The MQ silicone resin was synthesized by using chlorotrimethylsilane and tetraethyl orthosilicate and its structure was analyzed by means of Fourier transform infrared spectroscopy, 29Si-nuclear magnetic resonance and gel permeation chromatography. The silicone based pressure sensitive adhesive was obtained by condensation polymerization between the MQ resin and methyl silicone rubber terminated with hydroxyl group. The structure of the adhesive was characterized by FTIR, and its thermal properties were investigated via thermogravimetic analysis. The results show that the MQ resin successfully had a condensation polymerization reaction with the silicone rubber. The pressure sensitive adhesive had excellent tack, peel strength and high temperature resistance properties.
In order to study the humidity sensing property and sensing mechanism of Al-doped mesoporous silica SBA-15 (Al-SBA-15), Al-SBA-15 was prepared by a simple grind method following a heat-treatment process. Its structure and morphology was characterized by X-ray diffraction (XRD), Infrared (IR), scanning electron microscope (SEM). Humidity sensing response was studied and the results indicated that Al-SBA-15 displayed better sensing property when the frequency was 100 Hz. The impedance of Al-SBA-15 changes three orders of magnitude when relative humidity changes from 11% to 95%. Complex impedance spectra, the corresponding equivalent circuit under different relative humidity are carefully analyzed to explore the humidity sensing mechanism of this material. This material can be used as a promising humidity sensing material.
Water-in-oil emulsions are formed during crude oil production. Some natural surfactants (asphaltenes) aggregates are known to form viscoelastic film preventing coalescence of emulsified water droplets. The present research work investigates the interfacial properties and demulsifying capacity of Janus type magnetic nanoparticles. poly (methylmethacrylate-acrylicacid-divinylbenzene) iron oxide Janus nanoparticles with Interfacially active P(MMA-AA-DVB) block copolymer and iron oxide (magnetic) shows excellent interfacial and magnetic properties. Experiments performed at the oil-water interface indicates that Janus particles adsorb at the oil - water interface and separate the emulsified water from the external magnetic field. The external magnetic play important role demulsification of magnetically tagged emulsified water droplets, producing smaller volumes of sludge and decrease the hydrocarbon loss to waste aqueous phase. The chemical bonding of interfacially active P(MMA-AA-DVB) grafted with magnetic nanoparticles and the magnetic property of P(MMA-AA-DVB)/Fe3O4 allowed the used Janus nanoparticles to be readily recycled by magnetic separation and regenerated by solvent washing.
Efficient two-steps method for the synthesis of octa(aminopropylsilsesquioxane)(OAPS) was described in this paper. The chloride salt of OAPS was prepared by the hydrolytic condensation of γ-aminopropyltriethoxysilane in methanol, with hydrochloric as a catalyst. The influence of several processing on the synthesis has been ascertained. The chloride salt of OAPS can be obtained in 42.1% yield after a reaction time of 18h, which is a much shorter than that required for traditional method. Neutralization of the chloride salt of OAPS to OAPS was accomplished by eluting solutions of this hydrochloride in methanol through a column of Amberlite 717 ion-exchange resin. The structure of products was determined by FTIR, MS, Elemental analysis, 1H, 13C, and 29Si NMR. TG curve of OAPS shows that the compound has high decomposition temperature and higher char residue yield.
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