Reaction Duration Research Articles

Construction of a multifunctional dual-network chitosan composite aerogel with enhanced tunability

Typically, the tailorable versatility of biomass aerogels is attributed to the tunable internal molecular structure, providing broad application prospects. Herein, a simple and novel preparation strategy for developing multifunctional dual-network chitosan/itaconic acid (CSI) aerogel with tunability by using freeze-drying and vacuum heat treatment techniques. By regulating the temperature and duration of amidation reaction, electrostatic interactions between chitosan (CS) and itaconic acid (IA) was abstemiously converted into amide bond in frozen aerogel, with IA acting as an efficient in-situ cross-linking agent, which yielded CSI aerogels with different electrostatic/covalent cross-linking ratios. Heat treatment and tuning of the covalent cross-linking degree of CSI aerogel changed their microstructure and density, which led to enhanced performance. For example, the specific modulus of CSI1.5–160 °C-5 h (71.69 ± 2.55 MPa·cm3·g−1) increased by 119 % compared to that of CSI1.5 (32.73 ± 0.718 MPa·cm3·g−1), converting the material from superhydrophilic to hydrophobic (124° ± 3.6°), exhibiting favorable stability and heat transfer performance. In addition, part of -NH3+ of CS was retained in the electrostatic cross-linked network, endowing the aerogel with antibacterial properties. The findings of this study provide insights and a reliable strategy for fabricating biomass aerogel with good comprehensive performance via ingenious structural design and simple regulation methods.

Spectral response of sulfonated polystyrene photonic crystals with varying concentrations of ethanol

Modifying polystyrene (PS) spheres through sulfonation is a well-established method to enhance their hydrophilic properties, rendering them valuable in diverse applications. Fabrication of photonic crystals (PCs) with sulfonated polystyrene (SPS) spheres offers an important platform for sensing applications. The hydrophilic nature of such PC platform helps in improving the detection of water content. In the present work, monodispersed SPS spheres were synthesized by adjusting the duration of the sulfonation reaction on the PS spheres created via emulsifier-free emulsion polymerization. PC opal films were fabricated using self-assembled PS and SPS spheres. The opal films were characterized using various techniques, including Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), angle-resolved reflection spectroscopy (ARRS), zeta potential and dynamic light scattering, and the results were compared and analysed. The hydrophilicity of the opal films was investigated using the water contact angle measurement, and it was found to improved by sulfonation. The spectral response of the PC opal films was investigated by monitoring Bragg’s diffraction spectra from the films using UV–VIS spectrometer. As a demonstration of a specific application, the prepared PC opal films were used to measure the water content in ethanol. PS and SPS opal films exhibited a noticeable blue shift in their spectral response when the water content in ethanol was increased to 3.8% and 3.4%, respectively. The added hydrophilicity brought on by the attached sulfonic groups improved the SPS film’s sensitivity to the water in the ethanol. SPS spheres demonstrated an optical response over a significantly more extensive range of the water content in ethanol than PS, which has a limited response range of up to 50%. Sulfonating PS spheres enhances colloidal stability and minimizes the tendency for aggregation in solution. Sulfonation for more than 3 h is found to exhibit reduced mechanical strength. Though the sulfonation induces an increase in surface roughness, the quality of the ordered arrangement of the spheres remained the same in comparison with PS films. By taking advantage of SPS’s hydrophilicity, high reactivity, stability, and the possibility of attaching additional functional groups, the present study opens up new possibilities for sensing water content in ethanol.

Process Optimization of Biodiesel Production Using Waste Snail Shell as a Highly Active Nanocatalyst

In this work, we reported the transesterification of soybean oil (SO) to biodiesel using a basic CaO nanocatalyst produced by sequential calcination, hydration, and dehydration of waste snail shells. Response-surface methodology (RSM) and a central composite design (CCD) were used to predict several optimization parameters. 1H-NMR confirmed that 98.5% of the SO was transformed into methyl ester biodiesel. Under the optimal reaction parameters of catalyst loading of 6 wt. %, methanol to oil molar ratio of 8 : 1, reaction duration of 3 h, and temperature of 70°C, an excellent biodiesel yield of 96.1% was obtained. The transesterification of SO to biodiesel displayed a significantly low activation energy (30.45 kJ mol-1), whereas, the turnover frequency of the transesterification reaction was found to be 0.0063 mol g-1 h-1. The catalyst showed excellent stability and was consecutively used for six cycles without a significant decline in catalytic activity. Based on life cycle cost analysis (LCCA), the estimated cost for producing 1 kg of biodiesel in this study comes out to be just $0.935, signifying its strong potential for widespread commercial use.

Combining ozone and ultrasound technology to remove S2− in Bayer liquor

High content sulfur (S2−) in Bayer liquor can increase alkali consumption, accelerate equipment corrosion, especially seriously affect alumina production. The removal of S2− in Bayer liquor is studied using ultrasonic enhanced ozone method, which significantly improves the removal efficiency. Results indicate that the best removal efficiency of 93.83 % is obtained with reaction duration of 20 min, oxygen flow rate of 80 L/h, ultrasonic power of 60 W and reaction temperature of 60 °C. The comparative analysis shows that the removal efficiency of S2− is 25.34 % higher than that of ozone (O3) system after introducing ultrasound (US), indicating that US accelerates the mass transfer process of O3 and increases the hydroxyl radicals (OH) content. For further explanation of the mechanism of US/O3 system, EPR and XPS spectra are applied to analyze the content of free radical and the form of sulfur in Bayer liquor, indicating that the content of free radical in US/O3 system is more than US and O3 systems, and all sulfur is converted to SO42− after full oxidation.

Triclocarban transformation and removal in sludge conditioning using chalcopyrite–triggered percarbonate treatment

Herein, a facile combination approach of chalcopyrite and sodium percarbonate (CuFeS2+ SPC) was established to augment both TCC removal efficiency and sludge dewatering. Results showed that utilizing the CuFeS2 dosage of 600 mg/g total solids (TS) under the optimal condition, along with the SPC dosage of 12.5 mg/g TS, an initial pH of 4.0, and a reaction duration of 40 min, led to a substantial reduction of 53.9% in the TCC content within the sludge, accompanied by a notable decrease of 36.9% in the water content. Compared to well-studied iron-based advanced oxidation processes, CuFeS2 + SPC treatment proved to be more cost-effective and environmentally friendly. Mechanistic findings demonstrated that •OH oxidation played a significant role in TCC removal, with O2•− and 1O2 acting as secondary factors. During the CuFeS2 + SPC process, the received •OH, O2•−, and 1O2 destroyed the main binding sites of extracellular polymeric substances to TCC, including tryptophan-like protein, amide, CO stretch, and −COO− functional groups. As a result, approximately 50% of TCC was partially degraded within the solid sludge phase after the attack of radicals. Meanwhile, the decreased macromolecular organic compounds in solid sludge attenuated the binding efficacy of TCC, giving rise to the transfer of partial TCC to the liquid phase. Ultimately, the TCC in sludge was successfully removed, and five transformation products were identified. This study significantly contributes to our understanding regarding TCC transformation and removal in the sludge conditioning process.

Ultra-trace analysis of chromium ions (Cr3+/Cr6+) in water sample using selective fluorescence turn-off sensor with natural carbon dots mixed graphene quantum dots nanohybrid composite synthesis by pyrolysis

This study was aimed to implement the one-pot pyrolysis for hybrid nanomaterial synthesis consisting of graphene quantum dots (GQDs) from solid citric acid and carbon dots (CDs) which was hydrothermally derived from the herbal plant extract of “Houttuynia cordata”, denoted as Carbon Dots mixed Graphene Quantum Dots (CDs@GQDs). The nanohybrid were structurally characterized by XPS, FT-IR, Fluorescence, and UV–Visible absorption spectroscopy, and their morphological images were also analyzed by HR-TEM and FE-SEM/EDX. The quantum yield was found to be 15 %, higher than that of intact CDs or GQDs. Upon excitation at a maximum wavelength of 355 nm, and emission in the 450 nm. In this case, it was observed that the nanohybrid exhibit a high degree of selectivity towards Cr6+ ion when employed as a fluorescence quenching sensor from screening test with different metal ions. Therefore, the optimization conditions of solution pH, concentration of nanohybrid, H2O2 concentration as an oxidizing agent, reaction duration time with the aid of ultrasonication were carried out in details and the permissible limit of Cr3+ presence in the target analyte was all undertaken in order to enhance the detection of Cr6+ species. Its linear calibration curve was such y = 0.37x + 55.7, with a coefficient of determination (r2) value of 0.9816. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 17.2 nM, and 52.2 nM. Consequently, the nanohybrid as a green chelating agent in the selective assessment of ultra-trace amount of Cr6+ in spiked water sample model was also done with good recoveries in both bottled drinking water and tap water samples ranging from 102.86 to 114.23 %.

Boosting Biodiesel Production from Dairy-Washed Scum Oil Using Beetle Antennae Search Algorithm and Fuzzy Modelling

The major goal of this study was to develop a robust fuzzy model to mimic the generation of biodiesel from the transesterification of dairy-washed milk scum (DWMS) oil. Four process parameters were considered: the molar ratio of methanol to oil, the concentration of KOH, the reaction temperature, and the reaction time. The proposed technique was divided into two steps: fuzzy modelling and optimum parameter identification. The capability of fuzzy tools to capture and make use of linguistic variables and fuzzy sets is one of their main benefits. This means that fuzzy logic allows for the representation and manipulation of values that fall across a continuum rather than merely relying on crisp values or binary categories. When dealing with non-linear relationships, this is especially helpful since it gives a more accurate and nuanced depiction of the underlying data. As a result, an accurate fuzzy model was initially built based on collected data to simulate the biodiesel production in terms of the molar ratio of methanol to oil, the concentration of KOH, the temperature of the reaction, and the reaction duration. In the second phase, the beetle antennae search (BAS) algorithm was applied to identify the optimal values of the process parameters to boost the production of biodiesel. The BAS algorithm draws inspiration from beetle behavior, particularly how they navigate using their antennae. It employs a swarm-intelligence method by deploying virtual beetles that swarm over the problem area in search of the best solution. One of its main features is the BAS algorithm’s capacity to balance exploration and exploitation. This is accomplished through the algorithm’s adaptable step-size mechanism during the search phase. As a result, the algorithm can first investigate a large portion of the problem space before gradually moving closer to the ideal answer. Compared with ANOVA, and thanks to fuzzy, the RMSE decreased from 7 using ANOVA to 0.73 using fuzzy (a decrease of 89%). The predicted R2 increased from 0.8934 using ANOVA to 0.9614 using fuzzy (an increase of 7.6). Also, the optimisation results confirmed the superiority of the BAS algorithm. Biodiesel production increased from 92% to 98.16%.

Safety of Crovalimab Versus Eculizumab in Patients with Paroxysmal Nocturnal Hemoglobinuria (PNH): Pooled Results from the Phase III COMMODORE 1, COMMODORE 2, and COMMODORE 3 Studies

Introduction Crovalimab (crova) is a novel anti-C5 recycling antibody that allows for low-volume, subcutaneous (SC) self-administration every 4 weeks (q4w). The single arm COMMODORE 3 study (NCT04654468) in C5 inhibitor (C5i)-naive patients (pts) with PNH in China was the first Phase III study to show that crova is efficacious and well tolerated (primary analysis; Liu Am J Hematol 2023), and confirmed these findings after 6 additional months of crova exposure (Liu EHA 2023; #P785). COMMODORE 1 (NCT04432584) and COMMODORE 2 (NCT04434092) are global, randomized, open-label, multicenter, Phase III trials that evaluated crova versus eculizumab (ecu) in C5i-experienced and -naive pts with PNH, respectively. COMMODORE 2 demonstrated non-inferior efficacy for crova versus ecu, with a safety profile consistent between crova and ecu (Röth EHA 2023; #S181). COMMODORE 1 supported the favorable benefit-risk profile of crova (Scheinberg EHA 2023; #S183). Here, we report pooled safety data for crova and ecu from COMMODORE 1, 2, and 3. Methods In COMMODORE 1, C5i-experienced pts who were receiving ecu were randomized 1:1 to receive crova or ecu. Pts with the C5 polymorphism or receiving ravulizumab or high-dose ecu, and pediatric pts receiving ecu were enrolled in a descriptive arm to receive crova. In COMMODORE 2, C5i-naive pts were randomized 2:1 to receive crova or ecu. Pediatric pts were enrolled in a descriptive arm to receive crova. In COMMODORE 3, C5i-naive pts received crova. In all 3 studies, crova was administered per a weight-based tiered dosing approach that included loading doses followed by SC q4w maintenance. Ecu was given intravenously every 2 weeks. The primary treatment period was 24 weeks for all 3 studies; all pts continuing after Week 25 received crova. Safety data from the 3 studies were pooled and assessed by C5i-naive versus -switched status and in total. Results Safety data from 488 pts (crova, n=377 [naive, n=192; switched, n=185]; ecu, n=111) were analyzed. Baseline characteristics for the pooled population were generally balanced between the crova and ecu arms, and between the C5i-naive and -switched groups for crova. Median age at baseline was 38 y (range, 13−85) in the crova population and 44 y (17−85) in the ecu population, with 11 (3%) pts and 2 (2%) pts aged <18 y at enrollment, respectively. The median time from PNH diagnosis to enrollment was 4.8 y (range, 0.0-50.3) in crova pts and 5.7 y (range, 0.0-31.0) in ecu pts. At baseline, 38% of crova pts and 37% of ecu pts had a history of aplastic anemia; 3% and 5% of pts had myelodysplastic syndrome, respectively. At the respective clinical cutoff dates, the median treatment duration was 44.4 weeks for crova pts and 22.1 weeks for ecu pts (Table 1). There were 522 adverse events (AEs) per 100 pt years (PY) in crova pts and 583 in ecu pts. There were 7.4 serious infections per 100 PY in crova pts (6.1 naive; 9.3 switched) and 14.1 in ecu pts, with no meningococcal infections. The proportion of pts with common AEs and serious AEs is shown in Table 2. A higher percentage of C5i-naive pts appeared to experience AEs than C5i-switched pts or ecu pts, due to the inclusion of pts with a longer treatment duration from the single-arm COMMODORE 3 study in the C5i-naive group. Fatal AEs occurred in 4 (1%) crova pts (3 naive; 1 switched) and 1 (1%) ecu pt, all unrelated to treatment (Table 1). AEs leading to treatment discontinuation occurred in 1% of crova pts (1% naive; 2% switched) and 1% of ecu pts. 4% of crova pts (4% naive; 4% switched) and 3% of ecu pts had ≥1 AE leading to dose modification or interruption. In crova switched pts only, complexes formed with other C5i could lead to one-time Type III hypersensitivity (T3H) reactions, which occurred in 18% of switched pts. The median time to onset of the T3H reaction was 1.6 weeks (range, 0.7-4.4) and the median duration of T3H reactions was 1.9 weeks (0.4-34.1). The most frequently reported (≥5%) manifestations of T3H reactions were arthralgia (9%) and rash (6%); no pt had renal manifestations. Most T3H reactions were Grade 1-2; Grade 3 events occurred in 7% of switched pts. One pt discontinued crova due to a Grade 3 T3H. The safety profile was consistent between pediatric and adult pts. Conclusions Overall, pooled safety data from COMMODORE 1, 2, and 3 showed that the safety profile of crova was consistent with that of ecu in pts with PNH, and comparable between pts who were C5i-naive and switched from C5i to crova.

A brief nonattachment intervention based on the three marks of existence: development, rationale, and initial evidence

ABSTRACT Background The practices described in Buddhist philosophy are essentially a suite of non-theistic cognitive and behavioral interventions designed to induce nonattachment (N-A), which can be defined in terms of the absence of a need for one’s personal reality to be other than it is. Although meditative practices have received attention in multiple literatures, the cognitive analogs to these behaviorally-oriented practices have not. Design Two experiments involving undergraduate participants (total N = 239; M age = 19.04) investigated whether the provision of wisdom related to the Three Marks of Existence (i.e., some degree of suffering is inevitable, there is impermanence, and many events are not in our control) could result in (1) higher nonattachment attitudes, (2) lower threat appraisals, (3) lower stressor reactivity, and (4) shorter emotion reaction durations. Results With moderate to large effect sizes, the Three Marks trainings (relative to placebo or control conditions) resulted in (1) higher nonattachment attitudes, (2) lower threat appraisals, (3) no differences in negative emotional intensity, but 4) shorter emotion durations. Conclusions These results provide preliminary evidence that enduring cognitive trainings such as the Three Marks can be an effective tool to increase acceptance-related attitudes while attenuating negative reactivity.

Green Synthesis and Morphological Evolution for Bi2Te3 Nanosystems via a PVP-Assisted Hydrothermal Method.

Bi2Te3 has been extensively used because of its excellent thermoelectric properties at room temperature. Here, 230-420 nm of Bi2Te3 hexagonal nanosheets has been successfully synthesized via a "green" method by using ethylene glycol solution and applying polyvinyl pyrrolidone (PVP) as a surfactant. In addition, factors influencing morphological evolution are discussed in detail in this study. Among these parameters, the reaction temperature, molar mass of NaOH, different surfactants, and reaction duration are considered as the most essential. The results show that the existence of PVP is vital to the formation of a plate-like morphology. The reaction temperature and alkaline surroundings played essential roles in the formation of Bi2Te3 single crystals. By spark plasma sintering, the Bi2Te3 hexagonal nanosheets were hot pressed into solid-state samples. We also studied the transport properties of solid-state samples. The electrical conductivity σ was 18.5 × 103 Sm-1 to 28.69 × 103 Sm-1, and the Seebeck coefficient S was -90.4 to -113.3 µVK-1 over a temperature range of 300-550 K. In conclusion, the observation above could serve as a catalyst for future exploration into photocatalysis, solar cells, nonlinear optics, thermoelectric generators, and ultraviolet selective photodetectors of Bi2Te3 nanosheet-based photodetectors.

Дослідження сенсомоторних реакцій каратистів 10-13 років

Purpose: to determine the level of sensorimotor reactions of karateka of 10-13 years old. Material and methods. The following research methods were used in the present research: theoretical analysis and generalization of scientific and methodical literature; pedagogical supervision; psychophysiological measurements; mathematical and statistical methods of the research. The research was attended by karate juniors of the sports club «Centurion», Kharkiv, in the amount of 26 sportsmen who were divided into 2 groups of 13 people according to the age criterion. The first group of karateka is 10-11 years old, the second one is 12-13 years old. To determine the level of manifestation of sensorimotor reactions a complex of special programs for tablet computers under the control of iOS was used. The results of sensorimotor reactions of the athletes studied by the following tests were obtained: TestSTMemory (short-term visual memory); Visuomotor Choice Reaction (choice reactions); Reaction RMO (reactions to a moving object); TappingPro (number and duration of taps during the 1st minute). Results: the duration of a sensorimotor reaction is one of the neurophysiological indicators. It is the simplest, most accessible and at the same time very accurate neurophysiological indicator. It reflects the speed of neural processes and their switching, motor coordination, overall performance, and the dynamics of the central nervous system. The analysis of the study results showed that karateka aged 10-11 have 13 % less perceptual capacity than karateka aged 12-13. Older karateka were better at memorizing and passing tests faster because this cognitive activity is associated with memorizing the opponent's positions and differentiating hidden signals before motor actions. The choice reaction of older athletes is 26 % higher, which indicates that karateka aged 12-13 years have a more perfect control of the mechanism of movement. The reaction to a moving object in older athletes is 52 % more accurate. In the tapping test, older karateka made 11 % more taps due to their higher qualifications and physiological development. Statistically significant results were obtained in the Wilcoxon test – «Choice Reaction», «Short-term Visual Memory» and «Reaction to a Moving Object». The results of older athletes in the «Tepping Test» are better, but not statistically significant (p>0,05). The better results of older sportsmen in other tests are connected with the growth of the volume of special exercises, namely exercises with elements of martial arts. Conclusions. The above tests can be used in the training process of karateka for the definition of psychophysiological features, because according to the analysis and comparison of the received data in tests «Reaction of a choice», «Short-term visual memory» and «Reaction to a moving object» the senior karateka have statistically reliably better indicators than younger sportsmen (p<0,05). It is connected with the growth of the volume of special exercises in sportsmen of the senior group, namely exercises with elements of martial arts.

Three-dimensional analysis ofthe intracellular architecture by scanning electron microscopy.

The two-dimensional observation of ultrathin sections from resin-embedded specimens provides an insufficient understanding of the three-dimensional (3D) morphological information of membranous organelles. The osmium maceration method, developed by Professor Tanaka's group >40 years ago, is the only technique that allows direct observation of the 3D ultrastructure of membrane systems using scanning electron microscopy (SEM), without the need for any reconstruction process. With this method, the soluble cytoplasmic proteins are removed from the freeze-cracked surface of cells while preserving the integrity of membranous organelles, achieved by immersing tissues in a diluted osmium solution for several days. By employing the maceration method, researchers using SEM have revealed the 3D ultrastructure of organelles such as the Golgi apparatus, mitochondria and endoplasmic reticulum in various cell types. Recently, we have developed new SEM techniques based on the maceration method to explore further possibilities of this method. These include: (i) a rapid osmium maceration method that reduces the reaction duration of the procedure, (ii) a combination method that combines agarose embedding with osmium maceration to elucidate the 3D ultrastructure of organelles in free and cultured cells and (iii) a correlative immunofluorescence and SEM technique that combines cryosectioning with the osmium maceration method, enabling the correlation of the immunocytochemical localization of molecules with the 3D ultrastructure of organelles. In this paper, we review the novel osmium maceration methods described earlier and discuss their potential and future directions in the field of biology and biomedical research.

Green One-Pot Pseudo-Four Component Synthesis of Substituted 5-Cyano-2-imino-4-aryl/ heteroaryl-6-(phenylthio)-2H-pyran-3-carboxylic Acid Catalyzed by Montmorillonite K-10 Clay

A synthetic method of substituted 5-cyano-2-imino-4-aryl/heteroaryl-6-(phenylthio)-2H-pyran-3-carboxylic acid (4a-d) using Montmorillonite K-10 clay as catalyst was developed via one-pot pseudo-four-component reaction. Various aldehydes and thiophenols exhibit swift reactivity with cyanoacetic acid, resulting in satisfactory to exceptional yields (ranging from 70% to 90%) within an exceptionally short reaction duration of 0.75 to 1.5 h. The structural characterization of the synthesized compounds was conducted through IR, 1H, 13C NMR and elemental analysis. Safer technique, simple work-up as well as reusability of the catalyst for two runs are the characteristic features of this method. This multicomponent one-pot reaction approach demonstrates a straightforward synthetic strategy for the formation of two novel C-C bonds, one C-S bond, one C-O bond, and the formation of a new ring structure. Additionally, this reaction exhibits high efficiency as all the reactants are completely utilized.

Recent Advances in g-C3N4 Photocatalysts: A Review of Reaction Parameters, Structure Design and Exfoliation Methods

Graphitized carbon nitride (g-C3N4), as a metal-free, visible-light-responsive photocatalyst, has a very broad application prospect in the fields of solar energy conversion and environmental remediation. The g-C3N4 photocatalyst owns a series of conspicuous characteristics, such as very suitable band structure, strong physicochemical stability, abundant reserves, low cost, etc. Research on the g-C3N4 or g-C3N4-based photocatalysts for real applications has become a competitive hot topic and a frontier area with thousands of publications over the past 17 years. In this paper, we carefully reviewed the recent advances in the synthesis and structural design of g-C3N4 materials for efficient photocatalysts. First, the crucial synthesis parameters of g-C3N4 were fully discussed, including the categories of g-C3N4 precursors, reaction temperature, reaction atmosphere and reaction duration. Second, the construction approaches of various nanostructures were surveyed in detail, such as hard and soft template, supramolecular preorganization and template-free approaches. Third, the characteristics of different exfoliation methods were compared and summarized. At the end, the problems of g-C3N4 materials in photocatalysis and the prospect of further development were disclosed and proposed to provide some key guidance for designing more efficient and applicable g-C3N4 or g-C3N4-based photocatalysts.

Pt/NiCo2O4 nanocomposite with extremely low Pt loading as an oxidase-like nanozyme for colorimetric detection of acetaminophen in natural water

BackgroundIn the last COVID-19-three years, acetaminophen (AP) consumption has increased significantly, potentially causing water contamination. Due to its ease of use and great performance, colorimetric detection of AP based on Pt-based nanozymes is gaining popularity. A significant difficulty is how to reduce Pt loading content while retaining a high catalytic activity. MethodsControlling the deamination of Co-NH3 complexes, including Ni(OH)2, led to the formation of small NiCo2O4 nanoparticles, which were afterwards decorated with a 0.37wt% Pt loading. Significant findingsWith a low Michaelis-Menten constant of 0.0112 mM, the 3,3′,5,5′-tetramethylbenzidine (TMB) was oxidized with O2 utilizing the Pt(0.37wt%)/NiCo2O4 nanocomposite. The detection settings were tuned for nanozyme and TMB concentrations, pH, temperature, and reaction duration. Utilizing AP's inhibitory impact on the oxidase-like activity at pH = 1, an AP colorimetric sensor was created. It was possible to establish a linear response with a detection limit (LOD) of 2.4 μM and a range of 10 μM–0.25 mM. In natural water, such as spring, lake, and river water, this colorimetric sensor was effectively employed to detect AP with good selectivity over interfering substances.

Polyethyleneimine-enhanced silicon carbide membranes for efficient oil-water separation in high-temperature condensate

The primary objective of this research is to improve the efficiency of separating oil and water within the challenging environment of high-temperature condensate. This will be achieved through the innovative approach of surface modifying silicon carbide (SiC) membranes with polyethyleneimine (PEI). To begin, different concentrations of PEI aqueous solutions are formulated by mixing PEI with ultrapure water. Following this, a SiC ceramic membrane undergoes modification through immersion in the solution. This process yields a tailored separation membrane with hydrophilic and oleophobic properties, adjustable pore size, robust physicochemical stability, and surface anti-fouling attributes. This achievement stems from precise regulation of the reaction duration during the meticulous process. Notably, in the context of separating diesel-in-water emulsions across varying concentrations, the adapted membrane demonstrates an extraordinary separation efficiency surpassing 99.00 %. Additionally, it demonstrates impressive resilience against oil fouling, further highlighting its effectiveness. The membrane showcases commendable reusability, sustaining an oil interception rate that exceeds 99.00 % even after undergoing eight consecutive cycles. Furthermore, the coated membrane exhibits exceptional performance even in challenging conditions, including high salinity, extreme pH levels, and temperatures reaching up to 100 °C. At the same time, the membrane demonstrates outstanding mechanical properties. The findings from this study illustrate the promising real-world applications of this groundbreaking oil–water separation membrane.

Insights into the Growth of Ternary WSSe Nanotubes in an Atmospheric CVD Reactor.

The synthesis of complex new nanostructures is challenging but also bears the potential for observing new physiochemical properties and offers unique applications in the long run. High-temperature synthesis of ternary WSe2xS2(1-x) (denoted as WSSe) nanotubes in a pure phase and in substantial quantities is particularly challenging, requiring a unique reactor design and control over several parameters, simultaneously. Here, the growth of WSSe nanotubes with the composition 0 ≤ x < 1 from W18O49 nanowhiskers in an atmospheric chemical vapor deposition (CVD) flow reactor is investigated. The oxide precursor powder is found to be heavily agglomerated, with long nanowhiskers decorating the outer surface of the agglomerates and their core being enriched with oxide microcrystallites. The reaction kinetics with respect to the chalcogen vapors varies substantially between the two kinds of oxide morphologies. Insights into the chemical reactivity and diffusion kinetics of S and Se within W18O49 nanowhishkers and the micro-oxide crystallites were gained through detailed microscopic, spectroscopic analysis of the reaction products and also through density functional theory (DFT) calculations. For safety reasons, the reaction duration was limited to half an hour each. Under these circumstances, the reaction was completed for some 50% of the nanotubes and the other half remained with thick oxide core producing new WOx@WSSe core-shell nanotubes. Furthermore, the selenium reacted rather slowly with the WOx nanowhiskers, whereas the more ionic and smaller sulfur atoms were shown to diffuse and react faster. The yield of the combined hollow and core-shell nanotubes on the periphery of the agglomerated oxide was very high, approaching 100% in parts of the reactor boat. The nanotubes were found to be very thin (∼80% with a diameter <40 nm). The optical properties of the nanotubes were studied, and almost linear bandgap modulation was observed with respect to the selenium content in the nanotubes. This investigation paves the way for further scaling up the synthesis and for a detailed study of the different properties of WSSe nanotubes.

Removal of polymethyl methacrylate nanoplastics and silver nanoparticles by a novel ferrofluid-COF-aminated natural cotton-based hydrogel nanosorbent

In this work, an innovative nanosorbent is assembled based on the combination of Fe2VO6 ferrofluid, silane covalent organic frameworks (COFs) and gelatin/aminated natural cotton/chitosan hydrogel (FF-SiCOF@Gel-ANC@Ch.Hgel). The developed nanomaterial was fully identified using several characterization techniques such as FTIR, electron microscopy, XRD and XPS; and was then studied as an effective nanosorbent for removal of organic nanopollutants such as polymethyl methacrylate nanoplastics (PMMA) and inorganic nanopollutants such as silver nanoparticles from water. Optimization of experimental parameters such as reaction duration, nanosorbent mass, nanopollutant concentration, solution pH, temperature and medium ionic strength revealed promising removal efficiencies towards both nanopollutants with 98.3% and 99.2% recovery for Ag and PMMA nanopollutants, respectively. Kinetic studies confirmed that the adsorptive removal of both nanosorbent followed via a pseudo-second order chemisorption process. Thermodynamic investigations highlighted that spontaneity of the chemisorption process in terms of negative ΔG° values. Industrial scale applicability was confirmed with interestingly high removal efficiencies toward both nanopollutants (99.45% and 96.80% for Ag and PMMA, respectively) in industrial wastewater. Furthermore, proposed nanosorbent showed appreciable recyclability with little decrease in removal efficiencies (from 95.30% to 91.00% and from 97.20% to 93.00% for Ag and PMMA respectively) after 5 adsorption/regeneration cycles. Considering nanosorbent comparatively high adsorption capacities, together with its industrial applicability and reusability, it was proposed as a promising candidate for wastewater treatment applications. The green aspects in this study were investigated in terms of reusing the recovered Ag@FF-SiCOF@Gel-ANC@Ch.Hgel as a potential nanocatalyst in reductive degradation of sulfasalazine drug, a potentially hazardous pollutant. High degradation rates were deduced at optimal conditions providing 2.3 min−1pseudo-first order rate constant with only 3.18% drop in the catalytic activity after 5 successive reduction/regeneration cycles. This accounts for the promising potential of recycled Ag@FF-SiCOF@Gel-ANC@Ch.Hgel as reductive degradation catalyst for targeted water treatment applications.

Role of transition metal nanocomposites in organic reactions: A state of art as an alternative to conventional catalysts

Nanocomposites play vital role as catalyst during organic reactions because of high aspect ratio and greater surface area of nanostructured materials. The strong interfacial interaction of reactant with the surface of nanocomposites during reaction gives an enhancement in rate and yield of the product. The present review reveals a critical analysis regarding the function of transition metal based nanocomposites during catalytic action in various organic reactions. Catalytic action of transition metal based nanocomposites in combination with other carbon based nanomaterials, polymeric materials as well as with other metals or metal oxides are extensively elaborated in this review. The change in yields, duration of reaction, atom economy, and effect of solvent along with selectivity of organic reactions are monitored by various transition metal based nanocomposites. Reduction, oxidation, epoxidation, hydrogenation, halogenation and coupling reactions are appreciably reviewed considering the catalytic effect of these nanocomposites. The role of different nanocatalysts in various known name reactions in organic chemistry is also studied. Hence, present review explores new methods of using transition metal based nanostructured catalysts following the principle of green chemistry by replacing the traditional catalysts and reagents in organic synthesis.

Designing PdxCuy octahedra alloy nanocatalysts supported on solid substrates for solvent-free sonogashira cross-coupling reaction: Rational optimization of metal precursors

The current research details a scientific inquiry into an economic, reproducible, and adaptable synthetic process for the formation of PdxCuy octahedra (Oh) alloy nanocatalysts. Herein, several alloys such as Pd3Cu7, Pd4Cu6, Pd5Cu5, Pd6Cu4, and Pd7Cu3 are synthesized by altering the metal precursors quantities, resulting in a specific octahedral shape for all the ratios. After a thorough optimization study, Pd6Cu4 alloy was selected and anchored onto three solid substrates to achieve Pd6Cu4@hBNNs, Pd6Cu4@ZrO2 and Pd6Cu4@GONs nanocatalysts. Furthermore, the nanocatalysts were investigated for the Sonogashira cross-coupling reaction under solvent-free conditions, with the 15 wt% of the metal-support ratio of Pd6Cu4@hBNNs exhibiting remarkable catalytic activity when compared to the other two supported nanocatalysts. In advance, highly active Pd6Cu4@hBNNs nanocatalyst has many advantages, including mild reaction conditions, benign and minimum reaction duration. Moreover, the catalyst showed an efficient yield of 95 % for the model Sonogashira cross-coupling and considerable recyclability up to the 8th consecutive cycle achieving a 65 % yield. The outstanding performance of this economically viable nanocatalyst is most likely influenced by the synergistic effect of the catalyst and its strong metal-support contact.