Mixed Acetals Research Articles

Synergetic impact of binary/ternary zeolitic composites on cellulose acetate membranes for potential CO2 removal and antibacterial attributes

The aim of this research is to synthesize multifunctional mixed matrix cellulose acetate (CA) membranes that can provide better CO2/N2 selectivity and will simultaneously fight against bacteria, to immaculate the indoor environment. For that purpose, two different fillers labelled as binary ZnO@Zeolite (1:10, ZZ) and ternary ZnO–CuO@Zeolite (0.8:0.2:10, ZZC) composites have been synthesized via co-precipitation method to entrench into CA matrix with 8 wt% each. The solution mixing technique assisted by thermal evaporation process (TEAP) has been adopted to formulate the desired membranes. Surface morphology, crystalline structure, thermal decomposition, and mechanical properties of novel composites ZZ and ZZC, along with their respective corresponding membranes CA/ZZ-8 and CA/ZZC-8, have been analyzed using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and universal testing machine (UTM). The inclusion of tri-zeolitic composite (ZZC) favors the formation of denser CA membranes, with a smaller crystallite size (10.8 nm), higher thermal stability (%), and a notable increase in mechanical strength (MPa) in contrast to virgin CA as well as bi-zeolitic composite (ZZ) loaded membranes. The selectivity for CO2/N2 separation of tri-zeolitic composite loaded membranes (CA/ZZC-8) is almost six folds higher compared to the pristine CA membrane, whereas it is five folds for bi-zeolitic composite impregnated membrane (CA/ZZ-8). To eradicate bacterial fouling, bi/tri-zeolitic composite loaded membranes are tested against E. coli bacteria by broth culture method and the results validate their antibiotic nature. Synthesized novel CA membranes with hybrid composites provide convenient access towards the development of multipurpose membranes.

Synthesis and Applications of N-Alkoxymethylated Azaheterocycles

Abstract: Alkoxmethyl heterocycles play a significant role as bioactive compounds in pharmaceutical and bifunctional ligands in synthetic organic chemistry. N-Alkoxmethylation can lead toward multipurpose mixed acetals, natural product precursors, and task-specific functionalized ionic liquids. This report provides a comprehensive account of the synthesis and perspectives applications of alkoxymethyl azaheterocycles. The first part gives a detailed account of the different synthetic strategies employed to access N-alkoxy methyl heterocyclic compounds. The second part deals with their applications, owing to the unique reactivity of the alkoxymethyl group and the nature of heterocycle. Besides diverse biological and synthetic applications, alkoxymethyl benzotriazoles also provide substantial scope as a versatile anion stabilizer that can lead to diverse oxygen functionalities.

Solvent Influence in the Synthesis of Lead(II) Complexes Containing Benzoate Derivatives

A series of lead(II) complexes incorporating benzoate derivative ligands was prepared: [Pb(2MeOBz)2]n (1), [Pb(2MeOBz)2(H2O)]n (2), [Pb2(1,4Bzdiox)4(DMSO)]n (3), [Pb(1,4Bzdiox)2(H2O)]n (4), [Pb(Pip)2(H2O)]n (5), and [Pb(Ac)(Pip)2(MeOH)]n (6) (2MeOBz: 2-methoxybenzoate; 1,4Bzdiox: 1,4-benzodioxan-5-carboxylate; DMSO: dimethylsulfoxide; Ac: acetate; Pip: piperonylate; MeOH: methanol). All compounds were characterized via elemental analysis, ATR-FTIR spectroscopy, and powder XRD. In addition, the crystal structures of some compounds were elucidated. Compounds 1 and 2, involving 2-methoxybenzoate, were closely related, only differing in the presence of one extra aqua ligand found for the latter. However, this implies key changes in the studied properties, e.g., 2 shows solid-state luminescence that displays a different color as a function of the crystal orientation, while 1 does not. The crystal structure of 2 revealed a 1D coordination polymer. A similar relationship was found between compounds 3 and 4, incorporating 1,4-benzodioxan-5-carboxylate. In this pair, only 4, with aqua ligands, displayed a greenish-yellow-color solid-state luminescence. Furthermore, two new lead(II) piperonylate complexes, 5 and 6, were obtained from the reaction between lead(II) acetate and piperonylic acid. In water, all acetate ligands in the metal precursor were displaced and [Pb(Pip)2(H2O)]n (5) was isolated, while in methanol, a mixed acetate–piperonylate complex, [Pb(Ac)(Pip)2(MeOH)]n (6), was precipitated. Considering only conventional Pb-O bonds, the crystal structure of 6 was described as a 1D coordination polymer, although, additionally, the chains were associated via tetrel bonds, defining an extended 2D architecture.

Analysis of Salts and Clays for Conservation of Porous Cultural Heritage

Soluble salts and clays are major intrinsic causes of degradation of porous cultural heritage materials. Identifying their presence and concentrations can allow environmental control to prevent decay before it is observed. Such control is often energy- and carbon-intensive and better targeted towards those objects that require it rather than a general approach. The use of poultices has been investigated to determine salt species and concentrations in stone to replace drilling samples. A non-invasive method using two types of moisture meter has been developed to map the conductivity of salt solutions in stone. Fourier transform and near-infrared spectroscopies have been investigated to non-invasively quantify the amount of muscovite clay in limestones without the need to take drilled samples. Salts can react with extrinsic acetic acid from display and storage environments, causing extensive damaging surface efflorescences. A rapid analytical procedure based on external reflectance Fourier transform infra-red (FTIR) microscopy has been developed. This allows analysis of multiple salts on a cuneiform tablet surface. Analyses of soluble salts inside the tablets has indicated the sulphate-to-chloride ratio is a good predictor of whether mixed acetate efflorescences will occur on exposure.

Effect of mixed cation acetate electrolyte on synthesis of α‐hemihydrate gypsum from phosphogypsum

AbstractThe preparation of α‐hemihydrate gypsum (α‐HH) from phosphogypsum (PG) by atmospheric hydrothermal synthesis is a green and efficient method for the treatment of PG. The commonly used electrolyte solution today is mostly chlorine‐based. The prepared α‐HH based on chlorine salt solution is needlelike with a large aspect ratio, low strength, and high impurity. In this study, sodium‐ and calcium‐mixed cation acetate solution is designed and used as an organic multifunctional electrolyte to the synthesis of α‐HH for the first time. The effects of the mixed cation acetate electrolyte on crystal transformation, product morphology, and product purity of the prepared α‐HH were compared with those prepared with chloride solutions with the same mixed cations. Result showed that the morphology of α‐HH crystals prepared in acetate solutions is a stubby hexagonal prism. The aspect ratio of the prepared α‐HH crystals is close to 1, with 3‐day compressive strength four times higher than that of α‐HH prepared in chloride solutions. In addition, in comparison with chloride electrolyte, acetate electrolyte showed a complexation effect with impurity metal ions, which realized the efficient removal of impurities from PG and increased the purity of the synthesized α‐HH.

Novel Magnetic Mixed Cellulose Acetate Matrix Membranes with Oxygen-Enrichment Potential.

This work presents novel magnetic mixed cellulose-based matrix membranes that combine the advantages of a low-cost common polymer matrix, such as cellulose acetate (CA), and a low-cost magnetic filler. Moreover, the presented magnetic mixed CA matrix membranes were fabricated and used without applying an external magnetic field during either the membrane casting or the separating process. Poly(methylmethacrylate) and lithium chloride were used in order to improve the mechanical properties and porosity of the fabricated membranes. The iron-nickel magnetic alloys used were prepared through a simple chemical reduction method with unique morphologies (Fe10Ni90-starfish-like and Fe20Ni80-necklace-like). The novel magnetic mixed CA matrix membranes fabricated were characterized using different analysis techniques, including SEM, EDX, XRD, TGA, and FTIR-ATR analyses. Furthermore, the static water contact angle, membrane thickness, surface roughness, tensile strength, and membrane porosity (using ethanol and water) were determined. In addition, vibrating sample magnetometer (VSM) analysis was conducted and the oxygen transition rate (OTR) was studied. The magnetic mixed CA matrix membrane containing starfish-like Fe10Ni90 alloy was characterized by high coercivity (109 Oe) and an efficient 1.271 × 10-5 cm3/(m2·s) OTR compared to the blank CA membrane with 19.8 Oe coercivity and no OTR. The effects of the polymeric matrix composition, viscosity, and compatibility with the alloys/fillers used on the structure and performance of the fabricated mixed CA matrix membranes compared to the previously used poly(ethersufone) polymeric matrix are discussed and highlighted. The novel magnetic mixed CA matrix membranes presented have good potential for use in the oxygen-enrichment process.

Construction and metabolic analysis of acetone-butanol-ethanol fermentation using mixed acetic acid and lactic acid in wastewater

To reuse organic acids in wastewater, efficient acetone-butanol-ethanol (ABE) fermentation was constructed using mixed acetic acid and lactic acid. The mixed acids were co-consumed with glucose, producing higher butanol concentration (6.96 g/L) and butanol yield (0.494 C-mol/C-mol) than using each single acid (6.22 g/L and 0.432 C-mol/C-mol). This result was verified by 13 C tracer experiment that addition of lactic acid improved carbon distribution to butanol instead of acetone , while acetic acid was readily consumed than lactic acid at initial fermentation stage. Subsequently, pH-stat fed batch fermentation at low pH of 5.5 further improved acid consumptions (6.34 g/L acetic acid and 9.06 g/L lactic acid) and solvent productions (12.4 g/L butanol and 6.50 g/L acetone). Finally, ABE fermentation using wastewater of lactic acid fermentation was performed without inhibition. Thus, efficient ABE fermentation can be implemented using mixed acetic acid and lactic acid, which is superior to using single acid. • This is the first study using mixed acetate and lactate for ABE fermentation. • 13 C experiment verified the metabolic flux to butanol was improved by the acids. • pH and glucose played an important role in acid consumption and solvent production. • Fermentation from lactic acid fermentation broth was performed without inhibition.

Acid-Catalyzed Decomposition of O-Silylated α-Diazo-β-hydroxy Esters: Access to Mixed Monosilyl Acetals.

Acid-catalyzed decomposition of diazocarbonyl compounds triggers a wide range of transformations leading to synthetically useful building blocks with high diversity. In this field, the chemistry of α-diazo-β-hydroxy ester substrates is largely dominated by migration processes. We describe herein a new approach to original mixed monosilyl acetals from O-protected α-diazo-β-hydroxy-β-aryl esters and alcohols, catalyzed by trimethylsilyl trifluoromethanesulfonate (TMSOTf). The ratio between these original mixed acetals, the symmetric acetals, and the migration products fluctuates depending on the catalyst, the nature of the alcohols, and the substituent on the aromatic ring. Fifty-six examples are reported herein with yields up to 71% and diastereoselectivity up to 6:1. Such mixed monosilyl acetals constitute a synthetic equivalent of α-substituted β-oxoesters with high potential for further transformations.

Preliminary Investigation of Sequential Application of Different Calcium Oxalate Solutions for Carbonate Rock Conservation

Being inspired by nature, a series of experiments was carried out to deposit a calcium oxalate layer on the surface of the stone by the reaction between carbonate rock and oxalate salt. To increase the anti-dissolution properties of the calcium oxalate layer, the use of mixed oxalate solution has been proposed in the literature by two main routes: (1) adding acid agent to ammonium oxalate, which has the advantage of changing the particle structure and reducing layer porosity, and (2) using neutral methyl oxalate solution, which has the advantage of surface coverage due to slowly hydrolysis. In this study, we investigated the sequential application of ammonium oxalate, methyl oxalate, neutral mixed, and calcium acetate acid mixed solution. With this method, calcium carbonate and calcium oxalate solution can react inside the stone to reinforce it. The protective film’s coverage area can then be increased using dimethyl oxalate neutral mixed solution, and the crystal morphology can be modified with calcium oxalate acid mixed solution. The anti-dissolution properties of the coating were investigated using both a custom-designed apparatus and a selective outdoor environment. The coating displayed good acid resistance properties at pH 2–4. After one year of exposure, the coating is firmly bonded with the stone.

Lewis Acid-Catalyzed Synthesis of Alkoxymethylhalides for Multipurpose Mixed Acetals; Scope and Limitations

Abstract: The work describes a detailed account of the Lewis acid-catalyzed preparation of structurally variant alkoxymethyl halides. A series of Lewis acids with different halogenating agents are evaluated for the cleavage of bis-alkoxymethanes, where several readily available Lewis acids were found to exhibit high catalytic potential. SOCl2 with MgCl2 was found to be one of the best combinations for the facile and efficient preparation of structurally diverse alkoxymethyl halides under solvent-free conditions. The efficacy of the methodology was established to obtain a wide range of mixed acetals through alkoxymethylation of phosphorus, sulfur, nitrogen, and oxygen containing nucleophiles. The present procedure has significant advantages including simplicity, generality, rapidity, and availability of reagents.

A Review of Environmental DNA Field and Laboratory Protocols Applied in Fish Ecology and Environmental Health

Environmental DNA (eDNA) has been used in research relevant to fish ecology such as species diversity and conservation studies, threatened and invasive species monitoring, and analyses of population structure and distribution. How to choose the optimal laboratory protocols on the basis of the research targets is the first question to be considered when conducting an eDNA study. In this review, we searched 554 published articles using the topic subject ((eDNA or environmental DNA) and (fish)) within the time span 2011–2021 via Thompson Reuters Web of Science (WoS) and China National Knowledge Infrastructure (CNKI) literature databases, and screened 371 articles related to eDNA research on fish ecology. These articles were categorized into “article (334)”, “review (36)”, and “letter (1)” based on the type, and “article” was divided into “article (method research)” and “article (eDNA application)” in line with the study objectives. The experimental methods adopted in each study were reviewed, and advantages and disadvantages of the main protocols were analyzed for each step. We recommend a set of optimal protocols for regular eDNA-based fish diversity detection and present the following suggestions for water sample collection and subsequent sample processing and experiments. Sample size is suggested to be 2 L regardless of the type of water bodies; three water replicates are recommended per sampling site, and water collection sites should be designed to cover various water layers and micro-habitats within research areas. Filtration is the best method for collecting eDNA from the larger water samples; 0.45 μm glass fiber/glass microfiber (GF) filters and mixed cellulose acetate and nitrate (MCE) filters are recommended for use, and MCE filters are suitable for use in turbid waters; pre-filtration (>10 μm filtering membranes) can be used to prevent clogging. Freezing temperature storage can slow eDNA degradation, and this is the optimal way to store DNA no matter what filtering method is applied. The Qiagen DNeasy Blood and Tissue DNA extraction kit was the most economical and efficient DNA extraction method compared to other commercial kits. The 12S rRNA gene is the first choice for detecting interspecies variation in fishes, and five 12s primer sets, Ac12S, MDB07, Mi-Fish, Vert-12SV5, and Teleo, are recommended. The TruSeq DNA PCR-free LT Sample Prep kit and NEBNext DNA Library Prep Master Mix Set for the 454 kit can be chosen. The Illumina HiSeq platform can obtain sufficient data depth for fish species detection. QIIME and OBITools are independent software packages used for eDNA sequences analysis of fishes, and bioinformatic analyses include several indispensable steps such as filtering raw reads, clustering filtered reads into molecular operational taxonomic units (MOTUs) or amplicon sequence variants (ASVs), and completing taxon annotation. Contamination, inhibition, lack of reference DNA data, and bioinformatic analysis are key challenges in future eDNA research, and we should develop effective experimental techniques and analysis software regarding these aspects. This review intends to help eDNA beginners to quickly understand laboratory protocols applied in fish ecological research; the information will be useful for the improvement and development of eDNA techniques in the future.

Silt density index as a fouling propensity parameter of various membrane materials using dissolved organic matter

Silt density index (SDI) is the most widely used parameter for predicting fouling potential that occurs during reverse osmosis (RO) processes to assess and reduce fouling; however, this index cannot accurately predict fouling, particularly, organic fouling. Therefore, this study analyzed the application of five different membranes (i.e., mixed cellulose nitrate and cellulose acetate (MCE), cellulose nitrate (CN), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and polycarbonate (PC)) for measuring SDI and discerning the characteristics of organic foulants. The properties of the organic foulants on the membranes used to measure the SDI value were compared to those on the RO membrane. The quantitative fouling of the MCE, CN, PVDF, PC, and PTFE membranes in terms of the total organic carbon were 6.01 ± 0.03, 6.30 ± 0.14, 10.27 ± 0.10, 2.26 ± 0.12, and 3.08 ± 0.06 mg/L, respectively. In addition, liquid chromatography–organic carbon detection revealed that the MCE and CN were effective in predicting the fouling caused by building blocks and low-molecular-weight substances, respectively. The PVDF was effective in predicting fouling caused by biopolymers. The contaminants compositions on the PTFE and PC were similar; however, the PTFE was more effecting in detecting fouling caused by humic and low-molecular-weight substances. The composition of foulants on the PC was similar to that on the RO membrane, indicating that it can successfully predict the organic fouling of RO membrane. These results indicate that it is important to standardize the SDI value for PC membranes to make SDI a reliable index in the municipal wastewater reuse.

Synthesis of rare-earth nanosized phosphors using microwave processing

Nanomaterials find permanently extending applications in various areas of life. In particular, nanosized phosphors can be used as pharmaceutical carriers capable of emitting ultraviolet or visible light that activates a photosensitizer, thus significantly expanding the possibilities of photodynamic therapy in the treatment of oncological, bacterial and viral diseases. The conditions required for the use of nanosized phosphors in medicine include their fine dispersion and effective luminescence in the red region of visible light spectrum upon stimulation by X-ray radiation of the range accepted for medical applications, particularly for diagnostic and therapeutic purposes in many diseases. The aim of this work was to study the effect of microwave treatment of Y2O3:Eu phosphors prepared by hydrothermal synthesis in ethylene glycol at 230 °C for 6 hours, involving the decomposition of mixed acetate. In order to reduce the aggregation and growth of the resulting particles, Aerosil A300 with average particle size 7 nm was added to the reaction mixture in the course of hydrothermal synthesis in the ratio 1:1 relating to the obtained phosphor. The microwave treatment was carried out at 800 °C for 5 minutes. The developed method provided Y2O3:Eu phosphor samples featuring with increased luminescence intensity in the region 610…700 nm compared to similar phosphors earlier prepared using the rapid thermal annealing (RTA) procedure.

Synthesis of Y<sub>2</sub>O<sub>3</sub>: Eu Luminescent Phosphor with Increased Dispersion for Use in Medical Purposes

Photodynamic therapy (PDT) is a promising modern method for treatment of oncological, bacterial, fungal and viral diseases. However, its application is limited to diseases with superficial localization since the body tissues are not transparent for visible light. To address this problem and extend PDT application to abdominal diseases, an enhanced method of X-ray photodynamic therapy (XRPDT) is suggested, involving X-ray radiation easily penetrating the body tissues. The implementation of this approach requires the development of a pharmacological drug including a photosensitizer stimulated by visible light to yield active oxygen and a nanosized phosphor converting X-ray radiation into visible light with the wavelength required for the photosensitizer activation. This study is aimed at obtaining X-ray stimulated phosphors with nanosized particles suitable for XRPDT application. For this purpose, Y2O3:Eu phosphors were synthesized via hydrothermal processing of the corresponding mixed acetate followed by annealing. To prevent from the undesirable agglomeration of the particles in the course of hydrothermal synthesis and subsequent annealing, different techniques were used, including rapid thermal annealing (RTA), microwave annealing and addition of finely dispersed pyrogenic silica (aerosil) to the phosphor. The microwave annealing was carried out using a special installation including a resonance chamber for maintaining a standing wave of microwave radiation. The performed research allowed the determination of hydrothermal processing optimal duration affording the synthesis of phosphors with the highest luminescence brightness. The application of microwave annealing is found to provide phosphors with a more perfect crystal structure compared with RTA. The developed method of Y2O3:Eu phosphor synthesis involving pyrogenic silica addition to the autoclave allowed the preparation of samples with the amorphous structure and significantly reduced the particle size without a considerable decrease in the luminescence brightness. The particle size of the phosphor synthesized with aerosil addition is less than 100 nm that allows its implementation in pharmacological drugs for XRPDT.

Assessment of membrane type effects on in vitro performance of topical semi-solid products

In vitro release tests have been widely used to assess performance of topical products. Any interaction should not be observed between drug and synthetic membrane, but there is no conclusive information about relationship of membrane type and properties of drug substances. In this study, four types of membranes (regenerated cellulose, cellulose acetate, mixed cellulose ester, silicone) were used to evaluate in vitro release of hydrophilic, moderately lipophilic and highly lipophilic drug substances from their topical preparations. The relationship between membrane type and drug characteristics was investigated using Strat-M™ membrane resembling to human skin, and excised porcine skin for in vitro permeation studies. The release data revealed that acceptor/donor groups in drug substance and synthetic membrane could hinder drug release through membrane. Mixed cellulose ester or cellulose acetate membranes should be opted for in vitro release studies of drugs consisting of abundant, strong acceptor/donor groups. In vitro permeation data showed that drug lipophilicity might come into prominence for these studies. Strat-M™ membrane could be more useful to estimate permeability of lipophilic molecules rather than hydrophilic ones. The results suggest that molecular structure and lipophilicity of drug could be considered to select synthetic membrane used for in vitro release and permeation studies.

CO2/CH4 and He/N2 Separation Properties and Water Permeability Valuation of Mixed Matrix MWCNTs-Based Cellulose Acetate Flat Sheet Membranes: A Study of the Optimization of the Filler Material Dispersion Method.

The main scope of this work is to develop nano-carbon-based mixed matrix cellulose acetate membranes (MMMs) for the potential use in both gas and liquid separation processes. For this purpose, a variety of mixed matrix membranes, consisting of cellulose acetate (CA) polymer and carbon nanotubes as additive material were prepared, characterized, and tested. Multi-walled carbon nanotubes (MWCNTs) were used as filler material and diacetone alcohol (DAA) as solvent. The first main objective towards highly efficient composite membranes was the proper preparation of agglomerate-free MWCNTs dispersions. Rotor-stator system (RS) and ultrasonic sonotrode (USS) were used to achieve the nanofillers’ dispersion. In addition, the first results of the application of the three-roll mill (TRM) technology in the filler dispersion achieved were promising. The filler material, MWCNTs, was characterized by scanning electron microscopy (SEM) and liquid nitrogen (LN2) adsorption-desorption isotherms at 77 K. The derivatives CA-based mixed matrix membranes were characterized by tensile strength and water contact angle measurements, impedance spectroscopy, gas permeability/selectivity measurements, and water permeability tests. The studied membranes provide remarkable water permeation properties, 12–109 L/m2/h/bar, and also good separation factors of carbon dioxide and helium separations. Specifically, a separation factor of 87 for 10% He/N2 feed concentration and a selectivity value of 55.4 for 10% CO2/CH4 feed concentration were achieved.

Testing Different Membrane Filters for 16S rRNA Gene-Based Metabarcoding in Karstic Springs

Introduction: Karstic springs are used worldwide by rural communities as sources of fresh water for humans and livestock. In Romania, one-third of the population has no direct access to a public water supply. The present study is part of a country-wide project to develop simple, quick and cheap methods for seasonal environmental and microbiological monitoring of karstic springs used as drinking water by rural populations. Critical steps for monitoring workflow consist of evaluating water quality and selecting suitable membrane filters to efficiently capture environmental DNA for further microbial diversity estimation using 16S rRNA gene-based metabarcoding. Methods: Several commercial membrane filters of different compositions and pore sizes were tested on the water sampled from three karstic springs in Romania, followed by water chemistry and whole community 16S rRNA gene-based metabarcoding analysis. Results: We found that different types of applied membrane filters provide varying recovery in diversity and abundance of both overall and pathogenic bacteria. Conclusions: The result of the experiment with different filters shows that mixed cellulose ester, cellulose acetate, and nitrate membranes of 0.20 and 0.22 µm are the best for amplicon-based metabarcoding monitoring of karst springs.

Synthesis of Y<sub>2</sub>O<sub>3</sub>: Eu Nanosized Phosphor Using Hydrothermal Technique and Rapid Thermal Annealing (RTA)

The application of special nanomaterials is promising for the development of new methods for the diagnostics and treatment of cancer. Photodynamic therapy (PDT) is a well-known and recognized method of cancer treatment. This type of therapy is less carcinogenic and mutagenic compared to radiation and chemotherapy, since the applied photosensitizers do not bind to DNA of the cells. However, currently this technique is only applicable to skin cancer, while its extension to the treatment of abdominal tumors requires the creation of pharmacological drugs for PDT, which along with a photosensitizer include a colloidal solution of nanosized luminescent phosphor emitting visible light with the required wavelength under the influence of infrared, X-ray or γ-radiation, which easily penetrates the body tissues. Since photosensitizers are already available as commercial products, the most important goal is the development of nanosized phosphors providing the required radiation convertion. In this study, the effects of hydrothermal synthesis, duration and the conditions of rapid thermal annealing (RTA) on Y2O3:Eu phosphor particle size were studied. The hydrothermal synthesis technique was carried out in two ways: chloride (precipitation from a chloride solution using NaOH and NH4OH precipitators) and acetate (decomposition of mixed acetate either without a dispersant at 230° C for 24 hours, or using PEG-200 and PEG-2000 as dispersants at 230 °C for 12 hours). The rapid thermal annealing was performed either at 600 °C for 20 minutes, or at 800 °C for 5 minutes. The developed synthetic approaches afforded Y2O3:Eu nanosized phosphor samples with the particle size not exceeding 200 nm.

Iron-Catalyzed Direct Cross-Coupling of Ethers and Thioether with Alcohols for the Synthesis of Mixed Acetals

An iron-catalyzed direct O-alkylation of alcohols via α-C(sp3)–H activation of ethers and a thioether has been established that tolerates cyclic and acyclic ethers and alcohols containing aromatic N-heterocyclic moieties, providing an efficient and green method for the synthesis of mixed acetals with good to excellent yields. The robustness of this protocol is demonstrated by the late-stage oxidation of a structurally complex natural product.

Research on the effects of salt doping on the suiface morphology of alumina thin films

We envisage that by the method of adding salt compounds, then washing them after the film sintered can produce holes inside and in the surface of the alumina film such as cheese-like, so that the organic matter can enter the aluminum oxide inside. Alumina can play a role in protecting internal organic matter from friction and prolong the use of hydrophobic film in the use. In the experiment, we found that the surface of the thin film with mixed magnesium acetate can form a good roughness.