Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear
The phase transition of nanocomposite hydrogels made of N-isopropylacrylamide (NIPAm) and clay (Laponite<sup>®</sup> XLS) was investigated under mechanical shear influencing the gelation. The hydrogels were synthesized by free radical polymerization. For the processing of cross-linked ge...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-04-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/11/5/462 |
| _version_ | 1797569405955080192 |
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| author | Katinka Kohl |
| author_facet | Katinka Kohl |
| author_sort | Katinka Kohl |
| collection | DOAJ |
| description | The phase transition of nanocomposite hydrogels made of N-isopropylacrylamide (NIPAm) and clay (Laponite<sup>®</sup> XLS) was investigated under mechanical shear influencing the gelation. The hydrogels were synthesized by free radical polymerization. For the processing of cross-linked gels, the phase transition (liquid–solid) and its dependence on mechanical stress are of paramount importance. On the one hand, the determination of the gel point (<i>tg</i>) is possible with rheometry and, on the other hand, with dynamic light scattering (DLS). With rotational rheometry, by identifying the abrupt increase of viscosity, the gel point is evaluated. The DSL is an alternative method to rheometry, to investigate hydrogels under the action of the shear flow, to make results comparable to the rheometric investigations, with and without shear. Experimental parameters were chosen based on preparatory work to obtain comparable results regarding the determination of the gel point of a radically polymerized NIPAm hydrogel. |
| first_indexed | 2024-03-10T20:10:19Z |
| format | Article |
| id | doaj.art-3f1dff10317a40c298be89ccca19111d |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T20:10:19Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-3f1dff10317a40c298be89ccca19111d2023-11-19T22:57:38ZengMDPI AGMicromachines2072-666X2020-04-0111546210.3390/mi11050462Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical ShearKatinka Kohl0Chair of Magnetofluiddynamics, Measuring and Automation Technology, Technische Universität Dresden, 01069 Dresden, GermanyThe phase transition of nanocomposite hydrogels made of N-isopropylacrylamide (NIPAm) and clay (Laponite<sup>®</sup> XLS) was investigated under mechanical shear influencing the gelation. The hydrogels were synthesized by free radical polymerization. For the processing of cross-linked gels, the phase transition (liquid–solid) and its dependence on mechanical stress are of paramount importance. On the one hand, the determination of the gel point (<i>tg</i>) is possible with rheometry and, on the other hand, with dynamic light scattering (DLS). With rotational rheometry, by identifying the abrupt increase of viscosity, the gel point is evaluated. The DSL is an alternative method to rheometry, to investigate hydrogels under the action of the shear flow, to make results comparable to the rheometric investigations, with and without shear. Experimental parameters were chosen based on preparatory work to obtain comparable results regarding the determination of the gel point of a radically polymerized NIPAm hydrogel.https://www.mdpi.com/2072-666X/11/5/462rheometrydynamic light scattering (DLS)hydrogelgel pointmechanical shear |
| spellingShingle | Katinka Kohl Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear Micromachines rheometry dynamic light scattering (DLS) hydrogel gel point mechanical shear |
| title | Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear |
| title_full | Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear |
| title_fullStr | Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear |
| title_full_unstemmed | Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear |
| title_short | Comparison of Dynamic Light Scattering and Rheometrical Methods to Determine the Gel Point of a Radically Polymerized Hydrogel under Mechanical Shear |
| title_sort | comparison of dynamic light scattering and rheometrical methods to determine the gel point of a radically polymerized hydrogel under mechanical shear |
| topic | rheometry dynamic light scattering (DLS) hydrogel gel point mechanical shear |
| url | https://www.mdpi.com/2072-666X/11/5/462 |
| work_keys_str_mv | AT katinkakohl comparisonofdynamiclightscatteringandrheometricalmethodstodeterminethegelpointofaradicallypolymerizedhydrogelundermechanicalshear |