Refractometric study of systems water-poly(ethylene glycol) for preparation and characterization of Au nanoparticles dispersion

Abstract

Refractive index of binary systems water-poly(ethylene glycol) of different molecular weights at several temperatures from 283.15 to 363.15 K was measured. Refractive index strongly depends on molecular weight, mole fraction and temperature. Experimental data were correlated by four parameters’ relationship for dependence of refractive index on mole fraction of poly(ethylene glycol) and by three parameters’ relationship for dependence on molecular weight of poly(ethylene glycol). Obtained data can serve as an input data for subsequent study of these binary systems and especially for study of colloidal systems of metal nanoparticles in dispersion surrounding consisting of water and poly(ethylene glycol). Especially these data on refractive index are important for determination of nanoparticle size and zeta potential by dynamic light scattering. Obtained data on refractive index have been employed for correct and accurate determination of nanoparticle size and zeta potential. The size of Au nanoparticles was determined by dynamic light scattering. For comparison of this determination also a transmission electron microscopy and UV–vis spectroscopy have been employed in very good agreement. The optical properties of Au nanoparticles’ colloidal solutions were analyzed with UV–vis spectroscopy and showed a significant absorption peak maximum at 530 nm. Keywords: Water-poly(ethylene glycol), Refractive index, Temperature dependence, Data correlation, Au nanoparticles, Dynamic light scattering