Search Results (121)

In recent years, membrane separation technology has undergone continuous advancements. Microfiltration (MF) membranes, as an important type, are usually prepared by electrospinning—a simple and efficient method. This study reports the development of crosslinked polyvinyl alcohol/polyethylene glycol (cPVA/PEG) nanofiber membranes through a combination of electrospinning and chemical crosslinking, investigating the effects of different crosslinking concentrations on the membrane morphology, surface wettability, and tensile properties. Comprehensive characterization was carried out by using scanning electron microscopy (SEM), a Fourier-transform infrared spectrometer (FTIR), an X-ray diffractometer (XRD), a thermogravimetric (TG) analyzer, differential scanning calorimetry (DSC), a contact angle tester, a universal testing machine, etc. The results showed that at the crosslinking concentration of 15%, the cPVA/PEG fiber membrane achieved a breaking stress of 29.07 ± 2.60 MPa, a breaking strain of 77.60 ± 6.02%, and a porosity exceeding 43%. SEM, FTIR, XRD, TG, and DSC analyses collectively confirmed the occurrence of chemical crosslinking within the membrane structure. The cPVA/PEG-15 membrane exhibited no observable shrinkage or curling upon water contact, combined with excellent hydrophilicity and lipophilicity in the air. These properties indicate that the membrane can serve as a novel functional membrane substrate (e.g., as hydrophilic separation layers) and is expected to play an important role in fields such as seawater desalination and wastewater treatment, demonstrating significant application potential. Full article

In this work, polypropylene (PP) melt-blown nonwoven fabric was used as a raw material, which was plasma-treated and grafted with HBP/Ag nanoparticle (NP) solution. The surface wettability, surface morphology, and surface element composition after the treatment were evaluated through a contact angle test, field emission scanning electron microscopy (FE-SEM), energy-dispersive spectrometer (EDS), and Fourier transform infrared spectroscopy (FTIR), respectively. The antibacterial activity of PP fabrics treated with Ag NPs against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was measured. SEM and EDS results showed that Ag NPs were evenly dispersed on the surface of the PP fabrics. The PP fabrics treated with Ag NPs exhibited excellent antibacterial performance. Full article

Microbial Fuel Cell (MFC) is a novel bioelectrochemical system that catalyzes the oxidation of chemical energy in organic waste and converts it directly into electrical energy through the attachment and growth of electroactive microorganisms on the electrode surface. This technology realizes the synergistic effect of waste treatment and renewable energy production. A CF-NiO-PANI capacitor composite anode was prepared by loading polyaniline on a CF-NiO electrode to improve the capacitance of a CF electrode. The electrochemical characteristics of the composite anode were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the electrode materials were analyzed comprehensively by scanning electron microscopy (SEM), energy diffusion spectrometer (EDS), and Fourier transform infrared spectroscopy (FTIR). MFC system based on CF-NiO-PANI composite anode showed excellent energy conversion efficiency in potato starch wastewater treatment, and its maximum power density increased to 0.4 W/m³, which was 300% higher than that of the traditional CF anode. In the standard charge–discharge test (C1000/D1000), the charge storage capacity of the composite anode reached 2607.06 C/m², which was higher than that of the CF anode (348.77 C/m²). Microbial community analysis revealed that the CF-NiO-PANI anode surface formed a highly efficient electroactive biofilm dominated by electrogenic bacteria (accounting for 47.01%), confirming its excellent electron transfer ability. The development of this innovative capacitance-catalytic dual-function anode material provides a new technical path for the synergistic optimization of wastewater treatment and energy recovery in MFC systems. Full article

Main-chain conjugated and non-conjugated polyelectrolytes are an important class of materials that have many technological applications ranging from fire-retardant materials to carbon-nanotube composites, nonlinear optical materials, electrochromic materials for smart windows, and optical sensors for biomolecules. Here, we describe a series of poly(pyridinium salt)s-fluorene containing 9,9-bis(4-aminophenyl)fluorene moieties with various organic counterions that were synthesized using ring-transmutation polymerization and metathesis reactions, which are non-conjugated polyelectrolytes. Their chemical structures were characterized by Fourier transform infrared (FTIR), proton (¹H) and fluorine 19 (¹⁹F) nuclear magnetic resonance (NMR) spectrometers, and elemental analysis. They exhibited polyelectrolytic behavior in dimethyl sulfoxide. Their lyotropic liquid-crystalline phases were examined by polarizing optical microscopy (POM) and small angle X-ray scattering (SAXS) studies. Their emission spectra exhibited a positive solvatochromism on changing the polarity of solvents. They emitted greenish-yellow lights in polar organic solvents. They formed aggregates in polar aprotic and protic solvents with the addition of water (v/v, 0–90%), whose λ_em peaks were blue shifted. Full article

In this study, a graphene oxide (GO)/zinc oxide (ZnO)/hydroxyapatite (nHAp) composite coating was constructed on a pure titanium surface by microarc oxidation (MAO) pretreatment combined with hydrothermal technology (HT), thereby making it possible to explore the performance optimization of this coating for Ti-based implants. Scanning electron microscopy (SEM), an energy dispersion spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), Ramam spectroscopy (Ramam), etc., confirmed that the GO/ZnO/nHAp composites were successfully loaded onto the pure Ti surfaces. Through nanoindentation, differential thermal analysis (DiamondTG/DTA), and dynamic polarization potential detection, the GO/ZnO/nHAp composite coating imparts excellent nanohardness (2.7 + 1.0 GPa), elastic modulus (53.5 + 1.0 GPa), thermal stability, and corrosion resistance to pure Ti implants; hemolysis rate analysis, CCK-8, alkaline phosphatase (ALP) detection, alizarin red staining, and other experiments further show that the coating improves the hemocompatibility, biocompatibility, and bone guidance of the Ti implant surface. Studies have shown that GO/ZnO/nHAp composite coatings can effectively optimize the mechanical properties, corrosion resistance, biocompatibility, and bone guidance of pure Ti implants, so that they can obtain an elastic modulus that matches human bone. Full article

Mercury contamination in groundwater seriously affects human health and ecosystem security. The remediation of Hg-contaminated groundwater remains a challenging task. The applicability of an as-synthesized supramolecular polymer (SP) for low-concentration mercury in a high-salinity groundwater matrix has been verified through a batch process and column test. The remediation of mercury-contaminated groundwater, particularly in complex high-salinity environments, represents a significant and enduring challenge in environmental science. The batch test study demonstrated that the SP can efficiently adsorb Hg from groundwater with superior selectivity and a high uptake capacity (up to 926.1 ± 165.3 mg g⁻¹). Increasing the pH and dissolved organic matter (DOM) and reducing the ionic strength can facilitate Hg adsorption; the coexistence of heavy metal ions slightly weakens the removal. In terms of its performance as a permeable reactive barrier, the SP can intercept Hg in flowing groundwater with a capacity of up to 3187 mg g⁻¹. A low influent mercury concentration, low pore velocity, and high SP dosage can effectively extend the breakthrough time in column tests. Additionally, the Yan model (R² = 0.960−0.989) can accurately depict the whole dynamic interception process (150 PVs) of SPs in a fixed column, and the Adams–Bohart model (R² = 0.916−0.964) describes the initial stage (≤35 PVs) well. Considering the functional group in the SP and the Hg species in groundwater, complexation, electrostatic attraction, ion exchange, and precipitation/co-precipitation are the plausible mechanisms for mercury removal based on the characterization results of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometer (FT-IR). These impressive features render the SP a promising candidate for the remediation of trace Hg in saline groundwater using permeable reactive barrier (PRB) technology. Full article

During the extraction and utilization of coal resources, a large amount of CO₂ and coal-based solid wastes (CBSW), such as coal gangue, are generated. To reduce the carbon and waste emissions, an effective approach is to mineralize the CO₂ with the CBSW and then backfill the mineralized materials into the goaf area. However, efficient CO₂ mineralization is challenging due to the low reactivity of coal gangue. To this end, mechanical activation was used for the modification of coal gangue, and the mechanical activation mechanism of coal gangue was revealed from a microcosmic perspective by dry powder laser particle size testing (DPLPST), X-ray diffractometer (XRD) analysis, Fourier-transform infrared spectrometer (FTIR) analysis, and scanning electron microscopy (SEM). The results showed that compared with the unground coal gangue, the average particle size of coal gangue after 0.5 h, 1 h, and 1.5 h milling decreases by 94.3%, 95%, and 95.3%, respectively; additionally, the amorphous structures of the coal gangue after milling increase, and their edges and corners gradually diminish. After the pressure mineralization of coal gangues with different activation times, thermogravimetric (TG) analysis was performed, and the CO₂ mineralization effect of the mechanically activated coal gangue was explored. It is found that the carbon fixation capacity of the coal gangue after 0.5 h, 1.0 h, and 1.5 h mechanical activation is increased by 1.18%, 3.20%, and 7.57%, respectively. Through the XRD and SEM, the mechanism of CO₂ mineralization in coal gangue was revealed from a microcosmic perspective as follows: during the mineralization process, alkali metal ions of calcium and magnesium in anorthite and muscovite are leached and participate in the mineralization reaction, resulting in the formation of stable carbonates such as calcium carbonate. Full article

Nanoparticles and nanocomposites have been used in recent studies to improve oil reservoir recovery. With the introduction of a newly constructed smart water injection scenario, this work investigated the physicochemical characteristics of the polymeric carbon nitride/ZrO₂ nanocomposite (ZrO₂/g-C₃N₄), and the results were compared with pure ZrO₂ nanoparticles as a known enhanced oil recovery agent. The effects of ZrO₂/g-C₃N₄ and ZrO₂ on the wettability change, zeta potential, and interfacial tension under reservoir conditions (78 °C and 3800 psi) were determined after characterization experiments, which included X-ray powder diffraction (XRD), a Fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), a field emission scanning electron microscope (FESEM), energy-dispersive x-ray testing (EDX), and a Brunauer–Emmett–Teller (BET) analysis. Based on the highest zeta potential and the greatest reduction in the contact angle and interfacial tension, the optimum concentrations for ZrO₂/g-C₃N₄ and ZrO₂ were determined to be 30 and 40 ppm, respectively. Moreover, the ZrO₂/g-C₃N₄ nanocomposite demonstrated better results in enhancing the oil recovery parameters, and it was selected for low salinity flooding scenarios with three different salinities, including MgCl₂ + seawater (SW), CaCl₂ + SW, and MgSO₄ + SW, at 30 ppm of the nanocomposite. The best readings for the ZrO₂/g-C₃N₄ nanocomposite in its interfacial tension, contact angle, and zeta potential show that 1000 ppm has the best interfacial tension reduction among the tested concentrations of 500–50,000 ppm. At 30 ppm, MgCl₂ + SW had the maximum recovery (i.e., 49.36%), and this resulted from better interfacial tension reduction, contact angle reduction, and stability compared to other salinities. Full article

Anthocyanin (ACN) is a natural pigment with various biological activities, but their stability is compromised by external environmental factors, which limits their practical application in food processing. To enhance the stability of anthocyanin, double-layer-modified anthocyanin nanoliposomes (ACN-NLs) were prepared in this study using pea protein isolate (PPI) and inulin (IN) through layer-by-layer assembly in this study. The preparation conditions of unmodified, single-modified, and double-layer-modified nanoliposomes (ACN-NLs, PPI-ACN-NLs, and IN-PPI-ACN-NLs) were optimized via analysis of their average particle size, zeta potential, and encapsulation efficiency (EE). In addition, the structure of the nanoliposomes was characterized via transmission electron microscopy (TEM) and a Fourier transform infrared (FTIR) spectrometer. Furthermore, the thermal stability of nanoliposomes in hot cocoa and their release behavior during in vitro simulated digestion were evaluated. The results indicated that the optimal formulation for IN-PPI-ACN-NLs was 6% PPI and 2% IN. Under these conditions, the IN-PPI-ACN-NLs had a particle size of 270.2 ± 0.66 nm, a zeta potential of −15.76 ± 0.81 mV, and a high EE of 88.6 ± 0.71%. TEM analysis revealed that IN-PPI-ACN-NLs exhibited a spherical core–shell structure, while FTIR confirmed the interaction between ACNs and the encapsulating materials (PPI and IN). Compared with unmodified or monolayer-modified nanoliposomes, IN-PPI-ACN-NLs exhibited thermal stability in beverage systems and enhanced DPPH radical scavenging activity. During in vitro digestion, IN-PPI-ACN-NLs demonstrated a sustained-release effect and improved the digestive stability of ACN. These properties make it a promising functional additive for applications in the food and pharmaceutical industry. Full article

Two-dimensional molybdenum disulfide (MoS₂) exhibits interesting properties for applications in micro and nano-electronics. The key point for sensing properties of a device is the quality of the material’s surface. In this study, MoS₂ layers were deposited on polymers by pulsed laser deposition (PLD). This process was monitored by a mass quadrupole spectrometer to record the emissions of MoS₂ and evaluate the amount of molybdenum and sulfur compounds generated. The changes in laser parameters during the PLD strongly affect the properties of the formed MoS₂ film. The exploration of the composition and structure of the films was followed by Attenuated Total Reflectance–Fourier Transform Infrared (ATR-FTIR), Atomic Force Microscopy (AFM), and mass quadrupole spectrometer (MQS). The possible application of the fabricated composite as a sensor is preliminarily considered. Full article

Sillenite materials have been the focus of intense research in recent years due to their unique properties and distinct structure with the I23 space group. This electronic structure has reflected high-quality applications and results for some environmental processes such as photocatalysis. This paper investigates the synthesis of a new sillenite, Bi₁₂SnO_20, and its characteristics, emphasizing its potential for photocatalytic applications. The sillenite Bi₁₂SnO₂₀ has been synthesized through the co-precipitation method by mixing the appropriate ratio of Bi and Sn ions. The obtained particles after precipitation and drying were characterized by thermogravimetric analysis (TGA) and then calcined at different temperatures based on this analysis. The phase has been identified by structural analysis using X-ray diffraction (XRD), and its morphology after identification was carried out by scanning electron microscopy (SEM). The calcination temperature has been found to have a critical role in obtaining the phase, where the phase was found to be formed at temperatures between 310 and 400 °C and changed to other phases within higher temperatures. The physicochemical properties of this sillenite were also studied by Fourier-transform infrared spectroscopy (FTIR) and UV Visible Spectrometer (UV-Vis). To study the obtained phases at different calcination temperatures, performance testing was performed under visible light to remove different contaminants, which are Tetracycline, Bisphenol A, and Rhodamine B. The phase Bi₁₂SnO₂₀ obtained at 350 °C with a catalyst dose of 1 g/L showed the highest performance for removing these pollutants with concentrations of 20 mg/L, with an efficiency of almost 100% within 2 h. This work will be useful as an important resource and strategy for the development of this sillenite material in its pure phase. Full article

In this work, the surfaces of poly (ethylene terephthalate) track-etched membranes (PET TeMs) with pore sizes of 670–1310 nm were hydrophobized with 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate (DFHA) by photoinitiated graft polymerization. Attenuated total reflection FTIR spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray spectrometer (EDX), and contact angle measurements were used to identify and characterize the TeMs. The optimal parameters for graft polymerization were determined as follows: polymerization time of 60 min, monomer concentration of 30%, and distance from the UV source of 7 cm. The water contact angle of the modified membranes reached 97°, which is 51° for pristine membranes. The modified membranes were tested for water desalination using direct contact membrane distillation (DCMD) method. The effects of membrane pore size, the degree of grafting, and salt concentration on the performance of membrane distillation process were investigated. According to the results obtained, it has been concluded that large pore size hydrophobic TeMs modified by using DFHA could be used for desalinating water. Full article

In this study, a Ti₃C₂ MXene@g-C₃N₄ composite powder (TM-CN) was prepared by the ultrasonic self-assembly method and then loaded onto a carbon nanofiber membrane by the self-assembly properties of MXene for the treatment of organic pollutants in wastewater. The characterization of the TM-CN and the C-TM-CN was conducted via X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometer (FTIR) to ascertain the successful modification. The organic dye degradation experiments demonstrated that introducing an appropriate amount of Ti₃C₂ MXene resulted in the complete degradation of RhB within 60 min, three times the photocatalytic efficiency of a pure g-C₃N₄. The C-TM-CN exhibited the stable and outstanding photocatalytic degradation of the RhB solution over a wide range of pH values, indicating the characteristics of the photodegradation of organic pollutants in a wide range of aqueous environments. Furthermore, the results of the cyclic degradation experiments demonstrated that the C-TM-CN composite film maintained a degradation efficiency of over 85% after five cycles, thereby confirming a notable improvement in its cyclic stability. Consequently, the C-TM-CN composite film exhibits excellent photocatalytic performance and is readily recyclable, making it an auspicious eco-friendly material in water environment remediation. Full article

(1) Background: The present paper reports the results of the analyses performed on the wall paintings of Room E of the Domus delle Pitture (Room of the Paintings) in the Roman archaeological site of Volsinii Novi (Bolsena, Viterbo, Central Italy) aimed at supporting the recently concluded restoration. (2) Methods: ultraviolet fluorescence photography was conducted to evaluate the conservation state. Painting materials were investigated via portable X-ray fluorescence spectrometer (p-XRF), µ-Raman spectroscopy, cross-section analysis under polarizing microscope, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), and Fourier transform infrared (FTIR) spectroscopy. (3) Results: This analysis revealed the presence of traditional pigments used in Roman wall paintings, such as ochres, earths, and Egyptian blue. Additionally, it identified pigments from previous restoration containing titanium and chromium, along with other materials present in the surface and interface of the wall painting containing arsenic, copper, lead, and vanadium, where a bluish alteration was observed. In these samples, µ-Raman spectroscopy detected calcium oxalates but also copper arsenates, likely conichalcite and/or duftite. (4) Conclusions: This result is highly relevant from an analytical point of view and in relation to the restoration decisions. Addressing the irregular bluish stains on the wall paintings poses challenges in understanding, requiring a decision on whether to remove or retain them. Full article

The catalytic conversion of naturally rich and renewable biomass into high-value chemicals is of great significance for pursuing a sustainable future and a green economy. The preparation of pentanediol from furfuryl alcohol is an important means of high-value conversion of biomass. The Pt-based catalyst supported on MgO was applied to the selective hydrogenation of biomass furfuryl alcohol to prepare pentanediol. By adjusting parameters such as catalyst loading, reduction temperature, reaction temperature, and pressure, a highly active catalyst was designed and the optimal catalytic hydrogenation conditions were determined. The hydrogenation experiment results showed that the selectivity of the 2Pt/MgO-200 catalyst for 1,2-pentanediol and 1,5-pentanediol reached 59.4% and 15.2%, respectively, under 160 °C and 1 MPa hydrogen pressure. The catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), CO₂-temperature programmed desorption (CO₂-TPD), and other methods. The characterization results indicate that the reduction temperature has a significant impact on the metal Pt, and an appropriate reduction temperature is beneficial for the hydrogenation performance of the catalyst. In addition, the basic sites on the carrier are also another important factor affecting the activity of the catalyst. In addition, stability tests were conducted on the catalyst, and the reasons for catalyst deactivation were studied using methods such as thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The results showed that the activity of the catalyst decreased after five cycles, and the deactivation was due to the hydrolysis of the carrier, the increase in metal particle size, and the surface adsorption of organic matter. Full article