Surface rippling induced by periodic instabilities on a polymer surface
Autori: Gnecco E., Pedraz P., Nita P., Dinelli F., Napolitano S., Pingue P.
Affiliazione autori: IMDEA Nanociencia, Campus Universitario de Cantoblanco, Calle Faraday 9, E-28049 Madrid, Spain; Institute of Physics, Maria Curie-Skłodowska University, pl. M. Curie-Skłodowskiej 1, 20-031 Lublin, Poland; INO-CNR-via Moruzzi 1, I-56124 Pisa, Italy; Laboratory of Polymer and Soft Matter Dynamics, Faculté des Sciences, Université Libre de Bruxelles, Boulevard du Triomphe CP 223, Bâtiment NO, B-1050 Bruxelles, Belgium; Laboratorio NEST-Scuola Normale Superiore, and Istituto Nanoscienze—CNR, Piazza San Silvestro 12, I-56127 Pisa, Italy
Abstract: When the shear stress on a compliant surface exceeds the yield strength of the material, a periodic wrinkle pattern is often observed. This phenomenon has been also recognized at the nanometer scale on polymers, metals, ionic crystals and semiconductors. In those cases, the mechanical stress can be efficiently provided by a sharp indenter elastically driven at constant velocity along the surface. Here we suggest that the formation of such surface ripples can be explained by the competition between the driving spring force and the plastic response of the substrate. In particular, we show how the ripples are expected to disappear when the indentation rate is below a critical value or, alternatively, when the sliding velocity or the lateral stiffness of the contact are too high. The model results are compared to atomic force microscopy experiments on a solvent-enriched polystyrene surface, where the rippling formation is enhanced at room temperature, compared to bulk melts. A similar approach could be employed to describe rippling phenomena on larger scales.
Giornale/Rivista: NEW JOURNAL OF PHYSICS
Volume: 17 Da Pagina: 032001-1 A: 032001-9
Maggiori informazioni: The Spanish Ministry of Economy and Competitiveness (Project No. MAT2012-38810) is gratefully acknowledged for financial support. This work is supported in part by COST Action MP1303.Parole chiavi: surface patterning; Prandtl-Tomlinson model; polystyrene; ripples; atomic force microscopyDOI: 10.1088/1367-2630/17/3/032001Citazioni: 14dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2022-06-26Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui