[1] Pittsburg State Univ, Dept Chem, Pittsburg, KS 66762 USA
[2] Pittsburg State Univ, Dept Phys, Pittsburg, KS 66762 USA
[3] Univ Memphis, Dept Phys & Mat Sci, Memphis, TN 38152 USA
[4] Pittsburg State Univ, Kansas Polymer Res Ctr, Pittsburg, KS 66762 USA