Molecular weight dependence of the shear rheology of poly(methyl methacrylate) Langmuir films : a comparison between two different rheometry techniques
The surface shear rheology of Langmuir monolayers of poly(methyl methacrylate) (PMMA) has been studied as a function of polymer concentration (Gamma) and molecular weight (N). Two different rheology techniques were used, one based on free damped oscillations of a ring with a sharp edge and the other...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 25(2009), 13 vom: 07. Juli, Seite 7393-400 |
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| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2009
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | The surface shear rheology of Langmuir monolayers of poly(methyl methacrylate) (PMMA) has been studied as a function of polymer concentration (Gamma) and molecular weight (N). Two different rheology techniques were used, one based on free damped oscillations of a ring with a sharp edge and the other based on a forced oscillation of a biconical disk. Both instruments were used in the oscillatory mode at comparable oscillation frequency and amplitude, which gave access to the viscoelastic shear modulus (S). The two instruments, working in different viscosity ranges, provide complementary and mutually compatible data. The results obtained for four PMMA samples of molecular weight between 8x10(3) and 2.7x10(5) g.mol(-1) show powerlike behavior as S approximately Gamma10 and S approximately N4. These strong dependences suggest a structural scenario based on the 2D percolation of the polymer pancakes |
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| Beschreibung: | Date Completed 14.09.2009 Date Revised 30.06.2009 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la9003033 |