Process analytical approaches for the coil-to-globule transition of poly(N-isopropylacrylamide) in a concentrated aqueous suspension
- The coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM) microgel particles suspended in water has been investigated in situ as a function of heating and cooling rate with four optical process analytical technologies (PAT), sensitive to structural changes of the polymer. Photon Density Wave (PDW) spectroscopy, Focused Beam Reflectance Measurements (FBRM), turbidity measurements, and Particle Vision Microscope (PVM) measurements are found to be powerful tools for the monitoring of the temperature-dependent transition of such thermo-responsive polymers. These in-line technologies allow for monitoring of either the reduced scattering coefficient and the absorption coefficient, the chord length distribution, the reflected intensities, or the relative backscatter index via in-process imaging, respectively. Varying heating and cooling rates result in rate-dependent lower critical solution temperatures (LCST), with different impact of cooling and heating. Particularly, the data obtained by PDW spectroscopy can be used toThe coil-to-globule transition of poly(N-isopropylacrylamide) (PNIPAM) microgel particles suspended in water has been investigated in situ as a function of heating and cooling rate with four optical process analytical technologies (PAT), sensitive to structural changes of the polymer. Photon Density Wave (PDW) spectroscopy, Focused Beam Reflectance Measurements (FBRM), turbidity measurements, and Particle Vision Microscope (PVM) measurements are found to be powerful tools for the monitoring of the temperature-dependent transition of such thermo-responsive polymers. These in-line technologies allow for monitoring of either the reduced scattering coefficient and the absorption coefficient, the chord length distribution, the reflected intensities, or the relative backscatter index via in-process imaging, respectively. Varying heating and cooling rates result in rate-dependent lower critical solution temperatures (LCST), with different impact of cooling and heating. Particularly, the data obtained by PDW spectroscopy can be used to estimate the thermodynamic transition temperature of PNIPAM for infinitesimal heating or cooling rates. In addition, an inverse hysteresis and a reversible building of micrometer-sized agglomerates are observed for the PNIPAM transition process.…
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| Author details: | Peter Werner, Marvin MünzbergGND, Roland HassORCiDGND, Oliver ReichGND |
|---|---|
| URN: | urn:nbn:de:kobv:517-opus4-431162 |
| DOI: | https://doi.org/10.25932/publishup-43116 |
| ISSN: | 1866-8372 |
| Title of parent work (German): | Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe |
| Publication series (Volume number): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (944) |
| Publication type: | Postprint |
| Language: | English |
| Date of first publication: | 2020/06/04 |
| Publication year: | 2016 |
| Publishing institution: | Universität Potsdam |
| Release date: | 2020/06/04 |
| Tag: | Focused Beam Reflectance Measurement; Particle Vision Microscope measurement; Photon Density Wave spectroscopy; poly(N-isopropylacrylamide); rate-dependent lower critical solution temperature; turbidity measurement |
| Issue: | 944 |
| Number of pages: | 15 |
| First page: | 807 |
| Last Page: | 819 |
| Source: | Analytical and Bioanalytical Chemistry 409 (2017) 807–819 DOI: 10.1007/s00216-016-0050-7 |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
| Peer review: | Referiert |
| Publishing method: | Open Access |
| License (German): |  CC-BY - Namensnennung 4.0 International |
