152 research outputs found

    Dipole Interactions and Electrical Polarity in Nanosystems -- the Clausius-Mossotti and Related Models

    Full text link
    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

    Full text link
    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

    No full text
    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

    Inverse opals for optical affinity biosensing

    No full text
    • …
    corecore