Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Length-scale dependence of pH- and temperature-response of PDMAEMA-bPHPMA block copolymer self-assemblies in aqueous solutions
Δημιουργός/Συγγραφέας:	[EL] Παπαγιαννόπουλος, Αριστείδης[EN] Papagiannopoulos, Aristeidis Sentoukas, Theodore [EL] Πίσπας, Στέργιος[EN] Pispas, Stergios Radulescu, Aurel Pipich, Vitali Lang, Christian
Εκδότης:	Elsevier
Ημερομηνία:	2022-01-17
Γλώσσα:	Αγγλικά
DOI:	10.1016/j.polymer.2021.124428
Περίληψη:	Amphiphilic doubly responsive block copolymers poly(2-(dimethylamino)ethyl methacrylate)-b-poly(hydroxy propyl methacrylate) (PDMAEMA-b-PHPMA) were studied by very small angle and small angle neutron scattering (VS/SANS) in aqueous solutions. A multi-level hierarchical approach was used to fit the experimental data and Bayesian analysis was performed to explore possible interdependencies between the extracted parameters. Hydrophobic contacts between the block copolymer monomers appear to create local concentration inhomogeneities (2–4 nm) whose size and mass depends on the preparation protocol. A solvent-exchange solubilization protocol leads to smaller inhomogeneities in comparison to a direct solubilization protocol due to better arrangement of the PHPMA hydrophobic units. At acidic and neutral pH hierarchical structure is observed where the local inhomogeneities are organized within aggregates (∼200 nm) and grow or shrink with temperature depending on pH. At acidic pH aggregates are interconnected into large clusters. By increasing temperature, aggregates become larger in both afcidic and neutral pH, while this response is stronger for the solvent-exchange solubilization protocol. Very interestingly, aggregates transform into self-similar superstructures at basic pH (where PDMAEMA is uncharged) to an extend that it is strongly preparation protocol-dependent. These transitions at length scales from 1 to 1000 nm open many possibilities for advanced multiple stimuli-responsive loading and release of proteins and drug molecules in such polymeric nanostructures.
Τίτλος πηγής δημοσίευσης:	Polymer
Τόμος/Κεφάλαιο:	239
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Βιοχημεία[EN] Biochemistry [EL] Νανοτεχνολογία[EN] Nanotechnology
Λέξεις-Κλειδιά:	Copolymers Bayesian analysis Aqueous solution VS/SANS PDMAEMA-b-PHPMA
Κάτοχος πνευματικών δικαιωμάτων:	2021 Elsevier Ltd. All rights reserved.
Ηλεκτρονική διεύθυνση στον εκδότη (link):	https://doi.org/10.1016/j.polymer.2021.124428
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο