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By means of Monte Carlo simulations, we investigated the nucleation of polymers in frustrated spaces, i.e. in spaces where one dimension is much smaller (or larger) than other (or others). The obtained results were compared with those predicted by the Avrami equation. In the case of the spontaneous nucleation, we found similarities with respect to the ordinary crystallization case, but the Avrami index has smaller values. For instantaneous nucleation conditions, we observed to have two distinctive regimes: 3- dimensional crystallization at the beginning of the process, followed by a behavior which is similar with the one that occur in spaces with low dimensionalities. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the process of phase transformation in polymeric materials by imposing instantaneous nucleation conditions in the employed Monte Carlo type simulations. We calculated the overall crystallization rate constants and the Avrami indices for various simulation circumstances and the obtained results were equivalent with those predicted by the Avrami equation. The dependence of the crystallization rate constant on the growth velocity and concentration of the nuclei was also investigated and a comparison was made with the already existing theory. [ABSTRACT FROM AUTHOR]

Using Monte Carlo simulations, we investigated the sporadic nucleation of polymers and the results were compared with those obtained from the Avrami equation. From the simulation data, we calculated the overall crystallization rate constants and the Avrami indices. We considered isotropic growth of the nuclei in 1,2 and 3 dimension, the obtained results for the Avrami indices being in excellent agreement with theory and experiments. We also investigated the dependence of the overall crystallization rate constant on the crystallization velocity. [ABSTRACT FROM AUTHOR]

We report a Monte Carlo simulation based on the Lebwohl-Lasher model for characterizing the molecular director configuration in a nematic liquid crystal having a spherocylindrical particle immersed inside. We describe the molecular orientation and spatial behavior of the order parameter and we retrieve the presence of a disclination line with the shape of the Saturn ring defect. By applying an electric field, the order inside the simulation cell is considerably changed and we find that the plane of the disclination line is moved perpendicular to the field direction. As the intensity of the field is increaseed the disclination line eventually disappears, the order inside the cell becoming uniaxial. [ABSTRACT FROM AUTHOR]

By using Monte Carlo simulation we study the effect of an electric field on a negative dielectric anisotropy nematic liquid crystal presenting a spherocylindrical shaped particle located inside. We characterize the orientation of the nematic molecules inside the simulation box by means of the scalar and tensorial order parameter, field order parameter and radial order parameter, We also analyze how the system develops a Saturn ring type disclination line having the plane parallel with the direction of the applied electric field [ABSTRACT FROM AUTHOR]

For several years now the physics and chemistry of condensed matter attracts a great deal of attention, while also occupying an extremely important position in the research activity worldwide. Liquid crystalline materials, in particular, present numerous applications in the fields of science and technology. Since the development of the liquid crystals display (LCD) technology, a significant concern was devoted to the development and characterization of these fascinating mesophases. In the present paper we perform several Monte Carlo simulations, by using the Lebwohl-Lasher model, for investigating the molecular director configuration in a nematic liquid crystal cell having varying boundary anchoring conditions in asymmetric circumstances. For this geometry, we analyze the molecular spatial behaviour, while mapping the local order parameter distribution for a nematic phase temperature. We also characterize the shape of the transition regions which strongly depend on the distance to the boundaries, and analyze the neighboring spins behaviour throughout the bulk. Furthermore, by using the Müeller matrix approach, we simulated the transmission of light through the nematic cell at normal incidence under crossed polarizers condition. These investigations seek to enrich our scientific knowledge about the fascinating research topics homeotropic in condensed matter physics by exploring interesting issues related to the orientational and optical properties of liquid crystals in confined geometries. [ABSTRACT FROM AUTHOR]

Abstract: The fundamental understanding of the interaction between analytes and receptor surface in a sensing chain system is crucial in order to guide the design of appropriate materials for sensor devices. The interaction analyte–receptor generates a signal, which is amplified and correlated with analyte concentration. The platform is usually composed of a chemical sensing and a pattern-recognition system, thus providing sensitivity, specificity, and performances of such sensors. Each analyte captured by the sensing system produces a signature or “fingerprint”. Our goal is to develop computational approaches, in order to improve the design of polymer-receptor in biosensors. In order to investigate the influence of the architecture of the polymeric film used as a receptor, we have conducted simulation employing Monte Carlo ballistic deposition method for an analyte with four types of macromolecules: linear, two brushes configurations and star. The results of the simulations showed that the polymeric architectures play a crucial role in the time response, specificity, sensitivity, and stability of the biosensor. [Copyright &y& Elsevier]