Synthesis and Enhanced Electrorheological Properties of TS-1/Titanium Oxide Core/Shell Nanocomposite

Preparation of a MIL-125/MoS2/SiO2 Ternary Nanohybrid and Its Smart Electrorheological Behavior

In this work, a kind of ternary hybrid material, MIL-125/MoS2/SiO2, was prepared by a solvothermal and Stöber method. In this system, MIL-125, as the matrix material, not only furnishes a large specific surface area for MIL-125/MoS2/SiO2, thereby providing a basis for stronger interfacial polarization, but also effectively enhances the antisettlement ability of the electrorheological fluids (ERFs). Different characterizations, such as scanning electron microscopy, transmission electron microscopy, XRD, XPS, FT-IR, BET, electron mapping, etc., were used to analyze the ternary nanohybrid. The ERFs prepared by combining the different advantages of the three materials in the hybrid system were studied by a HAAKE high-speed rotary rheometer. In addition, the combination of MoS2 and SiO2 provides suitable electrical conductivity and dielectric properties for the system to promote the generation of interface polarization, ensuring that the entire system exhibits stronger electrorheological behavior without electrical breakdown and thus obtains higher shear stress.

IMPACT OF COMPOSITION AND STRUCTURAL PARAMETERS ON THE CATALYTIC ACTIVITY OF MFI TYPE TITANOSILIKALITES

Titanosilicalite of the MFI type was obtained by the hydrothermal method. Its initial and annealed at 75oC (TS-1P(75)) and 500oC (TS-1P(500)) forms were studied by X-ray powder diffraction (XRPD), X-ray...

Core-Shell Structured Magnetite-Poly(diphenylamine) Microspheres and Their Tunable Dual Response under Magnetic and Electric Fields

Core-shell type poly(diphenylamine)-coated magnetite (Fe₃O₄-PDPA) microspheres were designed and adopted as a novel actively tunable smart material which is responsive under both electric and magnetic fields. Their morphology, chemical structure, crystalline structure, and thermal properties were characterized using scanning electron microscopy, transmission electron microscope, Fourier transform-infrared spectroscopy, X-ray diffraction, and a thermal gravimetric analyzer. Their magnetic and dielectric properties were determined using vibrating-sample magnetometer and an LCR meter, respectively. They were dispersed in silicone oil and their electrorheological (ER) and magnetorheological (MR) responses under the electric and magnetic fields, respectively, were examined. The formation of chain structure of Fe₃O₄-PDPA based E/MR fluid under the application of electric field or magnetic field was observed by an optical microscopy and the sedimentation stability was observed by a Turbiscan optical analyzer system. It was observed that the yield stress, ER efficiency, and leakage current density increased with an increase in the particle concentration, while the slope of the electric field-dependent yield stress decreased. Several models such as the Bingham model, Herschel-Bulkley model, and Cho-Choi-Jhon equations were used to describe the shear stress curves of the ER fluid; the curves fitted well. For the dielectric properties, the two types of ER fluids tested displayed the same relaxation time and distribution; however, the one with the higher concentration had a higher dielectric constant and polarizability. The Fe₃O₄-PDPA based MR fluid (10 vol %) exhibited typical MR properties. In addition, the Herschel-Bulkley model matched well with the shear stress curves under a magnetic field.

Enhanced visible-light photoactivities of porous LaFeO3 by synchronously doping Ni2+ and coupling TS-1 for CO2 reduction and 2,4,6-trinitrophenol degradation

TOC showing the enhanced visible-light photoactivities of porous LaFeO3 by synchronously doping with Ni2+ and coupling with TS-1 for CO2 reduction and 2,4,6-trinitrophenol degradation.

Titanium oxide-coated titanium-loaded metal organic framework (MOF-Ti) nanoparticles show improved electrorheological performance

Uniform small-sized MOF-Ti nanoparticles were prepared by a one-step hydrothermal method, and then a 5-10 nm TiO2 shell was coated onto them by using the sol-gel method, and MOF-Ti/TiO2 with a specific surface area of 50.2 m2 g-1 was successfully prepared. The nanoparticles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption isotherms (BET), and X-ray photoelectron spectroscopy (XPS). The above-analyses have elaborated the experimental study of their morphology, elements, and energy of organic functional groups. At the same time, through the use of a high-voltage rotary rheometer to test their rheological properties, the analysis of shear stress, ER efficiency, shear viscosity, etc. was performed and their dielectric constant and dielectric loss were studied by using a broadband dielectric spectrometer. Finally, we found that MOF-Ti/TiO2 is a new core-shell nanocomposite particle with a small particle size and good electrorheological properties.