A Differential Temperature-Dependent Dielectric Relaxation Study of Organoclay Cloisite \(^{\mathrm{TM}}\)

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• 作者：Abhimanyu Sharma ; Rohtash Kumar ; K. Asokan…
• 关键词：Cloisite\(^{\mathrm{TM}}\) ; Dielectric relaxation ; Loss tangent ; Raman spectra ; Structural change ; X ; ray diffraction
• 刊名：International Journal of Thermophysics
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：38
• 期：1
• 全文大小：1,583 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Condensed Matter
  Mechanics
  Industrial Chemistry and Chemical Engineering
  Physical Chemistry
  
• 出版者：Springer Netherlands
• ISSN：1572-9567
• 卷排序：38

文摘

We report variation in the dielectric relaxation profiles of an important class of commercially available Cloisite\(^{\mathrm{TM}}\) organoclays, 25A, 15A, 30B and 10A, which are extensively used as rheology modifiers. A systematic and comprehensive comparison is made of their dielectric permittivity (\({{\upvarepsilon }^{\prime }})\), and loss (\({{\upvarepsilon }^{\prime \prime }})\), conductivity (\({\upsigma }^{\prime })\) and loss tangent (\(\tan \delta )\) parameters as function of temperature. The dispersion profiles showed relatively higher values for \({{\upvarepsilon }^{\prime }}\), \({\upvarepsilon }^{{\prime \prime }}\), \({\upsigma }^{\prime }\) and \(\tan \delta \) for the Cloisite\(^{\mathrm{TM}}\)30B samples in low-frequency region. A clear temperature-dependent transition in the values of \({{\upvarepsilon }^{\prime }}\) and \({{\upvarepsilon }^{\prime \prime }}\) was noticed for Cloisite\(^{\mathrm{TM}}\)25A sample at 436 K, which was independent of frequency, \(\omega \). The values of \({{\upvarepsilon }^{\prime }}\) and \({{\upvarepsilon }^{\prime \prime }}\) showed \(1/\omega \) dependence with temperature. Cloisite\(^{\mathrm{TM}}\)30B sample showed a marked decrease in the value of \(\tan \delta \) with increase in temperature compared to other samples. Thus, it was concluded that these clays bear signature dielectric properties regardless of the fact that they all belong to the same structural class of clays. Considering the large-scale use of these clays in many industrial products the above-mentioned results are of significant importance.