed that the pH of the IEP of the anatase was 5.7, and this is precisely the pH region where the suspension is least stable. With an increase in the pH of the suspension, stability of the anatase suspension increases in the region of the nega tive surface charge.…”

Section: Resultsmentioning

confidence: 99%

Determination of particle size in aqueous suspensions of hydrogels of iron(III), indium(III), aluminum, chromium(III), titanium(IV), and zirconium(IV) oxohydroxides

2005

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Dispersion of hydrogels of Fe III , In III , Al III , Cr III , Ti IV , and Zr IV oxohydroxides in an aqueous medium was studied by sedimentation analysis. The hydrogel dispersion depends on the metal nature, pH of precipitation, and suspension concentration. The systems are predomi nantly polydisperse, and the gel particle size ranges from 2 to 140 µm. The data obtained suggest that the gel particles are formed by three dimensional networks consisting of polymeric chains metal-oxygen and contain cavities filled with water.The role of nanoparticles in the genesis of gel systems has intensely been studied. 1 Hydrogels of tri and tetra valent metal oxohydroxides (MOH) are interesting repre sentatives of these systems. 2-6 The study of the rheologi cal properties of freshly prepared monolith gels, 7-10 whose three dimensional framework retained, suggests that the MOH hydrogels possess noticeable shear strength. They are continuous polymeric matrices in which liquid crys talline phases consisting of fragments with unstable struc ture can be formed. It remains unclear how far these conclusions can be extended to suspensions of gels ob tained by the fast alkali hydrolysis of aqueous solutions of the corresponding metal salts with continuous stirring in a vortex mode followed by washing from a mother liquor by multiple centrifuging and repulping. 3 In this work, we attempted to reveal the state of the MOH gels in suspensions using sedimentation analysis, which is widely used to determine the fractional composi tion of microheterogeneous systems. There are many vari ants of apparatus equipment and mathematical methods for processing results of sedimentation analysis, 11-15 which is poorly used for studying hydrogels. 13, 14 We have previously found that the properties of ob jects called MOH hydrogels change remarkably due to the interaction with electrolyte solutions. This concerns acid base and sorption characteristics, 5,6 consistency, and even color of the hydrogels. Due to partial crystallization, the concentrations of impurity ions and intramicellar water 4 and sedimentation rate change. We succeeded to develop a method for determination of the specific surface S sp of the oxohydroxide hydrogels from the limiting amount adsorbed of the OH groups 16 and showed that the S sp values for the freshly prepared MOH are independent of the pH of their precipitation. The S sp values of Fe III , Cr III , Zr IV , and In III oxohydroxides are equal to 585, 930, 420, and 240 m 2 g -1 , respectively.In this work, we studied the freshly precipitated at different pH and washed Fe III , In III , Al III , Cr III , Ti IV , and Zr IV oxohydroxides. The dispersion of their suspensions was studied by the sedimentation method in a gravitation field at different suspension concentrations in water and in an electrolyte (NaCl and Na 2 SO 4 ) solution. We at tempted to determine how the S sp values of the MOH hydrogels depend on dispersion. ExperimentalThe method of fast alkali hydrolysis of metal salt solutions was used to obtain MOH hydrogels...

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“…The same method is used to obtain non-silicate meso-structured ceramics, for example, anatase and rutile modifications of TiO 2 [26,27]. 2 The particles form as a result of reaction of hydrolysis and co-condensation in the following way.…”

Section: General Characteristics Of Sol-gel Reactionsmentioning

confidence: 99%

“…Probably, even more complicated is structural arrangement of composites based on poly(isoprene-block-ethylene oxide), in which phase-separated block-copolymers were mixed with alkoxide (3-glycidil oxypropyl)trimethoxysilane and aluminum butoxide in sol-gel process. Fixing of PEO macromolecules on the surface of metal oxides due to H-bonds of oxygen atoms with OH-groups of the surface conducts even through layers of coordinationcoupled with these groups water [26]. As a rule, strong hydrogen bonds usually form between organic and inorganic phases.…”

Section: àmentioning

confidence: 99%

See 1 more Smart Citation

Physics and Chemistry of Sol-Gel Nanocomposites Formation

Pomogailo

Джардималиева

2014

Nanostructured Materials Preparation via Condensation Ways

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This method called sol-gel or dip-and spin-on-glass process, spin-spray-coating, sol -gel glasses, which was widely used in the second half of the twentieth century [1] 1 is one of the most universal condensation ways of production of nanoparticles stabilized by inorganic oxide or polymeric matrices. A special interest is attracted to materials obtained by combination of sol-gel chemistry and aerosol or spray processes, and combination of sol-gel synthesis with intercalation. This also includes combinations of sol-gel processes with different types of thermolysis, and approaches met in nature in biomineralization processes, etc., which are new aspects of integrative chemistry approach. Traditional sol-gel concept is based on hydrolysis and condensation of metal alkoxides and many metalloids including different ways of their modification [2,3]. Main reactions proceed at relatively low temperatures with usage of prepared in advance or synthesized in parallel polymers, and are convenient techniques for preparation of organic-inorganic nanocomposites compared with commercial silicate-intercalation technique. Sizes of formed nanoparticles in a composite can be reduced to 10 nm by choice of relative conditions. Polymer-inorganic materials have high mechanical strength and thermal stability in combination with optimal heat transport properties. They are widely used in practice due to unique physical and chemical properties: incorporation of nanometric inorganic component into polymeric matrix improves mechanical properties of material [4][5][6][7], permeability of polymers [8]. Light-sensitive materials are used in optic and electronic industry, printed-circuit boards, photoconductive cells, as key elements in solid coatings, packing materials, as cover materials they have good transparency [9][10][11]. For example, sol-gel method was used to produce various polymer/TiO 2 composites with high refractive index [12]. Such type of composites are used for chromatographic carriers, membrane materials, these are the main class of plastics for different applications, including airspace. Controlled properties of the surface of these colloid 1 We refer here to the recent review devoted to celebration of 40th anniversary of innovation researches in polymer-inorganic ceramics produced by sol-gel technique [1].

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Cited by 18 publications

References 7 publications

Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

Nanocomposites with fumed silica/poly(vinyl pyrrolidone) prepared at a low content of solvents

Determination of particle size in aqueous suspensions of hydrogels of iron(III), indium(III), aluminum, chromium(III), titanium(IV), and zirconium(IV) oxohydroxides

Physics and Chemistry of Sol-Gel Nanocomposites Formation

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