Formation of colloidal TiO2 from organotitanate solutions used to produce crosslinked polymer gels

Kramer, Jeffrey F.; Prud'homme, Robert Krafft; Wiltzius, Pierre

doi:10.1016/0021-9797(87)90459-0

Cited by 22 publications

(15 citation statements)

References 2 publications

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“…For PPO300 hybrids the contribution of this band is observed for [O]/[Na] , 8 while for PPO2000 samples this band is observed for all [O]/[Na] ratios. On the other hand, the presence of the band at 765 cm 21 , related to free anions, is observed for all doping contents of both PPO300 and PPO2000 samples.…”

Section: Local Structure Of Anions and Polymer Conformationmentioning

confidence: 84%

“…In brief, 3-(isocyanatopropyl) triethoxysilane (IsoTrEOS) and O,O9-bis(2-aminopropyl)poly-(propylene oxide) in molar ratio 2 : 1 were stirred together in tetrahydrofuran (THF) under reflux for 15 h. THF was evaporated off and a stable hybrid precursor was obtained. This process was adopted for PPO molecular weights (M W ) of 2000 and 300 g mol 21 (labeled PPO2000 and PPO300 hybrids). The hybrid molecular formula is shown in Fig.…”

Section: Sample Preparation 27mentioning

confidence: 99%

“…In order to check the chemical environment of Na + ions coordinated by ether-type oxygen or urea groups, samples of doping salts dissolved in 18-crown-6 cavities were prepared, in neat PEO polymer and in dipropylurea matrix, labeled respectively as NaX-CROWN6, NaX-PEO and NaX-UREA. These samples were obtained by the dissolution of the appropriate amount of sodium salt ([O]/[Na] = 30) and dibenzyl 18-crown-6, PEO (M w = 20000 g mol 21 ) or dipropylurea in acetonitrile at 60 uC, followed by vacuum evaporation of the solvent.…”

Section: Reference Sample Preparationmentioning

confidence: 99%

“…[18][19][20] Furthermore, class {II} hybrids could be easily obtained in a two-step process, the synthesis of a reactive macromer polyether terminated by silicon trialkoxy groups, followed by the hydrolysis-condensation step to form the siloxane crosslinking nodes in the presence of the alkali salt. 21,22 In spite of an apparent synthetic simplicity, recent investigation of these materials indicate the effect of their inherent complexity on the ionic conductivity mechanisms. 23 As these nanocomposites can be considered as multifunctional, in this paper we will take account of the influence of each different component of these SPEs in the structure and conduction properties of such a material, that is: i) the siloxane aggregates, that are responsible for the rigidity of the solid network;…”

Section: Introductionmentioning

confidence: 99%

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Multi-scale structural description of siloxane–PPO hybrid ionic conductors doped by sodium salts

et al. 2007

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Section: Local Structure Of Anions and Polymer Conformationmentioning

confidence: 84%

Section: Sample Preparation 27mentioning

confidence: 99%

Section: Reference Sample Preparationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Multi-scale structural description of siloxane–PPO hybrid ionic conductors doped by sodium salts

et al. 2007

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“…Rather colloidal titanium dioxide particles were being formed in solution due to rapid hydrolysis of the-titanate crossiinker. A dynamic light scattering study of the formation of colloidal Ti0 2 [10,11] showed that particles with sizes from 10 A to several hundred A were formed. Figure 13 shows a representative light scattering result showing the formation of stable Ti0 2 particles resulting from the hydrolysis of TAA in an alcohol/water solution.…”

Section: Mechanism Of Titanate Crosslinkingmentioning

confidence: 99%

Characteristics of Metal-Polymer Interactions in Fracturing Fluid Systems

Kramer¹,

Prud'homme²,

Norman³

et al. 1987

Proceedings of SPE Annual Technical Conference and Exhibition

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A series of model derivatized guar polymer samples were crosslinked with three different metal-ion crosslinkers in order to better understand the complex chemical reactions involved in producing fracturing fluid gels. The gels were studied using steady shear viscosity and dynamic oscillatory measurements. Dynamic oscillatory mea~urements are often more sensitive probes of the structure of crosslinked gels than are steady shear viscosity measurements and, therefore, both viscosity and dynamic oscillatory measurements are needed to fully characterize fracturing fluids. We present examples of fluids with nearly identical viscosities but different moduli--indicating different network structures in the gel. The gels considered represent commonly used fracturing fluids such as titanat~ crosslinked hydroxypropyl guar (HPG), titanate crosslinked carboxymethyl hydroxypropyl guar (CMHPG), and aluminum crosslinked CMHPG. The effect of molar substitution of hydroxypropyl groups (MS level) on HPG crosslinked with two titanate crosslinkers is presented. The effects of MS and degree of substitution of carboxyl groups (DS level) changes for CMHPG gels crosslinked with titanates and aluminum ions are also presented.An explanation of the mechanism involved in titanate crosslinking is offered from evidence gathered from NMR and dynamic light scattering· experiments.

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