Fabrication of ammonium persulfate coated silica microsphere via chemical grafting and its electrorheology

Liu, Ying Dan; Quan, Xuemei; Lee, Bo Mi; Kim, In Gu; Choi, Hyoung Jin

doi:10.1007/s10853-013-7961-x

Cited by 17 publications

(14 citation statements)

References 34 publications

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“…Figure a graphs the dielectric constant (ε′) and dielectric loss factor (ε″) of SiO 2 , sSiO 2 , and SP-sSiO 2 nanoparticles dispersed in the mineral oil (the normal ER fluid) as a function of E field frequency ( f ). Generally, good ER activity is characterized by a large achievable polarizability (Δε) and small relaxation time (λ). , The former is related to the polarization tendency and the latter to the polarization rate of the material. The achievable polarizability is determined from the difference, Δε, between the static polarizability (ε 0 , where f → 0) and fictitious polarizability (ε ∞ , f → ∞) of the dielectric constant curve.…”

Section: Resultsmentioning

confidence: 99%

“…Generally, good ER activity is characterized by a large achievable polarizability (Δε) and small relaxation time (λ). 39,40 The former is related to the polarization tendency and the latter to the polarization rate of the material. The achievable polarizability is determined from the difference, Δε, between the static polarizability (ε 0 , where f → 0) and fictitious polarizability (ε ∞ , f → ∞) of the dielectric constant curve.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid

et al. 2017

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Electrophotorheological (EPR) fluids, whose rheological activity is dually responsive to light and electric fields (E fields), is formulated by mixing photosensitive spiropyran-decorated silica (SP-sSiO) nanoparticles with zwitterionic lecithin and mineral oil. A reversible photorheological (PR) activity of the EPR fluid is developed via the binding and releasing mechanism of lecithin and merocyanine (MC, a photoisomerized form of SP) under ultraviolet (UV) and visible (VIS) light applications. Moreover, the EPR fluid exhibits an 8-fold higher electrorheological (ER) performance compared to the SP-sSiO nanoparticle-based ER fluid (without lecithin) under an E field, which is attributed to the enhanced dielectric properties facilitated by the binding of the lecithin and SP molecules. Upon dual application of UV light and an E field, the EPR fluid exhibits high EPR performance (ca. 115.3 Pa) that far exceeds its separate PR (ca. 0.8 Pa) and ER (ca. 57.5 Pa) activities, because of the synergistic contributions of the PR and ER effects through rigid and fully connected fibril-like structures. Consequently, this study offers a strategy on formulation of dual-stimuli responsive smart fluid systems.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid

et al. 2017

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“…Indeed, several works have discussed the ER behavior of fluids containing silica [3,[5][6][7], and mesoporous silica [8][9][10][11]. Several strategies have also been adopted to improve the dielectric properties and polarizability of silica particles, including incorporation of small, such molecules as water [6], urea [12][13], as well as some cation ions [6,[14][15]. Another interesting approach involves the use of organically modified silica (ORMOSIL) to develop stable dispersions and increase the polarizability.…”

Section: Introductionmentioning

confidence: 99%

Ionic liquid-based organically modified silica for the development of new electrorheological fluids

Marins

Soares

2017

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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To cite this version:Jéssica Alves Marins, Bluma Soares. Ionic liquid-based organically modified silica for the development of new electrorheological fluids. Colloids The presence of the silylated ionic liquid covalently attached to the silica particles was confirmed by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The effect of the amount of imidazolium-based ionic liquid immobilized on the spherical silica particles on the electrorheological (ER) behavior of the corresponding suspensions in silicone oil was investigated. A significant ER effect was observed for the fluid containing silica modified with around 10%wt. of IL-TMOS. In fact, a very good, extremely rapid and reversible response under the action of an electric field at intensity to 4 kV/mm was achieved, with shear stress value as high as 2200 Pa. The dielectric properties were also evaluated to explain the ER response of these IL-ORMOSIL particles

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“…As a kind of smart material, electrorheological (ER) materials present tunable rheological or viscoelastic properties with the application of electric fields and have received increasing attention . ER fluids composed of polarizable particles dispersed within insulating oils are typical ER materials, and they have been studied extensively since they were first proposed by Winslow in 1949 .…”

Section: Introductionmentioning

confidence: 99%

Dynamic viscoelasticity and phenomenological model of electrorheological elastomers

Zhang

Dong

et al. 2017

J of Applied Polymer Sci

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Electrorheological elastomers (EREs) present a tunable viscoelasticity with the application of an electric field. For their application, it is necessary to investigate the viscoelasticity of the EREs under various loading conditions and establish an accurate constitutive model. In this study, anisotropic silicone-rubber-based EREs with 30 vol % TiO 2 -urea core-shell particles were prepared under an orientation electric field. We evaluated their viscoelasticities by testing their shear stress-shear strain hysteresis loops under various electric fields, frequencies, and strain amplitudes. On the basis of the experimental data, a nonlinear, revised Bouc-Wen phenomenological model was established, and the parameters in the model were identified. The results indicate that the revised model could accurately describe the viscoelastic properties of the EREs within a low frequency.

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Fabrication of ammonium persulfate coated silica microsphere via chemical grafting and its electrorheology

Cited by 17 publications

References 34 publications

Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid

Smart Fluid System Dually Responsive to Light and Electric Fields: An Electrophotorheological Fluid

Ionic liquid-based organically modified silica for the development of new electrorheological fluids

Dynamic viscoelasticity and phenomenological model of electrorheological elastomers

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