DECONTAMINATION CHIMIQUE. OXYDATION DE COMPOSES SOUFRES MODELES DE L'YPERITE DANS DIVERS SYSTEMES MOLECULAIRES ORGANISES

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Bifunctional poly(alkyleneoxides) with aminoalkyl and unsaturated termini and derivatives thereof US Pat. 11,236,200

A heterofunctional poly(alkyleneoxide) according to the invention contains a first polymer terminus containing a protected, unprotected, or derivatized amine or aminoalkyl functionality and a second polymer terminus containing an unsaturated functionality. Reaction products, derivatives, and methods of making these materials are also described. An amide reaction product of an acid chloride with a composition formed by the hydrosilylation of a siloxane with a heterofunctional poly(alkyleneoxide) having a linear poly(alkyleneoxide) backbone and first and second polymer termini, wherein the first polymer terminus comprises a protected, unprotected, or derivatized aminoalkyl functionality and the second polymer terminus comprises an unsaturated functionality. keywords: amine terminated PEG; styryl terminated PEG; allyl terminated PEG

Amphiphilic silicone architectures via anaerobic thiol-ene chemistry

Despite broad application, few silicone-based surfactants of known structure or, therefore, surfactancy have been prepared because of an absence of selective routes and instability of silicones to acid and base. Herein the synthesis of a library of explicit silicone-poly(ethylene glycol) (PEG) materials is reported. Pure silicone fragments were generated by the B(C(6)F(5))(3)-catalyzed condensation of alkoxysilanes and vinyl-functionalized hydrosilanes. The resulting pure products were coupled to thiol-terminated PEG materials using photogenerated radicals under anaerobic conditions

Nearly Monodisperse Silica Microparticles Form in Silicone (Pre)elastomer Mixtures

The formation of silica from a tetraalkoxysilane in a sol–gel process usually requires a highly polar, typically aqueous, medium that aids in the hydrolysis of the silane and leads to electrostatic stabilization of the growing silica particles. Formation of such silica particles in a hydrophobic medium is much more challenging. We report the formation of silica microspheres within silicone oils (hydroxy-terminated poly­(dimethylsiloxane), HO-PDMS) during elastomer cure using atmospheric humidity in a one-pot and one-step synthesis. Using tetraethyl orthosilicate (TEOS) as both cross-linker and silica precursor, and aminopropyl-terminated dimethylsiloxane oligomer (<b>AT-PDMS</b>) as a catalytic surfactant, silica particles of low polydispersity formed near or at the air interface of the elastomer: the presence of a hydrophilic polymer, poly­(ethylene glycol) (PEG), had an indirect effect on the particle formation, as it assisted with water transmission into the system, which resulted in particle formation over a wider range of parameters and facilitated silicone elastomer cure further away from the air interface. Depending on the relative humidity during cure, the sizes of particles presenting at the air interface varied from ∼6–7 μm under ambient conditions (20–30%RH) to ∼7–9 μm at high relative humidity (90% RH). The origin of the controlled particle synthesis is ascribed to the relative solubility of the catalyst and the efficiency of water permeation through the silicone matrix. <b>AT-PDMS</b> preferentially migrates to the air interface, as shown by ninhydrin staining, where it both catalyzes alkoxysilane hydrolysis and condensation, and stabilizes the growing silica particles prior to aggregation. Since reactions in the presence of this catalyst are slow, TEOS can migrate from within the pre-elastomer body to the interface faster than water can penetrate the silicone, such that the main locus of hydrolysis/condensation leading both to silica formation and elastomer cross-linking is at the air interface

Amphiphilic Silicone Architectures via Anaerobic Thiol-Ene Chemistry

Despite broad application, few silicone-based surfactants of known structure or, therefore, surfactants have been prepared because of an absence of selective routes and instability of silicon es to acid and base. Herein the synthesis of a library of explicit silicone-poly(ethylene glycol) (PEG) materials is reported. Pure silicone fragments were generated by the B(C₆F₅)₃-catalyzed condensation of alkoxysilanes and vinyl functionalized hydrosilanes. The resulting pure products were coupled to thiol-terminated PEG materials using photo generated radicals under anaerobic conditions

Silica Shell/Gold Core Nanoparticles: Correlating Shell Thickness with the Plasmonic Red Shift upon Aggregation

Differences in the wavelengths of the surface plasmon band of gold nanoparticles (AuNP) – before and after particle aggregation – are widely used in bioanalytical assays. However, the gold surfaces in such bioassays can suffer from exchange and desorption of noncovalently bound ligands and from nonspecific adsorption of biomolecules. Silica shells on the surfaces of the gold can extend the available surface chemistries for bioconjugation and potentially avoid these issues. Therefore, silica was grown on gold surfaces using either hydrolysis/condensation of tetraethyl orthosilicate <b>1</b> under basic conditions or diglyceroxysilane <b>2</b> at neutral pH. The former precursor permitted slow, controlled growth of shells from about 1.7 to 4.3 nm thickness. By contrast, 3–4 nm thick silica shells formed within an hour using diglyceroxysilane; thinner or thicker shells were not readily available. Within the range of shell thicknesses synthesized, the presence of a silica shell on the gold nanoparticle did not significantly affect the absorbance maximum (∼ 5 nm) of unaggregated particles. However, the change in absorbance wavelength upon aggregation of the particles was highly dependent on the thickness of the shell. With silica shells coating the AuNP, there was a significant decrease in the absorbance maximum of the aggregated particles, from ∼578 to ∼536 nm, as the shell thicknesses increased from ∼1.7 to ∼4.3 nm, because of increased distance between adjacent gold cores. These studies provide guidance for the development of colorimetric assays using silica-coated AuNP

Sweet supramolecular elastomers from alpha,omega-(beta-cyclodextrin terminated) PDMS

International audienceAzido beta-cyclodextrins were attached to propiolate-functionalized polydimethylsiloxanes by metal-free click chemistry. The obtained telechelic copolymers spontaneously produced elastomeric gums. Demixing and supramolecular associations are the driving forces for the construction of these strongly associated (but reversible) physical networks

Amphiphilic Silicone Architectures via Anaerobic Thiol–Ene Chemistry

Despite broad application, few silicone-based surfactants of known structure or, therefore, surfactancy have been prepared because of an absence of selective routes and instability of silicones to acid and base. Herein the synthesis of a library of explicit silicone-poly(ethylene glycol) (PEG) materials is reported. Pure silicone fragments were generated by the B(C₆F₅)₃-catalyzed condensation of alkoxysilanes and vinyl-functionalized hydrosilanes. The resulting pure products were coupled to thiol-terminated PEG materials using photogenerated radicals under anaerobic conditions