152 research outputs found
Dipole Interactions and Electrical Polarity in Nanosystems -- the Clausius-Mossotti and Related Models
Point polarizable molecules at fixed spatial positions have solvable
electrostatic properties in classical approximation, the most familiar being
the Clausius-Mossotti (CM) formula. This paper generalizes the model and
imagines various applications to nanosystems. The behavior is worked out for a
sequence of octahedral fragments of simple cubic crystals, and the crossover to
the bulk CM law is found. Some relations to fixed moment systems are discussed
and exploited. The one-dimensional dipole stack is introduced as an important
model system. The energy of interaction of parallel stacks is worked out, and
clarifies the diverse behavior found in different crystal structures. It also
suggests patterns of self-organization which polar molecules in solution might
adopt. A sum rule on the stack interaction is found and tested. Stability of
polarized states under thermal fluctuations is discussed, using the
one-dimensional domain wall as an example. Possible structures for polar hard
ellipsoids are considered. An idea is formulated for enhancing polarity of
nanosystems by intentionally adding metallic coatings.Comment: 18 pages (includes 6 embedded figures and 3 tables). New references,
and other small improvements. Scheduled for publication by J. Chem. Phys.,
Jan. 200
Modeling of graphite oxide
Based on density functional calculations, optimized structures of graphite
oxide are found for various coverage by oxygen and hydroxyl groups, as well as
their ratio corresponding to the minimum of total energy. The model proposed
describes well known experimental results. In particular, it explains why it is
so difficult to reduce the graphite oxide up to pure graphene. Evolution of the
electronic structure of graphite oxide with the coverage change is
investigated.Comment: 12 pages, 7 figures. Discussion about reduction to pure graphene and
several references added. Methodological part expanded. Accepted to J. Am.
Chem. So
Layer-by-layer self-assembly of metal nanoparticles on planar substrates : fabrication and properties
This chapter contains sections titled: Introduction Layer-by-layer Self-assembly from Preformed Building Blocks Functionalization of Nanoparticles Layer-by-layer Self-assembly of Metal Nanoparticles Alternate Polymer/Metal Particle Films Prepared by Salt Incubation into Polymer Multilayers Polyelectrolyte/Metal Particle System Diblock Copolymer/Metal Particle System Organization of Metal Nanoparticles on Planar Surfaces Electrostatic Self-organization Template-assisted Organization Properties of Metal Nanoparticle-containing Multilayers Optical Properties Electrical Properties Magnetic Properties Conclusion
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