Influence of molecular weight on nanoscale modification of poly(methyl methacrylate) due to simultaneous mechanical and chemical stimulation
We report observations of poly(methyl methacrylate) films modified by the synergistic effect of solvent exposure and mechanical stress applied by the tip of an atomic force microscope (AFM). We show that these modifications are sensitive to polymer molecular weight as well as solvent strength and th...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1999. - 22(2006), 7 vom: 28. März, Seite 3320-5 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2006
|
| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. Polymethyl Methacrylate 9011-14-7 |
| Zusammenfassung: | We report observations of poly(methyl methacrylate) films modified by the synergistic effect of solvent exposure and mechanical stress applied by the tip of an atomic force microscope (AFM). We show that these modifications are sensitive to polymer molecular weight as well as solvent strength and the force applied by the tip. Small-area scanning often produces localized patches of raised material as well as depressed areas. The volume change associated with the depressed areas generally increases with increasing solvent strength, increasing applied normal force, and decreasing polymer molecular weight. In contrast, the volume change associated with the raised patches is greatest for 25-145K Mw films in 60 and 100% ethanol solutions. In each case, the normal force applied by the AFM tip must exceed a threshold to significantly modify the surface; this threshold is associated with an increase in lateral force applied by the AFM tip during small-area scanning. We attribute the raised patches to mechanically enhanced swelling due to diffusion of solvent into near-surface material. Permanent net volume loss, when observed, is attributed to localized polymer dissolution |
|---|---|
| Beschreibung: | Date Completed 06.06.2007 Date Revised 21.03.2006 published: Print Citation Status MEDLINE |
| ISSN: | 1520-5827 |