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Metal halide perovskites are emerging as promising candidate materials for light-emitting diodes (LEDs) due to their high luminescence, color purity, tunable bandgaps, and solution processabilities...

Zinc phosphate films doped with Ce3+, Tb3+, Mn2+, Ce3+/Tb3+ and Ce3+/Tb3+/Mn2+ were deposited at 500 °C by the ultrasonic spray pyrolysis technique. Blue emission with color purity of 89.8% is generated from the Ce3+-singly doped film upon 280 nm excitation. The Mn2+-singly doped film emits neutral white light of 4896 K upon 410 nm excitation. The Tb3+-singly doped film excited at 377 nm emits in the green region. Yellowish-green emission is achieved by codoping with Ce3+ and Tb3+ upon Ce3+ excitation at 280 nm, such that Tb3+ is sensitized by Ce3+ through a non-radiative energy transfer with an efficiency of up to 25%. Yellow white emission of 2810 K can be generated from the film triply doped with Ce3+, Tb3+ and Mn2+ upon 280 nm excitation. Tb3+ and Mn2+ being sensitized by Ce3+ through a non-radiative energy transfer with an efficiency of 29%. The energy transfer from Ce3+ to Tb3+ and Mn2+, resulting in yellow white emission, as well the neutral white emission from the Mn2+-singly doped film, make the Mn2+ and Ce3+/Tb3+/Mn2+-doped zinc phosphate films versatile materials that could contribute to the design of efficient UV-blue LED pumped white phosphors.

Summary Near-infrared (NIR) emission is useful for numerous practical applications, such as communication, biomedical sensors, night vision, etc., which encourages researchers to develop materials and devices for the realization of efficient NIR organic light-emitting devices. Recently, the emerging organic thermally activated delayed fluorescence (TADF) emitters have attracted wide attention because of the full utilization of electron-generated excitons, which is crucial for achieving high device efficiency. Up to now, the TADF emitters have shown their potential in the deep red/NIR region. Considering the color purity and efficiency, however, the development of NIR TADF emitters still lags behind RGB TADF emitters, indicating that there is still much room to improve their performance. In this regard, this perspective mainly summarizes the past progress of molecular design on constructing TADF NIR emitters. We hope this perspective could provide a new vista in developing NIR materials and enlighten breakthroughs in both fundamental research and applications., Graphical Abstract, Organic Chemistry; Optical Materials; Photonics

This article studies two main ways of gamut expansion: improving the color purity of the primary color and increasing the number of primary colors. A program for the gamut coverage of the multi- primary color display system is written. The color coordinates of the laser TV developed by ourselves are measured and the actual value of color gamut is calculated. The test data verifies the simulation result.

It is known that the vegetable concentrates' composition includes dietary fibers, micro-elements, color-forming substances, which can be successfully used as a substitute for the main substance in a formulation. This paper reports the development of a technique to process vegetables into vegetable semi-finished products, the formulations of culinary meals based on vegetable concentrates, as well as the techniques of their heat treatment using electrocontact heating (ECH). A technique to process vegetables into vegetable semi-finished products using carrot as an example implies the separation of raw materials into juice and pomace followed by separate processing of each component. Depending on the technological tasks, it is possible to obtain a vegetable concentrate by mixing juice and dried pomace. The colorimetric quality assessment has helped establish the parameters for juice and pomace processing. A carrot-based concentrate has been studied in terms of the content of the dried pomace. It was established that adding it improves the quality of the product, namely the brightness and color purity become better. It has been proposed to use carrot pomace in the formulations for different culinary meals provided the heat treatment process is intensified by combining convective heating and ECH. Carrot pomace was used in formulations for several culinary meals (rice pudding, millet balls, as well as unleavened pastry). The combined thermal treatment of experimental products involving ECH provided several advantages in terms of the technological indicators, namely: the duration of heat treatment decreases by 20...40%, the output increases by 10...20%, and energy consumption decreases by 23...32%, which is an argument for its application. Based on the organoleptic assessment, it was noted that, in addition to the taste inherent in these products, the resulting products acquired a kind of pleasant taste of carrot, the increased juiciness and tenderness, which can attract the consumer

The glory is a small yet eye-catching and colorful optical phenomenon that can be viewed best from an airplane or elevated position above a sun-illuminated cloud. The glory is a back-scattering phenomenon that consists of colored rings centered on the anti-solar or shadow point. Its color purity and the size of its rings both contain information about the size distribution of cloud particles doing the scattering. Glories can be particularly fun to observe when your airplane is just entering or exiting a cloud layer, so that the geometric shadow of the airplane rapidly changes size while the constant-angle glory remains relatively unchanged. Cloudbows are essentially whitened versions of the rainbow, with colors removed because of the large degree of spectral overlap resulting from the cloud droplets being much smaller than rain drops. Tips will be given for understanding where and when to look to see and understand optical glories. Numerous photographs are shown to explain what to look for when you are flying and want to see a glory or cloudbow.

Mechanoluminescence (ML) materials are attracting increasing interest owing to promising applications in various areas. However, to date, it remains a major challenge to develop a precise and universal route to achieving organic ML materials. Herein, we show that ML can be easily realized in organic piezophotonic host-guest crystals, under conditions in which neither the host nor the guest is ML-active. The experimental and theoretical results reveal that excitons of the host generated by piezoelectricity can be harvested effectively by the guest for light emission, owing to the restraint of intersystem crossing process. Moreover, different host-guest crystals are constructed, wherein the emission color, intensity, color purity, and emission duration of ML can be manipulated. This work deepens our understanding of organic ML generation in piezophotonic host-guest crystals and provides an inspiring principle to design more organic ML materials.

In this study, CdSe/ZnS core-shell quantum dots (QDs) with various dimensions were used as the color conversion materials. QDs with dimensions of 3 nm and 5 nm were excited by gallium nitride (GaN)-based blue micro-light-emitting diodes (micro-LEDs) with a size of 30 &mu, m &times, 30 &mu, m to respectively form the green and red lights. The hybrid Bragg reflector (HBR) with high reflectivity at the regions of the blue, green, and red lights was fabricated on the bottom side of the micro-LEDs to reflect the downward light. This could enhance the intensity of the green and red lights for the green and red QDs/micro-LEDs to 11% and 10%. The distributed Bragg reflector (DBR) was fabricated on the QDs color conversion layers to reflect the non-absorbed blue light that was not absorbed by the QDs, which could increase the probability of the QDs excited by the reflected blue light. The blue light absorption material was deposited on the DBR to absorb the blue light that escaped from the DBR, which could enhance the color purity of the resulting green and red QDs/micro-LEDs to 90.9% and 90.3%, respectively.

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів, Державний вищий навчальний заклад "Український державний хіміко-технологічний університет", Національний технічний університет "Харківський політехнічний інститут", Харків, 2020. Дисертацію присвячено розвитку наукових основ технології екологічно безпечних захисно-декоративних склоемалевих покриттів широкої колірної гами по сталі і кольоровим металам, а також принципів регулювання та прогнозування їх колірних характеристик. Внаслідок проведення дослідження за темою дисертаційної роботи одержані такі наукові результати: - науково обгрунтовано та експериментально доведено, що отримання на кольорових металах емалевих покриттів, які не вміщують Плюмбум, можливе на основі стекол системи Na₂O–BaO–B₂O₃–SiO₂; за комплексом визначених властивостей та здатності утворювати найбільш якісні покриття на мідній основі виділена область базової системи, мол.%: Na₂O – 24,2–40,5; ВаО – 5,0–10,0; B₂O₃ – 15,2–30,5; SiO₂ – 24,0–53,5, яка у зрівнянні з межами цих компонентів в відомих складах безплюмбатних емалей характеризується збільшеним в 2 рази вмістом B₂O₃ і відносно невеликим вмістом SiO₂; - встановлені основні тенденції зміни колірного тону стекол системи Na₂O–BaO–B₂O₃–SiO₂, які суттєво відрізняються за хімічним складом та забарвлені іонними барвниками, з огляду на розташування максимумів ІЧ-спектрів стекол та їх кислотно-основні властивості; останні оцінювались двома розрахунковими структурними параметрами: fSi – ступінь зв’язності кремнекисневого каркасу і Ψв – орієнтовний показник координаційного стану Бору в структурі скла. Доведено, що між колірним тоном λ та Ψв існує значний кореляційний зв'язок для стекол, забарвлених CuO r*=−0,83 і CoO r*=−0,87 та слабкий – для стекол, забарвлених K₂Cr₂O₇ – r*=0,5; - виявлені закономірності забарвлення одної скломатриці і емалевого покриття на її основі в системі R₂O–ВаО–ZnO–Al₂O₃–В₂О₃–TiO₂–SiO₂ рядом іонними барвників. Незалежно від вмісту барвників, вони надають однаковий колірний тон як стеклам, так і покриттям на основі цих стекол, а саме: CuO (1,0–3,0 мас.%) λ=489–494 нм (синьо-зелений), Fe₂O₃ (0,5–2 мас.%) λ=575–585 нм (жовтий), K₂Cr₂O₇ (0,5–2,0 мас.%) λ=570–576 нм (жовто-зелений), CoO (0,5–1,0 мас.%) λ=441–463 нм (синьо-фіолетовий), NiO (0,5–1,0 мас.%) λскла=559′–571′ нм, λпокриттів=598–629 нм (коричневий). Доказано, що за ступенем інтенсивності забарвлення стекол та покриттів на їх основі барвники розташовуються в наступній послідовності: CoO > NiO > CuO > K₂Cr₂O₇ > Fe₂O₃; - вперше встановлений механізм глушіння прозорого матричного емалевого скла в системі R₂O–ВаО–ZnO–TiO₂–Al₂O₃–В₂О₃–TiO₂–SiO₂ при введені МоО3, в результаті якого виникає явище опалесценції, а саме: за рахунок дифракції при розповсюдженні хвиль в мікронеоднорідному середовищі, в якому розмір часток молібден(VI) оксиду (0,05–0,15 мкм) менше довжини хвиль білого світла; - вперше встановлена залежність коефіцієнта дифузного відбиття емалевих покриттів від хімічного складу емалевих фрит, яка отримана обробкою експериментальної вибірки 471 складу покривних емалевих фрит методом множинного кореляційного аналізу і представлена у вигляді математичної моделі, що дозволяє розрахувати хімічний склад покривних емалей із заданим КДВ; коефіцієнт кореляції між експериментальними і розрахунковими значеннями – 0,98; - використовуючи ідею про введенні в будь-який матеріал (скло, пігмент, ситал, метал) певних компонентів в незначній кількості для модифікації його властивостей, вперше виявлено наступне: «малий додаток» Fe₂O₃ у кількості 0,25 мас.% в складі безплюмбатних емалевих стекол на основі базової системи Na₂O–BaO–B₂O₃–SiO₂ і 1 мас.% в складі безфлуористих склоемалей на основі базової системи Na₂O–B₂O₃–SiO₂ активізує процеси лікваційного розшарування скла, що дозволяє збільшити в 1,5–2,5 рази інтенсивність глушіння покриттів, а також покращити оптико-колірні характеристики пігментнозабарвлених склопокриттів, зокрема, червоного кольору. «Малий додаток» ZrO₂ у кількості до 1 мас.% в складі малофлуористої титанової емалі сприяє активному виділенню анатазу в покритті під час випалу та покращенню його оптичних характеристик; - за допомогою розробленої спеціальної комп’ютерної програми COLOUR GLASS, яка автоматично розраховує координати кольорності x y, колірний тон λ, чистоту кольору Р та наносить колірні характеристики матеріалів на графік МКО, вперше доказано, що за картиною розташування точок кольору, по-перше, можна робити прогнози відносно рівноваги, яка утворюється між іонними забарвлюючими комплексами під час варки скла, по-друге, про колористичні можливості суміши пігментів - вперше в області технологій, які потребують підвищених температур, встановлені залежності координат кольору емалевих покриттів від складу суміші пігментів у вигляді поліноміальних математичних моделей, що дозволило вирішити складну матеріалознавчу колористичну проблему знаходження співвідношення пігментів для відтворення кольору зразка із заданими колірними характеристиками. Практичне значення отриманих результатів: - розроблено склади емалевих стекол для кольорових металів, які не містять Плюмбуму – одного із самих шкідливих для навколишнього середовища елемента, запропоновано основи технології одержання виробів з їх використанням. Нові емалі широкої палітри кольорів, різного ступеню прозорості створено на основі матричної прозорої емалі. Вони характеризуються однаковим інтервалом випалу 780–820 °С, у зв’язку з чим спрощується технологія отримання художніх і ювелірних виробів. Емалі пройшли випробування та рекомендовані до впровадження у виробництво з виготовлення художніх виробів в майстерні, що знаходиться в структурі Музею українського живопису (м. Дніпро), а також на підприємстві з виготовлення ювелірних виробів, компанія "Diadema", м. Вінниця. Палітра емалевих покриттів та вироби з них представлені під час доповіді на 24 Міжнародному Конгресі емальєрів в м. Чикаго у 2018 р. Згідно міжнародного договору між ДВНЗ УДХТУ та компанією "Richemont International SA Varinor SA" м. Делемонт, Щвейцарія, виготовлено і передано замовнику емалеві стекла у вигляді порошку і емальовані мідні зразки; - створено каталог зразків кольорів, в якому представлено склооснови, кількість барвників, глушників, відновників та оптико-колірні характеристики емалевих покриттів, що не містять Плюмбум. Назву кольорів встановлювали у відповідності із назвою кольорів системи RAL. Палітра розроблених емалей ювелірного та художнього призначення включає 54 кольори: жовто-червоні, синьо-зелені, оливково-гірчичні, пастельні та коричнево-чорні; - розроблено склади малофлуористих білих і світлозабарвлених титанових емалей, безфлуористої склооснови для отримання яскравозабарвлених емалевих покриттів пігментним способом, які випробувані в виробничих умовах ТОВ «Новомосковський посуд» і рекомендовані до серійного впровадження на заводах з випуску емальованих виробів господарчо-побутового призначення. Технологічні особливості виробництва запропонованих емалей дозволяють здійснювати високотемпературні операції варки емалей на 100 °С, а випалу покриттів – на 30–50 °С нижче відомих, що в епоху тотальної економії топливно-енергетичних ресурсів дуже актуально. Малофлуористі світлозабарвлені кремова і сіро-блакитна емалі впроваджені на ТОВ "Новомосковський посуд"; - вперше для технології емалевих покриттів на сталі розроблено метод колірного моделювання, завдяки якому побудовано колірний трикутник-номограму для виробничої склооснови і пігментів жовтого, червоного, синього, за допомогою якого задається необхідний колір і розраховується необхідне співвідношення пігментів. Метод колірного моделювання є універсальним і може бути застосованим до широкого асортименту силікатних матеріалів: глазуровані покриття на керамічній основі, кольорові будівельні матеріали та інші. У вступі обґрунтовано актуальність теми дисертації, сформульовано головну мету та завдання роботи, представлено наукову новизну та практичну цінність одержаних результатів. В першому розділі наведено аналіз патентної та науково-технічної літератури, що стосується отримання екологічно безпечних емалей широкої колірної гами, сучасного стану виробництва кольорових емалей та контролю їх колірних показників, механізмів забарвлення скла та емалей і факторів, що впливають на формування кольору. У другому розділі надано основні поняття та визначення, які використовуються в роботі, а також методики дослідження фізико-хімічних властивостей і структури стекол, покриттів та їх колірні характеристики. В третьому розділі представлено дослідження з розробки екологічно безпечних емалей для міді та прогнозування їх колірних характеристик. В четвертому розділі представлено результати досліджень з розробки легкоплавкої титанової емалі, яка відповідала б вимогам діючих стандартів та випалювалась в ресурсо- та енергозберігаючих умовах виробництва та була максимально екологічно безпечною для навколишнього середовища. П'ятий розділ присвячений дослідженням з розробки складів емалевих фрит, що не вміщують Флуор, які використовуються для отримання яскравозабарвлених емалевих покриттів для виробів господарчо-побутового призначення. В шостому розділі представлені результати розробки методу колірного моделювання. Відтворити, а тим більше спрогнозувати колір із заданими колірними характеристиками – надзвичайно складна багатопланова матеріалознавча проблема, навіть якщо відома рецептура скла і покриття, режими їх варки та випалу. В сьомому розділі надано результати промислової апробації, реалізації та впровадження отриманих матеріалів. Thesis for a Doctor of Science Degree in Specialty 05.17.11 – Refractory Non-Metallic Materials Technology, State Higher Educational Institution "Ukrainian State University of Chemical Technology", National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. The dissertation is devoted to creation of physicochemical bases of technology of ecologically safe protective and decorative glass-enamel coatings of wide color scale on steel and non-ferrous metals, development of principles of regulation and prediction of their color. As a result of the research on the topic of dissertation the following scientific results were obtained: - scientifically substantiated and experimentally proved that the production of lead-free enamel coatings on non-ferrous metals is possible on the basis of the Na₂O – BaO – B₂O₃ – SiO₂ glasses, by the complex of defined properties and the ability to form the highest quality coatings on a copper basis the selected region of the base system, mol %: Na₂O – 24,2–40,5; BaO – 5.0–10.0; B₂O₃ – 15.2–30.5; SiO₂ – 24,0–53,5, which in comparison with the limits of these components in known compositions of lead-free enamels, is characterized by a 2-fold increase in the content of B2O3 and a relatively small content of SiO₂; - the basic tendencies of color change of glasses of Na₂O–BaO–B₂O₃–SiO₂ system has been established, which differ significantly in chemical composition and has colored by ionic dyes, taking into account the structural features of glasses and their acid-basic properties. They has been evaluated by two calculated structural parameters: fSi is the degree of connectivity of the silica framework and Ψв is an indicative index of the coordination state of Boron in the structure of the glass. It had proved that there is a significant correlation between the colors λ and Ψv had proved for glasses colored CuO r * = - 0,83 and CoO r * = - 0,87 and weak – for glasses colored K₂Cr₂O₇, -r * = 0,5; - the patterns of coloring of one glass matrix and enamel coatings on its basis in the system R₂O–BaO–ZnO–Al₂O₃–B₂O₃–TiO₂–SiO₂ by a series of ionic dyes has been founded. Regardless of the content of the dyes, they give the same color tone to the glass and coatings based on these glasses, namely: CuO (1.0–3.0 wt%) λ = 489–494 nm (blue-green), Fe₂O₃ (0.5–2 wt%) λ = 575–585 nm (yellow), K₂Cr₂O₇ (0,5–2.0 wt%) λ = 570–576 nm (yellow-green), CoO (0.5–1.0 wt%) λ = 441–463 nm (blue-violet), NiO (0, 5-1.0 wt.%) λ glass = 559′ – 571 nm, λ coatings = 598–629 nm (brown). It has been proved that in the degree of color intensity of glasses and coatings based on them, the dyes has been arranged in the following sequence: CoO> NiO> CuO> K₂Cr₂O₇ > Fe₂O₃; - for the first time, the mechanism of silencing of transparent matrix enamel glass in R₂O–BaO–ZnO–TiO₂–Al₂O₃–B₂O₃–TiO₂–SiO₂ system with the introduction of MoO₃ has been established, which results in the phenomenon of opalescence, namely: due to diffraction at propagation of waves in micro inhomogeneous medium in which the particle size of molybdenum (VI) oxide is 0.05-0.15 μm less than the wavelength of white light; - for the first time, the dependence of the diffuse reflection coefficient (CDR) of enamel coatings on the chemical composition of enamel frits, obtained by processing the experimental sample 471 of the enamel frit composition by multiple correlation analysis, which is presented in the form of a mathematical model that allows you to calculate the chemical composition of the enamel coatings with a given CDR; the correlation coefficient between experimental and calculated values is 0.98; - using the idea of introducing into any material (glass, pigment, sitall, metal) certain components in a small amount to modify its properties, the following has been first discovered: "small addition" of Fe₂O₃ in the amount of 0.25 wt.% in the composition of lead-free enamel glasses based on the base system Na₂O–BaO–B₂O₃–SiO₂ and 1 wt.% in the composition of fluorless glass enamels based on the basic system Na₂O–B₂O₃–SiO₂ activates the processes of differentiation of the segregation-dropping structure of glass, which allows to increase the intensity of opaque coatings by 1.5–2.5 times, as well as to improve the optical-color characteristics of pigment-colored glass coatings, in particular, red. "Small addition" of ZrO₂ in the amount up to 1 wt.% in the composition of low-fluoride titanium enamel promotes the active release of anatase in the coating during firing and improving its optical characteristics; -with the help of a dedicated COLOR GLASS computer program that automatically calculates color coordinates x y, color tone λ, color purity P, and maps the color characteristics of materials to the СIE graph, it has been first demonstrated that the picture of the location of the color points, first, you can make predictions about the equilibrium that is formed between the ionic coloring complexes during the melting of glass, and secondly, about the color potential of the pigment mixture. - for the first time in the field of technologies requiring high temperatures, the dependences of the color coordinates of the enamel coatings on the composition of the pigment mixture in the form of polynomial mathematical models has been established, which made it possible to solve the complex material-coloristic problem of finding the ratio of pigments to reproduce the color of the sample with the specified color characteristics. The practical significance of the obtained results: - the compositions of enamel glasses for non-ferrous metals, which do not contain Plumbum - one of the most harmful for the environment element, had been developed; the basics of technology of obtaining products with their use had offered. New enamels of a wide range of colors with varying degrees of transparency had been created on the basis of matrix transparent enamel and they had characterized by the same firing interval of 780-820 °C, which makes the technology of obtaining artistic and jewelry easier. Enamels had been tested and recommended for implementation in the production of artistic products in the workshop, which locates in the structure of the Museum of Ukrainian Painting (Dnipro), as well as at the jewelry company, Diadema, Vinnytsia. The enamel coatings palette and their products had presented during a report at the 24th International Congress of Enamels in Chicago in 2018. According to an international agreement between the Ukrainian State University of Chemical Technology (Dnipro) and Richemont International SA Varinor SA, Delmont, Switzerland, enamel glass powder and enameled copper samples had been made and handed over to the customer; - a catalog of color samples, which presents the glass base, the number of dyes, opacifiers, reducing agents and the optic-color characteristics of enamel coatings which do not contain Plumbum, has been created. The color name was set in accordance with the color name of the RAL system. The palette of designed enamels of jewelry and artistic purpose includes transparent matrix enamel and 53 colors: yellow-red, blue-green, olive-mustard, pastel and brown-black; - a series of compositions of white and light-colored titanium enamels containing reduced amount of Fluorine, has been developed, also the composition of fluorless frites to obtain brightly colored enamel coatings pigmented way of color, which were fused and passed extensive testing in production conditions factories for the production of enameled household products, has been synthesized. Technological features of production of the enamels offered permits to carry out high-temperature operations of melting at 100oC below the known ones, and firing of coatings – by 30-50 °C, which is very relevant in the era of total saving of fuel and energy resources. Low-fluoride light-colored cream and gray-blue enamels has been introduced at "Novomoskovsk dishes"; - for the first time for the technology of enamel coatings on steel, a method of color modeling has been developed, through which a color triangle-nomogram has been constructed for the production glass base and pigments of yellow, red, blue, by which the required color is specified and the necessary ratio of pigments is calculated. The color modeling method is versatile and can be applied to a wide range of silicate materials: glazed ceramic coatings, colored building materials, and more. The introduction substantiates the relevance of the dissertation topic, formulates the main purpose and objectives of the work, presents the scientific novelty and practical value of the obtained results. The first section provides an analysis of the patent and scientific and technical literature concerning the production of environmentally safe enamels of a wide color range, the current state of production of colored enamels and the control of their color indices, the mechanisms of color of glass and enamels and factors affecting color formation. The second section provides the basic concepts and definitions used in the work, as well as methods for investigating the physicochemical properties and structure of glasses and coatings and their color characteristics. The third section presents studies on the development of environmentally safe enamels for copper and the prediction of their color characteristics. The fourth section presents the results of research on the development of fusible titanium enamel which would meet the requirements of current standards and be burned in resource- and energy-efficient production conditions and be the most environmentally safe for the environment. The fifth section is devoted to the research on the development of enamel frits that do not contain Fluorine and used to produce brightly colored enamel coatings for household products. The sixth section presents the results of the development the color modeling method. Reproduce, and even more so predict, color with predetermined color characteristics is an extremely complex multifaceted material science problem, even if glass and coating formulations, modes of melting and firing are known. In the seventh section the results of industrial testing, realization and implementation of the received materials has been presented.

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів, Державний вищий навчальний заклад "Український державний хіміко-технологічний університет", Національний технічний університет "Харківський політехнічний інститут". Дисертацію присвячено науковим основам технології екологічно безпечних склоемалевих покриттів широкої колірної гами для сталі і кольорових металів, розробці принципів регулювання та прогнозування їх кольору. Розроблена спеціальна комп’ютерна програма COLOUR GLASS, яка за визначеними координатами кольору XYZ автоматично розташовує точки кольору на графіку МКО. Отримані емалі ювелірного та художнього призначення на основі стекол системи Na₂O–BaO–B₂O₃–SiO₂. Розроблені малофлуористі білі і світлозабарвлені титанові емалі, безфлуориста основа для пігментного способу забарвлення. Створено метод колірного моделювання, за допомогою якого можна розрахувати співвідношення пігментів для відтворення кольору зразка за заданими колірними характеристиками. Thesis for a Doctor of Science Degree in Specialty 05.17.11 Refractory Non-Metallic Materials Technology, State Higher Educational Institution "Ukrainian State University of Chemical Technology", National Technical University "Kharkiv Polytechnic Institute". The dissertation is devoted to development of scientific bases of technology of ecologically safe protective and decorative glass-enamel coatings of wide color scale on steel and non-ferrous metals, making of principles of regulation and prediction of their color. The introduction substantiates the relevance of the dissertation topic, formulates the main purpose and objectives of the work. The first section provides an analysis of the patent and scientific and technical literature. The second section provides the basic concepts and definitions used in the work, methods for investigating the physicochemical properties and structure of glasses and coatings and their color characteristics. The third section presents studies on the development of environmentally safe enamels for copper and the prediction of their color characteristics. The fourth section presents the results of studies on the development of small fluoride titanium enamel with a firing temperature of 830 °C. The fifth section had devoted to scientific bases of technology of fluorless enamel frits for pigment method of coloring. The sixth section has devoted to the development of the color modeling method for reproducing the color of a sample with specified color characteristics. In the seventh section the results of industrial testing, implementation and implementation of the received materials has presented. As a result of the research on the topic of dissertation the following scientific results has obtained: - scientifically substantiated and experimentally proved that the production of lead-free enamel coatings on non-ferrous metals is possible on the basis of the Na₂O–BaO–B₂O₃–SiO₂ glasses, the regions of glass formation has been determined, and the regularities of changes in the properties of glasses depending on their chemical composition has been established; - the main tendencies of change of glasses color tone has established in the Na₂O–BaO–B₂O₃–SiO₂ system, which has colored by ionic dyes given the structural features of the glasses and their acid-base properties; - it has been proved that the degree of color intensity of glasses in the system R₂O –BaO – ZnO – Al₂O₃ – B₂O₃ – TiO₂ – SiO₂ and coatings based on them has been arranged in the following sequence: CoO> NiO> CuO> K₂Cr₂O₇> Fe₂O₃; - for the first time the mechanism of opacifying of transparent matrix enamel glass in the R₂O – BaO – ZnO – TiO₂ – Al₂O₃ – B₂O₃ – TiO₂ – SiO₂ system was introduced when MoO₃ has been established, namely: due to diffraction, which results in the phenomenon of opalescence; - for the first time the dependence of the diffuse reflection coefficient of enamel coatings on the chemical composition of enamel frits has been established, which is presented in the form of a mathematical model; the correlation coefficient between experimental and calculated values is 0.98; - for the first time the mechanism of opacifying of transparent matrix enamel glass in the R₂O – BaO – ZnO – TiO₂ – Al₂O₃ – B₂O₃ – TiO₂ – SiO₂ system was introduced when MoO3 has been established, namely: due to diffraction, which results in the phenomenon of opalescence; - for the first time it has been discovered that Fe₂O₃ "small additive" in the amount of 0.25 wt.% in the composition of lead-free enamel glasses on the basis of the Na₂O – BaO – B₂O₃ – SiO₂ base system and 1 wt. Fe₂O₃ in the composition of fluor-free enamel glasses on the basis of the Na₂O – B₂O₃ – SiO₂ base system activates the processes of glass removal stratification, which allows to increase 1.5-2.5 times the intensity of coating damping; - with the help of a special computer program COLOR GLASS, which automatically calculates the coordinates of the color x, y, the color tone λ, the purity of the color P and applies the color characteristics of the materials to the CIE graph, it has been proved for the first time that the chart of the location of color points can make forecasts about the equilibrium, which formed between ionic coloring complexes during glass melting; - for the first time in the field of technologies requiring high temperatures, the dependences of the color coordinates of enamel coatings on the composition of the pigment mixture in the form of polynomial mathematical models has been established, which allowed to solve the complex material-coloristic problem of finding the ratio of pigments to reproduce the color of the sample with the specified color characteristics. The practical significance of the obtained results: - the compositions of enamel art and jewelry glasses for non-ferrous metals, which do not contain Plumbum, has been developed. They are characterized by the same firing interval of 780-820 °C. A catalog of color samples has created. The palette includes fondon and 53 colors: yellow-red, blue-green, olive-mustard, pastel and brown-black; - a series of compositions of white and light-colored titanium enamels containing reduced amount of Fluorine (up to 2.5 wt.%), has been developed, also the composition of fluorless frites to obtain brightly colored enamel coatings pigmented way of color. Temperature operations of the enamel melting is 100 °C and firing of coatings is 30-50oC below the known ones.

A deep-blue emitting poly(2′,3′,6′,7′-tetraoctyl-2,7-spirosilabifluorene), namely PSSiBF, has been newly developed for PLEDs. Unlike the previously-reported alkyl-functionalized P27SiF, the unwanted aggregation can be effectively prevented in PSSiBF due to the perpendicular arrangement between two spiro-linked dibenzosilole moieties. Compared with P27SiF (ΦPL = 0.62), consequently, an improved PLQY of 0.84 is obtained for the film of PSSiBF accompanied by a significant reduction of the long-wavelength emission in the range of 450–550 nm. Based on a double-layer device configuration, PSSiBF gives a bright deep-blue electroluminescence, revealing a state-of-art EQE of 2.8% and CIE coordinates of (0.16, 0.06). The simultaneous realization of good color purity and high EQE clearly implies that the silicon-containing polymers do have the great potential in efficient PLEDs.

The imminent global energy crisis and continuing inefficient energy utilization are driving the development of smart energy-efficient devices for display and lighting applications. Energy-efficient organic light-emitting diodes (OLEDs) are considered one of the most competitive candidates for next-generation smart displays and particularly for future energy-saving lighting sources. Recently, much effort has been devoted to attempts to generate white OLEDs comprising both fluorescent and phosphorescent materials. Efficient blue-emitting materials are extremely essential for the commercialization of white OLEDs and play a vital role in energy-efficient solid-state lighting and smart display devices. The molecular designing of efficient deep-blue materials is limited due to their intrinsic wide bandgap, poor carrier charge balance, and low efficiency in the solid state. In recent decades, phenanthroimidazole (PI)-based materials have attracted tremendous interest (due to the ease of their chemical/structural modification at the N1 and C2 positions) to produce efficient deep-blue OLEDs (satisfying the color purity criteria given by the National Television System Committee (NTSC)) (CIE: 0.14, 0.08) and European Broadcasting Union (EBU) (CIE: 0.15, 0.06). This review mainly focuses on the design of PI-based blue/deep-blue emitting materials and their applications in OLEDs. Here at first, some of the PI-based blue-fluorescence emitters endowed with unipolar and bipolar-transporting abilities are comprehensively reviewed. Then attention is focused on the typical PI-based host materials for phosphorescent OLEDs. Finally, PI-based hybridized local and charge-transfer (HLCT) active fluorescent emitters are presented in brief. The rational molecular design concepts and general synthetic routes for PI-based materials are briefly discussed.

Simultaneously achieving excellent color purity approaching or surpassing the blue standard and outstanding device performance remains a big challenge for blue fluorescent emitters. In this study, two quaterphenyl derivatives are rationally designed and synthesized as deep-blue emitters with high photoluminescence quantum yields of nearly 80%. These emitters are applied in non-doped OLEDs yielding a peak EQE of 5.94% and CIE coordinates of (0.152, 0.085), approaching the NTSC blue standard. When applied to doped OLEDs, these derivatives emit violet-blue light with a peak EQE of 6.55% and CIE coordinates of (0.156, 0.055).

Although great advances have been achieved in organic electroluminescence fields, highly efficient true blue organic electroluminescence with small CIE coordinates and satisfactory color purity are still limited. Here, we practise a simple and effective molecular avenue for true blue organic electroluminescence, and the strategy is to use biphenyl-bridging hybrids of 1,2,4-triazoles (acceptors) and various donors (D) as the emitters. The as-prepared D–π–A hybrid (TPATZ) containing 2,3,4-triphenyl-1,2,4-triazole and triphenylamine emits bright blue light both in solution and in the solid state, and the non-doped device with TPATZ as an emitter exhibits true blue electroluminescence (EL) with the emission peak at 430 nm and the Commission Internationale de L’Eclairage coordinates of (0.155, 0.047). Moreover, the satisfactory EL color purity with the full width at half maximum (FWHM) of only 50 nm and the maximum external quantum efficiency of 5.92% is obtained, which is among the best true blue OLEDs reported to date. These impressive EL properties are experimentally and theoretically analyzed and emphasize that this simple D–π–A hybrid mode is an effective molecular strategy for highly efficient true blue EL emitters.

The purpose of this study was to develop new garnet phosphors for white LED applications. Numerous compositions were designed to explore new garnet structure phosphors. Among the candidates, Y2LuCaGaAl2SiO12 was selected as a host material, and Y2−xLuCaGaAl2SiO12:xLn (0 ≤ x ≤ 0.12; Ln = Ce3+, Eu3+, and Tb3+) phosphors were prepared by using the solid-state reaction method. The Rietveld refinement results showed that Y2−xLuCaGaAl2SiO12:xLn phosphors had a garnet type cubic structure with the Iad space group. The prepared phosphors emitted efficient green, red, and green light by doping Ce3+, Eu3+, and Tb3+, respectively, in Y2LuCaGaAl2SiO12, and showed good luminescence efficiency and high emission color purity. These results demonstrate that the Y2−xLuCaGaAl2SiO12:xLn phosphors can be useful for white light-emitting diode (LED) and solid-state lighting system applications.

By a novel one-step method with convenient and efficient process, porous cobalt aluminate (CoAl2O4) was prepared. The structure, size, morphology, color purity and oil absorption of the powders were characterized. The results indicated that when molar ratio of Co/Al reaches 1:3, the performance of cobalt aluminate is the best and most suitable to be anti-counterfeiting additive. To understand the color control mechanism of cobalt aluminate, the electronic properties were calculated by DFT + U method (where Ueff is set to 4.25 eV) which predicted a band gap of 1.18 eV for cobalt aluminate and illustrated the potential application of semiconductor. Density of states proved that the influential factor of color control depends on Co2 + 3d states and the color range of CoAl2O4 can be effectively adjusted.

Solid-state materials with tunable light emission characteristics offer an attractive prospect. Unique luminescence features of trivalent lanthanide (LnIII) ions—sharp characteristic emission in the visible and near-infrared (NIR) spectral regions, exceptional color purity, long luminescence lifetimes, high quantum yield and large Stokes shifts—afford them as promising white-light source materials. The review provides an overview of the recent developments in the Ln- complex-based solid-state white-light emitters with particular emphasis on different design strategies and photoluminescence features to augment the foundations of factual knowledge further. The approaches adopted in the lanthanide coordination complexes—logical codoping of LnIII in various compositions, lanthanide encapsulation in MOF pores, infinite coordination particles, and lanthanide incorporated composites—to attain tunable white-light emission, will be discussed. The pros and cons of different adopted strategies in term of further processing of the materials into real-world applications as well as the imminent challenges are also reviewed and put in prospect.

The objective of present study is to determine the influence of component composition of pigment complex on the formation of color of rhubarb and gooseberry that defines consumer properties of these plant products. We report comparative study of rhubarb of the botanical varieties Monarch, Linney, Krupnochereshkovyy, Ogrski, and of gooseberry of the varieties Malachite, Pavlovsky green, Green urozhainyy, Green butylochnyy, zoned in the eastern regions of Ukraine. To determine the content of pigment complex substances of rhubarb and gooseberry, we used methodology by V.F. Gavrilenko and L.M. Khandobina. The method of the International Commission on Illumination (ICI) was applied for quantitative characteristic of color. Results of research into qualitative and quantitative composition of pigment complex of berries of gooseberry and rhubarb stalks revealed that the main components are the chlorophylls whose overall content for different varieties of rhubarb is (3.7…4.5)∙10-3 %, for berries of gooseberry is (3.5…4.7)∙10-3 %. The color characteristics of the examined samples of gooseberry and rhubarb are correlated with the quantitative content of pigments in the raw materials and make it possible to determine the dominant tone (λd, nm) − green, color purity − green with shades of blue, brightness – green, light green, dark green, which coincide with the visual estimation of color. We show expediency of the application of the ICI XYZ method to characterize the color, which considerably facilitates the estimation of color when assessing the quality of food products.

Synthesis of Eu 3+ doped Y 2 O 3 nanophosphors via modified sonochemical method was presented. Morphologies of the prepared products were analyzed with respect to the influential parameters during the preparation time. The photoluminescence (PL) emission spectra exhibits several peaks at ∼537 nm, 598 nm, 613 nm and 662 nm attributed to 5 D 0 → 7 F J ( J = 0, 1–3) transitions of Eu 3+ ions in the host lattice. The types of energy transfer between the Eu 3+ ions were responsible for concentration quenching confirms the electric dipole–quadrupole interaction among the ions. The Judd-Ofelt intensity parameters and other radiative properties were estimated by using PL emission spectra. The photometric characteristics of the prepared samples indicate that the color co-ordinates were tune towards pure red emission with color purity of ∼88%. The results signified that the prepared Y 2 O 3 :Eu 3+ was a potential amber phosphor for solid state and LED’s applications.