0000000001101182
AUTHOR
V. Soria
Tribological properties of commercial optical disks estimated from nanoindentation and scratch techniques
Abstract The structure of optical disks is a complex superposition of several layers with different objectives. The most external layer is usually designed with a protective purpose. When the scratch of the substrate occurs, the optical properties of the device decrease inducing a deficiency in the storage or access of data. Nowadays, the latest commercial optical disks exhibit protective coatings made of polymeric materials (copolymers, and polymeric matrix composite materials). The efficiency of these layers depends on a combination of several mechanical properties like hardness and Young's modulus. In this work, a compositional and mechanical study was carried out on four commercial opti…
Stationary–mobile phase distribution coefficient for polystyrene standards
The measured shifts of the retention volume V R of polystyrene (PS) towards lower values in benzene–methanol (Bz–MeOH), and towards higher values in butanone–heptane (But–Hep) are in agreement with our theoretical model, in which both MeOH and But are adsorbed on Lichrospher. This paved way for us to model the chromatographic stationary (s)-phase as MeOH and the mobile (m)-phase as Bz–MeOH, and to calculate the distribution coefficients for PS. For But–Hep, the s-phase has been modeled as But, and the m-phase as But–Hep. A linear relation for the experimental equilibrium distribution P sm of PS is shown between the s- and m- phases in Bz–MeOH and But–Hep vs. the logarithm of the molecular m…