Oxygen-Controlled Phase Segregation in Poly(N‑isopropylacrylamide)/Laponite Nanocomposite Hydrogels
Author
Summary, in English
The combination of nanoparticles and polymers into nanocomposite
gels has been shown to be a promising route to creating soft materials with new or improved properties. In the present work, we have made use of Laponite nanoparticles in combination with a poly(N-isopropylacrylamide) (PNIPAAM)polymer and describe a phenomenon taking place during the polymerization and gelling of this system. The presence of small amounts of oxygen in the process induces two distinctly separated phases, one polymer-rich and one polymer-deficient water−clay phase. Complex interactions among clay, oxygen, and the polymer are found to govern the behavior of these phases. It is also observed that the initial clay concentration can be used to control the volume fraction of the
polymer-deficient phase directly. The dynamics of the phase boundary is found to be dependent on water penetration and in general to exhibit non-Fickian behavior. An approach using video recording to monitor hydrogel swelling is also presented, and its advantages are addressed.
gels has been shown to be a promising route to creating soft materials with new or improved properties. In the present work, we have made use of Laponite nanoparticles in combination with a poly(N-isopropylacrylamide) (PNIPAAM)polymer and describe a phenomenon taking place during the polymerization and gelling of this system. The presence of small amounts of oxygen in the process induces two distinctly separated phases, one polymer-rich and one polymer-deficient water−clay phase. Complex interactions among clay, oxygen, and the polymer are found to govern the behavior of these phases. It is also observed that the initial clay concentration can be used to control the volume fraction of the
polymer-deficient phase directly. The dynamics of the phase boundary is found to be dependent on water penetration and in general to exhibit non-Fickian behavior. An approach using video recording to monitor hydrogel swelling is also presented, and its advantages are addressed.
Department/s
Publishing year
2013
Language
English
Pages
371-379
Publication/Series
Langmuir
Volume
29
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Physical Sciences
- Natural Sciences
Keywords
- Nanocomposite hydrogel
- clay
- Laponite
- PNIPAAM
- phase segregation
- small angle x-ray scattering
Status
Published
ISBN/ISSN/Other
- ISSN: 0743-7463