Nanowear of polystyrene surfaces: molecular entanglement and bundle formation

Anno: 2005

Autori: Dinelli F., Shipway P.H., Leggett G.J.

Affiliazione autori: Department of Chemistry, University of Manchester Institute of Science and Technology, PO Box 88, Manchester M60 1QD, United Kingdom; School of Mechanical, Materials and Manufacturing Engineering, University of Nottingham, Nottingham NG7 2RD, United Kingdom; CNR, Istituto per lo Studio di Materiali Nanostrutturati (ISMN), Sezione di Bologna, via P Gobetti 101, I-40129 Bologna, Italy; Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, Sheffield S3 7HF, United Kingdom

Abstract: Contact mode scanning force microscopy was employed to produce permanent deformation in polystyrene films of molecular weight ranging from 5 to 483 kg mol(-1). Operating in a regime of small loads and a low number of scan cycles, a variety of wear types was observed, including the formation of grooves and bundles. These differences could be explained in terms of the entanglement density at the film surface. For completely disentangled films, long parallel grooves formed at the lateral edges of the scanned area as a consequence of molecular displacement. In the central region, wide bundles formed after only a few passages. For fully entangled films, discontinuous ridges were immediately generated with a much reduced spacing. A transition in wear behaviour occurred when, for molecular weight between 13 and 64 kg mol-1, entanglement was not fully developed. In this regime, the entanglement degree could be evaluated via measuring the threshold load at which fragments of material were torn off from the surface. Nanowear induced in such a controlled fashion on unknown polymeric surfaces can yield important insights into surface molecular organization.

Giornale/Rivista: NANOTECHNOLOGY

Volume: 16 (6)      Da Pagina: 675  A: 682

Parole chiavi: SCANNING FORCE MICROSCOPY; THIN-FILMS; POLYMERS; WEAR; PLASMA; HEXANE
DOI: 10.1088/0957-4484/16/6/009

Citazioni: 32
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-05-12
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