Organic Impurities Research Articles

The Influence of Argon Plasma on Organic Perovskite MAPbI3 Film Doped with Inorganic Perovskite CsPbI3 Quantum Dots (QDs)

In this study, the inorganic perovskite cesium lead triiodide (CsPbI3) quantum dots (QDs) produced by hot-injection method were added into the hybrid perovskite methylamine lead triiodide (CH3NH3PbI3; MAPbI3) to form composite perovskite film. It is not easy for argon (Ar) to react with perovskite. Therefore, argon plasma was used to optimize the properties of the surface. However, methylamine lead triiodide molecular will be degraded by excessive wattage. Therefore, the influence of plasma power acting on composite perovskite film was investigated. The experimental results show that the light absorption capacity can be increased by argon plasma power of 140 watt (W) acting on the surface of films because organic impurities are removed and surface morphology of film is changed.

Influence of oxygen content on the manifestation of hazardous properties of coal seams

Purpose. To improve the regulatory framework for the safe conduct of mining operations, to establish the effect of mineral impurities and moisture on the accuracy of determining the oxygen content, under conditions close to those of coal seams. Methodology is based on the fact that practically for all coal seams of Donbass and the Lvov-Volyn basin indicators of consumer qualities of solid fuels have been established, but they characterize only one organic (combustible) part per dry ash-free state. In this case, the effect of mineral impurities (their content for many reservoirs exceeds 30-40%) and moisture on the change in oxygen content is not taken into account. The manifestation of many hazardous properties of coal seams depends on the ratio of oxygen content with other components of the organic mass and mineral impurities. To bring the quality indicators of coals to a state close to the conditions of mining operations, they were recalculated for each coal seams, taking into account the actual yield of ash and total moisture. Findings. The indicator of the release of volatile substances used in the normative documents for the safe conduct of mining operations for assessing the metamorphic transformations of coal seams does not determine the type of coal by their reduction. Restorability determines the properties of the organic mass based on the ratio of oxygen to its other main components. In addition to the organic mass in the dry ash-free state, the composition of solid fuels includes mineral impurities and moisture. They significantly affect the change in the ratio between the main components. The carbon content in the organic (combustible) mass is more informative in comparison with the yield of volatile substances, an indicator. It functionally controls the sum of the remaining components - hydrogen, nitrogen, sulfur and oxygen. To a lesser extent, but rather high, the closeness of the correlation interdependence was established between the content of oxygen and carbon in the dry ash-free state of the fuel. Such interdependence is completely eliminated when considering the fuel for its working condition, which indicates the random nature of the relationship between the main components of the organic mass and mineral impurities, including moisture, for each considered coal seams. Originality. For the first time, on the basis of statistical processing of experimental data on the quality of coals for almost all coal seams of the Donbass and the Lviv-Volyn basins, the possible limits of the oxygen content for the working state of the fuel were established, which makes it possible to individually consider for each coal seam the ratio between the main components of the organic mass and mineral impurities, including the presence of moisture. Practical implications. The research results make it possible to develop proposals for improving the regulatory framework in terms of predicting the hazardous properties of coal seams during mining operations.

Optimized Operating Conditions for a Biological Treatment Process of Industrial Residual Process Brine Using a Halophilic Mixed Culture

Residual process brine is a sustainable raw material for chlor-alkali electrolysis processes. This study investigates the influence of critical process parameters on the performance of a continuous treatment process for residual process brine using halophilic microorganisms. The goal of the bioprocess is an efficient degradation of the organic impurities formate, aniline, phenol, and 4,4′-methylenedianline from this residual stream. It was shown that formate could be degraded with high efficiencies (89–98%) during the treatment process. It was observed that formate degradation was influenced by the co-substrate glycerol. The lowest residual formate concentrations were achieved with specific glycerol uptake rates of 8.0–16.0 × 10−3 g L−1 h−1 OD600−1. Moreover, a triple-nutrient limitation for glycerol, ammonium, and phosphate was successfully applied for continuous cultivations. Furthermore, it was shown that all aromatic impurities were degraded with an efficiency of 100%. Ultimately, this study proposed optimized operating conditions, allowing the efficient degradation of organics in the residual process brine under various process conditions. Future optimization steps will require a strategy to prevent the accumulation of potential intermediate degradation products formed at high aniline feed concentrations and increase the liquid dilution rates of the system to achieve a higher throughput of brines.

ВПЛИВ ПАРАМЕТРІВ РУХУ ВОДИ НА ЕНЕРГОЕФЕКТИВНІСТЬ ЇЇ ОБРОБКИ ІМПУЛЬСНИМ БАР’ЄРНИМ РОЗРЯДОМ

A study of the energy efficiency of the pulsed barrier discharge during water treatment in the aerosol state depending on the energy of the pulses (21-72 mJ), their repetition rate (50-300 Hz), the concentration of organic impurities in water (50-100 mg / l) and water content (1.6−3.2%) in the water-air mixture. The discharge was generated by unipolar short pulses (~ 100 ns) in an electrode system with vertically arranged cylindrical electrodes with a diameter of 2 mm, the distance between which was 2 mm. The highest energy yield, which was obtained by decomposing the impurity by 90%, was 32 g / kWh. In order to determine the influence of water movement parameters on the energy efficiency of a pulsed barrier discharge under similar conditions, the energy efficiency of this type of discharge during water movement in film, drip and aerosol states was compared. It is concluded that water treatment should be carried out in the drip state on the submillimeter size of the drops. In the case of such water movement, the energy efficiency of the pulsed barrier discharge is ≈30% higher than in aerosol. References 15, figures 6, table 1.

Ultraviolet photo-enhanced atomic layer deposition for improving dielectric properties of low temperature deposited Al2O3

Thin films of Al2O3 are deposited using in situ ultraviolet (UV) light enhanced atomic layer deposition (ALD) with trimethylaluminum and H2O and compared to those deposited using traditional thermal ALD at low temperatures of 45 and 80 °C. Coexposing the UV light with the H2O pulse enhanced the growth-per-cycle and refractive index. Metal/insulator/metal devices using the in situ UV enhanced Al2O3 films demonstrated a reduction in leakage current at ±1 MV/cm by nearly an order of magnitude at a deposition temperature of 45 °C as compared to standard thermal ALD films as well as thermal ALD films that received a postdeposition (in vacuo) UV exposure. In addition, capacitance–voltage behavior of UV enhanced Al2O3 showed a dramatic reduction in capacitance–voltage hysteresis. Taken together, these electrical results suggest that in situ UV enhanced ALD of Al2O3 results in a reduced density of electrically active defects that likely arise from incorporated H and potentially other organic impurities left by incomplete surface reactions. This proof-of-concept approach could enable low temperature fabrication of metal/insulator/metal and other devices in temperature-sensitive applications such as flexible electronics.

Impurity Profiling: A Review

Impurities are any substances, such as starting materials or intermediates, that coexist with the parent drug or arise from side reactions. Interest in impurities present in APIs continues to grow. Nowadays, not only purity profile but also impurity profile is mandated by various regulatory agencies. Impurity profiling is a generic name for a group of analytical working groups such as describing, quantifying and characterizing identified and unidentified impurities present in a new drug substance. Impurity profiling is a novel approach aimed at detecting, identifying, structuring and quantifying organic and inorganic impurities and residual solvents in pharmaceuticals. Various regulatory bodies, such as ICH, USFDA, UKMHRA, and India's CDSCO, focus on impurity profiling and have formulated guidelines for impurity management and restriction. Impurities are classified into different categories based on their origin, type of composition, and biological safety. The presence of these unwanted chemicals or substances may affect the safety and effectiveness of the final medicinal product. This review focuses on the sources of impurities, their classification, and various analytical methods for the identification and quantification of impurities. Terms such as residual solvent, by-product, transformation product, decomposition product, reaction product, and related products are often used to define impurities.

Sustainable and fast elimination of high Cr(III) concentrations from real tannery wastewater using an electrochemical-chemical process forming Cr2FeO4

Here, an electroprecipitation process is proposed to eliminate high concentrations of Cr(III) (5424.3 mg L-1), and organic impurities contained in a real tanning discharge. The electrochemical reactor is comprised of TiO2/RuO2 as cathode, and carbon steel (1018-type) as anode, evaluated at 10 and 20 mA cm−2 (applied current density), and pH values equal 5 and 6. The electroprecipitation of Cr(III) cannot be conducted at the original wastewater pH (4.53), due to impurities hampering the occurrence of this reaction, and the need of hydroxyl ions to enhance the metal removal, whereby the original pH was varied to pH 5 or 6. Using 20 mA cm−2 (current density), treatment times of 1 and 0.5 h are required to eliminate the entire Cr concentration at pH values of 5 and 6, respectively. 6 and 3.5 kWh m−3 of energy consumptions are estimated for these respective experimental conditions. This consumption considerably decays at 10 mA cm−2. It is found that Cr2FeO4(s) is the main solid precipitate recovered from the treatment method, subsequently low contents of CrO(OH)(s) and Cr(OH)3(s) are collected, regardless of the applied current density and solution pH. Visual inspection and Scanning Electron Microscopy (SEM) analysis reveal that organic impurities are also removed. X-ray photoelectron spectroscopy (XPS) confirms this information along with the formation of other Cr and Fe species on the surface of the precipitates. The electroprecipitation mechanism for Cr(III) removal is discussed based on Pourbaix-type diagrams, and X-ray diffraction (XRD) analysis of the recovered solids.

Influences of Impurity Incorporation in Electroplated Cu on the SnAgCu and Ni-Containing SnAgCu Solder Joints

SnAgCu and Ni-containing SnAgCu alloys are Pb-free solders widely used to join with Cu to construct the solder joints. Electrodeposition is a technology commonly used to fabricate Cu but co-deposition of organic impurities originating from additives is an inevitable reliability issue. This study investigates the impurity effect on the voiding propensity in the two solder joints (SnAgCu/Cu and SnAgCu-Ni/Cu) subjected to thermal aging at 200 °C. Results show that a high level of impurity incorporation causes massive void propagation along the SnAgCu/Cu and SnAgCu-Ni/Cu interface. Reduction of the impurity concentration by precise control of the additive formulas can weaken the impurity effect and effectively suppress the void propagation. The weakening phenomenon of the impurity effect is more pronounced in the SnAgCu-Ni/Cu joint, indicating that suppression of the Cu3Sn growth as well as Kirkendall voids by Ni addition is also helpful in reducing the influences of impurities.

Using liquid extraction to clean JSC «Kola MMC» nickel production solutions from impurities

Studies of the extractive recovery of Ca(II), Mg(II) и B(III) impurities from nickel production solutions at JSC «Kola Mining and Smelting Company» were conducted. As extraction agents, we used di-(2-ethylhexyl)phosphoric acid (D2EHPA), di-(2,4,4-trime-thylpentyl)phosphinic acid (Cyanex 272), trialkylamine (TAA), tributyl phosphate (TBP), aliphatic alcohols: octanol-1, 2-ethylhexanol and a by-product of its production – heavy product of 2-ethylhexanol distillation (TPRD). In order to assess the effect of conditions used to extract impurities from solutions, laboratory studies on the effect of aqueous phase acidity, extraction agent concentration, composition of organic impurities on their extractability were conducted. According to the research results, it was found that the optimal concentration of individual extraction agents is 20 vol.% each in the Escaid 100 solvent, and the mixture composition is 15 vol.% D2EHPA + 5 vol.% Cyanex 272 at Ca(II) and Mg(II) extraction. Individual D2EHPA predominantly extracts calcium (II): extraction of 62 % Ca(II) and 15 % Mg(II). When using Cyanex 272, the extraction of magnesium (II) predominates: extraction of 59 % Mg(II) and 20 % Ca(II). It was found that the extraction mixture has higher performance than individual extraction agents for Ca(II) and Mg(II) extraction from nickel solutions in the pH range of 3.0÷3.5, at which Ni(II) coextraction is negligible. With increasing pH values, Ca(II) extraction decreases due to the increasing extraction of nickel and the displacement of calcium by it from the organic phase. It was established that a mixture of 40 % TAA + + 60 % 2-octanone and heavy product of 2-ethylhexanol distillation exhibits high extraction ability with respect to B(III): the degree of boron extraction is 60.7 and 74.5 %, respectively. The paper provides the results of the extraction purification of the nickel electrolyte from JSC «Kola Mining and Smelting Company» with an extraction mixture in the Ni-form to exclude pH adjustment at each stage of the process. Based on the results of the studies conducted, a flowchart is recommended for obtaining pure NiSO4 solutions with a residual total B(III), Ca(II), Mg(II) and Cl– content of £0.010 g/dm3 .

An Urgent Industrial Scheme Both for Total Synthesis, and for Pharmaceutical Analytical Analysis of Umifenovir as an Anti-viral API for Treatment of COVID-19

This paper aims to reveal an urgent industrial scheme for a fast and facile total synthesis of umifenovir (arbidol) (by one-pot stages) as an antiviral agent for treating the 2019-nCoV virus via inhibiting its viral replication in the human cells. As COVID-19 takes thousands of lives all around the world, it seems that the medicinal resources would not be enough to supply billions of peoples currently living on the planet. Thus, this pandemic and its subsequent impacts on the natural order of our life would be one of the most important threats against the entire human race. In this project, we have made attempts to find an operative approach for synthesizing this compound as an active pharmaceutical ingredient (API), which showed it could be effective in inhibiting the newly emerged coronavirus.. The designed scheme uses relatively cheap precursors and contains one pot stage instead of seven time-consuming and more costly linear steps. Moreover, safe and cheap solvents have been used like water and ethanol, instead of toxic ones like methanol and pyridine which could cause rejection of the API in the organic volatile impurities (OVI) test of pharmacopeia analysis, as well as increase the concern of inflammability, explosivity, and carcinogenic properties of those common solvents. The most important pharmaceutical analytical methods containing OVI test (mainly ethanol (about 171 ppm) much lower than the limits, by gas chromatography-Flame Ionization Detector (GC-FID) instrument), assay content (about 99.6% by potentiometric titration), and related purity analysis (by high-performance liquid chromatography-Ultraviolet Detector (HPLCUV)) (about 99.8%) were performed and described to give a more clear industrial scheme.

Application of regenerated spent bleaching earth as an adsorbent for the carbon dioxide adsorption by gravimetric sorption system

Abstract The atmospheric level of carbon dioxide (CO2) is indicated to be alarming which in turn has contributed to the worldwide environmental issue such as global warming. The goal of this project was to study the adsorption of CO2 onto regenerated spent bleaching earth (RSBE). Spent bleaching earth (SBE) can be a good adsorbent but it has the weakness in surface area due to the organic impurities left in the pores after being generated from the edible oil processing. Thus, the regeneration processes of SBE by (a) direct heat treatment, and (b) heat treatment followed by nitric acid treatment were studied to enhance the surface area, thus increasing the CO2 adsorption capacity. The SBE were calcined at four temperatures of 400, 500, 650 and 800 °C in the regeneration process. The surface properties of RSBE were characterized using Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FTIR) analysis and Brunauer–Emmett–Teller (BET) surface area analysis. The CO2 adsorption capacity on RSBE produced by heat treatment followed by nitric acid treatment was shown to be more effective than RSBE produced by direct heat treatment. RSBE_500_HNO3 offered highest surface area (192.81 m2/g) and give highest CO2 adsorption capacity of 86.67 mg CO2/g. In comparison to the low pressure condition, the high pressure CO2 adsorption values recorded for both RSBE were significantly better.

Direct Sunlight Driven In2S3 Thin Film Based Water Treatment Proto-Type

A multi-faceted energy intensive technology that can be used for water disinfection and synthesis of electrolysed water (EW) is the need of the hour to achieve a sustainable post COVID 19 water management strategy. Direct sunlight driven processes are legislatively green technologies and hold the key in environmental sustenance. The development of a laboratory proto type reactor powered by a photovoltaic module for the treatment open source river water is described in this paper. This paper reports on the efficacy of the developed proto type technology for multipurpose application namely: (1) the production of Electrolysed water (EW) in a cost efficient manner using direct sunlight and (2) the removal of organic impurity from water using direct sunlight without the use of any photo catalyst or membrane. The prototype reactor utilizes chemical spray pyrolysis deposited highly photo-conducting indium sulphide thin films grown on fluorine doped tin oxide (F:SnO2) substrate (coated using chemical spray pyrolysis technique in-house) as the photo electrode. Dissolved organic matter arising in river water has distinctive fluorescence properties, and this research has utilized it to identify dissolved organic substances in both random samples and treated water. The work proves that photovoltaic module powered electrolytic reactors consisting of In2S3 electrodes can be used for treatment of river water. A diaphragm free, energy intensive route for the production of electrolysed water with the use of non-hazardous NaCl as the electrolyte has been demonstrated here. We conclude that In2S3 electrodes can be used for non-photo catalytic reduction of humic-derived impurities in river water. These results are also encouraging on the prospects of treating Nitrates present in the river water. The likes of techniques as described in this report that do not use photo catalyst or membranes may pave way for real time photovoltaic module powered floating reactors that can decontaminate water bodies on a large scale. The technique used by us demonstrates that a chlorine free route can be optimized for the synthesis of EW eliminating the production of large amounts of wastewater with high levels of biological oxygen demand (BOD).

Synthesis and Applications of Biopolymer /FeO Nanocomposites: A Review

Magnetic oxide nanoparticles have engaged most consideration due to their rare character, such as easy separation, surface-to- volume ratio, paramagnetic and high surface area. Natural biopolymers, namely, (Chitosan, Guar-Gum, Tamarind, Alginate, Dextran, Pectin) have posed as an incredible host for the preparation of magnetic nanoparticles. Biopolymer based magnetic nanocomposites have been fabricated from long time using method like co-precipitations, green synthesis, in-situ, hydrothermal and wet chemical method. Properties of biopolymer magnetic nanocomposites draw attention to the researchers towards fabricating at the nano level for various applications like as adsorptions inorganic metal, organic impurity, targeted drug-delivery, bio-sensing, catalysis activity, antimicrobial activity, antifungal activity, antioxidant activity, anti-cancer activity, energy, environmental remediation, waste water treatment and textiles. This review is designed to report very firstly reported biopolymer magnetic nanoparticles (BMNPs) in last ten years and attractive approach in various applications.

Temperature and Tumor Microenvironment Dual Responsive Mesoporous Magnetic Nanospheres for Magnetothermal Effect-Induced Cancer Theranostics

Temperature and Tumor Microenvironment Dual Responsive Mesoporous Magnetic Nanospheres for Magnetothermal Effect-Induced Cancer Theranostics

Recommendation of Single Time Point Leachables Testing for Lyophilized Biotechnology Products Stored in Rubber Stoppered Glass Vial Systems

As a popular format of primary container closure systems, rubber stoppered glass vials are often used in storing and delivering lyophilized and liquid formulated therapeutic protein products. Assessing extractables and leachables from rubber stoppered glass vial systems is required to ensure drug product quality and patient safety. Lyophilized biopharmaceutical drug products are generally considered as less impacted by leachables during storage and transportation than the liquid formulated drug products. Single time point leachables testing for lyophilized biopharmaceutic drug products is recommended. The recommendation is based on our published comprehensive leachable data collected at multiple time points for five lyophilized drug products stored in different rubber stoppered glass vial systems with additional supporting comprehensive leachable data collected for nineteen liquid formulated drug products stored in different syringe and vial systems, which is statistically and scientifically sound. The leachable data evaluated herein were generated based on a holistic approach which ensured successful qualification of different vial systems as primary containers and delivery systems for various biotherapeutic products. The organic and elemental impurities of the leachable profiles of all the twenty-four drug product samples were below the limit of detection at all the time points. For lyophilized drug products, product surface interaction during storage time and shipping is unlikely. Timing of single time point leachables testing can be flexible. Performing leachables testing at one-year time point is recommended as it allows for enough time for chemicals to leach out from product contact surfaces into drug products and thus provides the earliest opportunity for mitigation of unpredicted leachables of concern, if any. However, testing at other stability time points can also be considered depending on the development strategy of the sponsor. Therefore, recommendation of single time point leachables testing for lyophilized drug products stored in rubber stopped glass vials at an appropriate time point is a scientifically sound approach.

Selective extraction of cesium from high concentration rubidium chloride leach liquor of lepidolite

A special extractant, 4-tert-butyl-2-(α-methylbenzyl) phenol (t-BAMBP), was applied in cesium separation and purification from high concentration of rubidium chloride leach liquor. Effects of various parameters, such as feed liquid alkalinity, reagent concentration, contact time, and phase ratio, on extraction, scrubbing and stripping were systematic studied. The results demonstrated that the extraction rate of cesium reached 99.18% after five-stage countercurrent extraction, with the optimal extraction conditions that a feed liquid initial alkalinity of 10 g/L, t-BAMBP concentration of 1 mol/L, contact time of 1 min, and phase ratio (O/A) of 1:4. In addition, the loaded organic phase coextracted impurity elements (15.78% Rb, 0.5% K) was scrubbed with 0.1 mol/L HCl. After four-stage countercurrent scrubbing, the scrubbing rates of rubidium and potassium were 99.83% and 100% respectively, as well as 5.73% of cesium was lost. Almost all cesium (99%) was stripped with 0.05 mol/L HCl by two-stage countercurrent stripping after the organic phase was scrubbed. The slope method calculated the composition of the extraction complex as CsOR ∙ 2ROH(o), and the cation exchange reaction was proven to be the extraction mechanism.

SYNTHESIS AND CHARACTERIZATION OF CARBOXYMETHYL CELLULOSE (CMC) FROM DIFFERENT WASTE SOURCES CONTAINING CELLULOSE AND INVESTIGATION OF ITS USE IN THE CONSTRUCTION INDUSTRY

This study aimed at the recovery of cellulose from abundantly available wastes and its sustainable application. Firstly, in the cleaning process, cellulose-containing wastes, such as “air particle vacuum powder” (APVD), “towel clippings” (TC), and “cottonseed delintation residues” (CD), were thoroughly washed, separately, with tap water to remove some organic and inorganic impurities. The cotton slurry was purified by 17.5% NaOH at 90 oC for about 4 hours, then filtered and washed with tap water. Afterwards, the resulting pulp was bleached by NaOH and H2O2, and washed with distilled water until neutralized. Secondly, for the synthesis of carboxymethyl cellulose (CMC) from the above-dried celluloses, optimum conditions were achieved by varying the concentrations of components and ambient conditions. In the sample coded TCCMC3, a maximum degree substitution (DS) of 1.22, the highest consistency, the highest penetration time and the highest viscosity with 2520 centipoises (cP) were obtained from the reaction of towel clippings with 5.62 g sodium hydroxide and 13.12 g monochloroacetic acid (MCA) at 65 oC for 3 hours. Finally, the effect of these synthesized CMCs on the consistency and penetration time of a cement paste was investigated. The consistency of standard Portland cement (PC), without CMC addition, was 5 mm in the Vicat test, while the values measured for the cement pastes to which TCCMC3, APVDCMC3 and CDCMC3 were added reached 36.5 mm, 28.0 mm and 13.0 mm, respectively. While the setting time in the standard sample (Portland cement paste, PCP) was between 2.20-4.10 hours, this time shifted to 3.30-7.00 hours, with a maximum setting time recorded with the addition of TCCMC3. Besides, while the penetration time for APVDCMC3 started at 3.10 hours and was completed at 5.30 hours, for CDCMC3, it ranged between 2.40 and 4.40 hours, leaving it without hydration in a higher time interval than in the case of standard Portland cement paste. As a result, it has been found that carboxymethyl cellulose synthesized by the etherification reaction of cellulose obtained from recycled wastes for industrial uses, in an aqueous alkali environment, can be applied as a thickener in the construction industry and other fields.

Sonochemistry fabrication of Er2Sn2O7 nanoparticles with advanced photocatalytic performance of their carbonic nanocomposites

The insufficiency of clean water sources has become a perilous tension for the future of the world that one of the eco-friendly and cost-effective solutions is the photocatalytic process for removal of artificial dyes and poisonous organic impurities. In the current research, a simple sonochemistry process was accomplished to gain Er 2 Sn 2 O 7 (ESO) nanoparticles with progressive photo-catalytic proficiency. Various surfactants of cationic Cetyl Trimethyl Ammonium Bromide (CTAB), anionic Sodium dodecyl sulfate (SDS) and polymeric polyethylene glycol 6000 (PEG 6000) were utilized to the creation of pure Er 2 Sn 2 O 7 nanoparticles. The figure and dimension of products were studied by various characterization procedures of spectroscopic and microscopic. The photo-degradation performances of the pure Er 2 Sn 2 O 7 nanoparticles prepared in different conditions were tested to remove of diverse synthetic dyes. Carbon-based nanocomposites of graphitic carbon nitrides (g-C 3 N 4 ), graphene quantum dots (GQDs) and graphene oxide (GO) present enhanced photocatalytic activities. The outcome of the catalyst size, type of dye, kind of carbon structure and scavenger kind was labeled on modifying ability of Er–Sn–O nano-catalyst task. Optimized Er 2 Sn 2 O 7 /g-C 3 N 4 nanocomposites have an efficiency of 93.9% for degradation of acid red dye that OH radicals support photo-degradation of contamination. • Synthesis of Er 2 Sn 2 O 7 nanoparticles via rapid ultrasonic technique. • Investigation of diverse synthesis circumstances on dimension properties of nanostructures. • Consideration of photo-degradation efficiency of Er–Sn–O nanostructures in different experimental conditions. • Investigation of photocatalytic mechanism of Er 2 Sn 2 O 7 /g-C 3 N 4 nanocomposites and kinetic study.

Isoporous Polyvinylidene Fluoride Membranes with Selective Skin Layers via a Thermal-Vapor Assisted Phase Separation Method for Industrial Purification Applications.

The membrane filtration process is the most widely used purification process in various industries due to its high separation efficiency, process simplicity, and low cost. Although there is a wide range of membrane products with diverse materials and pore sizes on the market, there is a technological gap between microfiltration and ultrafiltration membranes. Here we developed highly porous polyvinylidene fluoride (PVDF) membranes with a selective skin layer with a pore size range of 20 to 80 nm by using a thermal-vapor assisted phase separation method. Porous and bi-continuous sublayers were generated from spinodal decomposition induced by cooling. The overall membrane structure and pore size changed with the dope composition, while the pore size and thickness of the selective skin layer were effectively controlled by water vapor exposure. The excellent nanoparticle removal efficiencies of the prepared PVDF membranes were confirmed, indicating their potential application in high-level purification processes to remove small trace organic or inorganic impurities from various industrial fluids.

Bioinspired Control of Calcium Phosphate Liesegang Patterns Using Anionic Polyelectrolytes.

The Liesegang phenomenon is a spontaneous pattern formation, which is a periodic distribution of the precipitate discovered in diffusion-limited systems. Over the past century, it has been experimentally attempted to control the periodicity of patterns and structures of precipitates by varying the concentration of the hydrogel or electrolytes, adding organic or inorganic impurities, and applying an electric or pH field. In this work, the periodic patterns of calcium phosphate were manipulated with an anionic macromolecular additive inspired by bone mineralization in which various noncollagenous proteins are involved in the formation of a polymer-induced liquid precursor. The periodic patterns were systematically controlled by adjusting the amount of poly(acrylic acid), and they were numerically simulated by adjusting the threshold concentration of nucleation. The change of the pattern is explained by improved stability and directional diffusion of the intermediate.