NMR analysis of Nile Blue (C. I. Basic Blue 12) and Thionine (C. I. 52000) in solution

The dyes Nile Blue (C. I. Basic Blue 12, NB) and Thionine (C. I. 52000, TH) were examined in both ionic and neutral forms in different solvents using NMR and UV-visible Spectroscopy to firmly establish the structures of the molecules and to assess the nature and extent of their aggregating characteristics. 1H and 13C NMR assignments and chemical shift data were used along with (for NB) nuclear Overhauser effect information enabling a structure for self-assembly to be proposed. In both cases these data were supplemented with variable temperature, dilution and diffusion-based experimental results using 1H NMR spectroscopy thereby enabling the extended aggregate structures to be assessed in terms of the relative strength of self-association and the extent to which extended aggregates could form. Full and detailed solution phase NMR analysis of such dyes, especially the two studied in this context, have either not been widely reported or have not been studied to the depth presented here. The data and their interpretation form an important addition to the analysis of this class of dye compounds and provide additional insight into the effects of self-assembly on the behaviour of such molecules in various solution-phase environments

Nemzeti érdekek az EU-ban. Az olasz európa-politika tanulságai, különös tekintettel az európai gazdasági kormányzásban betöltött szerepre = National Interests in the EU. Experiences of Italy’s European policy with special regard to its role in the European economic governance

A disszertáció a hazai és a nemzetközi szakirodalom elemzésén keresztül vizsgálja a nemzeti és az európai (közösségi) érdek viszonyát, ezek alakulását az integrációs folyamatban. Választ próbál találni arra, hogy mi a fő oka annak az utóbbi évtizedben egyre inkább erősödő jelenségnek, amely az EU nemzetek feletti jellegének visszaszorulásában, és ezzel párhuzamosan a közösségi szakpolitikák alakításakor a kormányközi logika érvényesülésének erősödésében összegezhető. Az elemzés során nem lehet eltekinteni az európai integráció társadalmi aspektusaitól, így ezek között kiemelten a projekttel való lakossági azonosulás, más szóval az egyébként sokdimenziós, tagállamonként és időben változó identitás problematikájától. A dolgozat kiemelten foglalkozik az olasz Európa-politika fejlődésével és érvényesülésével. Róma EU-politikájának elemzése már csak azért is érdekes feladat, mert Itália európai középhatalmi státuszából adódóan az a klasszikus közösségi-államközi, látszólag ellentétes „módszer” metszéspontjában található. Megnyilvánulási formái ennek megfelelően – a külső szemlélő számára akár bizonytalankodásnak hatóan - váltakozó hangsúllyal ötvözik a nemzetek feletti és a kormányközi stratégiát. Az olasz integrációs politika hagyományainak, általános geopolitikai-külpolitikai keretrendszerének, változásainak részletes elemzése elengedhetetlen az egyes szakpolitikák terén tanúsított olasz törekvések megértéséhez. (...

Development of colorimetric indicators based on Methylene Blue

This study largely focuses on the development of an oxygen indicating label for possible use in modified atmosphere packaging. The work presented here builds on a system developed by Mills et al., i.e. a UVA-light activated reversible oxygen indicator ink comprised of a nanoparticulate semiconducting photocatalyst (usually TiO₂), redox dye (usually methylene blue), sacrificial electron donor and an encapsulating polymer. This ink could be cast as a thin film activated by UV light which, upon its absorption by the photocatalyst, creates an electron-hole pair. The photogenerated holes oxidise the concomitant sacrificial electron donor while the photogenerated electrons reduce the redox dye. This results in a dramatic colour change (usually blue to colourless). A photobleached film thus remains colourless in the absence of oxygen but quickly regains its original blue colour if oxygen is reintroduced. However, this ink is water-soluble and not suitable for printing on common packaging materials; this problem is addressed in Chapters 3 and 5 where solvent-based alternative O2-sensitive inks are described. The development of a more photo-stable ink, activated by UVB rather then UVA light, is the subject of Chapter 4. Interesting observations made while working on the above indicators lead to development of a series of humidity and temperature indicators based on phenothiazine dyes (Chapter 6). Methylene Blue and urea within a supporting polymer makes an ink which casts as a pink opaque film which turns into transparent blue film after reaching a humidity threshold (>80% RH). In addition, a combination of a polymer (hydroxypropyl cellulose) and a phenothiazine dye cast as a film was found to change colour upon heating, which could then be reversed by exposing the film to a humid air stream. Potential uses of such indicators are discussed. Chapter 7 reports on the red coloured forms of Methylene Blue observed upon treatment with alkali and helps correct the literature associated with this effect. Publications resulting from this work are attached at the end of the thesis.This study largely focuses on the development of an oxygen indicating label for possible use in modified atmosphere packaging. The work presented here builds on a system developed by Mills et al., i.e. a UVA-light activated reversible oxygen indicator ink comprised of a nanoparticulate semiconducting photocatalyst (usually TiO₂), redox dye (usually methylene blue), sacrificial electron donor and an encapsulating polymer. This ink could be cast as a thin film activated by UV light which, upon its absorption by the photocatalyst, creates an electron-hole pair. The photogenerated holes oxidise the concomitant sacrificial electron donor while the photogenerated electrons reduce the redox dye. This results in a dramatic colour change (usually blue to colourless). A photobleached film thus remains colourless in the absence of oxygen but quickly regains its original blue colour if oxygen is reintroduced. However, this ink is water-soluble and not suitable for printing on common packaging materials; this problem is addressed in Chapters 3 and 5 where solvent-based alternative O2-sensitive inks are described. The development of a more photo-stable ink, activated by UVB rather then UVA light, is the subject of Chapter 4. Interesting observations made while working on the above indicators lead to development of a series of humidity and temperature indicators based on phenothiazine dyes (Chapter 6). Methylene Blue and urea within a supporting polymer makes an ink which casts as a pink opaque film which turns into transparent blue film after reaching a humidity threshold (>80% RH). In addition, a combination of a polymer (hydroxypropyl cellulose) and a phenothiazine dye cast as a film was found to change colour upon heating, which could then be reversed by exposing the film to a humid air stream. Potential uses of such indicators are discussed. Chapter 7 reports on the red coloured forms of Methylene Blue observed upon treatment with alkali and helps correct the literature associated with this effect. Publications resulting from this work are attached at the end of the thesis

Periodate – an alternative oxidant for testing potential water oxidation catalysts

Periodate is used as an alternative oxidant in the rapid screening of new potential water oxidation catalyst material powders.</p

Novel Temperature-activated humidity-sensitive optical sensor

Data underpinning the related paper - 'Novel temperature-activated, humidity-sensitive optical sensor', 31 Aug 2016, In : SENSORS AND ACTUATORS B-CHEMICAL