Ionic-liquid-modified TiO2 spheres and their enhanced electrorheological responses

Titanium Dioxide Nanoparticles Modified with Disulfonic Acid Functionalized Imidazolium Ionic Liquids for Use as Electrorheological Materials

“…The addition of ILs endows the inorganic ionogels with a faster electro-response and higher yield stress under electric field. For the synthesis of TiO 2 , acidic functionalized ILs can not only be used as a solvent to improve the solubility of Ti species, but also acts as a surface modifier and template to make TiO 2 grow along a specific direction. , Monofunctional ILs readily act on the surface of particles by chemical grafting or physical adsorption and increase the rate of electron migration on the particle surface, but a large current will lead to electrical breakdown of ER fluids under external electric field. , Therefore, we need to develop ILs that can be confined within the network structure of the inorganic matrix to reduce the distribution of ILs on the particle surface and thus decrease the conductivity of the particles to suit ER application. Both an improved ER effect and high thermal stability are expected in those inorganics containing confined ILs.…”

TiO2 Nanoparticles Dual-Modified with Ionic Liquid and Acetic Acid for Use as Electrorheological Materials to Achieve Ultrahigh and Stable Electroresponsive Performances

“…As temperature increases, the peak shifts to a higher frequency because of faster polarization of the electric field at higher temperatures. The dielectric spectra were fitted by the Havriliak–Negami (HN) equation, which includes the terms of Cole–Cole equation, a DC conductivity, and an electrode polarization, , to reveal the dielectric parameters of the nanoparticles. The HN equation is as follows ε * = ε ′ + normali ε ″ = ε ∞ ′ + normalΔ ε ′ false( 1 + false( normali ω τ false) α false) γ + σ normald normalc normali ε 0 ′ ω + normalA ω − n where Δε ′ = ε 0 ′ -ε ∞ ′ is the dielectric strength and refers to the polarizability of the dielectric particles and relaxation time τ = 1/(2π f max ), where f max refers to the frequency corresponding to the peak of dielectric loss and is related to the response speed of nanoparticles.…”

“…As temperature increases, the peak shifts to a higher frequency because of faster polarization of the electric field at higher temperatures. The dielectric spectra were fitted by the Havriliak−Negami (HN) equation, 35 which includes the terms of Cole−Cole equation, a DC conductivity, and an electrode polarization, 52,53 to reveal the dielectric parameters of the nanoparticles. The HN equation is as follows…”

“…The TiO 2 -based ionogel nanoparticles have shown a high yield stress of up to 5.2 kPa with a low particle volume fraction of 15−20% and excellent antisettling stability. 35,36 Despite this, the ER fluid remained deficient. The current density was relatively high such that current leakage would occur when the electric field strength or particle volume fraction was high, which prevented us from achieving higher yield stress in this type of ER fluids.…”

Semi-conducting microspheres formed from glucose for semi-active electric field-responsive electrorheological systems

“…However, after application of the electric field, they begin to form highly organized fibril structures in the direction of the field and as a result, the main rheological parameters (viscosity, yield stress, or viscoelastic moduli) are reversibly and very quickly changed in the order of milliseconds. 5,6 This phenomenon is called the ER effect. These smart ERFs have received significant attention in a wide range of engineering applications for many years, mainly for vibration suppression in damping devices, 7 or a medium for brakes, 8 clutches, 9 valves, 10 etc.…”