Аннотация
We investigate on the behaviour of a hydrophobic homopolymer in aqueous
solution by a simplified 2-dimensional model, defined on a triangular lattice.
The solvent model is of the Mercedes Benz type, and has
been previously shown to account for most thermodynamic anomalies
of pure water 1 and of hydrophobic solvation for monomeric solutes 2.
The polymer is modelled as a noninteracting self-avoiding walk on the same
lattice.
We perform equilibrium Monte Carlo simulations and work out a generalised
first order approximation, comparing the two approaches.
The model predicts low-temperature-induced swelling 3, i.e., an expansion of
the collapsed polymer globule, upon decreasing temperature.
Such an effect has been observed experimentally in thermoreversible
homopolymers (such as PNIPAM), and displays some analogies to the cold
unfolding of globular proteins.
We focus our attention on phenomena occurring at the water-polymer
interface, pointing out the relationship with the solvent anomalous
properties.
1) C. Buzano, E. De Stefanis, A. Pelizzola, and M. Pretti, Phys. Rev. E
69, 061502 (2004)\\
2) C. Buzano, E. De Stefanis, and M. Pretti, Phys. Rev. E 71, 051502 (2005)\\
3) C. Buzano, E. De Stefanis, and M. Pretti, J. Chem. Phys. 126,
074904 (2007)
Линки и ресурсы
тэги