%0 Journal Article
%T Role of Hard-Acid/Hard-Base Interaction on Structural and Dielectric Behavior of Solid Polymer Electrolytes Based on Chitosan-XCF3SO3 (X = Li+, Na+, Ag+)
%A Shujahadeen B. Aziz
%A Zul Hazrin Z. Abidin
%J Journal of Polymers
%D 2014
%R 10.1155/2014/906780
%X Solid films of pure chitosan, chitosan-LiCF3SO3, chitosan-NaCF3SO3, and chitosan-AgCF3SO3 were prepared using solution cast technique. The influence of cation size on the chitosan structure has been investigated by X-ray diffraction technique. The interaction between the alkali metal ions and the donor atoms of chitosan polymer is a strong hard-acid/hard-base interaction. It was found that the intensity of crystalline peaks of chitosan decreases with increase of cation size. The impedance analysis shows that ionic transport is high for the high amorphous system. The second semicircle in - plots and the surface plasmonic resonance (SPR) peaks in chitosan-AgCF3SO3 sample system reveal the formations of silver metal nanoparticles. It was found that the high amorphous sample exhibits the high dielectric constant and dielectric loss values. The increase of dielectric constant and dielectric loss with temperature for chitosan-salt membranes indicated an increase of charge carrier concentration. 1. Introduction Polymer electrolytes may be defined as a membrane having enhanced transport properties comparable with that of the common liquid ionic solution. The conductivity of these polymers can be controlled by changing their redox state by means of chemical or electrochemical reduction or oxidation accompanied by insertion of counter ion [1]. Due to the advantages that polymer electrolytes offer over conventional materials, including no internal shorting, leakage of electrolytes, ease of processing, productivity, and cost reduction [2]. In addition, polymer electrolytes possess the advantage of flexibility over inorganic solids [3]. Amorphous solid electrolytes (polymer salt complexes) have gained technological importance for their possible applications in a variety of devices such as lithium batteries, fuel cells, electrochromic displays, supercapacitors, and sensors [4¨C6]. Polymer electrolytes usually contain both crystalline and amorphous phases. It has been reported that the ion conduction takes place primarily in the amorphous phase [7]. Chitosan is a biocompatible and biosorbable biopolymer which is currently receiving a great deal of interest for medical and pharmaceutical applications due to its interesting intrinsic properties [8] and it is a polycationic polymer due to the existence of one amino group and two hydroxyl groups in their repeating units [9]. It is well known that chitosan is an outstanding sorbent of extremely high affinity for transition metal ions due to the abundance of polar groups (NH2 and OH) in chitosan chains which served as
%U http://www.hindawi.com/journals/jpol/2014/906780/