Excellent Separation Capability Research Articles

Analytical Methods for Assessing Thiol Antioxidants in Biological Fluids: A Review.

Redox metabolism is an integral part of the glutathione system, encompassing reduced and oxidized glutathione, hydrogen peroxide, and associated enzymes. This core process orchestrates a network of thiol antioxidants like thioredoxins and peroxiredoxins, alongside critical thiol-containing proteins such as mercaptoalbumin. Modifications to thiol-containing proteins, including oxidation and glutathionylation, regulate cellular signaling influencing gene activities in inflammation and carcinogenesis. Analyzing thiol antioxidants, especially glutathione, in biological fluids offers insights into pathological conditions. This review discusses the analytical methods for biothiol determination, mainly in blood plasma. The study includes all key methodological aspects of spectroscopy, chromatography, electrochemistry, and mass spectrometry, highlighting their principles, benefits, limitations, and recent advancements that were not included in previously published reviews. Sample preparation and factors affecting thiol antioxidant measurements are discussed. The review reveals that the choice of analytical procedures should be based on the specific requirements of the research. Spectrophotometric methods are simple and cost-effective but may need more specificity. Chromatographic techniques have excellent separation capabilities but require longer analysis times. Electrochemical methods enable real-time monitoring but have disadvantages such as interference. Mass spectrometry-based approaches have high sensitivity and selectivity but require sophisticated instrumentation. Combining multiple techniques can provide comprehensive information on thiol antioxidant levels in biological fluids, enabling clearer insights into their roles in health and disease. This review covers the time span from 2010 to mid-2024, and the data were obtained from the SciFinder® (ACS), Google Scholar (Google), PubMed®, and ScienceDirect (Scopus) databases through a combination search approach using keywords.

In situ constructing 2D/2D layered BiOBr/Bi2O2CO3 heterostructure for efficient photocatalytic reduction CO2 to CO

Photocatalytic reduction of CO2 to valuable energy materials is necessary for sustainable development. It is a considerable challenge to prepare photocatalysts for CO2 photoreduction with excellent separation capability of carriers by simple way. Herein, the BiOBr/Bi2O2CO3 type-II heterostructure was constructed by in situ conversion at room temperature. Combining the advantages of the 2D/2D layered structure can form a close contact interface and the type-II heterostructure can facilitate the transport of photogenerated charges, the BiOBr/Bi2O2CO3 composite showed significant enhancement in photocatalytic CO2 reduction performance. The most obvious performance enhancement was observed for 2.0-BiOBr/Bi2O2CO3, where CO yield could reach 29.55 μmol·g−1 for 3 h under light irradiation, it is 11 and 4 times higher than Bi2O2CO3 and BiOBr, respectively. And the sample exhibits excellent cycling stability in photocatalytic tests. In situ Fourier Transform Infrared spectroscopy confirmed that the important intermediates of the reaction are *COOH and *CO. The photocatalytic reduction mechanism of CO2 to CO in the BiOBr/Bi2O2CO3 type-II heterostructure was further analyzed. This study provides feasible solutions for selecting photocatalytic materials and designing facile preparation of efficient 2D/2D catalysts for photocatalytic reduction of CO2.

Charge transport properties and photostability of microcrystalline cellulose derived from Gigantochloa scortechinii-supported ZnO for enhanced acetaminophen degradation

A facile chemical mixing procedure was utilized to fabricate microcrystalline cellulose (MCC) derived from Gigantochloa scortechinii-supported ZnO photocatalysts, with different MCC content. The successful incorporation of ZnO onto the MCC surfaces was characterized by multitudinous characterization techniques. The photocatalytic evaluation studies were carried out under a very low UVC light intensity (9 W) against acetaminophen (ACE) in the aqueous solution. The MCC-supported ZnO (0.5:1) composites photocatalyst demonstrated a rapid and enhanced performance within 180 min under normal conditions, with a two-time higher value of rate constant k (1.12 ×10−2 min−1) as compared to pristine ZnO. The improved efficiency under UVC irradiation was associated with the excellent separation capability of photoexcited charge carriers, ease of electron migration, and electrons’ mediators by the MCC in the composite photocatalyst, as demonstrated by the band gap and photoluminescence analyses. The major reactive species were found to be hydroxyl radicals (•OH) and photoexcited holes (h+). The best photocatalyst has high photostability since it can be recycled up to five times towards ACE degradation without any regeneration step.

Physical Reservoir Computing Using van der Waals Ferroelectrics for Acoustic Keyword Spotting.

Acoustic keyword spotting (KWS) plays a pivotal role in the voice-activated systems of artificial intelligence (AI), allowing for hands-free interactions between humans and smart devices through information retrieval of the voice commands. The cloud computing technology integrated with the artificial neural networks has been employed to execute the KWS tasks, which however suffers from propagation delay and the risk of privacy breach. Here, we report a single-node reservoir computing (RC) system based on the CuInP2S6 (CIPS)/graphene heterostructure planar device for implementing the KWS task with low computation cost. Through deliberately tuning the Schottky barrier height at the ferroelectric CIPS interfaces for the thermionic injection and transport of the electrons, the typical nonlinear current response and fading memory characteristics are achieved in the device. Additionally, the device exhibits diverse synaptic plasticity with an excellent separation capability of the temporal information. We construct a RC system through employing the ferroelectric device as the physical node to spot the acoustic keywords, i.e., the natural numbers from 1 to 9 based on simulation, in which the system demonstrates outstanding performance with high accuracy rate (>94.6%) and recall rate (>92.0%). Our work promises physical RC in single-node configuration as a prospective computing platform to process the acoustic keywords, promoting its applications in the artificial auditory system at the edge.

Esterified styrene-maleic acid copolymer modified silica as mixed-mode polymer-brush stationary phases for chromatographic separation

Styrene-maleic acid (SMA) copolymer has received much attention for its excellent solubilization characteristics. In this work, SMA copolymer brush-based chromatographic stationary phases were exploited and developed for the first time. First, SMA copolymer brush was in situ grown on the surface of spherical silica via living/controlled reversible addition-fragmentation chain transfer (RAFT) polymerization method. Subsequently, as a proof-of-concept demonstration, the copolymer was esterified by diethylene glycol mono-2-ethylhexyl ether (DGME) and 2-(2-ethylhexyloxy) ethanol (EHOE), respectively. The obtained Sil-SMA-DGME and Sil-SMA-EHOE copolymer-brush chromatographic stationary phases were characterized by transmission electron microscopy, Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, and thermogravimetric analysis, respectively. The chromatographic retention mechanism indicated that both the two packed columns exhibited hydrophilic/reverse mixed-mode retention modes. The maximum column efficiency was up to 71,000 N/m. The chromatographic separation performance evaluation indicated that the novel kind of stationary phases had excellent separation capabilities for hydrophilic, hydrophobic compounds and phospholipid standards. In addition, by combination with mass spectrometry identification, the Sil-SMA-DGME column was further exploited for separation and identification of phospholipids in human lung cancer cells. Totally, 9 classes including 186 phospholipid species were successfully identified. The results demonstrated the promising application prospects of the novel kind of SMA copolymer-brush chromatographic stationary phases.

Construction of adamantane-based monolithic column with three-dimensionally porous structure for small molecules separation and biosample analysis

BackgroundThe fabrication technique of capillary column is the key to the development and application of capillary liquid chromatography (cLC) to improve separation efficiency for analytes. The capillary monolithic column possessed three-dimensionally connected porous or channel structures. Unique porous structure endows excellent permeability and high performance in diverse fields, especially in separation. Thereinto, organic monolithic columns have attracted widespread attention due to their advantages of simple preparation and excellent biocompatibility. However, their separation selectivity needs to be further developed and regulated to apply the separation of more diverse samples. ResultsA novel polymeric monolithic column was prepared via thermally initiated in situ copolymerization of 2-methyladamantan-2-yl acrylate (MADA) with ditrimethylolpropane tetraacrylate (DTTA) in fused silica. The prepared poly(MADA-co-DTTA) monolith showed adjustable permeability, developed porous structure and high thermal stability. Consequently, it exhibited excellent separation capability of small molecules (alkylbenzenes and polycyclic aromatic hydrocarbons). Especially, when acetonitrile/water (60/40, v/v) was used as the mobile phase, the theoretical plate numbers reached 84,000 plates m−1 for butylbenzene at a linear velocity of 0.5 mm s−1. Most importantly, the hydrophobicity of the poly(MADA-co-DTTA) monolithic column was regulated via host-guest interaction between adamantyl group and cucurbit [7]uril (CB[7]). Additionally, the poly(MADA-co-DTTA) monolith was further adopted for the analysis of the tryptic digest of proteins from HeLa by cLC-MS/MS. The 33,783 unique peptides and 5,299 proteins were identified on the monolith, which exhibited great separation ability for complex samples. Significance and noveltyDue to abundant pore structure and good chemical properties, the poly(MADA-co-DTTA) monolithic column exhibited high performance for the separations of small molecules and biological sample. Meanwhile, owing to the existence of adamantyl-group, CB[7] was immobilized on the poly(MADA-co-DTTA) monolithic column to fabricate poly(MADA-co-DTTA)-CB[7] by host-guest interaction. It is possible to adjust the surface chemistry of the monolithic materials to accommodate more complex analytes.

Co3O4–TiO2 supported into N-doped magnetic 3D porous microspheres as the “one stone with two birds” strategy for highly efficient removal of organic dyes via synergistic adsorption-photocatalysis

Constructing heterojunctions with rich porosity and unique microstructures is the main way to obtain efficient adsorption and photocatalysis. A ternary composite of Co3O4–TiO2 supported in N-doped magnetic 3D porous microspheres (Co3O4–TiO2/N-MCMs) was successfully constructed with hierarchical pore structures, large specific surface areas, and abundant active sites. The Co3O4–TiO2/N-MCMs possessed excellent adsorption and solar degradation capabilities for representative azo dye (methyl orange, MO) and triphenylmethane dye (rhodamine B, RhB), and the total removal rate of the two dyes with different initial concentration reached up to 99.0% and 99.2% within 2 h, respectively. MO and RhB were rapidly adsorbed and enrichment into Co3O4–TiO2/N-MCMs via pore filling, and then degraded by the nucleophilic reagents (•O– 2 and •OH). Characterizations and theoretical calculations demonstrated that Co3O4–TiO2/N-MCMs contained a sufficient amount of p-n type heterojunctions between Co3O4 and TiO2, which could effectively promote spatial separation of photogenerated e--h+ pairs to improve degradation ability and reduce band gap to extend visible-light absorption. Moreover, N-doping could further transfer photogenerated electrons from heterojunctions to reaction areas to effectively prolong the lifetime of photogenerated electrons. The LC-MS results showed that MO and RhB can be mineralized into H2O and CO2 without generating any secondary pollution. Furthermore, Co3O4–TiO2/N-MCMs exhibited excellent magnetic separation capability and reusability. This study designed a novel photocatalyst for highly efficient removal of organic dyes via “One stone with two birds” strategy of synergistic adsorption-photocatalysis, which could simplify the treating process and exhibit a highly promising in practical applications.

Determination of fatty acid composition after saponification of common oil pharmaceutical excipients by supercritical fluid-evaporative light scattering method and its application in oil identification

Oils and fats are commonly used in the pharmaceutical industry as solvents, emulsifiers, wetting agents, and dispersants, and are an important category of pharmaceutical excipients. Fatty acids with unique compositions are important components of oil pharmaceutical excipients. The Chinese Pharmacopoeia provides clear descriptions of the fatty acid types and limits suitable for individual oil pharmaceutical excipient. An unqualified fatty acid composition or content may indicate adulteration or deterioration. The fatty acid composition, as a key indicator for the identification and adulteration evaluation of oil pharmaceutical excipients, can directly affect the quality and safety of oil pharmaceutical excipients and preparations. Gas chromatography is the most widely used technique for fatty acid analysis, but it generally requires derivatization, which affects quantitative accuracy. Supercritical fluid chromatography (SFC), an environmentally friendly technique with excellent separation capability, offers an efficient method for detecting fatty acids without derivatization. Unlike other chromatographic methods, SFC does not use nonvolatile solvents (e. g., water) as the mobile phase, rendering it compatible with an evaporative light-scattering detector (ELSD) for enhanced detection sensitivity. However, the fatty acids in oil pharmaceutical excipients exist in the free and bound forms, and the low content of free fatty acids in these oil pharmaceutical excipients not only poses challenges for their detection but also complicates the determination of characteristic fatty acid compositions and contents. Moreover, the compositions and ratios of fatty acids are influenced by environmental factors, leading to interconversion between their two forms. In this context, saponification provides a simpler and faster alternative to derivatization. Saponification degrades oils and fats by utilizing the reaction between esters and an alkaline solution, ultimately releasing the corresponding fatty acids. Because this method is more cost effective than derivatization, it is a suitable pretreatment method for the detection of fatty acids in oil pharmaceutical excipients using the SFC-ELSD approach. In this study, we employed SFC-ELSD to simultaneously determine six fatty acids, namely, myristic acid, palmitic acid, stearic acid, arachidic acid, docosanoic acid, and lignoceric acid, in oil pharmaceutical excipients. Saponification of the oil pharmaceutical excipients using sodium hydroxide methanol solution effectively avoided the bias in the determination of fatty acid species and contents caused by the interconversion of fatty acids and esters. The separation of the six fatty acids was achieved within 12 min, with good linearity within their respective mass concentration ranges. The limits of detection and quantification were 5-10 mg/L and 10-25 mg/L, respectively, and the spiked recoveries were 80.93%-111.66%. The method proved to be sensitive, reproducible, and stable, adequately meeting requirements for the analysis of fatty acids in oil pharmaceutical excipients. Finally, the analytical method was successfully applied to the determination of six fatty acids in five types of oil pharmaceutical excipients, namely, corn oil, soybean oil, coconut oil, olive oil, and peanut oil. It can be combined with principal component analysis to accurately differentiate different types of oil pharmaceutical excipients, providing technical support for the rapid identification and quality control of oil pharmaceutical excipients. Thus, the proposed method may potentially be applied to the analysis of complex systems adulterated with oil pharmaceutical excipients.

Carbonic anhydrase immobilized on Zn(II)-geopolymer membrane for CO2 capture

Inorganic membranes are widely used in water filtration and gas separation due to their many advantages. In this work, we proposed an innovative approach for enzyme immobilization using a geopolymer based tubular inorganic membrane (GM) as a carrier. The GM has abundant mesopores, excellent mechanical strength and strong stability for continuous flow systems in biocatalysis field, and carbonic anhydrase (CA) was successfully loaded into this mesoporous membrane using adsorption-crosslinking method, relying on the excellent ion exchange capacity of geopolymers and large number of hydroxyl groups naturally present in the membrane's mesopores. The results of the immobilization experiments showed that the immobilized enzyme composite membrane (GZnM-CA) could achieve 63.7% enzyme recovery. This is a significant improvement over the enzyme recoveries obtained on organic membranes which are typically less than 50%. In stability tests, the membrane retained more than 90.0% relative activity after 10 consecutive uses. In the CO2 capture assay, the CO2 capture efficiency developed dramatically under the catalytic of GZnM-CA. To our delight, the membrane has excellent separation capability for CO2 gas mixtures, especially at low CO2 concentrations, achieving 99.90% CO2 removal rate, and this result can be maintained for a long period of time in a pH = 8.0 environment.

Preparation and chromatographic evaluation of 9-oxa-10-phosphophenanthrene 10-oxide bonded phenyl stationary phase and investigation of its retention mechanism through nuclear magnetic resonance spectroscopy

BackgroundIn reversed-phase liquid chromatography, the C18 alkyl bonded phase, as the primary stationary phase, is widely used in pharmaceutical and food analysis. The phenyl bonded phase often serves as a complementary choice to the C18 phase to enhance the separation performance of specific categories of compounds. However, both C18 and the currently available phenyl bonded phase chromatography columns show room for further optimization in improving the separation efficiency of specific compound classes, such as dihydroflavonoids. Additionally, the potential role and impact of introducing phosphorus groups into chromatographic stationary phases have not been fully explored, indicating a promising direction for research. ResultsIn the present work, we prepared a novel phenyl stationary phase by bonding 9-oxa-10-phosphaphenanthrene 10-oxide onto silica gel. The obtained material was characterized by scanning electron microscopy, fourier transforms infrared spectroscopy, and elemental analysis. The results show that 9-oxa-10-phosphaphenanthrene 10-oxide was successfully bonded on the silica surface with a load of 3.90 %. Further chromatographic characterization in high-performance liquid chromatography exhibited high column efficiency (40,792 plates m-1 for the determination of biphenyl) and good stability (RSD of 0.28 %∼5.38 %). Moreover, we made a detailed study of the column separation mechanism by nuclear magnetic resonance spectroscopy titration experiment. Comparing to commercial phenyl column, the proposed stationary phase showed shorter retention time and higher throughput. In addition, the stationary phase has a strong ability to separate multiple types of compounds, which provides a new strategy for the separation of complex samples, such as active ingredients in traditional Chinese medicine. SignificanceWe have developed a novel phenyl column and conducted a comprehensive examination of its chromatographic performance, demonstrating excellent separation capabilities and high efficiency for both nonpolar and moderately polar aromatic compounds. Additionally, we explored the impact of phosphorus-containing groups on the separation performance of chromatographic stationary phases.

Integrated Multiplatform Analysis and Separation of Thirteen Flavonoids and Anthraquinones in Seven Medicinal Cassia Species.

Cassia (Family: Fabaceae) species are a large group of flowering plants rich in bioactive anthraquinone and flavonoids used in botanical supplements and nutraceuticals. A simple and reliable high-performance liquid chromatography-photodiode array (HPLC-PDA) method was developed and validated for separating and quantifying 13 anthraquinone and flavonoids. These compounds were further confirmed using an LC-based electrospray ionization mass spectrometry (ESI-MS/MS) method in the leaves and flowers of selected Cassia species. A simple and rapid HPTLC method was developed for chemical fingerprint analysis of all Cassia species. All 13 compounds were chromatographically separated on a Zorbax TC18 (4.6 × 250, 5 μm particle size) analytical column, and 0.1% formic acid and acetonitrile as elution solvents at a flow rate of 0.8 mL/min with detection at 259 nm. For HPTLC fingerprinting, the mobile phase compositions of toluene, ethyl acetate, and formic acid (5.5:4.2:0.6, v/v/v) were optimized to separate and identify all compounds using silica gel 60F254 aluminum plates. The validation data for the developed HPLC-PDA method for 13 compounds showed good linearity (r2 >0.99) with a sensitive LOD (0.082-1.969 μg/mL), LOQ (0.250-5.967 μg/mL), and excellent recoveries (85.22-100.32%). The quantification results were found to be precise and accurate (<5.0% and relative error), -0.77-0.44 with ESI-MS/MS confirmation in the Cassia samples. The novel HPTLC method was excellent separation for 13 compounds, with Rf values ranging between 0.12 and 0.61. The developed HPLC-PDA method was simple and precise and could separate and quantify anthraquinones and flavonoids along with confirmation, using a novel LC-based ESI-MS/MS. The HPTLC method was found to be simple and precise, with excellent separation capabilities for these compounds. This novel multiplatform approach successfully identified and quantified 13 compounds simultaneously using an integration of data strategy in seven medicinally important Cassia species' leaves and flowers.

Nitrogen-rich magnetic hyper-cross-linked polymer as an efficient adsorbent for tetracycline

Antibiotic contamination remains a challenge for wastewater treatment. In this work, a hyper-cross-linked polymer (DHCP-TP3) with a dual nitrogen-rich structure was synthesized by a one-step facile Friedel-Crafts reaction, and a Fe3O4 @DHCP-TP3 composite was prepared by postmodification with the introduction of magnetic iron oxide nanoparticles (Fe3O4 NPs), which were applied to the adsorption of tetracycline (TC) from aqueous solution. The TC adsorption capacities of the DHCP-TP3 and Fe3O4 @DHCP-TP3 composites reached 519.65 and 893.85 mg·g−1, respectively, and the adsorption processes for both followed the pseudo-second-order kinetic model and the Freundlich isothermal model. Fe3O4 @DHCP-TP3 can achieve adsorption equilibrium for TC within 200 min, and also exhibits excellent regeneration and magnetic separation capabilities. Complexation, hydrogen bonding, cation exchange and π-π interactions were the main adsorption mechanisms. Moreover, Fe3O4 @DHCP-TP3 could also adsorb other pollutants, including sulfadiazine (SD), sulfamethoxazole (SMZ), methyl orange (MO), methylene blue (MB), 2,4-dichlorophenol (2,4-DCP), and iodine (I2). The brief synthesis, high adsorption capacity and easy regeneration certified that HCPs were ideal adsorbents for removing pollutants from wastewater.

A novel cage-based metal–organic framework for efficient separation of light hydrocarbons

A novel 3D MOF, SDU-CP-8, features an ellipsoid-shaped cage and a 3-nodal, (4,6,8)-connected network. It demonstrates excellent adsorption and separation capabilities for C3H8/C2H6/CH4 and C2H2/CO2 gas mixtures.

Recognition of C4 Olefins by an Ultramicroporous ftw-Type Yttrium-Based Metal-Organic Framework with Distorted Cages.

Developing porous adsorbents for efficient separation of C4 olefins is significant but challenging in the petrochemical industry due to their similar molecular sizes and physical properties. The separation efficiency is often limited when separating C4 olefins by a single separation mechanism. Herein, an ultramicroporous yttrium-based MOF, Y-dbai, is reported featuring cage-like pores connected by small windows, for recognition and efficient separation of C4 olefins through a synergistic effect of thermodynamic and kinetic mechanisms. At 298K and 1bar, the adsorption capacities of Y-dbai for C4H6, 1-C4H8, and i-C4H8 are 2.88, 1.07, and 0.14mmolg-1, respectively, indicating a molecular sieving effect toward i-C4H8. The C4H6/i-C4H8 and 1-C4H8/i-C4H8 uptake selectivities of Y-dbai are 20.6 and 7.6, respectively, outperforming most of the reported adsorbents. The static and kinetic adsorption experiments coupled with DFT calculations indicate the separation should be attributed to a combined effect of thermodynamically and kinetically controlled mechanism. Breakthrough experiments have confirmed the excellent separation capability of Y-dbai toward C4H6/1-C4H8, C4H6/i-C4H8, and C4H6/1-C4H8/i-C4H8 mixtures.

Fully biobased hydrogel based on chitosan and tannic acid coated cotton fabric for underwater superoleophobicity and efficient oil/water separation

Underwater superoleophobic (UWSO) materials have garnered significant attention in separating oil/water mixtures. But, the majority of these materials are made from non-degradable and non-renewable raw materials, polluting the environment and wasting scarce resources while using them. Against this backdrop, this study aimed to fabricate an environmental-friendly UWSO textile using biobased materials. To achieve this, hydrogel consisting of chitosan (CS) and poly(tannic acid) (PTA) were formed and coated on cotton fabric (CTF) via dip-coating followed by oxidative polymerization. CS&PTA hydrogel endowed the CTF with a rough surface and high surface energy, leading to an UWSO CTF with an underwater oil contact angle as high as 166.84°. The CS&PTA/CTF had excellent separation capability toward various oil/water mixtures, showing separation efficiency above 99.84 % and water flux higher than 23, 999 L m−2 h−1. Moreover, CS&PTA/CTF possessed excellent mechanical and environmental stability with underwater superoleophobicity unchanged after sandpaper friction, ultrasonication, organic solvents, NaCl (m/v, 30 %) solution, and acid/base solution immersion, due to the strong interaction between the hydrogel and cotton fabric generated by the mussel-inspired adhesion owing to the presence of PTA. The fully biobased UWSO CTF exhibits great promising to be an alternative to traditional superwetting materials for separation of oil/water mixtures.

Recovery of Chlorella biomass using Fe3O4 and Fe3O4@SiO2 magnetic nanoparticles: isotherm and thermodynamic characteristics of adsorption

AbstractHarvesting microalgae by centrifugation and filtration is very costly, affecting technical and economical feasibility of downstream processing of algal biomas to bioproducts. Flocculation is a potential technique for recovery of algae biomass. Particularly, flocculation using magnetic nanoparticles offers high separation efficiency due to their high surface area and magnetic properties. In this work, the synthesized magnetic nanoparticles including Fe3O4 and Fe3O4@SiO2 were used to harvest C. sorokiniana TH01 from aqueous suspension. The effects of pH, adsorbent dosage, algal biomass concentration, temperature and reaction time on harvesting performance were investigated. It was revealed that the optimal C. sorokiniana TH01 harvesting conditions for Fe3O4 were pH of 5, adsorbent dosage of 0.5 g/L, biomass concentration of 2‐2.5 g/L, temperature 25oC and reaction time 20‐30 min. For Fe3O4@SiO2, the optimal conditions were pH of 7, adsorbent dosage of 0.6 g/L, with the same biomass concentration, temperature and reaction time as Fe3O4. Under the optimal conditions, Fe3O4 and Fe3O4@SiO2 can be regenerated up to three cycles with harvesting efficiency till remained over 55%. Adsorption of C. sorokiniana TH01 on Fe3O4 and Fe3O4@SiO2 exhibited the best fitness with Langmuir isortherm with R2 and maximal adsorption capacity estimated of 0.995 and 6.55 g/g and 0.9971 and 9.53 g/g, respectively. Thermodynamics study revealed that an adsorption of C. sorokiniana TH01 on Fe3O4 and Fe3O4@SiO2 was exothermic process. Furthermore, XRD, EDS, SEM, TGA and FT‐IR data confirmed the successful binding of microalgae cells on surfaces of Fe3O4 and Fe3O4@SiO2. The super‐magnetization intensities (&gt; 22 emu/g) of the synthesized materials demonstrated an excellent separation capability with external magnetic devices.

Enhanced photocatalytic performance of W-doped TiO2 nanoparticles for treatment of Procion Red MX-5B azo dye in textile wastewater

Sol-gel synthesis of W-doped TiO2 nanoparticles (W-TiO2) as a photocatalyst for Procion Red MX-5B (MX-5B) azo dye treatment in textile wastewater was the main focus of this research. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS) structural studies of nanostructured photocatalysts showed that W was successfully incorporated into the TiO2 lattice. According to EIS investigations, W-TiO2 has a greater rate of charge transfer and excellent charge separation capabilities compared to a sample of pure TiO2. It shows the W-TiO2 nanostructured photocatalyst sample's exceptional photocatalytic performance. The band gap energies of TiO2 and W-TiO2 were determined through optical studies to be 3.22 eV and 2.93 eV, respectively, showing an improvement in the photocatalytic activity of TiO2 in the visible light domain. Studies of the photocatalytic performance indicated that the full treatment of MX-5B molecules was achieved after 105, 100, 95, 80, 70, 85, and 90 min of exposure to visible light for pure TiO2, W0.5-TiO2, W1-TiO2, W3-TiO2, W5-TiO2, W8-TiO2, and W10-TiO2, respectively. These studies revealed the great and quick photocatalytic treatment of MX-5B in the presence of doped TiO2. The results of a study that used 400 mL of a 40 mg/L MX-5B solution prepared with deionized water as a control sample and a sample of actual textile wastewater as a real sample showed that MX-5B from actual textile wastewater was effectively photocatalytically degraded in the presence of W5-TiO2 photocatalyst.

Utilizing three-dimensional ordered macroporous NiFe2O4 Loaded With g-C3N4 as a heterogeneous photo-Fenton catalyst for tetracycline degradation

Heterogeneous photo-Fenton technology, efficiently utilizing the solar energy and hydrogen peroxide, which combines photocatalysis and Fenton reaction, is one of the most efficient methods for eliminating organic contaminants. Here, graphitic carbon nitride (CN) and three-dimensionally ordered macroporous (3DOM) nickel ferrite (NFO) were combined to create highly catalytically active CN/3DOM-NFO composites. The composites were characterized with XRD, SEM, TEM, HRTEM, XPS, BET, DRS, and PL. And tetracycline (TC) photo-Fenton degradation catalytic activity of the composites was evaluated. The results showed that under visible light irradiation, the maximum rate constants of TC degradation of 10CN/3DOM-NFO were 7.3 times and 5.4 times that of pure g-C3N4 and bulk NFO, respectively. The optimum apparent reaction rate constant can reach as high as 0.0618 min−1 due to the synergistic interaction between the increased specific area and excellent charge carrier separation and transfer capabilities, resulting from the CN/3DOM-NFO heterojunction and the 3DOM structure, respectively. Finally, the mechanism of photo-Fenton-catalyzed degradation is briefly discussed. And this research reveals a new strategy to improve the efficiency of photo-Fenton-catalyzed degradation.

The Preparation of Novel Amino Acid Imidazole Ionic Liquids and Their Application as Stationary Phase for Capillary Gas Chromatographic Separations

AbstractIn this paper, two new amino acid imidazole ionic liquids IL‐3 and IL‐4 were synthesized for the first time, and their separation performance as the stationary phase for capillary gas chromatography (GC) was tested. The statically coated IL‐3 and IL‐4 capillary columns exhibited moderate to high polarity, and achieved the column efficiency of 2242 plates/m and 2487 plates/m respectively determined by n‐octanol at 120 °C. Importantly, the IL‐3 and IL‐4 columns exhibited excellent separation capability for analytes with varying polarity, including n‐alkanes, arenes, esters, alcohols, bromoalkanes, halogenobenzenes, and halogenated anilines. In addition, the IL‐3 and IL‐4 columns presented high selectivity and separation capability for positional, structural and cis‐/trans‐isomers. In particular, they showed high separation performance of the chloroaniline, bromaniline, iodoaniline and xylidine isomers as an important environmental pollutant. The IL‐3 and IL‐4 columns displayed advantageous resolving capability over the commercial HP‐35 column for aromatic amine isomers, and the separation performance of IL‐4 with long carbon chain was better than that of IL‐3. Moreover, it was applied to determine isomer impurities in real samples, and showing huge potential in GC applications. This work demonstrates the potential of the amino acid imidazole ionic liquids as a new type of stationary phase in GC separations.

GNs/MOF-based mixed matrix membranes for gas separations

NU-1000 and graphene nanosheet (GNs) with different loadings have been used as fillers to prepare mixed matrix membranes (MMMs) with polyethersulfone (PES). The high performance of the MMMs has been successfully fabricated for the evaluation of gas separation at 1 bar and various temperatures (20, 40, 60 °C). The successful fabrication of the MMMs were confirmed by using SEM, FTIR, AFM, and XRD. The crystalline nature of GNs and NU-1000 in the MMMs are evidenced by XRD, which confirms the successful fabrication of the MMMs. In addition, the thermal stability of the MMMs was enhanced with the increase of the GNs. Separation performance of H2 was superior to CO2, N2 and CH4 separation on the MMMs which is a critical for producing energy. The best gas separation results in terms of both permeability and selectivity were obtained with 0.03% GNs and 10% NU-1000. PG3N membrane presented maximum H2/CO2, H2/N2 and H2/CH4 selectivity of 5, 4.2, 3.3 at 20 C, respectively. With an increase in temperature, the permeability increased, while the selectivity of all the MMMs decreased. The MMMs exhibited excellent gas separation capability, which offers unique opportunities for potential large-scale practical applications.