Previous session Next session Session VP05 - Postdeadline Poster Session I.
POSTER session, Thursday morning, March 25
Hallway, GWCC On the magneto-roton gap and the Laughlin state stability Alejandro Cabo Montes de Oca (Group of Theoretical Physics, Instituto de Cibernetica Matematica y Fisica , Calle E No 309 Esq a 15 Vedado, La Habana, Cuba) It is argued that the Girvin, Mac Donald and Platzman (GMP) evaluation of the magneto-roton spectrum, in spite of being a sensible estimate of the excitation spectrum around the real FQHE ground state, does not imply the variational stability of the Laughlin state. The supplementary corrections needed to produce a variational calculation around the 1/3 filling factor Laughlin state, are evaluated approximately. These preliminary results indicate the existence of lower lying states for a range of wavevector values. Chain Dynamics at Polystyrene-Poly(bromo-styrene) Interfaces Erin Jablonski, Balaji Narasimhan (Rutgers University) The aim of this research is to understand the mechanism of interdiffusion at polystyrene (PS) - poly(bromo-styrene) (PBS) interfaces. PS/PBS bilayers were prepared and annealed at temperatures between the Tgs of the individual polymers. The polymers were characterized by NMR, UV-Vis spectroscopy, GPC, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry. The interdiffusion across the welded bilayers was studied by using Rutherford backscattering spectroscopy (RBS). The bromine concentration profile across the interface was used to calculate the diffusion coefficient of PBS within PS. The RBS information is analyzed together with the fracture strength measurements available for this system and mechanisms for interdiffusion and adhesion are proposed. These mechanisms are compared to predictions from reptation theory, Rouse dynamics, and entropic barrier theory. | |
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