Please use this identifier to cite or link to this item:
http://hdl.handle.net/2289/8672Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.author | Misra, Chandeshwar | - |
| dc.contributor.author | Kawale, Sonali Vasant | - |
| dc.contributor.author | Behera, Sanjay Kumar | - |
| dc.contributor.author | Bandyopadhyay, Ranjini | - |
| dc.date.accessioned | 2026-02-27T11:09:34Z | - |
| dc.date.available | 2026-02-27T11:09:34Z | - |
| dc.date.issued | 2024-10-18 | - |
| dc.identifier.citation | Physics of Fluids, 2024, Vol. 36, AR No. 103120 | en_US |
| dc.identifier.issn | 1089-7666 | - |
| dc.identifier.uri | http://hdl.handle.net/2289/8672 | - |
| dc.description | Open Access. | en_US |
| dc.description.abstract | We synthesized thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) colloidal microgel particles of different stiffnesses by controlling the concentration of a polar crosslinker in a precipitation polymerization synthesis method. When suspended in an aqueous medium, the particles collapsed by expelling water as the temperature was raised toward the volume phase transition temperature (VPTT) of ≈ 34 °C. We noted that the sizes of the stiffer particles, synthesized with higher crosslinker concentration, collapsed less abruptly. Using Fourier transform infrared spectroscopy, we observed enhanced particle dehydration with increasing temperature and decreasing particle stiffness. Oscillatory rheology experiments on dense aqueous PNIPAM suspensions, prepared at a fixed particle effective volume fraction ϕeff = 1.5 at 25°C, revealed that suspensions constituted by the stiffest particles are the most elastic over a broad temperature range. Above the VPTT, suspensions of particles of intermediate stiffnesses exhibited two-step yielding, a typical signature of fragile gel formation. Zeta potential measurements showed that PNIPAM particles of lower stiffnesses are rendered electrostatically unstable in aqueous suspension. Combining cryogenic scanning electron microscopy and rheology, we noted a glass–glass transition when the temperature of a dense suspension of stiff PNIPAM particles was raised across the VPTT. In contrast, suspensions of particles of the lowest stiffnesses showed a gel-viscoelastic liquid–gel transition during an identical temperature ramp experiment. Our study reveals that temperature-induced phase transformations in dense PNIPAM suspensions depend sensitively on the stiffness of the constituent particles and can be explained by considering amphiphilicity-driven morphological changes in the suspension microstructures. | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | Physics of Fluids | en_US |
| dc.relation.uri | ui.adsabs.harvard.edu/abs/2024PhFl...36j3120M/abstract | en_US |
| dc.relation.uri | https://doi.org/10.1063/5.0232833 | en_US |
| dc.rights | © 2024 Author(s) | en_US |
| dc.title | Effect of particle stiffness on microgel self-assembly and suspension phase behavior over a broad temperature range | en_US |
| dc.type | Article | en_US |
| Appears in Collections: | Research Papers (SCM) | |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 2024_Physics of Fluids_Vol 36_AR No 103120.pdf Restricted Access | Open Access | 2.67 MB | Adobe PDF | View/Open Request a copy |
Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.