27252-80-8Relevant articles and documents
Dendritic, nanosized building block for Siloxane-based materials: A spherosilicate dendrimer
Kawahara, Kazufumi,Hagiwara, Yoshiaki,Kuroda, Kazuyuki
, p. 13188 - 13196 (2011)
A spherosilicate dendrimer (DMS-1) with closely spaced reaction sites (Si-H groups) on the dendrimer surface has been synthesized by stepwise silylation of double-four-ring silicate with chlorotriethoxysilane (ClSi(OEt)3) and subsequently with chlorodimethylsilane (ClSiHMe2). DMS-1 consists of a maximum of 40 Si atoms in the interior frameworks and 24 reactive Si-H groups on the surface. Because DMS-1 is spherical and about 1.5 nm in diameter, it can be regarded as the smallest well-defined silica-based nanoparticle. DMS-1 also forms molecular crystals and is soluble in typical organic solvents. A molecularly ordered silica-based hybrid can be prepared by heating a cast film of DMS-1 at 180 °C for 5 days. The surface of DMS-1 can be modified by hydrosilylation with 1-hexadecene, triethoxyvinylsilane, and allylic-terminated tetraethylene glycol monomethyl ether. More than 20 Si-H groups out of 24 react with these reagents. The solubilities of the products depend on the modification. DMS-1 is not only a building block for nanohybrids, but also the smallest and most precisely designed siloxane-based nanoparticle.
Thiol - Ene click reaction as a general route to functional trialkoxysilanes for surface coating applications
Tucker-Schwartz, Alexander K.,Farrell, Richard A.,Garrell, Robin L.
, p. 11026 - 11029 (2011)
Functionalized trialkoxysilanes are widely used to modify the surface properties of materials and devices. It will be shown that the photoinitiated radical-based thiol - ene "click" reaction provides a simple and efficient route to diverse trialkoxysilanes. A total of 15 trialkoxysilanes were synthesized by reacting either alkenes with 3-mercaptopropyltrialkoxysilane or thiols with allyltrialkoxysilanes in the presence of a photoinitiator. The functionalized trialkoxysilanes were obtained in quantitative to near-quantitative yields with high purity. The photochemical reactions can be run neat in standard borosilicate glassware using a low power 15-W blacklight. A wide range of functional groups is tolerated in this approach, and even complex alkenes click with the silane precursors. To demonstrate that these silanes can be used as surface coating agents, several were reacted with iron oxide superparamagnetic nanoparticles and the loadings quantified. The photoinitiated thiol - ene reaction thus offers a facile and efficient method for preparing surface-active functional trialkoxysilanes.
Ruthenium-catalyzed selective hydrosilylation reaction of allyl-functionalized PEG derivatives
Inomata, Koya,Naganawa, Yuki,Guo, Haiqing,Sato, Kazuhiko,Nakajima, Yumiko
supporting information, (2019/09/17)
Reactions of allyl-functionalized poly(ethylene glycol) (PEG) derivatives with alkoxysilanes proceeded efficiently to furnish the corresponding hydrosilylated products in good to excellent yields using a ruthenium catalyst, [RuCl2(nbd)]n. A preliminary mechanistic study supported the pivotal role of the PEG moiety, which coordinated to the ruthenium atom during the reaction to achieve high reaction selectivity. This method may be applicable to the synthesis of various PEGs with a silyl terminus, which is useful as biocompatible and low toxic silane coupling agents.
Careful investigation of the hydrosilylation of olefins at poly(ethylene glycol) chain ends and development of a new silyl hydride to avoid side reactions
Shin, Hyunseo,Moon, Bongjin
, p. 527 - 536 (2018/01/27)
Hydrosilylation of olefin groups at poly(ethylene glycol) chain ends catalyzed by Karstedt catalyst often results in undesired side reactions such as olefin isomerization, hydrogenation, and dehydrosilylation. Since unwanted polymers obtained by side reactions deteriorate the quality of end-functional polymers, maximizing the hydrosilylation efficiency at polymer chain ends becomes crucial. After careful investigation of the factors that govern side reactions under various conditions, it was related that the short lifetime of the unstable Pt catalyst intermediate led to the formation of more side products under the inherently dilute conditions for polymers. Based on these results, two new chelating hydrosilylation reagents, tris(2-methoxyethoxy)silane (5) and 2,10-dimethyl-3,6,9-trioxa-2,10-disilaundecane (6), have been developed. It was demonstrated that the hydrosilylation efficiency at polymer chain ends was significantly increased by employing the internally coordinating hydrosilane 5. In addition, employment of the internally coordinating disilane species 6 in an addition polymerization with 1,5-hexadiene by hydrosilylation reaction yielded a polymer with high molecular weight (Mn = 9300 g/mol), which was significantly higher than that (Mn = 2600 g/mol) of the corresponding polymer obtained with non-chelating dihydrosilane, 1,1,3,3-tetramethyldisiloxane.
Anion Receptor, Electrolyte Containing the Anion Receptor and Lithium Ion Battery and Lithium Ion Capacitor Using the Electrolyte
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Paragraph 0088-0090, (2018/09/30)
The present invention relates to a novel anion acceptor having a high cation transport rate and improved lifespan, an electrolyte containing the same, and a lithium ion battery and a lithium ion capacitor manufactured using the electrolyte and, more specifically, to a compound represented by chemical formula 1. In the chemical formula 1, n is an integer from 1 to 50, and X is one or more selected from the group consisting of -NR_1R_2, -NR_3R_4, -Ph(-(m)-R_5), and -O-(CH_2CH_2O)_y-CH_3.COPYRIGHT KIPO 2018
Thermodynamic Properties of Carbosilane Dendrimers of the Sixth Generation with Ethylene Oxide Terminal Groups
Sologubov, Semen S.,Markin, Alexey V.,Smirnova, Natalia N.,Novozhilova, Natalia A.,Tatarinova, Elena A.,Muzafarov, Aziz M.
, p. 14527 - 14535 (2015/11/23)
The temperature dependences of heat capacities of carbosilane dendrimers of the sixth generation with ethyleneoxide terminal groups, denoted as G6[(OCH2CH2)1OCH3]256 and G6[(OCH2CH2)3OCH3]256, were measured in the temperature range from T = (6 to 520) K by precision adiabatic calorimetry and differential scanning calorimetry (DSC). In the above temperature range the physical transformations, such as glass transition and high-temperature relaxation transition, were detected. The standard thermodynamic characteristics of the revealed transformations were determined and analyzed. The standard thermodynamic functions, namely, heat capacity Cp°(T), enthalpy H°(T) - H°(0), entropy S°(T) - S°(0), and Gibbs energy G°(T) - H°(0) for the range from T → 0 to 520 K, and the standard entropies of formation ΔfS°of the investigated dendrimers in the devitrified state at T = 298.15 K, were calculated per corresponding moles of the notional structural units. The standard thermodynamic properties of dendrimers under study were discussed and compared with literature data for carbosilane dendrimers with different functional terminal groups.
Plasticizing Li single-ion conductors with low-volatility siloxane copolymers and oligomers containing ethylene oxide and cyclic carbonates
Liang, Siwei,Chen, Quan,Choi, U Hyeok,Bartels, Joshua,Bao, Nanqi,Runt, James,Colby, Ralph H.
, p. 21269 - 21276 (2015/11/09)
To prepare a safe electrolyte for lithium ion batteries, two groups of novel low-volatility plasticizers combining pendant cyclic carbonates and short ethylene oxide chains have been successfully synthesized, as confirmed by 1H, 13C and 29Si NMR spectroscopy. The Fox equation describes the composition dependence of the glass transition temperature (Tg) very well for the random polysiloxane-based copolymer plasticizers (11000 g as much as 20 K lower than the Fox equation prediction because of their lower molecular weight (450 g. Mixing with 20 wt% polysiloxane tetraphenyl borate-Li ionomer (14 mol% borate and 86 mol% cyclic carbonate) increases conductivity relative to the neat ionomer by lowering Tg, increasing dielectric constant and providing better solvation of Li+. The best oligomeric plasticizer only has Tg 10 K lower than the Fox prediction but has dielectric constant 30% larger than expected by the Landau-Lifshitz mixing rule, owing to a surprisingly low viscosity, resulting in ambient conductivity 2 × 10-5 S cm-1. For both groups of plasticizers, the fraction of cyclic carbonates relative to ethylene oxide governs the magnitude and temperature dependence of the ionic conductivity.
SYMMETRICAL AND UNSYMMETRICAL ORGANOSILICON MOLECULES AND ELECTROLYTE COMPOSITIONS
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Page/Page column 40, (2014/03/26)
Described are organosilicon electrolyte compositions having improved thermostability and electrochemical properties and electrochemical devices that contain the organosilicon electrolyte compositions.
High ion content siloxane phosphonium ionomers with very low T g
Liang, Siwei,Oreilly, Michael V.,Choi, U Hyeok,Shiau, Huai-Suen,Bartels, Joshua,Chen, Quan,Runt, James,Winey, Karen I.,Colby, Ralph H.
, p. 4428 - 4437 (2014/07/22)
Polysiloxane phosphonium single-ion conductors grafted with oligomeric PEO and with ion contents ranging from 5 to 22 mol % were synthesized via hydrosilylation reaction. The parent Br- anion was exchanged to F- or bis(trifluoromethanesulfonyl)imide (TFSI-). X-ray scattering data suggest ion aggregation is absent in these phosphonium ionomers, which contributes to low glass transition temperatures (below -70 °C) with only a weak dependence on both ion content and counteranion type. Conductivities weakly increase with ion content but exhibit a strong dependence on anion type. The highest conductivity at 30 °C is 20 μS/cm for dry neat ionomer, with the TFSI- anion, consistent with its relatively delocalized negative charge and large size that weaken interactions between TFSI- and the phosphonium cation.
Synthesis and properties of carbosilane dendrimers of the third and sixth generations with the ethylene oxide surface layer in bulk and in monolayers at the air-water interface
Novozhilova,Malakhova,Buzin,Buzin,Tatarinova,Vasilenko,Muzafarov
, p. 2514 - 2526 (2014/11/08)
A number of carbosilane dendrimers with the ethylene oxide surface layer was synthesized. The density of the surface layer determines their capability to form a physical network due to intermolecular entanglements. The specific interactions of the ethylene oxide fragments exert a minor effect on the thermal behavior of dendritic macromolecules. The compression-expansion isotherms of Langmuir films together with Brewster angle microscopy data show that an increase in the core rigidity with increasing the generation number favors the formation of ordered molecular multilayers. The appearance of a pronounced hysteresis in the compression-expansion cycles is a common phenomenon for amphiphilic dendrimers of high generations.
