Yun-Ling Jia

Preparation and Electrorheological Property of NaNO3-Doped Y2O3 Material

Abstract A new class of electrorheological (ER) material using rare earth (RE = Y) oxide as the substrate, NaNO3doped Y2O3 materials, were synthesized using Na2CO3 and Y(NO3)3 as starting materials. Their ER performance, dielectric property, and crystal structure were studied. The results show that doping NaNO3 can markedly enhance the ER activity of the Y2O3 material. For the suspensions of these materials in dimethyl silicone oil, a clear dependence of the shear stress on the doping degree of NaNO3 was observed, and the optimal value of Na/Y molar ratio of 0.6 in doping degree was discovered, the relative viscosity ηr(ηE/ηO, E = 4.2 kV·mm−1) of the suspensions is nine times higher than that of pure Y2O3 material. The new results of the relationship between ER effect and the microstructure were obtained, which are helpful for further understanding the mechanism of ER effect and synthesizing a good ER material.

A novel multifunction material with both electrorheological performance and luminescence property

Abstract A multifunctional material with both electrorheological (ER) performance and luminescence property was synthesized by a simple coprecipitation. The tetrabutyl titanate, as well as the Tb(NO 3 ) 3 ·6H 2 O and sulphosalicylic acid (C 7 H 6 O 6 S·2H 2 O, SSA) were chosen as starting materials. The composition, ER performance and luminescence property of the material were studied. The results showed that a novel material (TiTbSSA) with both ER performance and luminescence property was obtained. The relative shear stress τ r ( τ r = τ E / τ 0 , τ E and τ 0 were the shear stresses of the suspension with and without an applied electric field) of the suspension (30 wt.%) of the material in silicone oil reached 32.7 at a shear rate of 12.5 s −1 and an electric field strength of 4 kV/mm (DC electric field). The material containing the rare earth (RE=Tb) complex exhibited fine luminescence performance and higher ER activity. Therefore, it is a novel multifunction material which would have wide application prospect.

Preparation and Electrorheological Property of Y4O(OH)9(NO3)-NH4NO3 Materials

Abstract The new electrorheological (ER) material, a particle material composed of Y 4 O(OH) 9 (NO 3 ) and NH 4 NO 3 , was obtained. They display better ER performance. The shear stress of the suspension of Y 4 O(OH) 9 (NO 3 ) (NH 4 NO 3 ) 2.8 material in dimethyl silicone oil reaches 1469 Pa at an electric field strength ( E ) of 4.2 kV. mm −1 and the shear rate (γ) of 150s −1 . The relative shear stress, τ E /τ 0 (τ E and τ 0 are the shear stresses at E = 4.2 and O kV-mm −1 , respectively), is up to 29, which is 19 times that of pure Y 2 O 3 material. The dielectric and conductive property of the materials play important roles in the modification of the ER effect of the particle materials. The researches on these new ER materials are very useful for obtaining a better understanding on the mechanism of the ER effect and finding an ideal ER material.

New multifunction materials with both electrorheological performance and luminescence property

Novel multifunctional materials, the composites AlOOH-NaYFTb5 and AlOOH-NaYFTb10, containing AlO(OH) and β-NaYF4:5%Tb3+, have been synthesized via a facile hydrothermal route and a simple grinding method. The boehmite [AlO(OH)], yttrium nitrate [Y(NO3)3·6H2O], terbium nitrate, [Tb(NO3)3·6H2O], sodium citrate (Na3C6H5O7·2H2O) and sodium fluoride (NaF) were used as starting materials. The composition, electrorheological (ER) performance, and luminescence property of the functional materials were studied. Our results show that the composites not only have good electrorheological (ER) performance, but also have good optics property. The relative shear stress τr (τr = τE/τ0, τE and τ0 are the shear stresses at the electric field strength E = 4 and 0 kV/mm, respectively) values of the suspension (25 wt.%) of AlOOHNaYFTb5 material in silicone oil are all larger than 50 in a shear rate ranging from 0.06 to 26 s−1, the τr value reaches 1333 at a shear rate of 0.06 s−1. The material with such high ER activity and favorable luminescence performance is advantageous in its application as a multifunctional material.