Title
Temperature- and pH-dependent aggregation behavior of hydrophilic dual-sensitive poly(2-oxazoline)s block copolymers as latent amphiphilic macromolecules
Date Issued
01 March 2017
Access level
metadata only access
Resource Type
journal article
Author(s)
Publisher(s)
Elsevier Ltd
Abstract
A variety of hydrophilic diblock and triblock copolymers of AB and ABA type with temperature-sensitive poly(2-isopropyl-2-oxazoline) blocks und pH-sensitive poly(2-carboxyethyl-2-oxazoline) blocks have been synthesized. The temperature- and pH-induced reversible phase transition renders the block copolymers as amphiphilic macromolecules and allows for defined aggregation through self-assembly following the packing parameter of amphiphilic macromolecules. Size, structure and arrangement of the individual block copolymer segments define the temperature and pH values of the transitions as well as the nature of the formed aggregates. DLS measurements were used to determine the transition temperatures at selected pH values in aqueous solution whereas AFM was used to visualize and characterize the formed aggregates adsorbed on Si wafer surfaces. In the case of vesicles formed by the diblock and triblock copolymers, double and monolayer membranes could be verified. The tendency of different states of organization of poly(2-isopropyl-2-oxazoline) blocks from crystalline to amorphous is assumed to be the cause for the different box-like structures determined on Si wafer surfaces.
Start page
623
End page
635
Volume
88
Language
English
OCDE Knowledge area
Electroquímica
Química analítica
Subjects
Scopus EID
2-s2.0-85007036279
Source
European Polymer Journal
ISSN of the container
00143057
Sponsor(s)
DAAD (individual grants and PPP Projekt-ID 57222461), FINCYT (research project PUCP-DGI-2032), Catholic University Peru (PUCP) as well as IPF Dresden are gratefully acknowledged for financially supporting the collaboration between Prof. Juan Rueda (PUPC) and IPF Dresden over the last years. Authors thank Mrs. Treppe for carrying out SEC measurements and analysis of SEC graphs.
Sources of information:
Directorio de Producción Científica
Scopus