Seminars are are currently organized by Dott. Lara Querciagrossa.
Seminars are held (except when explicitly indicated otherwise) in ex Biblioteca di Chimica Fisica, Dipartimento di Chimica Industriale "Toso Montanari", Viale Risorgimento,4, Bologna. Everybody is welcome!
Friday 18 November 2016
Prof. Hiroyuki Yoshida,
Division of Electrical, Electronic and Informational Engineering,
Osaka University, Japan
"Fabrication and control of colloidal particles in liquid crystals"
Abstract We present a new simulation method to calculate the free energy and the chemical potential of hard particle systems. The method relies on the introduction of a parameter dependent potential to smoothly transform between the hard particle system and the corresponding ideal gas. We applied the method to study the phase transition behavior of monodispersed infinitely thin square platelets. First, we equilibrated the square platelet system for different reduced pressures with a usual isobaric Monte Carlo (MC) simulation and obtained a reduced pressure-chemical potential plot. Then we introduce the parametrized potential to interpolate the system between theideal gas and the hard particles. After selecting the potential, we performed isochoric MC runs, ranging from the ideal gas to the hard particle limit.Through an iterative procedure, we compute the free energy and the chemical potential of the square platelet system by evaluating the volume of the phase space attributed to the hard particles, and then we find the coexistence pressure of the system. Our method provides an intuitive approach to investigate the phase transitions of hard particle systems.
15 May 2009 at 11.00, Aula 3: Dr. Adriana Pietropaolo, ETH Zurich, Computational Science, Lugano, Switzerland and Università di Catania, : "Free energy landscape using metadynamics: unravelling the different stability of the D-Trehalose bound to L and D-carnosine forming copper(II) dimers"
6 May 2009 at 11.00, Aula 3, Prof. Mikhail Osipov, Head of the Continuum Mechanics and Liquid Crystal Group, Department of Mathematics, University of Strathclyde, UK: "General formulae for Frank elastic constants. How are they derived?"
29 April 2009 at 15.00: Dr. Sameet K. Shriyan, Nanosoft Lab, Dept. of ECE, Drexel University, Philadelphia, PA, USA, "Improved electro-optical response of PDLC doped with oxidised multi-wall nanotubes"
29 April 2009 at 11.00, Dr. Otello M. Roscioni , Department of Chemistry, University of Southampton (UK), "A Close Look at Heterogeneous Catalysts, using Theoretical Simulations of Surface Species"
2009 at 15.00, Dr. Enrico
Da Como, Photonics and Optoelectronics Group, Department of Physics and
Ludwig-Maximilians-Universität, Munich (Germany), "Revisiting charge transfer excitons: the case of conjugated polymers mixed with fullerenes"
28 January 2009 at 15.00, Dr. Emel Kilit, Department of Physics, Middle East Technical University, Ankara, Turkey, "Analyzing properties close to the phase transitions in some liquid crystals"
Supramolecular Organization of Thiophene-based Oligomers".
21 November 2007 at 11.00: Dr. Antonio Pizzirusso, Dipartimento di Chimica Fisica e Inorganica, Università di Bologna: "Computer simulation of solutes in a nematic solvent".
26 October 2007 at 15.00: Dr. Antonio Monari, Dipartimento di Chimica Fisica e Inorganica, Università di Bologna: "High level computation on small systems: 1) Lithium Clusters and the 'no-pair' bonding. 2) The Precursor of Metal Insulator Transition in Li chains.".
20 September 2007 at 12.00: Dr. Domenico Summa, Dipartimento di Neuroscienze, Sez. Farmacologia, Università di Siena: "Protein-thiol substitution or protein dethiolation by sh/ss exchange Reactions: the albumin model".
20 July 2007 at 12.00: Dr. Saeedeh Shoarinejad, Department of Physics, Isfahan University (IR): " Guest-host interaction of some dye molecules dopant in liquid crystalline matrix".
13 July 2007 at 15.00: Dr. Kashma Rai, Department of Electrical and Computer Engineering, Drexel University, Philadelphia (US): Innovative Electro Optic Applications and Morphological Studies of Holographic Polymer Dispersed Liquid Crystals.
30 May 2007 at 15.00, Aula 2: Dr. Anke Hoffmann, Institut fuer Makromolekulare Chemie Albert-Ludwigs-Universitaet Freiburg: 2H NMR Studies on Phase Biaxiality in Side-Chain Liquid Crystalline Elastomers.
24 April 2007 at 10.30 : Dr. Francesca Costanzo, Dipartimento di Chimica Fisica e Inorganica, Università di Bologna: Dinamica molecolare ab initio applicata a molecole in soluzione e chemisorbite su superfici.
9 March 2007 at 15.00, Aula 2 : Dr. P. Marsal, Laboratory for Photochemistry & Spectroscopy, Chemistry Department, Katholieke Universiteit Leuven (BE): How a theoretical chemist can help a spectroscopist. Two experimental problems.
22 February 2007 at 11.00, Prof. M. Osipov, Department of Mathematics, University of Strathclyde, Glasgow (UK): Molecular models for SmA-Sm C phase transiton: de Vries behaviour and the role of biaxiality.
7 February 2007 at 11.00, Dr. Marco Giorgetti, Dipartimento di Chimica Fisica e Inorganica, Università di Bologna: Spettroscopia di Assorbimento di Raggi X come sonda strutturale: Introduzione ed Esempi.
The presentation focuses on the fabrication of nano-structures using lyotropic liquid crystals with discotic shaped molecules in which the orientation of the grapheme layers can be manipulated using surface anchoring techniques. It will also be shown how to create patterned arrays of nanotubes using a pen writable technique and some of the work at Brown University on continuous surface boundary conditions created through a holographic exposure process of linear photopolymerizable polymer (LPP) alignment layers.
(ii) the phenomenological Landau-de Gennes theory.
The first approach shows the existence of a weak subsurface deformation, while the anchoring strength resulting from the model is rather large.
The second approach, on the other hand, shows that a localized subsurface variation of the scalar order parameter can also induce a subsurface deformation and can result in an additional intrinsic contribution to the effective anchoring.