Jump to main content
Jump to site search


Swelling behaviour of core–shell microgels in H2O, analysed by temperature-dependent FTIR spectroscopy

Author affiliations

Abstract

Stimuli-responsive microgels are colloidal particles and promising candidates for applications such as targeted drug delivery, matrices for catalysts, nanoactuators and smart surface coatings. To tailor the response, the architecture of microgels is of paramount importance with respect to these applications. Statistical copolymer microgels based on N-isopropylmethacrylamide (NiPMAM) and N-n-propylacrylamide (NnPAM) show a cooperative phase transition leading to a collapse at a specific temperature. Interestingly, some core–shell microgel particles reveal a linear response of the hydrodynamic radius with temperature. Such observations were made by photon correlation spectroscopy (PCS), which is limited to the diffusion properties dominated by the particle shell. In this work we investigate the molecular hydration within the network of microgels in H2O by temperature-dependent FTIR spectroscopy. The phase transition temperature was determined by the shift in frequency of the NH bending vibration in homopolymer and statistical copolymer microgels and the results are in accordance with those from PCS. In contrast, experiments on core–shell particles show a broadening and shift of the respective phase transition temperatures of the core and shell indicating an interaction of the core and shell polymers on a molecular level that extends far into the core. In conclusion, temperature-dependent FTIR spectroscopy is a convenient approach to elucidate the internal architecture of complex microgel particles in H2O.

Graphical abstract: Swelling behaviour of core–shell microgels in H2O, analysed by temperature-dependent FTIR spectroscopy

Back to tab navigation

Supplementary files

Publication details

The article was received on 19 Sep 2018, accepted on 02 Dec 2018 and first published on 03 Dec 2018


Article type: Paper
DOI: 10.1039/C8CP05911J
Citation: Phys. Chem. Chem. Phys., 2019, Advance Article
  •   Request permissions

    Swelling behaviour of core–shell microgels in H2O, analysed by temperature-dependent FTIR spectroscopy

    L. Wiehemeier, M. Cors, O. Wrede, J. Oberdisse, T. Hellweg and T. Kottke, Phys. Chem. Chem. Phys., 2019, Advance Article , DOI: 10.1039/C8CP05911J

Search articles by author

Spotlight

Advertisements