Soluble phthalocyanines as optical gas sensing materials

A novel soluble phthalocyanine compound, i.e zinc phthalocyanine (sulfonamide) has been synthesized by chemical substitution of zinc phthalocyanine and used to produce thin solid films by means of the spin coating technique. The chemical structure of the spin coated films has been investigated by FT-IR analysis. Atomic Force Microscopy (AFM) has been used to characterize the film morphology and to measure the film thickness. The spin coated films have been tested as optical sensing materials of volatile organic compounds such as methanol, ethanol and 2-propanol. The change of optical reflectance of the films upon exposure to alcohol-vapour-containing atmospheres has been measured versus alcohol concentration and exposure time. The films exhibit a fast and reproducible response, with a complete and fast recovery in methanol and ethanol-containing atmospheres, while diffusion-driven effects appear during exposure to 2-propanol. The response and sensitivity of the films to ethanol vapour is higher than to methanol and 2-propanol

Porphyrin-containing polyimide films deposited by high vacuum co-evaporation

Abstract Thin films of porphyrin-containing polyimide were produced by high vacuum co-evaporation of 4,4′-hexafluoroisopropylidene diphthalic anhydride (6FDA), 3,3′-diaminodiphenyl sulfone (DDS) and 5,10,15,20 meso-tetraphenyl porphyrin (TPP). The films were characterized by FT-IR analysis, optical absorption and emission spectroscopy. FT-IR analysis shows that the film matrix is comprised of only unreacted monomers. The conversion of monomers to polyamic acid and the following condensation to polyimide were studied by curing the samples at temperatures up to 240 °C. The amount of polyamic acid increases from room temperature to 120 °C, while at higher temperature it starts to condense to polyimide. Optical analysis shows that TPP is incorporated in the film matrix and its chemical state is determined by the interaction with the monomers, polyamic acid and polyimide. After curing the TPP molecules are finely dispersed in the polyimide matrix and their absorption and fluorescence properties are wholly preserved

Comparative results on collimation of the SPS beam of protons and Pb ions with bent crystals

New experiments on crystal assisted collimation have been carried out at the CERN SPS with stored beams of 120 GeV/. c protons and Pb ions. Bent silicon crystals of 2 mm long with about 170 μrad bend angle and a small residual torsion were used as primary collimators. In channeling conditions, the beam loss rate induced by inelastic interactions of particles with the crystal nuclei is minimal. The loss reduction was about 6 for protons and about 3 for Pb ions. Lower reduction value for Pb ions can be explained by their considerably larger ionization losses in the crystal. In one of the crystals, the measured fraction of the Pb ion beam halo deflected in channeling conditions was 74%, a value very close to that for protons. The intensity of the off-momentum halo leaking out from the collimation station was measured in the first high dispersion area downstream. The particle population in the shadow of the secondary collimator-absorber was considerably smaller in channeling conditions than for amorphous orientations of the crystal. The corresponding reduction was in the range of 2-5 for both protons and Pb ions.peer-reviewe

Observation of parametric X-rays produced by 400 GeV/c protons in bent crystals

Spectral maxima of parametric X-ray radiation (PXR) produced by 400 GeV/c protons in bent silicon crystals aligned with the beam have been observed in an experiment at the H8 external beam of the CERN SPS. The total yield of PXR photons was about 10-6 per proton. Agreement between calculations and the experimental data shows that the PXR kinematic theory is valid for bent crystals with sufficiently small curvature as used in the experiment. The intensity of PXR emitted from halo protons in a bent crystal used as a primary collimator in a circular accelerator may be considered as a possible tool to control its crystal structure, which is slowly damaged because of irradiation. The intensity distribution of PXR peaks depends on the crystal thickness intersected by the beam, which changes for different orientations of a crystal collimator. This dependence may be used to control crystal collimator alignment by analyzing PXR spectra produced by halo protons.peer-reviewe

Porphyrin Solid Films: Growing Processes, Physical Features, and Optical Properties

Porphyrin Solid Films: Growing Processes, Physical Features, and Optical Propertie

Soluble phthalocyanines as optical gas sensing materials

A novel soluble phthalocyanine compound, i.e zinc phthalocyanine (sulfonamide) has been synthesized by chemical substitution of zinc phthalocyanine and used to produce thin solid films by means of the spin coating technique. The chemical structure of the spin coated films has been investigated by FT-IR analysis. Atomic Force Microscopy (AFM) has been used to characterize the film morphology and to measure the film thickness. The spin coated films have been tested as optical sensing materials of volatile organic compounds such as methanol, ethanol and 2-propanol. The change of optical reflectance of the films upon exposure to alcohol-vapour-containing atmospheres has been measured versus alcohol concentration and exposure time. The films exhibit a fast and reproducible response, with a complete and fast recovery in methanol and ethanol-containing atmospheres, while diffusion-driven effects appear during exposure to 2-propanol. The response and sensitivity of the films to ethanol vapour is higher than to methanol and 2-propanol

Vapour Deposition Techniques for Producing Advanced Optical Materials

Vapour Deposition Techniques for Producing Advanced Optical Material

CONCENTRATORE SOLARE

L’invenzione riguarda un concentratore solare per sistemi fotovoltaici, il quale è provvisto di una superficie frontale d’ingresso(7), sostanzialmente piana e trasparente alla radiazione solare (100), di uno specchio concavo (1), posizionato dietro la superficie frontale d’ingresso (7) per ricevere, riflettere e concentrare la radiazione solare (100, e di un elemento ottico rifrattivo (2) presentante a sua volta una superficie rifrattiva (23) esposta alla radiazione solare riflessa dallo specchio concavo (1), una superficie riflettente (21) esposta alla radiazione solare rifratta dalla superficie rifrattiva (23), ed una guida di luce (22) avente la funzione di guidare la radiazione solare concentrata (101), riflessa dalla superficie riflettente (21), verso almeno un ricevitore fotovoltaico (5); l’elemento ottico rifrattivo (2) è realizzato in un unico blocco integrato e sono previsti elementi meccanici di allineamento (8) tra l’elemento ottico rifrattivo (2) stesso e lo specchio concavo (1) per assicurare la sovrapposizione e il parallelismo tra gli assi ottici dei due componenti

SISTEMA FOTOVOLTAICO

Un sistema fotovoltaico di illuminazione (1) che comprende: una prima lastra (3) comprendente una pluralità di sistemi fluorescenti e/o fosforescenti (6) ed accoppiata con un circuito di alimentazione comprendente almeno una cella (12) fotovoltaica accoppiata otticamente a detta prima lastra (3) per convertire in corrente elettrica, in uso, almeno una porzione (R1) di una radiazione (R) incidente la prima lastra (3); almeno un emettitore (16) di luce in comunicazione con il circuito (11) di alimentazione ed alimentato tramite la cella (12) fotovoltaica; una seconda lastra (4) accoppiata otticamente con l’emettitore (16) di luce che proietta, in uso, una radiazione (R3) luminosa all’interno della seconda lastra (4) stessa; la seconda lastra (4) presenta delle regioni (22) diffusive per estrarre dalla seconda lastra (4) almeno parte (23) della radiazione (R3) luminosa proiettata nella seconda lastra (4)