1583 Research Article Received: 29 January 2013 Revised: 26 March 2013 Accepted: 8 April 2013 Published online in Wiley Online Library: 4 June 2013 (wileyonlinelibrary.com) DOI 10.1002/pi.4542 Electrical conductivity of LTA-zeolite in the presence of poly(vinyl alcohol) and poly(vinyl pyrrolidone) polymers Maryam Salimian, a Olena Okhay, a Rahul Krishna, a Elby Titus, a,* Jos ´ e Gracio, a Lu´ ıs Guerra, b Jo˜ ao Ventura, b Cristina Freire, c Clara Pereira, c P. Ramesh Babu d and Rajendra S. Khairnar e Abstract In this work we studied the electrical behavior of Linde type A zeolite (K + ) in the presence of two polymers, poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP), with excellent film forming properties. Homogeneous composite thin films of PVA/LTA-zeolite and PVP/LTA-zeolite were prepared with different zeolite concentrations. The current-voltage (I-V ) characteristics of the composites were measured at different applied voltages. The results show that the conductivity properties are composition-ratio-dependent and are also related to the type of polymers. Moreover, a well-defined step-like change was detected in the I-V curve of PVP/LTA-zeolite at very high applied voltage. c  2013 Society of Chemical Industry Keywords: electrical conductivity; zeolite (LTA); polyvinyl alcohol; polyvinylpyrrolidone INTRODUCTION Today polymer-based nanocomposites draw a lot of attention due to their excellent functional properties, such as mechanical, thermal and electrical conductivity superior to pure polymers. 1 Among all polymers, poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) are widely used because of their good film forming and water solubility properties. Inherently, PVA and PVP are insulators with extremely low conductivity. However, enforcement or doping with another material can transform them into conducting materials. 2 On the other hand, zeolite is a crystalline, porous aluminosilicate with low electrical conductivity. 3 It generally contains silicon, aluminium and oxygen in its framework and cations, water and/or other molecules within its pores. 4 Zeolite (LTA) with a cubic structure has a three-dimensional pore system. One unit cell with diameter a = 24.56 ˚ A consists of a supercage (cavity) with a dimension of 11.4 ˚ A. The supercage is surrounded by eight sodalite cages, each one with an internal radius of 5 ˚ A connected to another by channels. Eight rings of oxygen build the supercage window with a diameter of about 6.8 ˚ A which makes it possible for adsorbents to enter inside the cavities. The unit cell of zeolite (LTA) contains 96 K + cations that are located in the cavity, cages and channels. Each sodalite cage and channel contains eight cations and one cation respectively inside and the remaining 24 cations are located inside the cavity facing the sodalite cages. 5 – 7 Due to pore opening of the zeolites they are used for a wide range of applications such as gas separation and adsorption, ion exchange and catalysis. 8,9 It has already been reported that water molecules can easily diffuse inside the cavity and cages. So, zeolite material is readily used in laundry detergents for washing purposes as a filler with surfactant (alkylbenzenesulfonate) and highly water soluble polymers. 10,11 Moreover, due to the presence of charge balancing cations inside the pores it is highly desirable for various electrical/electronics applications for likely switching, memristor and low dielectric constant materials in the energy/semiconductor industries. 12 It has also been reported that zeolite−polymer based composite materials can be used for various electronics applications. For instance, the conductivities of zeolite− poly(tetrafluoroethylene) with different types of zeolite (Na-Y, Na-X, Na-MOR, Na-ZSM and Na-LTA) have been studied as a function of temperature. It was shown that hydrophilic zeolites are more conductive than hydrophobic zeolites in polymer−composite membranes. 13 Also the amount of water adsorbed by zeolite plays an important role in conductivity properties. Recently the electrical behavior of poly(vinylidene fluoride) (PVDF)/NaY-zeolite composite films ∗ Correspondence to: Elby Titus, Center for Mechanical Technology and Automation, Department of Mechanical Engineering, University of Aveiro, 3810-193, Portugal. E-mail: elby@ua.pt a Center for Mechanical Technology and Automation, Department of Mechanical Engineering, University of Aveiro, 3810-193, Portugal b IFIMUP-IN and Faculty of Sciences, University of Porto, Porto, Portugal c REQUIMTE, Departamento de Qu´ ımica e Bioqu´ ımica, Faculdade de Ciˆ encias, Universidade do Porto, 4169-007 Porto, Portugal d School of Physics, Centre for Research on Adaptive Nanostructures & Nanodevices (CRANN), Trinity College Dublin, Dublin 2, Ireland e Swami Ramanand Teerth Marathwada University, Vishnupuri, Nanded-431 606, Maharashtra, India Polym Int 2013; 62: 1583–1588 www.soci.org c  2013 Society of Chemical Industry