International Journal of Engineering & Technology IJET-IJENS Vol:12 No:04 98 127804-4343-IJET-IJENS © August 2012 IJENS I J E N S Abstract— Poly ethyle methacrylate (PEMA) films doped with different contents of mixed salt (CoCl 2 and LiBr) were prepared using the casting technique. The amorphous feature of the filled polymer was depicted using XRD scans and degree of crystallinity was found to decrease with increasing filler content. Fourier transform infrared spectroscopy display significant structural changes within the polymeric matrix indicating a complexation between the pristine polymer and mixed filler. UV-Vis. optical absorption spectrum indicate a variation in both intensity and optical energy gap with different doping level. Both values of direct and indirect energy gaps are calculated and discussed. Obtained data shows a defect formation which increases with increasing filler content and supported by both XRD and UV-Vis. Data Index Term— Mixed filler ; PEMA, FTIR, UV-Visible; X- ray diffraction I. INTRODUCTION Organic and polymeric thin films doped with metal halide salts have been attracting increasing interest in the last few years in view of potential applications in photonics, bio-sensing, microlithography, microelectronics, packaging, and so on. Many authors discuss Langmuir–Blodgett–Kuhn (LBK) multilayer assemblies, self-assembled monolayers (SAMs), polymer surfaces and interfaces, and thin spin-cast polymer films [1], and their optical properties [2,3] and addressed molecular orientation and packing as well as molecular motion including phase transitions, melting, and other phenomena, e.g. relaxation processes. Recently, studies on the optical and thermo-electrical properties of polymers have attracted much attention from fundamental and practical viewpoints [4]. Infrared (IR) spectroscopy is a mature research tool, which has enjoyed a renaissance in recent years due to the introduction of the Fourier-transform (FT) technique [5]. The infrared spectrum E.M. AbdelRazek is serving in the Physics Dept., Faculty of Science, Mansoura Univ., Mansoura, 35516, Egypt. A.M. Abdelghany is serving in the Spectroscopy Dept., Physics Division, National Research Center, Cairo, 12311, Egypt A.H. Oraby is serving in the Physics Dept., Faculty of Science, Mansoura Univ., Mansoura, 35516, Egypt. G.M. Asnag is serving in the Physics Dept., Faculty of Science, Mansoura Univ., Mansoura, 35516, Egypt characterizes the vibrational modes of a molecule and has included within it much information on chemical structure. For polymers, this includes subtle structural variation such as tacticity and neighboring group interactions [5, 6]. In previous work [7, 8], compatibility, relaxation behavior and compensation phenomena in PEMA and PEMA polyblend with different fillers have been investigated in detail. The present work deals with extensive studies using optical UV-Vis. absorption, FTIR spectroscopy and X-ray diffraction to illustrate the nature and properties of the prepared samples before and after filling with different filling levels (FL) of PEMA. II. MATERIAL AND EXPERIMENTAL WORK A. Materials Poly(ethyle methacrylate) (PEMA, MW =50,000, CAS = 9003-42-3, Aldrich) in powder form, LiBr was supplied by (Aldrich), CAS = 7550-35-8, and CoCl 2 of purity 99%, Hayashi Ltd. Japan). PEMA doped with mixed filler were prepared by solvent- casting technique. To complete dissolution, a specific quantity of PEMA was added to pure acetone and it as kept for 48 h to swell the pellets on an oven at 50 C. Equal quantity of CoCl 2 and LiBr was also dissolved in acetone and added to the polymeric solution. The solution was kept at ambient temperature until suitable viscosity was obtained. The solution was poured onto petri dishes and dried in an oven at 50 C. After drying, the films were peeled of and kept in vacuum desiccators, until use. The thickness of the obtained films was in the range 80–100 m. PEMA films doped with mixed of mass fractions 0, 2.5, 5.0, 7.5, 10.0, 12.5, and 15.0 wt% were prepared using the following equation; where W d and W p are the weight of dopant and polymer, respectively. . B. Characterization techniques X-ray diffraction (XRD) scans were obtained using PANalytical X`Pert PRO XRD system using Cu K  radiation (where,  = 1.540 Å, the tube operated at 30 kV, the Bragg’s angle (2) in the range of 5-50). Fourier Transform Infrared (FTIR) measurements were carried out using single beam Investigation of Mixed Filler Effect on Optical and Structural Properties of PEMA Films E.M. Abdelrazek , A.M. Abdelghany , A.H. Oraby and G.M. Asnag