INVESTIGADORES
TAGLIAZUCCHI Mario Eugenio
artículos
Título:
Dissipative self-assembly of particles interacting through time-oscillatory potentials
Autor/es:
MARIO TAGLIAZUCCHI; EMILY A. WEISS; IGAL SZLEIFER
Revista:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Editorial:
NATL ACAD SCIENCES
Referencias:
Lugar: Washington; Año: 2014 vol. 111 p. 9751 - 9756
ISSN:
0027-8424
Resumen:
Dissipative self-assembly is the emergence of order within a system due
to the continuous input of energy. This form of nonequilibrium
self-organization allows the creation of
structures that are inaccessible in equilibrium self-assembly. However,
design strategies
for dissipative self-assembly are limited
by a lack of fundamental understanding of the process. This work
proposes a novel
route for dissipative self-assembly via
the oscillation of interparticle potentials. It is demonstrated that in
the limit
of fast potential oscillations the
structure of the system is exactly described by an effective potential
that is the time
average of the oscillatory potential. This
effective potential depends on the shape of the oscillations and can
lead to effective
interactions that are physically
inaccessible in equilibrium. As a proof of concept, Brownian dynamics
simulations were performed
on a binary mixture of particles coated by
weak acids and weak bases under externally controlled oscillations of
pH. Dissipative
steady-state structures were formed when
the period of the pH oscillations was smaller than the diffusional
timescale of the
particles, whereas disordered oscillating
structures were observed for longer oscillation periods. Some of the
dissipative
structures (dimers, fibers, and
honeycombs) cannot be obtained in equilibrium (fixed pH) simulations for
the same system of
particles. The transition from dissipative
self-assembled structures for fast oscillations to disordered
oscillating structures
for slow oscillations is characterized by a
maximum in the energy dissipated per oscillation cycle. The generality
of the
concept is demonstrated in a second system
with oscillating particle sizes.