Comparative study of gamma and ion beam irradiation of polymeric nanocomposite on electrical conductivity S. Lotfy , 1 A. Atta, 2 E. Abdeltwab 3 1 Polymer Chemistry Department, National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. Box 29, Nasr City Cairo, Egypt 2 Radiation Physics Department, National Center for Radiation Research and Technology, Atomic Energy Authority, P.O. Box 29, Nasr City Cairo, Egypt 3 Physics Department, Faculty of Science (Girls Branch), Al-Azhar University, Cairo, Egypt Correspondence to: S. Lotfy (E - mail: samaz711@yahoo.com) ABSTRACT: Poly(vinyl alcohol) (PVA) was used to prepare nanocomposites of multi-wall carbon nanotubes (MWCNT) and functional- ized carbon nanotubes (MWCNT-NH 2 ) in existence of 2-carboxyethyl acrylate oligomers (CEA). Radiation-induced crosslinking of the prepared matrix was carried out via gamma and ion beam irradiation. A comparative study of gamma and ion beam irradiation effect on the electrical conductivity of nanocomposite was conducted. The gelation of the gamma irradiated matrix outperforms the ion beam irra- diated matrix. The order of gelation is PVA > (PVA/CEA) > (PVA/CEA)-MWCNT > (PVA/CEA)-MWCNT-NH 2 . There is a significant reduction in the swelling of the nanocomposite. The formation of nanocomposites was confirmed by scanning electron microscopy, energy- dispersive X-ray (EDX) and FTIR examinations. The direct current electrical properties of PVA/nanocomposites are examined at room tem- perature by applying electric voltage from 1 to 20 V. The results revealed that the electrical conductivity is increased by adding the carbon nanotubes and irradiation by gamma and ion beam. At an applied electric voltage 20 V, in the electrical conductivity of the unirradiated PVA was from 9.20 3 10 28 S cm 21 . After adding MWCNT an increase up to 4.70 3 10 25 S cm 21 was observed. While after ion beam irradiation, a further increase up to 9.30 3 10 25 S cm 21 was noticed. V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46146. KEYWORDS: DC conductivity; gamma and ion beam irradiation; nanocomposites Received 6 August 2017; accepted 5 December 2017 DOI: 10.1002/app.46146 INTRODUCTION Types of nanocomposites such as polymer–polymer, metal– ceramic, and polymer–inorganic particle nanocomposites are being of a growing interest for researchers. Polymer nanocompo- sites have many applications fields such as electrical and optical devices, biosensors, photoconductors, biochips, biodegradable scaffolds, drug delivery system, and filter systems. 1 The addition of fillers of the polymer matrices could enhance the electrical properties of the polymers depending on their reactivity with the host matrix. The production of the conglomerate materials via combination of the polymer properties such as high strength, flexibility, and mold ability with the good properties of inorganic materials such as heat strength, heat stability, high strength, and chemical resistance. 2–4 The electrical properties are of many appli- cations such as filters, sensors, catalysis, synthetics tissue engi- neering, wound dressing, and scaffolding by coalesce inorganic nanoparticles in their structures. 5–7 Impregnate the conductive filler nanoparticles such as multi-wall carbon nanotubes (MWCNT) and MWCNT-NH 2 in insulating matrices are able to lower the overall resistivity by several orders of magnitude when a network established at full length the matrices. Poly(vinyl alcohol) (PVA) polymer is insulating material with a lower ionic conductivity and hydrophilic in nature. 8 The chemical crosslinking of PVA by glutaraldehyde increased crosslink density, which enhanced the mechanical strength, but reduced water uptake and proton conductivities of the mem- branes. 9 The functional polymer composite materials family comprised of an insulating polymer matrix and electrically conductive fillers (MWCNT and MWCNT-NH 2 ). These poly- mer nanocomposites plays an essential role in modern indus- tries due to the advantages of light weight, chemical stability, effectiveness and easy regulation of mechanical performance, and electrical conductivity. 10 For the mechanism of conductiv- ity, two important considerations must be one observed the movement of electrons along the electrical paths and the sec- ond focuses on the formation of electrical paths through the composite samples. The two mechanisms are dependent on the filler content. 11,12 V C 2017 Wiley Periodicals, Inc. J. APPL. POLYM. SCI. 2018, DOI: 10.1002/APP.46146 46146 (1 of 7)