On the Positron Annihilation Spectroscopy and Tensile Behavior of COOH-MWCNTs/Epoxy Nanocomposites

Document Type : Research Article

Authors

1 Physics Department, University of Sistan and Baluchestan

2 Department of Physics, Faculty of Science, University of Sistan and Balcuchestan

3 University of Sistan and Baluchestan

Abstract

Positron Annihilation Lifetime Spectroscopy (PALS) is sensitive to the material voids/free volume on the atomic scale. For this reason, in recent years, this method has been used as a unique technology to measure the free volume and structural defects in the polymers. In the present study, the epoxy-matrix nanocomposites having different carboxylic acid functionalized multiwalled carbon nanotubes (COOH-MWCNTs) loadings (0.1-0.7 wt.% at a step of 0.2) were fabricated. The influence of COOH-MWCNTs loading on the free volume properties and tensile behavior of the prepared nanocomposites were explored. The measurement of positron annihilation lifetime was done using a conventional synchronization system based on a 22Na radioactive source with 20 μCi activity. The detectors used in this work were fast plastic scintillator (type: NT-850) with ns time response. The results demonstrated that the tensile strength of the nanocomposites decreased with the increase in the lifetime of the ortho-positronium annihilation (increase in the radius and free volume) in the samples. The 0.3 wt.% COOH-MWCNTs/epoxy nanocomposite showed the maximum tensile strength. Overall, the results of this work clearly revealed that there was a strong relationship between the tensile strength and free volume in the polymer nanocomposites.

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Articles in Press, Accepted Manuscript
Available Online from 01 September 2024
  • Receive Date: 26 July 2024
  • Revise Date: 27 August 2024
  • Accept Date: 01 September 2024