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硫酸改性TiO2粒子的表征与电流变性能研究

高 兰, 马会茹, 刘秧生, 官建国   

  1. (武汉理工大学 材料复合新技术国家重点实验室, 武汉 430070)
  • 收稿日期:2009-03-02 修回日期:2009-04-27 出版日期:2009-11-20 网络出版日期:2010-04-22

Characterization and Electrorheological Effect of H2SO4-modified TiO2 Particles

GAO Lan, MA Hui-Ru, LIU Yang-Sheng, GUAN Jian-Guo   

  1. (State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China)

  • Received:2009-03-02 Revised:2009-04-27 Published:2009-11-20 Online:2010-04-22

摘要:

采用硫酸溶液浸渍TiO2干凝胶的方法制备了硫酸改性的TiO2粒子, 并组成了具有显著电流变性能的电流变材料. 用FT-IR、XRD、比表面积分析仪等表征了样品结构, 并测试了其电流变性能. 结果表明:由于硫酸根对晶粒生长的阻碍作用, 与纯TiO2粒子相比, 硫酸改性的TiO2粒子的晶粒尺寸降低, 比表面积提高, 并含有大量的强极性键SO. 当电场强度为3kV/mm时, 纯TiO2粒子电流变液的场致剪切应力与零场剪切应力之比(τE/τ0)仅为80, 而硫酸改性TiO2电流变液的τE/τ0高达500. 产生这些现象可归因于硫酸改性TiO2粒子带来的结构改变赋予其明显的界面极化能力.

关键词: 二氧化钛, 硫酸改性, 界面极化, 电流变性能

Abstract:

H2SO4-modified TiO2 particles were prepared using a sol-gel method followed by impregnating the dry gels with sulphuric acid and were used to fabricate an electrorheological (ER) fluid with high ER activity. The as-synthesized H2SO4-modified TiO2 particles were characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), BET N2 adsorption-desorption isotherm analysis, and the ER effect and dielectric spectra of the ER fluids were measured. The results show that H2SO4-modified TiO2 particles have smaller size of crystal grains and higher specific surface area due to the restraint of SO42- from the grain growth. Under the same measured condition and electric field strength of 3kV/mm, the ratio of fieldinduced shear stress to zero field shear stress (τE/τ0) of TiO2 particles is 80, while that of H2SO4-modified TiO2 particles is more than 500. The observed ER performances are reasonably explained by the stronger interfacial polarization, which is brought by the specific structures of the H2SO4-modified TiO2 particles.

Key words: titania, sulfuric acid, interfacial polarization, electrorheological effect

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