Hydrolysis behavior of a precursor for bridged polysilsesquioxane 1,4-bis(triethoxysilyl)benzene: a 29Si NMR study

Saito, Hitomi; Nishio, Yu; Kobayashi, Manabu; Sugahara, Yoshiyuki

doi:10.1007/s10971-010-2323-5

Cited by 16 publications

(14 citation statements)

References 54 publications

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“…In our synthesis, negatively charged organosilica species (O − ) interact with positively charged surfactants (S + ) through electrostatic interaction to form silica/surfactant composites (O − S + ), which further self‐assemble into mesostructures . Compared to their inorganic counterparts, hydrolyzed organosilica species have a lower charge density because of the electron donating effect of benzene groups, which destabilize the deprotonated silanols . Hence, the interaction between O − S + is weaker and energetically less favored, which explains the much less reports on MOSNs compared to MSNs.…”

Section: Methodsmentioning

confidence: 98%

“…[ 30 ] Compared to their inorganic counterparts, hydrolyzed organosilica species have a lower charge density because of the electron donating effect of benzene groups, which destabilize the deprotonated silanols. [ 31 ] Hence, the interaction between O − S + is weaker and energetically less favored, which explains the much less reports on MOSNs compared to MSNs. On the other hand, further condensation of hydrolyzed organosilica species may occur (O − O − ), which forms crosslinked organosilica without defi ned mesostructures.…”

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confidence: 99%

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Biphasic Synthesis of Large‐Pore and Well‐Dispersed Benzene Bridged Mesoporous Organosilica Nanoparticles for Intracellular Protein Delivery

Yang

Niu

Zhang

et al. 2015

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Section: Methodsmentioning

confidence: 98%

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confidence: 99%

Biphasic Synthesis of Large‐Pore and Well‐Dispersed Benzene Bridged Mesoporous Organosilica Nanoparticles for Intracellular Protein Delivery

Yang

Niu

Zhang

et al. 2015

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“…Other precursors that can be used are bridged systems of the type (RO) 3 Si–R–Si(OR) 3. These precursors contain the organic group (–R–) as a spacer between two alkoxysilyl [(OR) 3 Si–] units.…”

Section: Introductionmentioning

confidence: 99%

“…[13] Examples for these so-called single-source precursors are organic functionalized alkoxysilanes [2,14] R x Si(OR) 4 À x with R being (functionalized) alkyl or aryl groups (x = 1-3). Other precursors that can be used are bridged systems of the type (RO) 3 Si-R-Si(OR) 3. [2, [14][15][16][17][18] These precursors contain the organic group (-R-) as a spacer between two alkoxysilyl [(OR) 3 Si-] units.…”

Section: Introductionmentioning

confidence: 99%

An s‐triazine briged silylalkyl sol–gel precursor—synthesis, structure and coating formation for electrical insulation of copper wire and corrosion protection of construction steel

Pfeifer

Gutiérrez²,

Kroke

2014

Polymers for Advanced Techs

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An aminoalkylalkoxysilane modified s‐triazine was prepared and used as single‐source precursor for hybrid coatings. These coating materials were applied and tested for the electrical insulation of fine copper wires and for corrosion protection of construction steel. The molecular precursor was comprehensively analyzed using FT‐IR, 1H, 13C and 29Si NMR spectroscopy. Besides, the initial stages of hydrolysis and condensation reactions under acidic conditions were examined with solution 29Si NMR spectroscopy. Structures of gelled and heat‐treated samples were analyzed with CP/MAS 29Si NMR and FT‐IR spectroscopy. Sols were applied on fine copper wires using industrial coating and curing techniques. The performance of the hybrid coatings was characterized by electrical breakdown tests, pinhole tests and mechanical strength measurements. The anti‐corrosion behavior of the s‐triazine precursor derived coatings on steel substrates was studied by electrical impedance spectroscopy. The spectra were interpreted with respect to different hydrolysis and condensation rates, curing temperatures and coating thicknesses. Copyright © 2014 John Wiley & Sons, Ltd.

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“…[107] Compared to their inorganic counterparts, hydrolysed organosilica species have a lower charge density because of the electron donating effect of benzene groups, which destabilize the deprotonated silanols. [108] Hence, The large pore sizes of MOSNs obtained in our biphasic system suggest that upper oil phase not only influences the assembly between surfactants and organosilica precursors, but also acts as a pore swelling agent. At first, the toluene molecules in the upper oil phase diffuse into the lower aqueous phase with the help of surfactants and locate in the core of the micelles to enlarge the volume of hydrophobic core, leading to enlarged mesopores in the final products size (Scheme 1A(a)).…”

Section: Iron Oxidementioning

confidence: 73%

Synthesis of self-assembled nanoporous silica for therapeutic delivery

Yang¹

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In the recent years, nanoporous silica materials have been regarded as promising nanocarriers to deliver various therapeutic agents, due to their high pore volume and surface area, ease of surface functionalization and excellent biocompatibility. Although numerous porous silica nanoparticles have been developed for therapeutic delivery, more efforts are still needed in the synthesis of nanoporous silica nanoparticles simultaneously possessing good dispersity, high uniformity, small particle size (< 200 nm) for efficient cellular uptake and sufficient pore size to encapsulate desired therapeutic agents with large molecular sizes. This thesis focuses on synthesizing self assembled porous silica nanoparticles for high performance of biomedical applications. Three types of porous silica nanoparticles, including silica vesicles, SBA-15 rods and mesoporous organosilica nanoparticles will be synthesized. The self assembly based formation mechanism will be discussed, which is believed as a key to design porous silica nanoparticles with superior and more controllable structures and properties. In addition, their drug/protein loading capacity and release profile, biocompatibility, cellular uptake performance, and therapeutic efficacy will be evaluated in vitro.The first part of the experimental chapters focuses on the synthesis of silica vesicles (SVs) with a diameter of 30 nm and reduced aggregation using mixed triblock copolymer surfactants as the structure-directing agents, tetraethyl orthosilicate (TEOS) and tetrapropyl orthosilicate (TPOS) as mixed silica sources. The reduced aggregation is attributed to the incompletely hydrolysed hydrophobic -OCH 2 CH 2 CH 3 groups of TPOS on the surface of SVs, thus preventing the inter-particle aggregation. The drug delivery performance of SVs is evaluated using a photosensitizer ─ silicon phthalocyanine The cellular uptake of SR-3.40, SR-3.88 and MCM-41 in human osteosarcoma cancer cells is visualized using confocal image and quantified using ICP technique, revealing the significantly enhance cellular uptake efficiency of SR-3.88 (7.4 pg/cell) compared to SR-3.40 (2.0 pg/cell) and MCM-41 (6.1 pg/cell). Hence, the SBA-15 rods with small particle sizes, large pores as well as excellent biocompatibility are believed as a promising delivery system for cellular delivery of large molecular weight therapeutic agents with improved efficacy.Lastly, we tuned the composition of porous silica nanoparticles by incorporating benzene groups in the silica framework to synthesize large pore well dispersed mesoporous organosilica nanoparticles (MOSNs) by using a biphase synthesis approach. The role of the biphase system has been demonstrated essential to enlarge pore size and facilitate the surfanctant/organosilica precursor assembly. The obtained MOSNs with pore size of 7.6 nm show enhanced protein loading capacity at 144.5 μg mg -1 and sustained release profile over 72 hours. In order to investigate the potential in biomedical application, the efficient cell uptake is firstly visualized...

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Hydrolysis behavior of a precursor for bridged polysilsesquioxane 1,4-bis(triethoxysilyl)benzene: a 29Si NMR study

Cited by 16 publications

References 54 publications

Biphasic Synthesis of Large‐Pore and Well‐Dispersed Benzene Bridged Mesoporous Organosilica Nanoparticles for Intracellular Protein Delivery

Biphasic Synthesis of Large‐Pore and Well‐Dispersed Benzene Bridged Mesoporous Organosilica Nanoparticles for Intracellular Protein Delivery

An s‐triazine briged silylalkyl sol–gel precursor—synthesis, structure and coating formation for electrical insulation of copper wire and corrosion protection of construction steel

Synthesis of self-assembled nanoporous silica for therapeutic delivery

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