화학공학소재연구정보센터
Journal of Physical Chemistry B, Vol.115, No.4, 648-652, 2011
Conformation of Poly(ethylene oxide) Dissolved in Ethylammonium Nitrate
Small angle neutron scattering has been used to investigate the morphology of 38 kDa PEO dissolved in ethylammonium nitrate (EAN) in the dilute and semidilute concentration regions. At infinite dilution, the radius of gyration, R-g, is 8.1 nm. This value decreases through the dilute regime according to a concentration (c) dependence of R-g approximate to c(-0.24), while above the overlap concentration a c(-1) dependence is followed. These values differ from aqueous solution behavior, which we attribute to EAN being a poorer solvent for PEO than water; EAN is in fact close to a theta solvent. The polymer structure on length scales less than 3 nm is unaffected by increasing polymer concentration, suggesting that the overall decrease in coil dimensions is a consequence of tighter packing of similar to 3 nm polymer "blobs" into a smaller volume.