Clayton LaNetra M, Knudsen Bernard, Cinke Martin, Meyyappan M, Harmon Julie P
Department of Chemistry, University of South Florida, 4202 E Fowler Avenue, Tampa, FL 33620-5250, USA.
J Nanosci Nanotechnol. 2007 Oct;7(10):3572-9. doi: 10.1166/jnn.2007.850.
This work focuses on the DC conductivity and interfacial polarization of poly(methyl methacrylate) (PMMA) composites made with single wall nanotubes (SWNTs) and nanotube precursor soot. We aim to compare and contrast the behavior of the two nanofillers in an effort to determine if the precursor material imparts tunable electrical properties to PMMA. The DC activity of the polymers and composites was determined by extrapolating AC conductivity versus frequency plots to zero. Activation energies and DC conductivities were obtained through Arrhenius plots. The conductivity increased with temperature for all the samples in conjunction with viscous flow. Both nanotubes and nanosoot increased the DC conductivities. Activation energies for the SWNT decreased slightly upon the addition of nanotubes to the matrix. However, the activation energies increased with soot content in the matrix, indicating obstruction of motion or possible bridging caused by the soot. Cole-Cole plots were effectively used to determine the extent of interfacial polarization in the composite samples. Plots shifted toward the origin with the addition of carbon nanotubes or with soot concentration indicating a Maxwell-Wagner-Sillars process.
这项工作聚焦于由单壁纳米管（SWNTs）和纳米管前驱体烟灰制成的聚甲基丙烯酸甲酯（PMMA）复合材料的直流电导率和界面极化。我们旨在比较和对比这两种纳米填料的行为，以确定前驱体材料是否赋予PMMA可调节的电学性能。聚合物和复合材料的直流活性通过将交流电导率与频率曲线外推至零来确定。通过阿伦尼乌斯曲线获得活化能和直流电导率。所有样品的电导率都随温度升高而增加，这与粘性流动有关。纳米管和纳米烟灰都提高了直流电导率。向基体中添加纳米管后，SWNT的活化能略有降低。然而，活化能随基体中烟灰含量的增加而增加，这表明烟灰导致了运动受阻或可能的桥连。科尔 - 科尔曲线有效地用于确定复合样品中界面极化的程度。随着碳纳米管的添加或烟灰浓度的增加，曲线向原点移动，表明存在麦克斯韦 - 瓦格纳 - 西勒斯过程。
