Kinetics of collapse transition and cluster formation in a thermoresponsive micellar solution of P(S-b-NIPAM-b-S) induced by a temperature jump.
Structural changes at the intra- as well as intermicellar level were induced by the LCST-type collapse transition of poly(N-isopropyl acrylamide) in ABA triblock copolymer micelles in water. The distinct process kinetics was followed in situ and in real-time using time-resolved small-angle neutron scattering (SANS), while a micellar solution of a triblock copolymer, consisting of two short deuterated polystyrene endblocks and a long thermoresponsive poly(N-isopropyl acrylamide) middle block, was heated rapidly above its cloud point. A very fast collapse together with a multistep aggregation behavior is observed. The findings of the transition occurring at several size and time levels may have implications for the design and application of such thermoresponsive self-assembled systems.
Technische Universität München, Physikdepartment, Fachgebiet Physik der weichen Materie/Lehrstuhl für funktionelle Materialien, Garching, Germany.
Joseph
J
Adelsberger
Ezzeldin
E
Metwalli
Alexander
A
Diethert
Isabelle
I
Grillo
Achille M
AM
Bivigou-Koumba
André
A
Laschewsky
Peter
P
Müller-Buschbaum
Christine M
CM
Papadakis
D000178:Acrylamides / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D007700:Kinetics; D008823:Micelles; D008956:Models, Chemical; D011137:Polystyrenes / Q000737:chemistry*; D053838:Scattering, Small Angle; D013696:Temperature; D014867:Water / Q000737:chemistry
D000178:Acrylamides; D020100:Hydrogels; D008823:Micelles; D011137:Polystyrenes; D014867:Water; C067295:N-isopropylacrylamide