Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	pH-Dependent Self-Assembly of Polystyrene-block-Poly((sulfamate-carboxylate)isoprene) Copolymer in Aqueous Media
Δημιουργός/Συγγραφέας:	Uchman, Mariusz Prochazka, Karel Stepanek, Miroslav Mountrichas, Grigoris [EL] Πίσπας, Στέργιος[EN] Pispas, Stergios Spirkova, Milena Walther, Andreas
Εκδότης:	American Chemical Society
Τόπος έκδοσης:	WASHINGTON
Ημερομηνία:	2008-10-21
Γλώσσα:	Αγγλικά
ISSN:	0743-7463
DOI:	10.1021/la8025842
Περίληψη:	The amphiphilic polystyrene-block-poly ((sulfamate-carboxyl ate) isoprene) (PS-PISC) diblock copolymer was synthesized from the precursor diblock copolymer polystyrene-block-isoprene by reaction with chlorosulfonyl isocyanate. The structure and behavior of self-assembled PS-PISC nanoparticles was studied in alkaline and acidic aqueous solutions by a combination of static and dynamic light scattering, analytical ultracentrifugation, atomic force and cryogenic transmission electron microscopies, NMR spectroscopy, potentiometric titration, and fluorometry using pyrene as a polarity-sensitive fluorescent probe. It was found that PS-PISC exists in aqueous solutions in the form of micellar aggregates. The aggregation tendency increases with decreasing effective charge density in the shelf, that is, with decreasing pH of the solution, and aggregates found in alkaline aqueous media have much smaller molar masses than those formed in acidic media. The latter are dense, collapsed structures with immobile PISC domains in which most of the COOH and NH(2)(+)SO(3)(-) groups are buried inside of the nanoparticles. The swelling of PISC domains and disentanglement of PISC chains after addition of a base are slow processes occurring on the time scale of days.
Τίτλος πηγής δημοσίευσης:	Langmuir
Τόμος/Κεφάλαιο:	24
Τεύχος:	20
Σελίδες:	12017-12025
Θεματική Κατηγορία:	[EL] Χημεία (Γενικά)[EN] Chemistry (General) [EL] Επιστήμη (Γενικά)[EN] Science (General) [EL] Τεχνολογία (Γενικά)[EN] Technology (General)
Λέξεις-Κλειδιά:	Chemistry, Multidisciplinary Chemistry, Physical Materials Science, Multidisciplinary
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© AMER CHEMICAL SOC
Ηλεκτρονική διεύθυνση περιοδικού (link) :	http://pubs.acs.org/langmuir
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο