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Tesi etd-02192017-084218


Thesis type
Tesi di laurea magistrale
Author
FORCIERI, LEONARDO
URN
etd-02192017-084218
Title
STUDYING THE MOBILITY AT THE FREE INTERFACE THROUGH SURFACE PATTERN DECAY: EXPERIMENTS ON POLYMERIC FILMS
Struttura
FISICA
Corso di studi
FISICA
Commissione
relatore Prof. Capaccioli, Simone
relatore Dott. Cecchini, Marco
Parole chiave
  • nanofabrication
  • atomic-force microscopy
  • polymer
  • surface dynamics
  • glass transition
Data inizio appello
13/03/2017;
Consultabilità
parziale
Data di rilascio
13/03/2020
Riassunto analitico
We studied the time evolution of the dynamics of a (3 kg/mol molecular mass) polystyrene film patterned with a sinusoidal waveform with various wavelengths, spanning a range from μm to hundreds of nm.
The analysis of the pattern decay by white light interferometry and atomic-force microscopy techniques, allowed to determine that the viscous flow diffusion controls the surface flattening in a wide temperature range: from the glass transition temperature of the polymer to tens of degrees above it.
Moreover, we have simulated the polystyrene dynamics in the glassy state showing that the surface diffusion would overcome the viscous flow in a region some degrees below the glass transition temperature, determining a dynamic decoupling.
We have also developed a new procedure through the application of multiple techniques and with the use of different polymers to realize a quasi-sinusoidal molds (PFPE) with an aspect ratio lower than 0.1 and wavelengths spanning from 450 to 4500 nm, to use a master for the patterning of the polystyrene films.
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