Kinetic study of silicon alkoxides gelation by acoustic and rheology investigations

Griesmar, Pascal; Ponton, Alain; Serfaty, Sylvia; Senouci, Brahim; Gindre, M.; Gouédard, G.; Warlus, S.

doi:10.1016/s0022-3093(02)01957-9

Cited by 20 publications

(12 citation statements)

References 19 publications

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“…Generally, increasing the r-value, temperature, and initial concentration, decreases t g . Equations (20) to (22) [85], which describe the relation between the gelation time and these three parameters, were developed:tg=normalC[Si(OCH3)4]0−α tg=Bh−β ln(tg)=A′+Ea′RT where, [Si(OCH3)4] is the concentration of tetramethoxy silane (TMOS), C = 113 mM−α, α = 3.16, and the correlation coefficient ( R 2 ) is 0.994. B = 173, β = 0.93, and R 2 = 0.998.…”

Section: Phase Separationmentioning

confidence: 99%

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

2019

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Scientists from various different fields use organo-trialkoxysilanes and tetraalkoxysilanes in a number of applications. The silica-based materials are sometimes synthesized without a good understanding of the underlying reaction kinetics. This literature review attempts to be a comprehensive and more technical article in which the kinetics of alkoxysilanes polymerization are discussed. The kinetics of polymerization are controlled by primary factors, such as catalysts, water/silane ratio, pH, and organo-functional groups, while secondary factors, such as temperature, solvent, ionic strength, leaving group, and silane concentration, also have an influence on the reaction rates. Experiments to find correlations between these factors and reaction rates are restricted to certain conditions and most of them disregard the properties of the solvent. In this review, polymerization kinetics are discussed in the first two sections, with the first section covering early stage reactions when the reaction medium is homogenous, and the second section covering when phase separation occurs and the reaction medium becomes heterogeneous. Nuclear magnetic resonance (NMR) spectroscopy and other techniques are discussed in the third section. The last section summarizes the study of reaction mechanisms by using ab initio and Density Functional Theory (DFT) methods alone, and in combination with molecular dynamics (MD) or Monte Carlo (MC) methods.

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Section: Phase Separationmentioning

confidence: 99%

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

2019

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“…Therefore, the times required for the PDMAAm network formation were determined from the results shown in Figures S16-S19 (Supporting Information) and plotted against the gelation temperature in Figure S20 (Supporting Information). [40,41] The solid and broken lines in Figure S20 (Supporting Information) represent the calculated values for each network formation using the apparent Arrhenius parameters determined from Figure S21 in the Supporting Information. Because the reciprocals of the network formation time could be considered as the apparent network formation rates, they were plotted against the temperature according to the Arrhenius relationship ( Figure S21, Supporting Information).…”

Section: Ion Gelsmentioning

confidence: 99%

Inorganic/Organic Double‐Network Gels Containing Ionic Liquids

et al. 2017

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Highly robust ion gels, termed double-network (DN) ion gels, composed of inorganic/organic interpenetrating networks and a large amount of ionic liquids (ILs), are fabricated. The DN ion gels with an 80 wt% IL content show extraordinarily high mechanical strength: more than 28 MPa of compressive fracture stress. In the DN ion gel preparation, a brittle inorganic network of physically bonded silica nanoparticles and a ductile organic network of polydimethylacrylamide (PDMAAm) are formed in the IL. Because of the different reaction mechanisms of the inorganic/organic networks, the DN ion gels can be formed by an easy and free-shapeable one-pot synthesis. They can be prepared in a controllable manner by manipulating the formation order of the inorganic and organic networks via not only multistep but also single-step processes. When silica particles form a network prior to the PDMAAm network formation, DN ion gels can be prepared. The brittle silica particle network in the DN ion gel, serving as sacrificial bonds, easily ruptures under loading to dissipate energy, while the ductile PDMAAm network maintains the shape of the material by the rubber elasticity. Given the reversible physical bonding between the silica particles, the DN ion gels exhibit a significant degree of self-recovery by annealing.

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“…The elaboration mode has already been detailed in a previous paper [9]. The aggregated structure of our silica gels depends on [10]:…”

Section: A Sol Gel Matricesmentioning

confidence: 96%

Monitoring of different complex materials with TSM resonators array

Caplain

Serfaty

Griesmar

et al. 2009

2009 IEEE International Ultrasonics Symposium

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To perform a spatial monitoring of complex fluids, a new sensors made of an array of Thickness Shear Mode Resonator (TSMR) is used. TSMR gives access to the spatial mechanical parameters such as the complex shear modulus. Using a network analyzer, the variation of the impedance of the TSMR around its resonance frequency can be measured. From this impedance measurement, previous works have shown that the complex shear modulus can accurately be extracted using an appropriate electrical model. To perform a spatial monitoring in inhomogeneous materials, a new sensor made of a TSMR array is proposed. This paper presents a new associated model of the TSMR array. Experimental study using water-glycerol mixtures confirm its validity. The efficiency of the rheological measurement using this type of sensor is also proved for gels formation monitoring.

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Kinetic study of silicon alkoxides gelation by acoustic and rheology investigations

Cited by 20 publications

References 19 publications

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

Kinetics of Alkoxysilanes and Organoalkoxysilanes Polymerization: A Review

Inorganic/Organic Double‐Network Gels Containing Ionic Liquids

Monitoring of different complex materials with TSM resonators array

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