Determination of Chitosan Scattering Parameters by Using Multi Angle Static Laser Light Scattering(MASLLS )

Document Type : Research and Reference

Authors

1 Laser Laboratory, Physics department, Faculty of sciences, Tanta University, Tanta, Egypt

2 Laser Laboratory, Physics department, Faculty of sciences, Tanta University, Tanta,

3 Polymer Research group, Chemistry Department, Faculty of Sciences, Tanta University, Tanta, Egypt

Abstract

Measurement of polymer characteristics by using the static laser light scattering experiment needs a precise
determination of its refractive index increment, dn/dc. Through the dependence of Rayleigh scattering coefficient on the square
value of the refractive index increment(dn/dc)2. The average molecular weight of the investigated polymer is determined using a
home built of Mach-Zehender Interferometer(MZI) which has been constructed to measure the refractive index, n, of Chitosan at
different concentration ranging from 0.002 to 0.008 gm/L. The measurements are carried out through the dependence of fringe
numbers on the laser incidence angle of polymer’s solutions. The used laser beam is a He-Ne laser with 543 nm wavelength and
2mw in power (from Meridith). The obtained value of dn/dc is 0.198011 L/gm . A static laser light scattering(SLLS) experiment
is constructed in our lab to measure the angular distribution of the scattered laser light intensity. From which the Rayleigh ratio
Rθ, molecular weight MW, second virial coefficient A2 and the square radius of gyration <RG
2> are calculated through what is
called as Zimm plot method .

Keywords