Small angle neutron (SANS) and X-ray (SAXS) Scattering measurements on aggregate formation of block copolymers in water and in near-critical and supercritical CO2 are reported here. Time Resolved SAXS (TR-SAXS) has also been performed in the supercritical region. Experiments have been carried out for a series of different thermodynamic conditions, changing the solvent density by profiling the pressure at constant temperature. A sharp transition between monomers dissolved as random coils and micelles characterized by a solvo-philic shell and a solvo-phobic core occurs when the solvent density reaches the critical micellization value, This is easily shown in the case of scCO(2). (C) 2002 Elsevier Science B.V. All rights reserved.
Dilute and semi dilute solutions of block copolymers in water, near-critical and super-critical CO2: a small angle scattering study of the monomer-aggregate transition
Triolo A;
2002
Abstract
Small angle neutron (SANS) and X-ray (SAXS) Scattering measurements on aggregate formation of block copolymers in water and in near-critical and supercritical CO2 are reported here. Time Resolved SAXS (TR-SAXS) has also been performed in the supercritical region. Experiments have been carried out for a series of different thermodynamic conditions, changing the solvent density by profiling the pressure at constant temperature. A sharp transition between monomers dissolved as random coils and micelles characterized by a solvo-philic shell and a solvo-phobic core occurs when the solvent density reaches the critical micellization value, This is easily shown in the case of scCO(2). (C) 2002 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
