Mixed micelles of oppositely charged poly(N‐isopropylacrylamide) diblock copolymers |
| |
| Authors: | Solmaz Bayati Karl‐Erik Bergquist Kaizheng Zhu Bo Nyström Jan Skov Pedersen Luciano Galantini Karin Schillén |
| |
| Institution: | 1. Division of Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden;2. Center for Analysis and Synthesis, Department of Chemistry, Lund University, Lund, Sweden;3. Department of Chemistry, University of Oslo, Blindern, Oslo, Norway;4. Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus C, Denmark;5. Department of Chemistry, “La Sapienza” University of Rome, Rome, Italy |
| |
| Abstract: | Mixed micelle formation between two oppositely charged diblock copolymers that have a common thermosensitive nonionic block of poly(N‐isopropylacrylamide) (PNIPAAM) has been studied. The block copolymer mixed solutions were investigated under equimolar charge conditions as a function of both temperature and total polymer concentrations by turbidimetry, differential scanning calorimetry, two‐dimensional proton nuclear magnetic nuclear Overhauser effect spectroscopy (2D 1H NMR NOESY), dynamic light scattering, and small angle X‐ray scattering measurements. Well‐defined and electroneutral cylindrical micelles were formed with a radius and a length of about 3 nm and 35 nm, respectively. In the micelles, the charged blocks built up a core, which was surrounded by a corona of PNIPAAM chains. The 2D 1H NMR NOESY experiments showed that a minor block mixing occurred between the core blocks and the PNIPAAM blocks. By approaching the lower critical solution temperature of PNIPAAM, the PNIPAAM chains collapsed, which induced aggregation of the micelles. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1457–1469 |
| |
| Keywords: | diblock copolymers oppositely charged poly(N‐isopropylacrylamide) micelles self‐organization |
|
|
