Toward Exploiting the Behavior of Niobium-Containing Mesoporous Silicates vs. Polyoxometalates in Catalysis

Classification of polyoxometalates (POMs) is based on their chemical composition, basically represented by two general formulae: a) [MmOy]p− b) [XxMmOy]q−, where M is the main transition metal, O is the oxygen atom and X can be a non-metal atom such as Si. Additionally, in the most cases, the structure of the polyoxometalates is derived from a combination of octahedral units MO6 with a central metal atom M and the oxygen atoms placed at their corners. In such octahedra, oxygen atoms allow the condensation between two octahedral units, while one oxygen atom (or max. two atoms) makes double bond with the central metal atom and is not shared with other metal atoms within the complex (terminal oxygens). On the other hand, niobium-containing mesoporous silicates contain mainly MO4 tetrahedra and reveal superior activity in heterogeneous catalysis. Thus, the proper coordination of niobium is crucial for the catalytic activity and will be deeply discussed. The similarity in the catalytic behavior of niobium-polyoxometalates and heterogeneous niobium single-site catalysts in selective oxidations will be demonstrated

The use of mesoporous molecular sieves in the synthesis of chemicals from renewable sources

Wydział Chemii: Pracownia Chemii StosowanejCelem pracy było zastosowanie mezoporowatych sit molekularnych zawierających niob do celów katalizy heterogenicznej. Wykorzystano różne typy mezoporowatych sit molekularnych, tj. MCM-41, SBA-15, SBA-16, FDU-1 i MSU-X. Wykazano, że mezoporowate sita molekularne zawierające Nb nie tylko dostarczają pożądanych właściwości redoks, ale także strukturalnych i kształtoselektywnych, które są charakterystyczne dla tych materiałów. Dodatkowo, mezoporowate materiały z jednej strony posiadają zaletę charakteryzowania się wysoką powierzchnią właściwą oraz objętością porów. Z drugiej zaś strony mogą służyć jako dobre katalizatory dla: (i) utleniania terpenowych cząsteczek, które są zbyt duże aby docierać do miejsc aktywnych w materiałach mikroporowatych i (ii) transformacji glicerolu do wartościowych chemikaliów. Dlatego też duża liczba procesów o wysokiej ważności dla rozwoju czystych technologii została przestudiowana z użyciem ww. katalizatorów adresowanych do łagodnego utleniania terpenów (geraniol, limonen, -pinen) z nadtlenkiem wodoru. Wewnętrzna powierzchnia mezoporowatych krzemionek była także w taki sposób konstruowana aby dawać z wysoką wydajnością nowe związki zwane sowo-surfaktantami w reakcjach acetalizacji, ketalizacji i eteryfikacji glicerolu na miejscach aktywnych opartych na formach Nb(V). Taki typ związków chemicznych posiada zarówno właściwości rozpuszczalnika, tj. lotność, jak i surfaktantu: obniżenie napięcia powierzchniowego i tworzenie (mikro)emulsji. Otrzymane chemikalia mogą być stosowane w przemyśle kosmetycznym, farmaceutycznym i chemicznym.The aim of this work was the application of mesoporous molecular sieves containing niobium in the field of heterogeneous catalysis. Different types of molecular sieves, i.e., MCM-41, SBA-15, SBA-16, FDU-1 and MSU-X were used for this purpose. It was found that molecular sieves containing Nb species provide not only the desired redox properties, but the likewise structural and shape-selective properties which are characteristic of this sort of material. Additionally, on one hand mesoporous materials have the advantage of presenting high surface areas and pore volumes. On the other hand, they may afford good catalysts for: (i) the oxidation of terpenic molecules which are too large to have access to catalytic sites in microporous material and (ii) transformation of glycerol into valuable chemicals. Thus, a number of one-step processes of paramount importance in the development of clean technology were studied with catalysts designed to oxidise terpenes (geraniol, limonene, -pinene) with hydrogen peroxide under mild conditions. The inner surfaces of mesoporous silicas were also engineered to yield high-performance products of acetalization, ketalization and etherification of glycerol to new compounds, called solvo-surfactants at Nb(V)-centred active sites. These types of chemicals are of great interests since they exhibit both properties of solvents, e.g. volatility and surfactants, e.g. reduction of interfacial tensions, formation of emulsions and microemulsions. The obtained chemicals may be used in cosmetic, pharmaceutical and chemical industry

Nanomaterials as Photocatalysts—Synthesis and Their Potential Applications

Increasing demand for energy and environmental degradation are the most serious problems facing the man. An interesting issue that can contribute to solving these problems is the use of photocatalysis. According to literature, solar energy in the presence of a photocatalyst can effectively (i) be converted into electricity/fuel, (ii) break down chemical and microbial pollutants, and (iii) help water purification. Therefore, the search for new, efficient, and stable photocatalysts with high application potential is a point of great interest. The photocatalysts must be characterized by the ability to absorb radiation from a wide spectral range of light, the appropriate position of the semiconductor energy bands in relation to the redox reaction potentials, and the long diffusion path of charge carriers, besides the thermodynamic, electrochemical, and photoelectrochemical stabilities. Meeting these requirements by semiconductors is very difficult. Therefore, efforts are being made to increase the efficiency of photo processes by changing the electron structure, surface morphology, and crystal structure of semiconductors. This paper reviews the recent literature covering the synthesis and application of nanomaterials in photocatalysis

Analitical methods for identification and determination of some cosmetics ingredients

Techniki analityczne, takie jak: chromatografia gazowa (GC) i wysokosprawna chromatografia cieczowa (HPLC) stają się użytecznym narzędziem do udowodnienia jakości kosmetyków. W ostatnich latach interesującą metodą analityczną stała się kombinacja chromatografii gazowej (GC) i cieczowej (HPLC) ze spektrometrią mas (GC-MS i HPLC-MS). Metody te są szybkie, charakteryzują wysoce selektywną detekcją, oceną jakościową oraz pozwalają rozwiązywać skomplikowane struktury molekularne ze złożonej mieszaniny. W niniejszej pracy zostaną opisane metody preparatyki znajdujące zastosowanie w perfumerii oraz preparatach zawierających filtry UV.Analytical techniques, such as gas chromatography (GC) and high- performance liquid chromatography (HPLC) are very useful tools for evaluation of the quality of cosmetics. In recent years a powerful analytical device has become a combination of GC and HPLC with mass spectrometry (GC-MS and HPLC-MS). These methods are fast, give highly selective detection and quantification and are also able to solve complicated molecular structures in complex mixtures. The methods of preparation of perfumes and UV-filters are also discussed

Potential of Icariin–Glucosamine Combination in the Treatment of Osteoarthritis by Topical Application: Development of Topical Formulation and In Vitro Permeation Study

The aim of this study was to develop a topically applied formulation with the potential to alleviate arthritis ailments. A combination of two active ingredients, icariin from Epimedium L. (Species: Epimedium Koreanum) extract as a potential promoter of chondrogenesis and glucosamine sulfate as a precursor of cartilage tissues, was tested. In permeation studies, the potential for skin permeation of both substances was confirmed; however, the in vitro release test did not accurately reflect the degree of skin permeation. The in vitro release of icariin was at a level of 15.0–19.0% for the plant-extract-derived icariin and 29.0–35.0% for the pure substance. The level of glucosamine sulfate release was 38.4% (on average). For icariin of both origins, the release results were higher than those obtained via oral administration (about 12.0%), which shows the potential superiority of topical application. In addition, the physicochemical parameters that affect the in vitro release and performance of topical formulations were addressed. This preliminary research and permeation analysis of the formulation produced a promising picture of its prospects regarding arthritis treatment, although further investigation is needed

The use of gas chromatography coupled with mass spectrometry (GC-MS) to the identification of fine chemicals

Technika analityczna GC-MS jest użytecznym narzędziem do udowodnienia jakości chemikaliów. Chromatografia gazowa - spektrometr mas (GC-MS) stanowi połączenie chromatografu gazowego i spektrometru mas do identyfikacji różnych substancji w analizie próbek. Zastosowanie GC-MS obejmuje oznaczanie narkotyków, analizę środowiskową oraz identyfikowanie nieznanych próbek. Metoda ta jest szybka, charakteryzuje się selektywną detekcją, umożliwia ocenę jakościową, a także pozwala zidentyfikować skomplikowane struktury molekularne ze złożonej mieszaniny. W niniejszej pracy technika GC-MS została wykorzystania do scharakteryzowania produktów reakcji utleniania terpenów.Gas chromatography - mass spectrometry (GC-MS) is very useful analytical method for evaluation of the quality of chemicals. It combines the features of gas chromatography and mass spectrometry to help identify different substances within the tested sample. Applications of GC-MS include drug detection, environmental analysis and identification of unknown samples. This method is fast, enables a highly selective detection and quantification and is also helpful in solving complicated molecular structures in complex mixtures. In this paper GC-MS was used for the identification of reaction products in the oxidation of terpenes

Microencapsulation as a Route for Obtaining Encapsulated Flavors and Fragrances

Microencapsulation methods for active substances, such as fragrance compounds and aromas, have long been of interest to researchers. Fragrance compositions and aromas are added to cosmetics, household, and food products. This is often because the choice of a particular product is dictated by its fragrance. Fragrance compositions and aromas are, therefore, a very important part of the composition of these items. During production, when a fragrance composition or aroma is introduced into a system, unfavorable conditions often exist. High temperatures and strong mixing have a detrimental effect on some fragrance compounds. The environments of selected products, such as high- or low-pH surfactants, all affect the fragrance, often destructively. The simple storage of fragrances where they are exposed to light, oxygen, or heat also has an adverse effect. The solution to most of these problems may be the encapsulation process, namely surrounding small fragrance droplets with an inert coating that protects them from the external environment, whether during storage, transport or application, until they are in the right conditions to release the fragrance. The aim of this article was to present the possible, available and most commonly used methods for obtaining encapsulated fragrances and aromas, which can then be used in various industries. In addition, the advantages and disadvantages of each method were pointed out, so that the selection of the appropriate technology for the production of encapsulated fragrances and aromas will be simpler

The use of glycosaminoglycans in cosmetic products

Glikozaminoglikany (GAG) są bogato reprezentowanymi składnikami macierzy międzykomórkowej, odgrywającej istotną rolę w funkcjonowaniu tkanek. Związki te należą do grupy hetero polisacharydów. Składają się z aminocukru oraz kwasu uronowego. Większość GAG tworzy kowalencyjne wiązania z białkami tworząc w efekcie proteoglikany. Obecność w strukturze tych związków dużej ilości grup -OH oraz ładunków ujemnych sprawia, że wykazują one zdolność wiązania dużej ilości cząsteczek wody oraz pęcznienia. Ze względu na te właściwości glikozaminoglikany są szeroko stosowanymi składnikami preparatów kosmetycznych, w których wykazują przede wszystkim aktywność nawilżającą, przyczyniając się jednocześnie do poprawy jędrności i elastyczności skóry.Glycosaminoglycans (GAGs) are richly represented components of connective tissue, matrix which plays an important role in the functioning of tissues. These compounds belong to the group heteropolysaccharides, and they occur as long chains of repeated disaccharide units, consisting of amino sugar and uronic acid. Most of GAGs form covalent bonds with proteins to produce proteoglycans in effect. Because of the presence of a large number of -OH groups and negative charge, GAGs are capable of binding great numbers of water molecules inducing the effect of swelling. For this reason GAGs are widely used cosmetic ingredients responsible for moisturizing effect, while contributing to the improvement of skin firmness and elasticity

Photodynamic Light-Triggered Release of Curcumin from Hierarchical FAU Zeolite

Photodynamic therapy (PDT) is a method used in the treatment of various diseases and represents a promising alternative to classical active substance release methods. According to the United States National Institute of Health, this therapy exploits the health-promoting potential of active substances, referred to as “photosensitizers”, and radiation of specific energy. Curcumin is a natural “photosensitizer” that exhibits anti-inflammatory, antioxidant, and anti-cancer effects. Despite the novelty and innovation of PDT, the method is limited by the difficulty of using “photosensitizers” such as curcumin because of its low solubility in water, which hinders the clinical application of this technique. The use of a “photosensitizer” along with suitable carriers such as hierarchical zeolites is a potential strategy to offset this difficulty. Therefore, the objective of this study was to develop the photodynamic release of curcumin from hierarchical zeolites using the classical open-circuit release method and a novel closed-circuit release technique involving light of different wavelengths. Based on the obtained data, it was possible to unequivocally state that the speed and efficiency of curcumin release from the zeolite carrier is influenced by light with a wavelength in the range of 430–525 nm (blue-cyan-green). As much as 53.24% of the active substance was released upon light exposure

Microencapsulation as a Route for Obtaining Encapsulated Flavors and Fragrances

Microencapsulation methods for active substances, such as fragrance compounds and aromas, have long been of interest to researchers. Fragrance compositions and aromas are added to cosmetics, household, and food products. This is often because the choice of a particular product is dictated by its fragrance. Fragrance compositions and aromas are, therefore, a very important part of the composition of these items. During production, when a fragrance composition or aroma is introduced into a system, unfavorable conditions often exist. High temperatures and strong mixing have a detrimental effect on some fragrance compounds. The environments of selected products, such as high- or low-pH surfactants, all affect the fragrance, often destructively. The simple storage of fragrances where they are exposed to light, oxygen, or heat also has an adverse effect. The solution to most of these problems may be the encapsulation process, namely surrounding small fragrance droplets with an inert coating that protects them from the external environment, whether during storage, transport or application, until they are in the right conditions to release the fragrance. The aim of this article was to present the possible, available and most commonly used methods for obtaining encapsulated fragrances and aromas, which can then be used in various industries. In addition, the advantages and disadvantages of each method were pointed out, so that the selection of the appropriate technology for the production of encapsulated fragrances and aromas will be simpler