New Method For Synthesis Research Articles

A new method for synthesis and designing transmissive linear-to-circular polarization converters based on branch line circuit model

This paper proposes a new design method of a linear-to-circular polarization converter based on the branch line circuit model. The series branches are implemented by dielectric spacers and the shunt branches are implemented by anisotropic admittance sheets. The admittance matrix of the anisotropic admittance sheets is derived by even and odd mode analysis. A unit cell consisting of two metal layers and a dielectric spacer is then designed using an iterative algorithm for operation from 15.5 to 23 GHz. Results indicate that the axial ratio and insertion loss of the designed polarizer are better than 3 and 1.5 dB respectively, for incident angles between ±45°. To validate the simulation results, a waveguide-based test setup is designed and fabricated, with measurement results indicating good agreement with simulations. The proposed method can be potentially applied to design other anisotropic structures such as half-plate polarizers and polarization rotators.

Polymer System Based on Polyethylene Glycol and TFE Telomers for Producing Films with Switchable Wettability.

Today a lot of attention is paid to the formation of thermosensitive systems for biomedical and industrial applications. The development of new methods for synthesis of such systems is a dynamically developing direction in chemistry and materials science. In this regard, this paper presents results of the studies of a new synthesized supramolecular polymer system based on polyethylene glycol and tetrafluoroethylene telomers. The films formed from the polymer substance have the property of switching wettability depending on temperature after heating activation. It has been established that the wettability changes at 60 °C. The contact angle of activated hydrophobic polymer film reaches 143°. Additionally, the system exhibits its properties regardless of the pH of the environment. Based on data obtained by the methods of infrared and x-ray photoelectron spectroscopy, differential thermal analysis and thermal analysis in conjunction with wettability and morphology, a model of the behavior of molecules in a polymer system was built that ensures switching of the hydrophilic/hydrophobic surface state. The resulting polymer system, as well as films based on it, can be used in targeted drug delivery, implantation surgery, as sensors, etc.

Exploring the effects of ultraviolet radiation on the properties of Fe3O4/PANI nanostructures

The properties of any material are the basis for the most diverse applications of science, which allows for the dazzling development of new technologies. In this work, we present a new method of synthesis of Fe3O4/PANI nanostructures using ultraviolet radiation. We show that the nanostructures produced by our method have exceptional properties, evidenced by the high stability and quality of the nanostructures. Among the highly stable properties, the magnetic ones stand out, where the nanostructures have high coercivity and remanence, in addition to a well-defined saturation magnetization. Such characteristics of this type from nanostructure indicate the method is promising for producing thin films with high stability and excellent magnetic and conductive properties.

Unlocking the Potential of Bismuth‐Based Materials in Supercapacitor Technology: A Comprehensive Review

AbstractSupercapacitors (SCs) have attracted significant attention in the realm of energy storage devices due to their exceptional features, such as enhanced charge storage capacity, fast charge‐discharge rates, and high power density. The emergence of cost‐effective and highly productive SCs is a topic of interest among industrial and scientific communities. Ferrites with a perovskite crystal structure are often considered excellent electrode materials due to their intrinsic properties, affordability, low environmental impact, and widespread availability. An in‐depth investigation of perovskite ferrites in the context of SCs is necessary to advance the understanding of these materials. The techniques used in the synthesis of ABO3‐type perovskite bismuth ferrite materials are comprehensively reviewed in this review. The review starts by analyzing various types of SCs classified based on their electrode materials. The review provides a comprehensive understanding of the design and functionality of these devices, serving as an important source of inspiration for new methods of synthesis and fabrication methodologies that aim to produce environmentally friendly SCs.

Raisins in a Hydrogen Pie: Ultrastable Cesium and Rubidium Polyhydrides

AbstractA new method for synthesis of metal polyhydrides via high‐pressure thermal decomposition of corresponding amidoboranes in diamond anvil cells is proposed. Within this approach, molecular semiconducting cesium (P4/nmm‐CsH7, P1‐CsH15+x) and rubidium (RbH9‐x) polyhydrides with a very high hydrogen content reaching 93 at.% are synthesized. Preservation of CsH7 at near ambient conditions, confirmed both experimentally and theoretically, represents a significant advance in the stabilization of hydrogen‐rich compounds. In addition, two crystalline modifications of RbH9‐x with pseudohexagonal and pseudotetragonal structures identified by synchrotron X‐ray diffraction, and Raman measurements are synthesized. Both phases are stable at 8–10 GPa. This is an unprecedentedly low stabilization pressure for polyhydrides. These discoveries open up possibilities for modifying existing hydrogen storage materials to increase their efficiency.

Development of a new method for synthesis, controlling the particle size and morphology of ZIF and considering its effect on the Oxygen reduction reaction

For the first time, this study examined one aspect of the synthesis conditions of zeolitic imidazolate framework (ZIF) and its impact on its morphology and structural properties. Specifically, the study investigated the effect of the time of adding the precursor on ZIF's properties. The study used various analytical techniques, including field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDS), N2 adsorption-desorption isotherms, BET, BJH, and XRD to investigate ZIF's properties. The study found that increasing the addition-precursor time effectively increased the particle size, and the surface area and pore size were affected by changing the time of addition. The study also examined the synthesis condition of electrocatalysts for the oxygen reduction reaction (ORR) in acidic media obtained from Fe/Co-ZIF-8(T) pyrolysis at 1000 °C. The study found that the precursors-adding time affected the graphitic structure after pyrolysis. The onset potential of Fe/Co-NC(10 h) was about 0.86 VRHE, and the limiting current density was about 4.38 mA cm−2 in a 0.5 M H2SO4 solution. The measured kinetic parameters showed that the electron transfer number (n) and the Tafel slope of Fe/Co-NC(10 h) were 3.91 and 74 mV dec−1, respectively. The results showed that by changing the time in the precursors-adding method, the ZIF crystal structure could be engineered, and extensive studies based on this synthesis method could be designed for structural engineering.

Harnessing the Oxygen Vacancies in Metal Oxides for Nitroreduction

AbstractOxygen vacancies are one of the prominent types of defects in metal oxides. In addition to their role in modifying the electronic properties in solids, these sites have been shown to activate chemical bonds. As a result, the use of defect‐rich metal oxides in the organic transformations is promising. The article gives an overview of various chemical processes that are in use for the chemical reduction of aromatic nitro compounds to amines. Recently, application of oxygen vacancies in transition metal oxide for the selective reduction of aromatic nitro compounds to the corresponding amines has emerged as a new method of synthesis of amines. Oxygen vacancies in reducible oxide such as CuO have been shown to decompose hydrazine hydrate to H2 and in situ cause the reduction of nitro arenes to corresponding amines. This concept article discusses the literature pertaining to the synthesis of nitro reduction reaction, various strategies employed thus far and the place the defect‐mediated synthesis holds. The article also discusses the perspectives and challenges that remain to be addressed to gain more insights into the mechanistic understanding of the role of oxygen vacancies in nitro reduction and beyond.

A new method for synthesis of modified cellulose‐graft‐poly(acrylic acid) copolymer using 4‐cyano‐4‐[(phenylcarbothioyl)solfanyl]pentanoic acid to serve as RAFT agent

AbstractIn this study, cellulose was first treated with 4‐cyano‐4‐((phenyl carbonothioyl)solfanyl) pentanoic acid to serve as the reversible addition‐fragmentation chain transfer polymerization (RAFT) agent, then the controlled grafting polymerization of acrylic acid was successfully performed. A well‐defined, cellulose‐graft‐acrylic acid copolymer (Cell‐g‐PAA), has been prepared by RAFT polymerization technique using three different approaches: RAFT agent was prepared by substitution of dithiobenzoate magnesium bromide with 4,4'‐azobis(4‐cyanopentanoic acid) in ethyl acetate as a solvent, mediated cellulose (Cell) block as the macromolecular Cell‐RAFT agent and (cellulose‐co‐acrylic acid) copolymer with alternating sequence. The resulting (Cell‐RAFT) for “living” free radical polymerization was then heated in the adjacent acrylic acid monomer for the development of the controlled graft copolymer onto cellulose. The structures of the intermediate, graft copolymer were investigated by FT‐IR, DSC, 1H NMR, scanning electron microscopy, and thermo gravimetric. The results demonstrate that the preparation of graft copolymers was successfully confirmed. This approach would provide an extensive classification of molecular designs to obtain modern types of tailored hybrid materials derived from natural polysaccharides and synthetic polymers. Also, using a macro‐initiator is an excellent method for synthesizing new materials.

Hybrid Silver-Containing Nanocomposites Based on Bacterial Cellulose: New Methods for Synthesis, Structure and Properties

New silver-containing hybrid materials based on bacterial cellulose were obtained by a technological approach that combines three techniques: the formation of bacterial cellulose under static conditions, the modification of its surface by plasma treatment, and the introduction of silver nanoparticles obtained by metal vapor synthesis. The plasma treatment is found to significantly change the morphology and composition of the polymer surface. The oxidation state of silver is shown to correspond to Ag0. The resulting systems exhibit antimicrobial activity.

Occupational safety assessment of biogenic urea nanofertilisers using in vitro pulmonary, and in vivo ocular models

Nanomaterials (NMs) are now gaining popularity to be used in agriculture as fertilisers to reduce the dose of conventional fertilisers and enhance nutrient use efficiency. Urea has found its application as a conventional nitrogenous fertiliser since long, however, the nutrient use efficiency of the bulk form of urea is low due to issues related to ammonia volatilisation. This study proposes a biogenic synthesis route to develop urea nanoparticles that can be used as nano-fertiliser for better uptake and hence improved nutrient efficiency. Large scale production and widespread application of these nano-fertilisers to the agricultural fields will enhance the direct exposure to workers and farmers. Therefore, the occupational safety evaluation becomes critical. In this study, we report a new method for synthesis of urea nanoparticles (TNU, absolute size: 12.14 ± 7.79 nm) followed by nano-safety evaluation. Herein, the pulmonary and ocular compatibilities of TNU were investigated in vitro and in vivo respectively. The assay for cellular mitochondrial activity was carried out on human lung fibroblasts (WI-38) under varied TNU exposure concentrations up to 72 h. The acute biocompatibility effect, ocular irritation and sub-lethal effects were measured on New Zealand Rabbit. The results show that TNU do not exhibit any cytotoxicity and detrimental cell mitochondrial activity up to the highest tested concentration of 1000 μg/mL and 72 h of testing. The animal experiment results also show that neither acute nor sub-lethal toxic effects can be detected after TNU ocular instillation up to 21 days when tested up to environmentally relevant concentration of 15 μg/mL. These results suggest the occupational safety of biogenic urea nanoparticles and support its application as nanofertiliser.

Free‐standing δ‐MnO2 atomic sheets

Abstractδ‐Manganese dioxide (δ‐MnO2) is a 2D material which possesses distinct properties and features due to its unique atomic structure and has already been utilized in numerous disciplines recently, especially in the field of magnetism, energy storage, magnetic resonance imaging, biocatalysts, and fluorescence sensing. Keeping an eye on the huge potential of this 2D material, we report our recent discovery of single‐step synthesis of MnO2 nanosheets via bottom‐up laser crystallization (of aqueous KMnO4 solution) and top‐down sonochemical exfoliation of bulk MnO2 powder. The successful synthesis of δ‐MnO2 nanosheets has been proved through the observation of characteristic Raman peaks at 173 and 634 cm−1 and characteristic X‐ray diffraction peaks. The optical band gap was found to be 1.64 and 1.45 eV for both methods. We also demonstrated that 2D‐MnO2 is a prominent candidate material for ammonia sensing and strain sensing. δ‐MnO2 powder, when employed as cathode material in Li‐ion batteries, results in a stable voltage of ˜0.5 V and in contrast, gives ˜1 V when used in Li‐S batteries and the attained voltage is stable even for >5 h. New methods of synthesis of δ‐MnO2 and its hybrids with graphene will lead to future generation devices, it is expected.

Evolution of anticancer, antioxidant and photocatalytic activities of biosynthesized MnO2 nanoparticles using aqueous extract of Sida acuta

Recently, scientists have become interested in the biosynthesis of nanoparticles due to the need to develop new methods of synthesis that are cost-effective, safe, and efficient. In a diversity of applications, nanoparticles of metal oxide are gaining increasing attention. In this study, biosynthesized MnO2 nanoparticles using Sida acuta extract, a non-toxic hydrocolloid, a natural, and investigated their potential anticancer and antioxidant applications. MnO2 nanoparticles were characterized using XRD, FESEM, UV-visible, and FTIR spectroscopies. The results demonstrated that the synthesized MnO2 nanoparticles possess a significant capacity for scavenging free radicals. However, MnO2 nanoparticles could serve as anticancer and antioxidants. MnO2 nanoparticles are highly harmful to a renal cancer cell line (ACHN), as shown by invitro cytotoxicity studies. In the presence of xenon lamp radiation, the synthesized MnO2 nanoparticles exhibited photocatalytic activity against the degradation of rhodamine-B and methylene blue dyes. The degradation efficiency of chemically and biosynthesized MnO2 nanoparticles against rhodamine-B and methylene blue dyes was determined to be 90% and 84%, respectively.

Synthesis and characterization of Methylammonium tin iodide (CH3NH3SnI3) absorber layer for photovoltaic applications

In this work, a halide perovskite i.e. Methylammonium tin iodide (CH3NH3SnI3) has been synthesized through chemical route. This synthesis route involves two processes: i) Formation of SnI2, and ii) Formation of CH3NH3SnI3. After synthesis of CH3NH3SnI3 powder, thin films were deposited using doctor blade’s technique. The compositional, structural and morphological analysis of SnI2 powder, CH3NH3SnI3 powder and CH3NH3SnI3 thin films have been studied using EDXRF, XRD and FESEM respectively. The optical properties of the CH3NH3SnI3 films were also studied using UV–Vis spectrophotometer. The characterization of the thin films shows an optical bandgap of 1.4 eV with broad absorption, ranging between 300 nm and 900 nm. The morphological study of SnI2 powder shows rod-like structure with roughness average of 39.38 µm and that of perovskite powder and film shows flake-like structure with roughness average of 42.87 µm and 39.10 µm respectively. A new method of synthesis has been proposed. Also a brief characterization study of SnI2 powder, CH3NH3SnI3 powder and CH3NH3SnI3 thin films have been done, in order to analyse the photovoltaic properties of the thin films.

Microwave-Assisted Synthesis of New 4-Amino Acid Substituted 1,2,4-Triazole Derivative Derived from 1,2,3-Oxadiazole Nucleus and Their Anti-Bacterial and Anti-Oxidant Potential

Heterocyclic compounds especially, five or six-member heterocyclic compounds, having one to three hetero-atoms in their nucleus take part in metabolism of all living cells. And this information gives the lead for synthesizing heterocyclic derivatives. This research work has focused on development of new method for synthesis of some new amino acid substituted 1,2,4-trizole derivative from 1, 3, 4-Oxadizole nucleus. The nucleus of the 1, 3, 4-Oxadizole was first produced by reaction of Isoniazide and 3-chlorobenzeldehyde which is then converted into 1,2,4-trizole derivative by the loss of water molecule. After that incorporation of different amino acid (luecine and glycin) leads new amino acid substituted 1,2,4-trizole derivative. The newly synthesized derivative Compound A1 and A2 were characterized by optical rotation, melting point, TLC, UV spectroscopy and IR. The antibacterial was screened using Disc diffusion method with ciprofloxacin as reference drug and antioxidant activity by in-vitro DPPH method using ascorbic acid as standard drug. Synthesized compound A1 showed maximum MIC against S. aureus as compared to Compound A2. For antioxidant activity, compound A1 showed maximum percentage inhibition as compared to Compound A2.

RESEARCH OF ACID PROPERTIES OF COMPLEX OXIDE CATALYST 50%Cu3(PO4)2•50%Ni3(PO4)2

Individual orthophosphates of copper (II) and nickel (II) were synthesized and a new method of synthesis was developed, and a new complex catalytic system based on them of the type xCu3(PO4)2×yNi3(PO4)2 - 50%Cu3(PO4)2∙50%Ni3(PO4)2 was obtained, which has the predicted optimal acidic surface properties and the corresponding active centers. The acidic properties of the surface of the obtained individual copper (II) and nickel (II) phosphates and complex copper-nickel phosphate catalytic systems and the distribution of active centers on them were investigated. The peculiarities of the influence of synthesis conditions and temperature on the composition, structure and acidic properties of the surface of the obtained catalysts, as well as the nature and character of the formation of active centers of different strengths, were studied. It is established that calcination of the new synthesized copper-nickel phosphate catalytic system in the studied temperature range (120-700оС) allows not only to carry out complete dehydration of the obtained crystalline hydrate, but also contributes to a gradual change in the value of surface acidity. This leads to the formation on the surface of the synthesized complex copper-nickel phosphate catalytic system 50%Cu3(PO4)2∙50%Ni3(PO4)2 acidic active centers of appropriate strength. The promoting role of nickel ions Nі2+ in the structure of the copper-phosphate catalyst was confirmed and the presence of a synergistic effect of both these phosphates on the value of acidity in the structure of the synthesized complex catalytic system was established. A new active and cheap acidic complex catalyst – 50%Cu3(PO4)2∙50%Ni3(PO4)2, which has the necessary structure, optimal acidic surface properties, and appropriate active centers, has been obtained; therefore, it can be used for research in the chemical industry as an active and efficient catalyst for the partial oxidation of hydrocarbons into valuable products.
 Keywords: catalysts; heterogeneous catalysis; phosphates; complex oxides; oxidation; n-alkanes; hydrocarbons; ethane; ethylene.

Ozonolytic synthesis of 2-hydroxybenzyl alcohol for the production of gastrodin

2-Hydroxybenzyl alcohol is an important active pharmaceutical ingredient for the production of many drugs, in particular gastrodin, which has a wide range of beneficial effects on epilepsy, Alzheimer’s disease, Parkinson’s disease, affective disorders, cerebral ischemia, cognitive disorders. It is known that 2- and 4-hydroxybenzyl alcohols and mixtures of both compounds are obtained by the interaction of phenol with formaldehyde in the presence of basic catalysts. Due to its high reactivity with formaldehyde, the isolation of pure compounds from the reaction mixtures obtained during the interaction of phenol with formaldehyde is a big problem. Isolation of 2-hydroxybenzyl alcohol in pure form from reaction mixtures is possible only using processes that cannot be carried out on an industrial scale and is accompanied by low yields of the target product. It is possible to get rid of these problems by means of the process of direct oxidation of the 2-hydroxytoluene with ozone in the liquid phase since methods of selective ozonation of methylbenzene to the oxygen derivatives are already known. Therefore, the development of a new low-temperature synthesis of 2-hydroxybenzyl alcohol using ozone is an urgent task. The aim of the work is to study the reaction of the oxidation of 2-hydroxytoluene by ozone in a solution of a stop reagent and catalytic impurities of compounds of transition metals and mineral acids for the development of a new method of synthesis of 2-hydroxybenzyl alcohol. Materials and methods. For the experiments, acetic anhydride of p. a. qualification was used; glacial acetic acid of puriss. qualification, which before use was purified by distillation under vacuum in the presence of potassium permanganate, 2-hydroxytoluene of puriss. Qualification, manganese (II) acetate of pur. Qualification, sulfuric and phosphoric acids of puriss. qualification. To determine the concentration of ozone in the gas phase, a spectrophotometric method was used, based on the measurement of the optical density of the gas flow in the UV region. For this purpose, a spectrophotometer SF-46 LOMO was used, in the measuring chamber of which a flow cuvette with quartz windows was installed. The material of the cuvette was Teflon. Continuous monitoring of the current concentration of ozone, with the recording of the analysis results in the form of a kinetic curve, was carried out when ozone-containing gas passed through the curette at a certain wavelength of a monochromatic light source. Results. The reaction of oxidation of 2-hydroxytoluene by ozone in a solution of the stop reagent – acetic anhydride was studied. It was shown that in the presence of sulfuric acid, it was possible to carry out direct ozonation of 2-hydroxytoluene to 2-hydroxybenzyl alcohol, which was formed in the kind of 2-acetoxybenzyl acetate with a yield of 13.0 %. The main products of the reaction under these conditions are aliphatic compounds, which are formed after the destruction of the aromatic ring. The selectivity of oxidation by alcohol was significantly increased when a catalyst – manganese (II) acetate – was added to the system. In its presence, a catalytic system As2O – H2SO4 – Mn(III) was created, which prevents ozonolysis and directed oxidation mainly to the methyl group of the substrate with the formation of 2-acetoxybenzyl acetate with a yield of 63.2 %. Conclusions. An environmentally friendly, low-temperature method for the synthesis of 2-hydroxybenzyl alcohol was developed by conducting the oxidation of 2-hydroxytoluene with ozone in a solution of the stop reagent – acetic anhydride in the presence of sulfuric acid and manganese (II) acetate.

Mechanochemical synthesis of LAGP/PEG hybrid solid electrolyte: Investigation of surface structure and chemistry

The drive towards all solid state lithium ion batteries requires discovery of new methods for synthesis of true hybrid solid electrolytes in which organic and inorganic components are chemically associated to simultaneously maximize lithium ion conductivity and processability. Herein, the first mechanochemical milling synthesis of an ambient processable hybrid lithium aluminum germanium phosphate (Li1.5Al0.5Ge1.5(PO4)3)/polyethylene glycol (PEG) solid electrolyte is presented. Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) provide evidence that the mechanochemical milling procedure impels a condensation reaction between the ceramic and organic phases which produces a surface product, water. Solid state nuclear magnetic resonance (NMR) spectroscopy confirms that protons from the polymer or associated surface water product are in bonding proximity to the Q2 metaphosphate sites of the glassy phase of the ceramic. This work thus establishes the viability of mechanochemical milling as a synthetic pathway for a class of promising ambient processable hybrid electrolytes.

Differentiation between Isomeric 4,5-Functionalized 1,2,3-Thiadiazoles and 1,2,3-Triazoles by ESI-HRMS and IR Ion Spectroscopy.

A large variety of 1,2,3-thiadiazoles and 1,2,3-triazoles are used extensively in modern pure and applied organic chemistry as important structural blocks of numerous valuable products. Creation of new methods of synthesis of these isomeric compounds requires the development of reliable analytical tools to reveal the structural characteristics of these novel compounds, which are able to distinguish between isomers. Mass spectrometry (MS) is a clear choice for this task due to its selectivity, sensitivity, informational capacity, and reliability. Here, the application of electrospray ionization (ESI) with ion detection in positive and negative modes was demonstrated to be useful in structural studies. Additionally, interconversion of isomeric 4,5-functionalized 1,2,3-triazoles and 1,2,3-thiadiazoles was demonstrated. Application of accurate mass measurements and tandem mass spectrometry in MS2 and MS3 modes indicated the occurrence of gas-phase rearrangement of 1,2,3-triazoles into 1,2,3-thiadiazoles under (+)ESI-MS/MS conditions, independent of the nature of substituents, in line with the reaction in the condensed phase. Infrared multiple photon dissociation (IRMPD) spectroscopy enabled the establishment of structures of some of the most crucial common fragment ions, including [M+H-N2]+ and [M+H-N2-RSO2]+ species. The (-)ESI-MS/MS experiments were significantly more informative for the sulfonyl alkyl derivatives compared to the sulfonyl aryl ones. However, there was insufficient evidence to confirm the solution-phase transformation of 1,2,3-thiadiazoles into the corresponding 1,2,3-triazoles.

New method for synthesis of 7-hydroxydibenzopyran-6-ones: Benzannulation of coumarins by three-component condensation

We have achieved a simple, facile and three-component synthesis of C8 and C9 alkyl/aryl C7-hydroxydibenzopyrans-6-ones involving C3-acyl coumarins, selective active methylene compounds and some methyl ketones (reagent/solvent) under basic (K2CO3) conditions. Overall, our method worked by benzannulation of the existing coumarins. In this work, we used the 2-NB group (2-NB = 2-nitrobenzyl) as a surrogate for C7–OH to engineer the construction of the ring C of the 3-hydroxydibenzopyran-6-ones. Subsequently, the photolabile 2-NB was removed under neutral conditions to reveal the C3–OH.

New Method for Synthesis of N-Borylated Amino Acids Based on closo-Decaborate and closo-Dodecaborate Anions

New Method for Synthesis of N-Borylated Amino Acids Based on closo-Decaborate and closo-Dodecaborate Anions