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Photochromic Polypropylene Filaments: Impacts of Mechanical Properties on Kinetic Behaviour

Periyasamy Aravin Prince, Viková Martina, Vik Michal

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 3 (135)

19--25

EN

Spiro [2H-indole-2,3’–[3H]naphth[2,1-b][1,4]oxazine],1,3-dihydro-1,3,3-trimethyl-6’–(1-piperidinyl) was incorporated onto polypropylene and photochromic polypropylene multifilaments produced through the mass coloration technique. Subsequently the polypropylene (PP) filaments were doped with a different concentration of photochromic pigment, and after producing the filaments different drawing ratios were applied. The photochromic colour build was found to be maximum with the highest concentration of dyes as well as with the lowest drawing ratio. Also the colour differences for L*, a*, b* and ΔE* were analysed with respect to the different concentrations and drawing ratios of the filament. The filaments generally showed good stability of photocoloration during the colour measurement till five cycles. The results for the optical density were reduced by increasing the fineness of the filament. In this experimental work, the impact of the drawing ratio on the optical and mechanical properties of these multifilaments were investigated.

PL

W pracy przedstawiono efekty wprowadzenia spiro [2H-indolo-2,3’ ‚– [3H] nafta [2,1-b][1,4] oksazyna], 1,3-dihydro-1,3,3-trimetylo-6’ – (1- piperydynylu) do polipropylenu i fotochromowych polipropylenowych multifilamentów wytwarzanych techniką masowego zabarwienia. Następnie włókna polipropylenowe (PP) domieszkowano różnym stężeniem pigmentu fotochromowego, a po wytworzeniu włókien zastosowano różne współczynniki rozciągania. Stwierdzono, że kolor fotochromowy jest maksymalny przy najwyższym stężeniu barwników, jak również przy najniższym stosunku rozciągania. Analizowano również różnice koloru dla L*, a*, b* i ΔE* w odniesieniu do różnych stężeń i współczynników rozciągania. Włókna na ogół wykazywały dobrą stabilność fotokoloracji podczas pomiaru barwy do pięciu cykli. Wyniki gęstości optycznej zmniejszono przez zwiększenie rozdrobnienia włókna. W pracy zbadano również wpływ współczynnika rozciągania na właściwości optyczne i mechaniczne włókien.

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New organic photochromic materials and selected applications

Żmija J., Małachowski M. J.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 41, nr 1-2

48-56

EN

Purpose: The aim of this work is to perform the review of the recent most important results of experimental and theoretical investigations connected with the photochromic materials and their selected applications. Design/methodology/approach: The recent achievements in the field of designing and preparation methods of organic photochromic materials and devices operating as tree-dimensional optical data storage. Findings: We pointed out the important role that play the photochromic effect in organic materials and which can be used as the above mentioned devices. Research limitations/implications: The main disadvantage of organic materials are reported to be to short their lives and weak resistivity to the moist but the improvements are advancing. Originality/value: Our review concerns the most recent findings in this area. We also show some recent examples of photochromic organic material application in 3D memory devices.

3

Notes on the Fluorescence and the Nature of the Photocoloured Form in Photochromic Azomethines

Knyazhansky M. I.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 4

795-806

EN

The analysis of the results obtained by recent investigations of photochromic azomethines (anils), including the author's data, shows that the path way for the photo-coloured product generation proceeds consecutively via (i) the S1 excited state of the NH structure (S1 NHflu), arising from the excited state intramolecular proton transfer OH→NH and responsible for the fluorescence with the anomalous Stokes shift (ASSflu); (ii) the ASSflu quenching TICT structure (S1 state) with the twisted "keto" ring (alfa = 90°) in the trans isomer (with respect to the C-N bond, beta = 0°); (iii) the unstable trans twisted post1TICT structure (alfa = 90°, beta = 0°) in the S 0 state, which is the immediate precursor of (iv) low-stability post2TICT cis structure twisted in the S0 state (alfa = 90°, beta asymptotic to 180°). The latter is responsible for the photochromism of anils and stabilized by steric interactions and rigid media.

4

Kinetics of photochemical processes n photochromic azobenzene derivatives. Effect of matrix and of the phase stability

Janus K., Matczyszyn K., Sworakowski J.

Materials Science

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2002

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Vol. 20, No. 3

45-55

EN

The contribution discusses the effect of environmental constraints on the kinetics of photochromic processes occurring in two groups of azobenzene derivatives: azobenzene-containing crown ethers dissolved in various polymer matrices, and para-disubstituted azobenzenes dissolved in liquid-crystalline matrices. In the azobenzene-containing crown ethers, the presence of the crown is expected to affect the isomerisation kinetics. The experiments demonstrated that the crown create constraints which modify the molecular structure, thus influencing the isomerisation kinetics as was indeed found in our experiments. In the shortest crown, the room-temperature rate constant of the thermal isomerisation is c.a. two orders of magnitude lower than the respective rate in the parent azobenzene. Measurements of the kinetics of isomerisation of photochromic 4-fluoro-4?-methoxyazobenzene dissolved in the liquid-crystalline pentylocyanobiphenyl (5CB) were carried out. Deviations from the expected Arrhenius behaviour were observed for the thermal cis-trans reaction near the phase transition temperature of 5CB (308 K). It was also found that the isomerisation reaction may trigger the nematic-to-isotropic phase transition at the temperature substantially lower than the thermodynamic transition temperature.

5

Współczesne postępy w wybranych aspektach chemii spiranów

Jamrozik J., Schab S.

Wiadomości Chemiczne

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1998

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[Z] 52, 3-4

269--281

EN

The chemistry of spiranes has been studied extensively from many points of view and has already been the subject of many papers. Generally the spiranes are not a new class of compounds in the chemical sense, but they retain the chemical properties of their parent moieties. Much interest has been focused on the bonding character of the central spiro-atom. This review describes all aspects of spirane chemistry that have been developed in the last few years:spiroconjugation, helical structure, conformational transmission, photochromism and biologically active spiranes. When two perpendicular p systems are joined by a common tetrahedral atom, it is postulated that electronic delocalization will produce important and characteristic effects in the electronic spectrum [10, 11] and in chemical reactivity [14, 15]. This special case of homoconjugation has been called spiroconjugation (Schemes 1, 2). The presence of hypochromism suggests that the dominant conformation of spiranes is helical (Schemes 4, 5), [20-23]. The effect of conformational transmission in the series of new spirane systems was studied with the aid of 1H-NMR spectra (Schemes 7, 8), [36-38]. The photochromic behaviour of spiropyrans is based on the reversibility between the colourless 'closed' spiropyran from and the coloured 'open' merocyanine dye via heterolytic cleavage of the spiro oxygen-carbon bond (Scheme 9), [47, 48]. The spiropyrans and related compounds (spirooxazines) continue to arise a strong interest in various fields such as: non-silver high resolution photography [45], optical devices and holographic systems [46]. Many representatives of spiranes have a useful biological activity (Schemes 10, 11), [49-55]. For example 1,7-dioxaspiro[5.5]undecane is the major component of the sex pheromone of the olive fruit fly [56]. The purpose of this article is to show a 'phenomenon' of the spiro-atom and to present the most representative examples.