Effect of pressure on hydrodynamic properties of poly(ethylene oxide) in deuterated and in non-deuterated solvents

Dynamic light scattering measurements of poly(ethylene oxide) (PEO) in deuterated methanol (CH 3OD and CD 3OD) and in non-deuterated methanol have been carried out in the pressure range 1–2500 bar. The pressure dependence of the hydrodynamic radius of PEO is observed to be quite different depending on the degree of isotope substitution of the solvent. The pressure dependence of the diffusion coefficient is also reported for these polymer-solvent pairs. At elevated pressure all polymer-solvent systems exhibit signs indicating formation of molecular clusters, which probably are associated with the preliminary stage of a pressure induced solution crystallization process.