Article (Scientific journals)
Aggregates formed by amphoteric diblock copolymers in water
Gohy, Jean-François; Creutz, Serge; Garcia, Myriam et al.
2000In Macromolecules, 33 (17), p. 6378-6387
Peer Reviewed verified by ORBi
 

Files


Full Text
Gohy JF 2000 Macromolecules 6378.pdf
Publisher postprint (486.54 kB)
Request a copy

All documents in ORBi are protected by a user license.

Send to



Details



Keywords :
self-assembly in solution; block copolymer
Abstract :
[en] The associating behavior of a series of monodisperse poly(2-(dimethylamino)ethyl methacrylate)-b-poly(methacrylic acid) (PDMAEMA-b-PMAA) ampholytic diblock copolymers has been studied in water in the dilute regime as a function of pH and salt concentration. Dynamic light scattering (DLS) has been used to monitor the association behavior and transmission electron microscopy (TEM) to visualize the morphology of the aggregates. At and around the isoelectric point (IEP) of the ampholytic diblocks, strong electrostatic interactions occur and lead to the formation of insoluble complexes between negatively and positively charged blocks. These electrostatic interactions can be screened by the addition of salt, which leads to the partial dissolution of the material, according to Debye screening. For samples containing a major PDMAEMA block, spherical micelles are observed below the IEP. These micelles consist of a PMAA core surrounded by a water-soluble protonated PDMAEMA corona. At and above the IEP, these samples are insoluble. Spherical micelles are also formed below the IEP for samples containing a minor PDMAEMA block. These copolymers are insoluble at and around the IEP, whereas solubility is observed above the IEP with formation of aggregates of remarkable morphologies, including hollow spheres and complex compartmentalized aggregates. This aggregation is most favorable at high pH, and it cannot be accounted for only by electrostatic interaction between oppositely charged blocks. Indeed, short-range hydrophobic interaction between uncharged PDMAEMA blocks seems to play a key role in the association process. This is emphasized by quaternized poly(2-(dimethylamino)ethyl methacrylate)-b-poly(methacrylic acid) ampholytic copolymers which are carrying a permanent positive charge on the aminated monomeric units and do not form these particular aggregates.
Research center :
Center for Education and Research on Macromolecules (CERM)
Disciplines :
Materials science & engineering
Chemistry
Author, co-author :
Gohy, Jean-François;  Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Creutz, Serge;  Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Garcia, Myriam;  Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Mahltig, Boris;  Max-Planck-Institut für Polymerforschung, Mainz, Germany
Stamm, Manfred;  Max-Planck-Institut für Polymerforschung, Mainz, Germany
Jérôme, Robert ;  Université de Liège - ULiège > Department of Chemistry > Center for Education and Research on Macromolecules (CERM)
Language :
English
Title :
Aggregates formed by amphoteric diblock copolymers in water
Publication date :
22 August 2000
Journal title :
Macromolecules
ISSN :
0024-9297
eISSN :
1520-5835
Publisher :
Amer Chemical Soc, Washington, United States - Washington
Volume :
33
Issue :
17
Pages :
6378-6387
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
BELSPO - SPP Politique scientifique - Service Public Fédéral de Programmation Politique scientifique
Available on ORBi :
since 14 May 2009

Statistics


Number of views
99 (7 by ULiège)
Number of downloads
0 (0 by ULiège)

Scopus citations®
 
172
Scopus citations®
without self-citations
156
OpenCitations
 
164

Bibliography


Similar publications



Contact ORBi