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Abstract: SiO2 was firstly coated onto the surface of carbon microspheres (CMSs) using tetraethyl orthosilicate (TEOS) as precursor by Stöber method. Then SiO2-encapsulated CMS (CMS@SiO2) composites were self-assembled by vertical deposition, in which the effects of deposition temperature and suspension concentration on the quality of self-assembling film were investigated. Morphologies and structures of the samples were characterized by field emission scanning electron microscopy, Fourier transformation infrared spectrometry, X-ray diffraction and thermogravimetry. The results show that uniform CMS@SiO2 composites with good mono-dispersion were prepared by Stőber method with 0.5g of CMSs, 2mL of TEOS, 30mL of ammonia and 12h of reaction time, the CMSs-based films with ordered and denser structure were prepared by vertical deposition using CMS@SiO2 composites as monodipersion spheres under suspension concentration of 1wt% and deposition temperature of 50°C. The ultraviolet-visible absorption measurement shows that the absorbance of CMS@SiO2 composite films grew steadily with increasing suspension concentration. [Copyright &y& Elsevier]

Carbon microspheres (CMSs) as a core material had been coated by two capsule walls: an inorganic material of magnesium hydroxide (MH) as inner shell layer and an organic material of poly (ethylene terephthalate) (PET) as outer shell layer. MH coating CMSs (MCMSs) were fabricated by liquid phase deposition method, then grafted 3-Aminopropyltriethoxysilane (APTS) to obtain the Si-MCMSs. Microencapsulated Si-MCMSs (PMCMSs) was prepared by in situ polymerization method. Morphology structure, dispersion, flame retardant and other properties of PMCMSs have been investigated. A series of PET blends were prepared by melt compounding. The results showed that MH and PET as two layers were coated on CMSs surface with the optimal thickness of about 70 nm. The PMCMSs owned better dispersion in PET matrix. Compared with MCMSs/PET composites, the mechanical property of PMCMSs/PET composites had significantly increased because of the strong interface binding force between PMCMSs and PET matrix. Moreover, PMCMSs was proved to be an effective flame retardant. For PMCMSs/PET with 2 wt% PMCMSs, the limiting oxygen index (LOI) value increased from 21.0% (pristine PET) to 27.2%, and the peak heat release rate (pk-HRR) decreased from 513.22 kW/m 2 to 352.14 kW/m 2 . The decreased smoke production rate (SPR) and total smoke production (TSP) values demonstrated PMCMSs suppressed the smoke production. The increased Fire performance index (FPI) value illustrated PMCMSs significantly reduced the fire risk of PET. Overall, the two capsular walls endowed the PMCMSs/PET composites with good mechanical and flame-retardant properties. [ABSTRACT FROM AUTHOR]

The effects of surface modifications of multi-walled carbon nanotubes (MWCNTs) on the morphology, dynamic mechanical and tribological properties of multi-walled carbon nanotube/poly(ether ether ketone) (MWCNT/PEEK) composites have been investigated. MWCNTs were treated with mixed acids to obtain acid-functionalized MWCNTs. Then the acid-functionalized MWCNTs were modified with ethanolamine (named e-MWCNTs). The MWCNT/PEEK composites were prepared by a solution-blending method. A more homogeneous distribution of e-MWCNTs within the composites was found with scanning electron microscopy. Dynamic mechanical analysis demonstrated a clear increase in the storage modulus of e-MWCNT/PEEK composites because of the improved interfacial adhesion strength between e-MWCNTs and PEEK. Furthermore, the presence of e-MWCNTs caused an enhancement in the glass transition temperature of the composites. Wear tests have shown that the friction coefficient of e-MWCNT/PEEK composites decreased significantly during the test after the running-in period. This suggests that there is an obvious improvement in tribological properties of e-MWCNT/PEEK composites. Overall, the e-MWCNT/PEEK composites have exhibited improved properties and are promising for their applications in industry. [ABSTRACT FROM AUTHOR]

In this work, commercial Ni foams are directly oxidized into Ni@Ni(OH) 2 foams in a mild NH 4 NO 3 solution at 80 °C. When used as binder-free electrodes, these Ni@Ni(OH) 2 electrodes demonstrate a high areal capacitance of 6.4 F/cm 2 at a current density of 2.5 mA/cm 2 , or 1.62 F/cm 2 at a high current density of 30 mA/cm 2 . Nevertheless, they show a poor cycling ability with 70.4% (or 42%) capacitance retention after 2000 (or 5000) cycles at 30 mA/cm 2 . This kind of electrodes has a promising application in low-cost, high-performance supercapacitor, if an effective strategy is found to improve their cycling ability. [ABSTRACT FROM AUTHOR]

Highlights: [•] A mild acid etching treatment on VO2 films was performance to adjust the surface state of the VO2 particles, while leaving the phase composition, crystallinity, grain size, and stoichiometry unchanged. [•] Acid etching affects only the IMT (insulator–metal transition) characteristics of films, but keeps MIT properties almost constant. [•] These results directly correlate the nucleation of metal-phase VO2 with surface-localized defects, suggesting a potential particle surface engineering to independently regulate MIT and IMT. [ABSTRACT FROM AUTHOR]

Highlights: [•] The effects of glucose concentration and hydrothermal reaction time on the size and morphology of CMSs were studied. [•] RF plasma reduced Ag+ ions to metallic nanoparticles. [•] The formation mechanism of the structure of Ag decorated CMSs was discussed. [•] RF plasma produced Ag/CMSs hybrid materials showed superior antibacterial property. [ABSTRACT FROM AUTHOR]