Kinetics of Irreversible Chain Adsorption
Caroline Housmans
Michele Sferrazza
Simone Napolitano
10.1021/ma500506r.s001
https://acs.figshare.com/articles/journal_contribution/Kinetics_of_Irreversible_Chain_Adsorption/2288551
Recent
experimental evidence showed a strong correlation between
the behavior of polymers under confinement and the presence of a layer
irreversibly adsorbed onto the supporting substrate, hinting at the
possibility to tailor the properties of ultrathin films by controlling
the adsorption kinetics. At the state of the art, however, the study
of physisorption of polymer melts is mainly limited to theory and
simulations. To overcome this gap, we present the results of an extensive
investigation of the kinetics of irreversible adsorption of entangled
melts of polystyrene onto silicon oxide. We show that the process
of chain pinning proceeds via a first order reaction mechanism, which
slows down at large surface coverage, and the adsorbed amount scales
with the predictions of reflected random walk. We propose an analytical
form of the time evolution of the thickness of the adsorbed layer
with two well-defined regimes: linear at short times and logarithmic
at longer times, separated by a temperature independent crossover
thickness and a molecular weight independent crossover time, in line
with simulations and theory.
2014-05-27 00:00:00
polymer
crossover time
adsorption kinetics
crossover thickness
ultrathin films
surface coverage
Irreversible Chain AdsorptionRecent
order reaction mechanism
amount scales
time evolution
simulation
silicon oxide