title: Quantifying the Interactions in the Aggregation of Thermoresponsive Polymers: The Effect of Cononsolvency.
abstract: The aggregation kinetics of thermoresponsive core-shell micelles with a poly(N-isopropyl acrylamide) shell in pure water or in mixtures of water with the cosolvents methanol or ethanol at mole fractions of 5% is investigated during a temperature jump across the respective cloud point. Characteristically, these mixtures give rise to cononsolvency behavior. At the cloud point, aggregates are formed, and their growth is followed with time-resolved small-angle neutron scattering. Using the reversible association model, the interaction potential between the aggregates is determined from their growth rate in dependence on the cosolvents. The effect of the cosolvent is attributed to the interaction potential on the structured layer of hydration water around the aggregates. It is surmised that the latter is perturbed by the cosolvent and thus the residual repulsive hydration force between the aggregates is reduced. The larger the molar volume of the cosolvent, the more pronounced is the effect. This framework provides a molecular-level understanding of solvent-mediated effective interactions in polymer solutions and new opportunities for the rational control of self-assembly in complex soft matter systems.
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kyriakos
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Martine
authors.initials: M
authors.lastname: Philipp
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Che-Hung
authors.initials: CH
authors.lastname: Lin
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Margarita
authors.initials: M
authors.lastname: Dyakonova
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Natalya
authors.initials: N
authors.lastname: Vishnevetskaya
authors.affiliation: Large Scale Structures Group, Institut Laue-Langevin, 71, Avenue des Martyrs, 38042, Grenoble, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Grillo
authors.affiliation: Theorie weicher Materie, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Alessio
authors.initials: A
authors.lastname: Zaccone
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Miasnikova
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany.|Fraunhofer IAP, PO Box 600 651, 14406, Potsdam, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Laschewsky
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Müller-Buschbaum
authors.affiliation: Fachgebiet Physik weicher Materie/Lehrstuhl für Funktionelle Materialien, Physik-Department, Technische Universität München, James-Franck-Str. 1, 85748, Garching, Germany.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Papadakis
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D005427:Flocculation; D000432:Methanol / Q000737:chemistry; D033363:Neutron Diffraction; D053838:Scattering, Small Angle; D012995:Solubility; D013696:Temperature; D014867:Water / Q000737:chemistry; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D000431:Ethanol; D000432:Methanol; D014867:Water; D000099166:Polyacrylamides
keywords: colloidal aggregation; cononsolvency; interaction potential; polymer solutions; self-assembled micelles; thermoresponsive polymers