HIGH AC VOLTAGE FLOW-MODIFIED PERMITTIVITY AND RHEOLOGICAL PROPERTIES OF CARBON-DOPED NANO TiO₂ ER FLUIDS

Abstract

The associated effects of polarization strength, polarization rate, and dielectric loss on ER performance ware studied hy means of the correlation of rheological properties of carbon-doped Ti0 2 ER fluids with experimental results of flow-modified permittivity (FMP). We prepared ER fluids with carbon-doped Ti02 powders of different conductivity via controlling carbonization temperature and organic contents. The experiments present the optimum organic contents of 4.6% to 9.2% and the optimum carbonization temperature of around 673 K for the better ER activity. The role of conductivity in ER performance is testified. FMP measurements of fluids were performed under weak and strong exciting fields respectively. Under weak exciting field, FMP effects are hardly detectable; while under high exciting field, FMP effects become significant which reflect ER particle configurations, particle orientations, and limited dielectric response time in the combined electric and shear fields. The shear field strength, exciting field strength and frequency are the three main factors influencing the FMP effects. The FMP data can be modeled and qualitatively explained by introducing two characteristic shear rates of D c i and D c2 , J=Jo+Jiexp(-D/D c i)+ J2exp(-D/D c2 ) with D being shear rate.

Electro-rheological polymers

“…Other reported GER fluids are Gd 2 O 3 : Tb in silicone oil [83], barium titanayl oxalate coated with urea suspended in silicone oil [77] which resulted in a yield stress of more than 250 kPa at 5 kV mm −1 , titanium nanowhiskers dispersed in silicone oil [69] with a yield stress of 1.1 kPa at 3 kV mm −1 . Hollow polyaniline nanoparticles [84], calcium titanate nanoparticles [78], titanium oxide nanoparticles [85], carbon nanotube/polyaniline nanoparticles [86], and many others combination of nanoparticles have been synthesized and studied for the GER effect [87][88][89][90][91][92][93][94][95].…”

Effect of microstructure, grain size, and rare earth doping on the electrorheological performance of nanosized particle materials

“…Nanosized ER materials have been synthesized, 24,25 however, few research works have addressed the question of how the size of a nanosized particle material could influence its ER effect. 26,27 In order to obtain further understanding of the mechanism of the ER effect, we synthesized twelve types of nanosized particle materials containing TiO 2 or ZrO 2 .…”

β-环糊精聚合物与取代水杨酸、3-羟基-2-萘甲酸超分子配合物的构筑及其电流变性能

“…由于环糊精的空腔可以提供与模型底物 荧光光谱用PE LS50B荧光/磷光发光仪测定, 其中所 测样品均在λ ex = 350 nm, 发射狭缝S em = 10 nm/ S ex = 3.5 nm时进行. 电流变液的流变学性能由自制的测 试仪 [5] 测定. 用 GYW-010…”