Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Effect of Hydrogen-Bonding Complexation on the Interfacial Behavior of Poly(isoprene)-b-Poly(ethylene oxide) and Poly(isoprene)-b-Poly(acrylic acid) Langmuir Monolayers
Δημιουργός/Συγγραφέας:	Xie, Dinghai Rezende, Camilla A. Liu, Guangming [EL] Πίσπας, Στέργιος[EN] Pispas, Stergios Zhang, Guangzhao Lee, Lay-Theng
Εκδότης:	American Chemical Society
Τόπος έκδοσης:	WASHINGTON
Ημερομηνία:	2009-01-22
Γλώσσα:	Αγγλικά
ISSN:	1520-6106
DOI:	10.1021/jp808821s
Περίληψη:	The effect of hydrogen-bonding complexation on the interfacial behavior of poly(isoprene)-b-poly(ethylene oxide) (PI-b-PEO) diblock copolymer at the air-water interface has been investigated by Langmuir balance and neutron reflectivity. PI-b-PEO forms Langmuir monolayers with PI as the anchoring block. Introduction of a second diblock, poly(isoprene)-b-poly(acrylic acid) (PI-b-PAA) yields PI-b-PEO/PI-b-PAA mixed layers with interfacial behavior that is pH-dependent. At pH 10.0 and 5.7, the compression (pi-A) isotherms exhibit three regions that are characteristic of PEO-type tethered layers, (i) a low-pressure 2-D "pancake" region (region I), (ii) a pseudoplateau where PEO segments desorb and are immerse in the subphase (region II), and (iii) a steep pressure rise region commonly considered as the "brush" regime (region III). At pH 2.5, on the other hand, the pi-A isotherm shows only two regions, (I) and (III). This novel behavior is attributed to hydrogen-bonding complexation between the undissociated carboxylic acids and the PEO, forming very compact layers. It appears that desorption of PEO segments is hindered as a consequence of this complexation. Furthermore, no brush-like structure is observed in region III of the isotherml; thus, the steep rise in surface pressure in this case arises primarily from interactions of the anchoring block. The hydrogen-bonded complex of PI-b-PEO/PI-b-PAA monolayers thus shows enhanced surface stability.
Τίτλος πηγής δημοσίευσης:	Journal of Physical Chemistry B
Τόμος/Κεφάλαιο:	113
Τεύχος:	3
Σελίδες:	739-744
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© AMER CHEMICAL SOC
Ηλεκτρονική διεύθυνση περιοδικού (link) :	http://www.pubs.acs.org/jpcb
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο