Showing papers by "Ludvik Martinu published in 2002"
TL;DR: A simple method for considering optical dispersion in the synthesis of multiband rugate filter designs is proposed and model filters designed with this method were fabricated on glass and polycarbonate substrates.
Abstract: Inverse Fourier transform method has been commonly used for designing complex inhomogeneous optical coatings. Since it assumes dispersion-free optical constants, introducing real optical materials induces shifts in the position of reflectance bands in multiband inhomogeneous minus (rugate) filters. We propose a simple method for considering optical dispersion in the synthesis of multiband rugate filter designs. Model filters designed with this method were fabricated on glass and polycarbonate substrates by plasma-enhanced chemical vapor deposition of silicon oxynitrides and SiO2/TiO2 mixtures with precisely controlled composition gradients.
51 citations
TL;DR: In this paper, various polymer specimens (polyethylene, polypropylene, polyethylene terephthalate, and polyimide) were placed directly on an electrode which contains the sampling aperture into a quadrupole mass spectrometer.
Abstract: Surface modification of polymers by low-pressure plasmas has gained scientific and industrial importance for controlling adhesion of coatings, wettability, printability, bio-compatibility and other surface-related properties. However, more is to be learned about the complex interactions at the plasma-polymer interface. The present study is designed to investigate these plasma-polymer surface interactions by means of mass spectrometry. Various polymer specimens (polyethylene, polypropylene, polyethylene terephthalate, and polyimide) were placed directly on an electrode which contains the sampling aperture into a quadrupole mass spectrometer. We have identified various molecular fragments from these polymers, which were liberated by chain scissions provoked by various energetic plasma constituents, in particular, bombarding ions and vacuum ultraviolet (VUV) photons.
41 citations
Patent•
08 Mar 2002
TL;DR: In this article, a method of making a preformed hydrogel attach to a polymer backing comprising exposing a surface of the backing to an activated gas and depositing the preformed hydragel on the exposed surface of a polyamide backing was presented.
Abstract: The present invention relates to a method of making a preformed hydrogel attach to a polymer backing comprising exposing a surface of the backing to an activated gas and depositing the preformed hydrogel on the exposed surface of the backing, and hydrogel products so formed. This hydrogel product can be used as an active ingredient delivery device, a wound cover and a diagnostic tool. It advantageously replaces hydrogel products using chemicals as adhesive agents.
12 citations
01 Jan 2002
TL;DR: In this article, the dependence of the optical constants on the details of the sample preparation arises from variations in the microstructural characteristics of the samples, all of which will affect the calculations of the dielectric function of the metal, em.
Abstract: The characterization of the optical constants of metals is extensive and dates back many decades.1 Particular emphasis has been placed on gold, with calculations of the dielectric function performed using both photometric 2,3 (reflection and transmission) and ellipsometric 4–8 measurements. Depending on the type of sample being measured (thin film or bulk), the deposition method used, and the post-deposition annealing, slightly different optical constants have been determined. The dependence of the optical constants on the details of the sample preparation arises from variations in the microstructural characteristics of the samples. Different grain morphologies will affect the surface roughness, void content, strain-induced lattice deformation, and electron scattering, all of which will affect the calculations of the dielectric function of the metal, em.9