Study of Optical Properties For (Lithium Fluoride-Poly- vinyl alcohol) Composites
Bahaa H. Rabee , Majeed Ali Habeeb and Ahmed Hashim
Babylon University, College of Education , Department of physics, Iraq.
E-Mail: ahmed_taay@yahoo.com
E-Mail: majeed_ali74@yahoo.com
Abstract
In this work , the optical properties of composites of poly-vinyl alcohol(PVA) and lithium fluoride were prepared by different concentrations of lithium fluoride. Results showed that the absorbance increases with increase the weight percentage of lithium fluoride, absorption coefficient, extinction coefficient, refractive index and real and imaginary parts of dielectric constants are increasing with increase the lithium fluoride content.
Keyword: optical properties lithium fluoride, polyvinyl alcohol.
Introduction
Optical properties of polymers constitute an important aspects in study of electronic transition and the possibility of their application as optical filters, a cover in solar collection, selection surfaces and green house. The information about the electronic structure of crystalline and amorphous semiconductors has been mostly accumulated from the studies of optical properties in wide frequency range. The significance of amorphous semiconductors is in its energy gap[1]. Poly(vinyl alcohol) (PVA), as it is well known for its interesting behavior and its versatile applications. In water, there exist two possible intermolecular interactions among PVA chains or between PVA and water, as follows: (1) H-bonding between modified hydroxyl groups on PVA chains and (2) H-bonding between the —OH groups of PVA and water molecules[2].
Experimental Procedure
The materials used in this paper are polyvinyl alcohol and lithium fluoride. The weight percentages of lithium fluoride are (0,5,10 and 15)wt.%. The samples were prepared using casting technique thickness ranged between (210-418)?m.
The transmission and absorption spectra of PVA-LiF composites have been recording in the length range (190-850) nm using double-beam spectrophotometer (UV-210oA shimedza ).