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Encapsulated polypyrrole (PPy) with different amount in the channels of mesoporous silica (SBA-15) was synthesized. The XRD and N2 adsorption/desorption isotherms analysis show that PPy with different loadings in the channels does not affect the ordered hexagonal structure of resultant PPy/SBA-15 nanocomposites. Further, the electrorheological (ER) properties of the nanocomposites with different PPy loadings were investigated by steady and oscillatory shear experiments. The results reveal that PPy/SBA-15 fluids exhibit typical ER and viscoelastic behavior under the applied electric field and ER response depends mainly on PPy loadings and there is an optimum PPy loading for strong ER effect. [ABSTRACT FROM AUTHOR]

The article discusses on a new type of anhydrous electrorheological fluid based on conducting polypyrrole confined in mesoporous silica (MCM-41) channels is prepared and its electrorheological behavior is also investigated. The preparation of MCM-41 followed the method described in literature. Incorporation of polypyrrole in the pores of mesoporous silica is worth investigating, as it can be beneficial for further exploring electronic characteristics and applications of the resultant composite.

Abstract: A new nanocomposite with conducting polypyrrole (PPy) confined in ordered mesoporous silica SBA-15 channels has been synthesized by an in situ polymerization technique. The resulting material was characterized by X-ray diffraction (XRD), N2 adsorption/desorption, high-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectra (FT-IR) and thermogravimetric analysis (TGA). The results show that PPy is formed in the channels instead of coating the outer surface of SBA-15 and nanocomposite possesses well-ordered hexagonal structure. Further, nanocomposite particles were used as dispersed phase in silicone oil for electrorheological (ER) investigation. Suspension of PPy–SBA-15 displays notable ER characteristics under external electric fields. [Copyright &y& Elsevier]

Abstract: Mesoporous silica nanofibers and Ag-doped composite nanoribbons were synthesized by a facile combination of an electrospinning technique and the sol–gel method. Tetraethyl orthosilicate, polyvinylpyrrolidone (PVP), triblock poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), copolymer Pluronic P123, and silver nitrate (AgNO3) were the components of sol for the production of Ag-doped hybrid silica ribbons. Heat removal of structure-directing agent P123 in the hybrid fibers at high temperatures resulted in a mesoporous morphology, and the degradation of PVP caused AgNO3 to convert into silver in the form of nanoparticles. The size and content of the particles in the hybrid ribbons could be controlled by the concentration of AgNO3 and thermal treatment conditions. Scanning electron microscopy, N2 adsorption–desorption isotherm, transmission electron microscopy, X-ray diffraction, and UV–Vis spectroscopy were used to characterize the composite ribbons. The catalytic activity of the ribbons was evaluated by reduction of methylene blue dye and found to be better than in previous studies. [Copyright &y& Elsevier]

Abstract: In this work, mesoporous silica (MCM-41) was modified by triethanolamine (TEA) by a wet impregnation method. The structure and morphology of modified MCM-41 particles were characterized by X-ray diffraction, N2 adsorption/desorption, Fourier-transform infrared spectra, scanning electron microscopy, particle size analyzer and thermogravimetric analysis. The results show that the interior channels of MCM-41 are modified by TEA without destroying its mesoporous structure. Further, pure MCM-41and TEA-modified particles were adopted as dispersed phase in silicone oil for electrorheological (ER) investigation. The TEA-MCM-41 (modified with 7wt.% TEA)-based ER fluid with a volume fraction of 5% exhibits stronger ER activity than pure MCM-41 fluid. The possible mechanism related to dielectric properties is also provided. [Copyright &y& Elsevier]