Zeta Potential Measurements Research Articles

Influence of synergistic effect of polyacrylamide and surfactant on dewatering performance of flotation clean coal

ABSTRACT The moisture content of flotation clean coal products is a critical factor influencing their calorific value, making dewatering research vital for the efficient utilization of coal. In this study, cationic polyacrylamide (CPAM) was employed as a high molecular weight flocculant and filter aid to investigate the mechanisms by which the anionic sodium dodecyl sulfate (SDS), cationic dodecyltrimethylammonium bromide (DTAB), and nonionic polyoxyethylene lauryl ether (Brij L23) affect the dewatering of flotation clean coal. The influence of these surfactants on the dewatering performance of flotation clean coal in conjunction with CPAM was examined through filter aid experiments, density functional theory, zeta potential measurements, agglomeration of flotation clean coal particles, and Nuclear Magnetic Resonance (NMR) analysis. The results indicated that DTAB and SDS exhibited a larger positive electrostatic potential compared to Brij L23, demonstrating stronger electrostatic adsorption on the molecules of flotation clean coal. However, the -OSO3 groups in SDS interacted more strongly with the molecules of flotation clean coal than the tertiary amine groups in DTAB. The ether and hydroxyl groups in Brij L23 interacted weakly with the molecules of flotation clean coal. The surfactants increased the compactness and structural complexity between particles within the flocs, leading to an increase in the fractal dimension of the flocs. Additionally, the surfactants enlarged the pores within the filter cake of flotation clean coal, which was beneficial for the removal of moisture.

Development and characterization of hydrogel beads with carboxymethyl chitosan/graphene quantum dots@Pectin/MIL-88 for targeted doxorubicin delivery: An adaptable nanocomposite approach.

Hydrogels are adaptable substances with a 3D framework able to hold large quantities of water, which is why they are ideal for use in the field of biomedicine. This research project focused on creating a new hydrogel combining carboxymethyl chitosan (CMCS), graphene quantum dots (GQDs), pectin (Pe), and MIL-88 for precise and controlled release of the cancer drug doxorubicin (DOX). The creation of CMCS/GQDs@Pe/MIL-88 hydrogel beads was achieved through an eco-friendly one-step synthesis method. The hydrogel beads were then analyzed using various techniques including FE-SEM, EDX, FT-IR, XRD, BET surface area, DLS, and zeta potential measurements. The hydrogel beads showed great swelling ability and controlled breakdown in different pH environments, mimicking the conditions of the gastrointestinal tract and body. Research on drug loading and release showed that the hydrogel components can be adjusted to control the release of DOX. Cytotoxicity tests in a lab setting using K562 cells demonstrated successful delivery of DOX and the ability to target cancer cells specifically while reducing negative effects. Adding GQDs improved both the imaging abilities and the stability and mechanical characteristics of the hydrogel. This research indicates that the CMCS/GQDs@Pe/MIL-88 combination hydrogel beads show great potential for advanced drug delivery systems, especially in cancer treatment.

Ultrasound assisted complexation of soybean peptide aggregates and soluble soybean polysaccharide: pH optimization, structure characterization, and emulsifying behavior.

This study aims to enhance the emulsifying properties of soybean peptide aggregates (SPA) by preparing SPA-soluble soybean polysaccharide (SSPS) composite particles at the assistance of ultrasound technique. The optimal pH for SPA and SSPS complexation was determined by measuring the charge and particle size of the composites. The effects of ultrasound power and duration on the physicochemical properties of the composite particles were assessed through measurements of particle size, zeta potential, contact angle, FTIR, and SEM. The influence of ultrasound duration on the emulsifying properties of the composite particles was evaluated by particle size, zeta potential, microstructure, rheology, and in vitro digestibility. The optimal pH for SPA and SSPS complexation was determined to be 4.0. Zeta potential and FTIR analyses indicated that ultrasound enhanced the electrostatic interactions and hydrogen bonding between SPA and SSPS. Emulsions stabilized with ultrasonicated composite particles exhibited reduced particle sizes, increased viscosity, improved viscoelastic properties, and better in vitro digestibility. The results suggest that moderate ultrasound treatment can strengthen the interactions between SPA and SSPS, thereby enhancing their emulsifying properties. This study offers valuable insights into enhancing the emulsifying performance of highly hydrophobic protein particles.

Development and characterization of bael fruit gum-pectin hydrogel for enhanced antimicrobial activity.

Natural polymers are crucial for developing sustainable biomedical solutions, as their bioactivity, biocompatibility, and biodegradability make them superior alternatives to synthetic materials. The objective of the study is to develop and characterize a chemically modified bael fruit gum (BFG) and pectin hydrogel to enhance antimicrobial activity. Due to BFG's anionic nature, it was chemically modified to introduce cationic groups, facilitating cross-linking with pectin. Physicochemical characterization of BFG and pectin was conducted using FTIR and DSC, which confirmed functional groups and thermal stability, respectively. Hydrogel optimization was achieved through Central Composite Design (CCD). Rheological evaluations indicated shear-thinning behavior with a viscosity reduction under high shear stress, reflecting thixotropic properties. The hydrogel exhibited satisfactory erosion and swelling within 24h, suggesting controlled release. Zeta potential measurements confirmed the hydrogel's stability, attributed to its negative surface charge. SEM revealed a porous structure, aiding in drug encapsulation and release. Antimicrobial testing showed synergistic antimicrobial effects with inhibition zones of 1.4cm and 1.5cm against Staphylococcus aureus and Escherichia coli, respectively. Stability studies demonstrated robustness over time. Overall, this study highlights the potential of natural polymer-based hydrogels as sustainable alternatives to synthetic polymers in pharmaceutical and biomedical fields, offering safer, environmentally friendly solutions.

Comparison on the performance of green and conventional magnetic chitosan-based composites in the removal of complex dyes: Synergetic effect, experimental and theoretical studies.

The presence of complex dyes, which possess four or more aromatic rings, is pervasive in environmental matrices. Nanomaterials offer a promising avenue for their removal. In this study, we synthesized novel magnetic nanocomposites comprising nanochitosan (nCS) and iron nanoparticles through the application of green and conventional protocols. In the preparation of the green composite, designated as G-nCS@FeNPs, eucalyptus leaves extract and proanthocyanidins were employed as reducing and crosslinking agents, respectively. In contrast, the conventional composite, designated as C-nCS@FeNPs, utilized ammonia and glutaraldehyde as the reducing and crosslinking agents, respectively. The G-nCS@FeNPs exhibited a more electropositive surface, and prominent magnetic properties. The zeta potential measurements of the G-nCS@FeNPs (ranging from +36 to +30mV) were more positive than those of the C-nCS@FeNPs (+35 to -2.79mV). Additionally, the C content in C-nCS@FeNPs was less (36.4%) than in G-nCS@FeNPs (57.2%), which is likely due to the higher nanochitosan content and the presence of proanthocyanidins in the green nanocomposite. The G-nCS@FeNPs exhibited a tridimensional porous structure, whereas the conventional composite appeared to form a CS film with an uneven surface and embedded FeNPs. G-nCS@FeNPs demonstrated remarkable potential as an adsorbent material for the removal of anionic reactive dyes, namely orange 122 (RO122) and red 250 (RR250). It exhibited an exceptional adsorption capacity of 3005mg.g-1 for RO122. A DFT study revealed that the RO122 molecule displays enhanced reactivity towards the adsorbent surface. Moreover, experiments conducted in saline media and XPS and FTIR analyses post-adsorption indicated that 78.8% of the interactions between RO122 and the adsorbent are based on electrostatic and ion exchange, while the remaining 22.2% are attributed to π-π and hydrogen bonds. Also, G-nCS@FeNPs demonstrated a synergistic effect on the removal of the cationic dye safranin in multicomponent systems, exhibiting an increase in removal capacity from 0 to 169mg.g-1.

Topical delivery performance of Pickering emulsions stabilized by differently charged spirulina protein isolate/Chitosan composite particles.

Pickering emulsions, stabilized by particulate particles, have emerged as a promising vehicle for topical delivery. Herein, Pickering emulsions stabilized by differently charged spirulina protein isolate - chitosan (SC) composite particles were studied for effective topical delivery of α-Bisabolol (ABS). The composite particles were synthesized via electrostatic assembly of spirulina protein isolate (SPI) and chitosan (CS), and their surface charge was assessed using zeta potential measurements. The Pickering emulsions stabilized by SC composite particles with different charges were all stable over 30 days and had a high encapsulation efficiency for ABS. In vitro skin permeation study revealed that positively charged emulsions significantly increased ABS retention within the skin, predominantly in the stratum corneum layer. The underlying delivery mechanism was further explored using attenuated total reflection Fourier transform infrared spectroscopy. Lastly, the influence of particle concentration and oil phase volume fraction on the topical delivery efficiency was conducted to optimize the Pickering formulations. This study provides insight into the role of particle charge in enhancing topical delivery of Pickering emulsions.

Preparation and Properties of Epoxy Modified Acrylic Polymer

This paper describes the synthesis of a viscosity-reducing agent using butyl acrylate (BA), ethyl methacrylate (EMA), acrylic acid (AA) and N-hydroxymethylacrylamide (N-MAM) monomers through emulsion polymerization. A series of viscosity-reducing agents were developed by incorporating varying amounts of glycidyl methacrylate (GMA) monomers. The reaction mechanism of epoxy acrylate viscosity reducer was analyzed by Fourier transform infrared spectroscopy (FTIR). Additionally, the particle size and Zeta potential were used to analyze the stability of the polymer and the difference in the polymer after adding GMA monomer. Thermogravimetric (TG) analysis indicated a significant improvement in the thermal stability of the resin due to GMA modification. The viscosity reduction test results demonstrated a substantial decrease in the viscosity of heavy oil, along with a notable increase in the viscosity reduction rate. The FTIR analysis results confirmed that GMA successfully introduced polyacrylate molecular chains. Furthermore, particle size and Zeta potential measurements showed that the average particle size of the emulsion increased from 132 nm to 187 nm, while the Zeta potential changed from −43 mV to −40 mV with the addition of 15% GMA. Compared with W0, the final thermal degradation temperature of W15 increased from 450 °C to 517 °C. When the GMA content reached 15 wt%, the maximum weight loss temperature increased by approximately 12 °C compared to the sample without GMA. Specifically, adding 8% W15 epoxy acrylate resulted in an 89% viscosity reduction rate for heavy oil, demonstrating an excellent viscosity reduction effect. This study successfully developed a novel epoxy acrylate viscosity reducer using a simple synthesis method, showcasing excellent stability, cost-effectiveness and remarkable viscosity reduction.

Selective Flotation Separation of Chalcopyrite from Copper-Activated Pyrite and Pyrrhotite Using Oxidized Starch as Depressant

The disadvantages of using lime to depress the flotation of copper-activated pyrite and pyrrhotite are well known. In this study, oxidized starch, prepared by the ozone nanobubble technology, was employed as an eco-friendly depressant for copper-activated pyrite and pyrrhotite in the flotation of chalcopyrite. Single mineral flotation showed that oxidized starch inhibited the flotation of copper-activated pyrite and pyrrhotite at pH 5.5 while having no significant impact on chalcopyrite flotation. Zeta potential and adsorption measurements, together with XPS analysis and EDTA extraction, were conducted to understand the mechanism underpinning the selective depression behavior of oxidized starch. It was found that oxidized starch had a stronger affinity for copper-activated pyrite and pyrrhotite than for chalcopyrite. The depression of pyrite and pyrrhotite by oxidized starch was due to the combined effect of the formation of hydrophilic Cu-starch complex and the oxidation of Cu(I) on their surfaces. Further, oxidized starch was examined in the flotation of an actual bulk sulfur concentrate where a comparable depression performance to that of lime was shown. This investigation may contribute to the greening of the chalcopyrite flotation process by demonstrating the promising potential of oxidized starch for copper-activated pyrite and pyrrhotite depression.

Green synthesis of silica-coated gold nanoparticles employing femtosecond laser, solid targets, and water

Gold nanoparticles are widely used in biomedical applications due to their unique properties. However, traditional synthesis methods generate contaminants that cause cytotoxicity and compromise the biocompatibility of the nanomaterials. Therefore, green synthesis methods are essential to produce pure and biocompatible nanoparticles, ensuring their effectiveness in biomedical applications. This study introduces a novel approach for synthesizing silica-coated gold nanoparticles (AuNP@SiO₂) using femtosecond laser ablation in water, eliminating the need for chemical reagents. The process involves three key laser-based steps: Si ablation, SiNP@SiO₂ fragmentation, and Au ablation, all conducted in a liquid environment. The resulting AuNP@SiO₂ were characterized using transmission electron microscopy (TEM), UV–Vis absorption spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential measurements. The results demonstrated that the AuNP@SiO₂ nanoparticles exhibit high colloidal stability, with a notably negative zeta potential of (-72.0 ± 0.3) mV, effectively preventing particle aggregation. TEM analysis confirmed predominantly spherical nanoparticles with an average diameter of (15.87 ± 0.70) nm, encapsulated by a SiO₂ layer ranging from 1 to 3 nm in thickness. The synthesis approach produced nanoparticles with an average size distribution below 35 nm. This green synthesis method not only produces stable and well-characterized AuNP@SiO₂ nanoparticles but also represents a significant step towards more sustainable nanomaterial production, with promising implications for biomedical applications.

Utilization of a Solid Waste Inhibitor for the Clean Flotation Enrichment of Phosphate Ores.

The accumulation of phosphogypsum (PG) in the phosphorus chemical industry poses significant environmental challenges. Therefore, developing a harmless utilization method is crucial for alleviating these burdens and promoting sustainable industry practices. In this study, PG was used as a flotation inhibitor, enabling the flotation separation of apatite and dolomite based on the main components and dissolution behavior of PG. A microflotation study revealed that 0.875 g/L PG selectively inhibited dolomite when the sodium oleate (NaOL) concentration was 1.5 × 10-4 mol/L, reducing dolomite recovery 76% to 10% at pH in the range of 7-11. Conversely, apatite recovery remained above 90% at pH 7-9 and was only slightly inhibited at pH in the range of pH 9-11. When CaSO4·2H2O and CaHPO4·2H2O were added as flotation inhibitors, they also inhibited dolomite, though their effects were weaker than PG. Measurements of contact angles, zeta potentials, and adsorption capacities indicated that PG enhanced the hydrophilicity of dolomite, hindering NaOL adsorption thereon, while it had little effect on the floatability of apatite. Atomic force and scanning electron microscopy revealed selective PG was adsorbed on the dolomite surface, altering its properties, while PG was weakly adsorbed on the apatite surface and had minimal impact on its properties. The solution chemical composition and microthermal results showed that CaSO4 and CaHPO4 are the effective components of PG inhibition. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry confirmed that CaSO4 and CaHPO4 in PG were selectively adsorbed at Ca and Mg ion sites on the dolomite surface. Molecular dynamics simulations showed that CaSO4 interacts with the surface of dolomite, and CaHPO4 can promote the adsorption of CaSO4 on the surface of dolomite. Utilizing PG as a flotation inhibitor provides a novel approach for the environmentally safe use of PG resources.

Experimental study on the simultaneous effect of smart water and clay particles on the stability of asphaltene molecule and emulsion phase

Enhancing oil recovery in sandstone reservoirs, particularly through smart water flooding, is an appealing area of research that has been thoroughly documented. However, few studies have examined the formation of water-in-heavy oil emulsion because of the incompatibility between the injected water-folded ions, clay particles, and heavy fraction in the oil phase. In this study, we investigated the synergistic roles of asphaltene and clay in the smart water flooding process using a novel experimental approach. Our results provide new insights into how the behavior and properties of water in heavy oil emulsions are affected by changes in ion-tuned water in clay-rich sandstone reservoirs. To investigate this, heavy oil was combined with aqueous phases (in the absence and presence of clay) for 20 days at 80 °C. Then, the emulsion phases were centrifuged to separate the oil and brine phases (aged oil and brine). The separated oil phases were analyzed using Interfacial Tension (IFT), oil viscosity measurements, and asphaltene onset point precipitation (AOP) experiments. We observed significant decreases in viscosity and AOP when crude oil was exposed to the aqueous phases containing brine and clay, which was also reflected in the IP-143 results. Additionally, ATR (Attenuated Total Reflection) results and elemental analysis obtained from asphaltenes extracted from the aged oil phase, along with zeta potential measurements of the aged oils, indicated a reduction in the concentration of aliphatic groups as well as in the polar and negative components of the asphaltene molecular structure from the oil phases. Furthermore, the analysis of the simultaneous effects of ion-tuned water and clay on emulsion properties revealed differing impacts on the stability of the emulsion phase. These variations were attributed to the contribution of polar asphaltene components at the interface. These findings could potentially reduce undesirable emulsion damage during heavy oil recovery with ion-tuned water flooding in clay-rich reservoirs.

Synthesize and characterization of a novel sol–gel-driven Bi2O3 semiconductor: complete degradation and fast photocatalytic activity for paracetamol

Abstract The pollutants are getting released fluently as a waste from the pharmaceutical pollutants leading to the decrease in quality of water. The widespread occurrence of pharmaceutical pollutants poses a serious threat to the environment and human health. Besides, today carbon dioxide emissions and other forms of pollution appear to be a critical global issue. In this study, Bi2O3 catalyst has been prepared via co-precipitation (CP) and a facile sol–gel (SG) methods used as photocatalyst for the degradation of paracetamol (PAR) under different light sources. The preparation method has significant effect on the optical and structural properties of the catalysts. The tetragonal phase of Bi2O3, the presence of more surface OH groups and lower band gap energy remarkably improved the sun-light-driven photoactivity of PAR. The photocatalysts have been characterized by some structural and morphological analysis techniques and optical analysis techniques. In addition, zeta potential (ZP) measurements were performed to explain the impact of the initial pH of solution on photocatalytic degradation. Identification of PAR and the reaction intermediates was determined using Liquid Chromatography-Mass/Mass Spectrometry (LC-MS/MS) technique. Higher photocatalytic activity was obtained with the Bi2O3-SG (1:2) catalyst at pH 5 compared to the activity of Bi2O3-CP. Moreover, Bi2O3-SG (1:2) achieved the highest photocatalytic activity at pH 3. The photocatalytic activity was enhanced, and the time required for 100% degradation of PAR was reduced from 60 min to 30 min and 15 min under UVB irradiation and directly sun light irradiation, respectively. The highest reaction rate (0.086 (min−1)) were obtained in 15 min with the Bi2O3-SG (1:2) catalyst. The results showed TOC removal could be achieved in 60 min 99.19 and 88.97% for Bi2O3-SG and Bi2O3-CP, respectively. In general, sol–gel-driven Bi2O3 as a flower and needle-like morphology, can reveal excellent opportunities in the photocatalytic technology. Graphical Abstract

Chitosan-DNA nanoparticles: synthesis and optimization for long-term storage and effective delivery.

Chitosan nanoparticles (CsNPs) are an effective and inexpensive approach for DNA delivery into live cells. However, most CsNP synthesis protocols are not optimized to allow long-term storage of CsNPs without loss of function. Here, we describe a protocol for CsNP synthesis, lyophilization, and sonication, to store CsNPs and maintain transfection efficiency. The size and zeta potential of CsNPs were analyzed by dynamic light scattering (DLS) and the morphology of CsNPs was assessed by transmission electron microscopy (TEM). HEK293 cells were transfected with CsNPs, and expression of H2B-CMV-mScarlet plasmid was assessed by flow cytometry. Confocal microscopy was used to visualize post-transfection gene expression. Time, volume, and effect of sonication were tested to optimize the lyophilization process. DLS and TEM analysis indicated amine groups on chitosan to phosphate groups on DNA (N:P) ratios yielded smaller CsNPs sizes. Transfection efficiency, measured by FACS and confocal microscopy, peaked at N:P ratios of 2:1 and 3:1 for both fresh and lyophilized CsNPs. Chitosan/DNA complexes remained stable in solution for at least 72 h at a ratio ≥2:1 as assessed by agarose gel electrophoresis. A lower surface charge with lower N:P ratios was indicated by zeta potential measurements. Lyophilized CsNPs lost 50% transfection efficiency compared to those freshly made. In contrast, sonication of lyophilized CsNPs restored their transfection efficiency to the level of fresh CsNPs. Sonicated CsNPs maintained spherical morphology, while unsonicated CsNPs showed aggregates. Cytotoxicity assays revealed high cell viability (>90%) after CsNPs transfection for a ratio of 2:1 or 3:1. This optimized CsNPs synthesis protocol opens the possibility of long-term storage for CsNPs, which would provide broader applications of this technology.

Enhanced Photocatalytic Degradation of Organic Dyes in Water Using Oak Leaf-Synthesized Iron Nanoparticles: A Study on Environmental Remediation and Antioxidant Potential

This study applies green chemistry principles to promote sustainable and environmentally friendly chemical processes by utilizing plant extracts, which are rich in bioactive compounds, as a sustainable resource for synthesizing nanoparticles. Iron nanoparticles (FeNPs) were synthesized using ferric chloride (FeCl3) and kermes oak (Quercus coccifera L.) leaf extract. The synthesized FeNPs were characterized using UV–Vis spectroscopy, Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS), and Zeta potential measurements. The antioxidant and dye degradation capabilities of the FeNPs were evaluated. The results revealed that the extract is rich in phenolic and flavonoid compounds. According to SEM analysis, FeNPs appeared aggregated and granular. The FeNPs exhibited ABTS and DPPH radical scavenging activities with values of 4.95 ± 0.52 µg/mL and 1.54 ± 0.014 μg/mL, respectively. The FeNPs demonstrated exceptional photocatalytic activity in degrading Methylene Blue, Crystal Violet, Congo Red, and Methylene Orange dyes. Experiments conducted over 180 min showed that FeNPs degraded Methylene Blue, Crystal Violet, Congo Red, and Methylene Orange dyes by 89.8%, 73.1%, 50.7%, and 37.9%, respectively. This study highlights the potential of FeNPs for the photocatalytic degradation of organic dyes, emphasizing their importance in wastewater treatment applications.

Small extracellular vesicles derived from sequential stimulation of canine adipose-derived mesenchymal stem cells enhance anti-inflammatory activity

BackgroundSmall extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) are recognized for their therapeutic potential in immune modulation and tissue repair, especially in veterinary medicine. This study introduces an innovative sequential stimulation (IVES) technique, involving low-oxygen gas mixture preconditioning using in vitro fertilization gas (IVFG) and direct current electrical stimulation (ES20), to enhance the anti-inflammatory properties of sEVs from canine adipose-derived MSCs (cAD-MSCs). Initial steps involved isolation and comprehensive characterization of cAD-MSCs, including morphology, gene expression, and differentiation potentials, alongside validation of the electrical stimulation protocol. IVFG, ES20, and IVES were applied simultaneously with a control condition. Stimulated cAD-MSCs were evaluated for morphological changes, cell viability, and gene expressions. Conditioned media were collected and purified for sEV isolation on Day1, Day2, and Day3. To validate the efficacy of IVES for sEV production, various analyses were conducted, including microscopic examination, surface marker assessment, zeta-potential measurement, protein quantification, nanoparticle tracking analysis, and determination of anti-inflammatory activity.ResultsWe found that IVES demonstrated non-cytotoxicity and induced crucial genotypic changes associated with sEV production in cAD-MSCs. Interestingly, IVFG influenced cellular adaptation, while ES20 induced hypoxia activation. By merging these stimulations, IVES enhanced sEV stability and quality profiles. The cAD-MSC-derived sEVs exhibited anti-inflammatory activity in lipopolysaccharide-induced RAW264.7 macrophages, emphasizing their improved effectiveness without cytotoxicity or immunogenicity. These effects were consistent across day 3 collection, indicating the establishment of an effective protocol for sEV production.ConclusionsThis research established an innovative sequential stimulation method with positive impact on sEV characteristics including stability, quality, and anti-inflammatory activity. This study not only contributes to the enhancement of sEV production but also sheds light on their functional aspects for therapeutic interventions.

Study the influence of various surfactants on the stability of oil-in-water emulsions by optical tweezers

Study on the stability of oil-in-water (O/W) emulsions is significant for breaking O/W emulsions, which is a key problem in oilfield wastewater treatment. So far, the traditional methods for exploring the stability of emulsions are mostly bulk measurements. Here, we report directly observing the sticking propability of pairs of emulsion droplets by optical tweezers to investigate the stability of O/W emulsions at the microscale. It was confirmed that resins in the oil phase and various types of surfactants in the aqueous phase are all beneficial for the stability of O/W emulsions. Besides, the conventional bulk measurements of Zeta potential and interfacial tension were also carried out to study the influence of the above species on the stability of O/W emulsions. The resultant data are well consistent with those obtained from the optical tweezer method (OTM). Our results show that optical tweezer is a new and reliable approach to evaluate the stability of oil-in-water emulsions and it opens up a bright road for exploring the stability of emulsions at microscale.

Green Synthesis of Zinc Oxide Nanoparticles Including Rosehip (Rosa canina L.) Seed Extract: Evaluation of Its Characterization and Bioactivity Properties.

The use of bioactive compounds in plants as reducing, stabilizing, and capping agents in nanoparticle manufacturing is an exceptionally eco-friendly approach. This work used rosehip seed extract, acquired by automatic solvent extraction, in the microwave-assisted green production of zinc oxide nanoparticles (ZnO NPs). The total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of the extracted materials and nanoparticles (NPs) were assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The ideal synthesis parameters were established as 25mL of extract, pH 12, 360W of microwave power, and a metal salt concentration of 0.05M for a duration of 7min. The characterization of the ZnO NPs synthesized under these conditions was performed using x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy with energy-dispersive x-ray analysis (SEM-EDX), dynamic light scattering (DLS), zeta potential measurements, and UV-Vis spectrophotometry. High-purity, nano-sized, antioxidant ZnO NPs were manufactured using an ecologically friendly, sustainable, and ecological technique.

Novel Ultrafiltration Polyethersulfone Membranes Blended with Carrageenan.

The development of ultrafiltration (UF) polymeric membranes with high flux and enhanced antifouling properties bridges a critical gap in the polymeric membrane fabrication research field. In the present work, the preparation of novel PES membranes incorporated with carrageenan (CAR), which is a natural polymer derived from edible red seaweed, is reported for the first time. The PES/CAR membranes were prepared by using the nonsolvent-induced phase separation (NIPS) method at 0.1-4.0 wt.% CAR loadings in the casting solutions. The use of dimethylsulfoxide (DMSO), which is a bio-based and low-toxic solvent, is reported. Scanning electron microscopy, atomic force microscopy, water contact angle, porosity, and zeta potential measurements were used to evaluate the surface morphology, structure, pore size, hydrophilicity, and surface charge of the prepared membranes. The filtration performance of PES/CAR membranes was tested with bovine serum albumin (BSA) solutions. It was shown that CAR incorporation in the casting solutions notably increased hydrophilicity, porosity, pore size, surface charge, and fouling resistance of the prepared membranes compared with plain PES membranes due to the hydrophilic nature and pore-forming properties of CAR. The PES/CAR membranes showed a significant reduction in irreversible and total fouling during filtration of BSA solutions by 38% and 32%, respectively, an enhancement in the flux recovery ratio by 20-40%, and an improvement in mechanical properties by 1.5-fold when compared with plain PES membranes. The findings of the present study indicate that CAR can be used as a promising additive for the development of PES UF membranes with enhanced properties and performance for water treatment applications.

Highly porous activated carbon derived from the papaya plant (stems and leaves) for superior adsorption of alizarin red s and methylene blue dyes from wastewater.

In this study, stems and leaves of the papaya plant were employed to prepare a high-quality porous adsorbent via carbonization and chemical activation using phosphoric acid. This adsorbent demonstrates superior adsorption capabilities for the efficient removal of hazardous alizarin red s (ARS) and methylene blue (MB) dyes. Thus, it contributes to waste reduction and promotes sustainable practices in environmental remediation, aligning with global efforts to develop sustainable materials that address water pollution while supporting circular economy principles. The structural properties of the activated carbon were characterized through various techniques, including BET surface area, FTIR, SEM, XPS, zeta potential measurements, and determination of the zero-point charge. The characterization results confirmed the preparation of highly porous activated carbon from papaya stems with a high surface area of 1053.52 m2 g-1. The batch experiments revealed that the maximum adsorption capacities for the stem-activated carbon (SAC) were 931 mg g-1 for ARS and 990 mg g-1 for MB. For the leave-activated carbon (LAC), the capacities were 410 mg g-1 for ARS and 642 mg g-1 for MB. SAC exhibited 100% removal of MB or ARS with concentrations lower than 150 ppm in 15 min. The data fitted well with the Langmuir model and pseudo-second-order model. Moreover, the reusability revealed that the SAC can be reused over 5 cycles without significant change in the removal efficiency. Overall, SAC and LAC derived from papaya plants exhibited excellent dye adsorption performance, suggesting potential for large-scale applications.

Silica Nanoparticles Modified by Biphenyl Groups for Crack-Free Coating on Synthetic Paper.

Water-based acrylic emulsions are a crucial component of water-based ink. Preventing visible cracks in emulsion coating during drying is a great challenge due to the high polarity and high surface tension of water. Herein, we propose that the cracking resistance of the coating can be enhanced through the incorporation of hydrophobic silica nanoparticles. The hydrophobic silica nanoparticles were fabricated by the modification of biphenyl groups to the surface of silica nanoparticles through postcoating using dimethoxydiphenylsilane. The presence of phenyl groups on the surface of biphenyl-modified silica nanoparticles (BPSNs) was confirmed by the Raman spectrum, Sears number, and zeta potential measurements. The formation of large cracks was significantly reduced by the incorporation of BPSN into water-based acrylic emulsion coatings. BPSN strengthens the forces of attraction between the resin particles in coatings, enabling the coating to resist the stresses caused by drying. This work provides a simple method to obtain crack-free coatings of water-based acrylic emulsion on a nonabsorbent substrate, offering a promising strategy for the printing industry to broaden the application of water-based ink.