Effect of montmorillonite on the properties of thermosensitive poly(N-isopropylacrylamide) composite hydrogels
| Autor: | Isabella Peroni, Giorgio Ramorino, Fabio Bignotti, Maurizio Penco, Luciana Sartore |
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| Rok vydání: | 2004 |
| Předmět: |
Materials science
Polymers and Plastics Sodium chemistry.chemical_element stimuli-sensitive polymers complex mixtures chemistry.chemical_compound nanocomposites Materials Chemistry medicine Composite material hydrogels chemistry.chemical_classification Nanocomposite General Chemistry Polymer Surfaces Coatings and Films Montmorillonite chemistry Chemical engineering Ionic strength modulus Self-healing hydrogels Poly(N-isopropylacrylamide) Clay Swelling medicine.symptom |
| Zdroj: | Journal of Applied Polymer Science. 93:1964-1971 |
| ISSN: | 1097-4628 0021-8995 |
| Popis: | Thermosensitive composite hydrogels containing various amounts of sodium montmorillonite (NaMM) and poly(N-isopropylacrylamide) (pNIPAAm) were synthesized. Their equilibrium degree of swelling (DS) was measured in NaCl solutions of different ionic strength and at various temperatures. The DS decreased when increasing the clay content and no substantial shift in the phase transition temperature was noticed. The composite hydrogels investigated had a NaMM content ranging between 1.0 and 5.7 wt % (in 0.1M NaCl at 25°C). A considerable enhancement in the response to thermal stimuli was observed for NaMM contents >2–3 wt %. It is suggested that when the NaMM concentration approaches a critical value, the clay platelets can inhibit the formation of the hydrophobic skin layer that hinders shrinking in conventional pNIPAAm hydrogels. The effect of montmorillonite on the mechanical properties of the hydrogels was investigated by uniaxial compression tests, which showed that the modulus increases with the NaMM content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1964–1971, 2004 |
| Databáze: | OpenAIRE |
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