Contact Angle Test Research Articles

Epoxy resin‐based biomass composites based on modified corn stalks: Preparation, properties, and toughening mechanism

AbstractIn this study, a series of sustainable eco‐friendly epoxy resin (EP)‐based biomass composites (DSA‐CS/EP) were prepared using bisphenol A EP as matrix, 2‐methylimidazole as curing agent, and corn stalk (CS) esterified with dodecene succinic anhydride (DSA) as filler. The static contact angle test results showed that the hydrophobicity of CS after esterification with DSA (DSA‐CS) was enhanced, which results in the compatibility of DSA‐CS with EP matrix was improved. And then, the DSA‐CSs were dispersed homogeneously in the matrix without agglomerating. The morphology and properties of the biomass composites were studied and analyzed in order to elucidate the toughening mechanism of CS and DSA‐CS. When the content of DSA‐CS is 15 wt%, the tensile strength and impact strength of DSA‐CS/EP reached a maximum value of 30.39 MPa and 3.34 KJ/m2, which were increased by 128.49% and 81.52% compared with pure EP. Finally, it is deduced that the possible toughening mechanism is that DSA‐CS can not only share part of the external stress but also a mutual solute region is formed between DSA‐CS and EP matrix.Highlights Corn stalks esterified by DSA were used as reinforcement filler for epoxy resin. The cellulose in CS was mainly esterified. The tensile and impact strength of DSA‐CS 15/EP reached a maximum value. A mutual solute region is formed between filler and matrix.

A novel approach for flotation separation of talc and molybdenite: Scrap steel-molybdenite galvanic corrosion treatment and its mechanism

Molybdenum is an important strategic resource. Talc-type molybdenite is abundant in reserves, but it is difficult to separate talc and molybdenite efficiently and cleanly because of their similar strong hydrophobicity. In this paper, the effect of galvanic corrosion between scrap steel and molybdenite on flotation behavior of molybdenite was studied under different conditions (different scrap steel materials, slurry water content, galvanic corrosion time and galvanic corrosion ambient temperature).The method for flotation separation of molybdenite and talc by galvanic corrosion of scrap steel-molybdenite was established for the first time. In addition, XPS, SEM, TOF-SIMS, contact Angle test and electrochemical test were used to study the effect of galvanic corrosion of scrap steel-molybdenite on the surface properties of molybdenite and talc. The results show that strong galvanic corrosion between scrap steel and molybdenite can significantly reduce the hydrophobicity of molybdenite, but there is no galvanic corrosion between scrap steel and talc under the same conditions, and scrap steel has no significant effect on the surface hydrophobicity of talc. Therefore, the galvanic corrosion of scrap steel-molybdenite can effectively expand the floatability difference between talc and molybdenite, and strengthen the flotation separation of molybdenite and talc. The flotation test results of artificial mixed ore show that in the case of mineral mixing, the galvanic corrosion of scrap steel-molybdenite still shows a strong inhibition effect on molybdenite flotation, so that 97.04 % of molybdenite in the mixed ore is inhibited into the tailings (molybdenite products). The research results expand the new high-value utilization way of scrap steel in sulfide ore flotation, and help to promote the sustainable development of iron and steel industry and sulfide ores industry. In addition, the research results also have reference significance for the use of scrap steel galvanic corrosion to inhibit other sulfide ores such as pyrite and arsenopyrite.

Titanium Implant Modified With Zinc-Doped Carbon Dot Layer as an Innovative Coating for the Development of Local Drug Delivery System for Ciprofloxacin.

This study presents a new innovative drug delivery system for ciprofloxacin, which is based on the formation of a zinc-doped carbon dots layer on the surface of a titanium alloy (TiAl4V6). In the study, the effectiveness of the synthesis method of a zinc-doped carbon dots layer was determined. The distribution of the layer of carbon dots on the surface of the titanium alloy was investigated using the FT-IR mapping technique, which confirmed the efficiency of the synthesis. The effective synthesis of carbon dots and the coordination of zinc ions on their surface opens the possibility of sorption of ciprofloxacin, which results in a high application potential of the obtained biomaterial. The introduction of zinc cations on the surface of the carbon dots layer resulted in high sorption results of the active substance (40 μg of drug per 1 cm2 of implant). The release profile of ciprofloxacin from the modified surface of the titanium alloy indicates that this active substance can be released for up to 4 h. The biomaterial obtained in this work is also hydrophilic (about 40°), which was shown by the contact angle tests. This is an important feature and indicates a high application potential of the performed modification. The resulting layer has antibacterial properties. Growth inhibition for microorganisms such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Candida albicans ranged from 74% to 96%. The creation of such a layer on the titanium alloy may reduce the risk of infection during the implantation procedure.

The synergetic collecting effect of N-oleoyl sarcosine (N-OSS) and dodecylamine (DDA) on the selective flotation of spodumene from albite

In this study, N-OSS combined with DDA was examined as an novel collector. The collecting performances and their synergetic interaction mechanisms were investigated comprehensively. The micro-flotation results illustrated it exhibited excellent selectivity on separation without pre-activation. Contact angle tests revealed N-OSS/DDA could selectively enhance the hydrophobicity of spodumene, whereas, it barely affected that of albite. FTIR, SEM-EDS and Zeta potential revealed N-OSS/DDA might co-adsorb on spodumene surface rather than that of albite. XPS analysis and DFT calculations inferred the O1 2p orbitals of COO within N-OSS could bond with Al 3s orbitals and the NH3+ groups of DDA adsorbed onto the surface of spodumene via hydrogen bonding and electrostatic attraction. Meanwhile, the hydrogen bonding between N-OSS and DDA promoted the co-adsorption on spodumene surface. While N-OSS/DDA weakly adsorbed on the surface of albite through physical adsorption. N-OSS/DDA exhibited outstanding floatability, which maybe a good substitute for conventional collectors in future.

Influence of water-repellent admixtures ( Sitren and Stearate materials) on the microstructure and mechanical performance of conventional Portland cement paste and mortar

The longevity of mortar and concrete structures can be compromised by the absorption of water and other fluids, leading to deterioration and aesthetic issues. To address this, water-repellent admixtures are employed to enhance the service life of mortar and concrete components by improving their mechanical and microstructural characteristics. This study focus on the effects of incorporating Sitren P 750 and various stearate materials (calcium, zinc, aluminum, and barium) as admixtures with ordinary Portland cement at mortar and paste dosages of 0.5%, 1.0%, and 1.5% of the cement content. We found that mortars with water-repellent admixtures exhibited competitive mechanical properties at all curing ages. Additionally, the study confirmed the contribution of these admixtures to the production of hydration products and the structural development of the mortars, as investigated through scanning electron microscopy, thermogravimetric–derivative thermogravimetric, and X-ray diffraction analyses. Despite alterations in several physical properties and hydration kinetics due to the water-repellent compounds and their dosages, all admixtures provided effective water-repellent protection. This was further corroborated by water contact angle tests and the measurement of the capillary water absorption coefficient for all samples. Identifying the optimal mixture ratio for construction technology and effectively incorporating repellence features is a crucial aspect of this research.

Surface characteristics evolution of 316L stainless steel induced by tension loading

316L stainless steel has been employed as a medical implant material owing to its advantageous biocompatibility and durability. The microstructure and surface characteristics of 316L play a crucial role in implant application. Diverse processing methods were utilized to modify the surface properties of 316L to customize the characteristics of medical devices. Mechanical deformation induces changes in the microstructure and causes changes in surface topography. In this study, we introduced deformation to 316L by applying uniaxial tension at strain values ranging from 2% to 25%. During sample preparation, electrochemical polishing was employed to eliminate the deformed layers generated by mechanical grinding. After the tensile test, a contact angle test was conducted. The surface relief of 316L was examined using three-dimensional (3D) laser scanning microscopy and atomic force microscopy. X-ray diffraction with CuK radiation in the Bragg–Brentano (θ–θ) mode was also employed to identify the phase transformation. It can be concluded that higher strain levels increased surface roughness and the number of slip lines. At higher strain levels, samples exhibited a martensitic transformation, affecting topography changes and the surface free energy. The contact angle measurement results and surface free energy determination showed improved wettability following plastic deformation. Determining the factors that affect surface wettability requires an understanding of the relationship between surface free energy, topography, and surface roughness. Deformation-induced martensite can significantly increase the surface free energy and wettability of 316L stainless steel (SS) by altering strain levels. It is important to consider surface characteristics to understand slip mechanisms at grain boundaries, particularly in cases where surfaces have been electropolished. Nevertheless, the surface also manifested deformation-induced martensitic (DIM) transformation, potentially posing a risk to the passive film and contributing to corrosion, consequently reducing the implant’s lifespan.

Galvanic Interaction between Galena and Pyrite in the Presence of Sodium Lignosulfonate and Its Effects on Flotation.

In the flotation process, there is galvanic corrosion between sulfide mineral particles, which increases the difficulty of separation between minerals. Therefore, the selection of suitable reagents to weaken this corrosion is of great significance. In this article, macromolecular organic reagent sodium lignosulfonate (SLC) was used to weaken the galvanic corrosion between galena and pyrite. Meanwhile, the effect of SLC on the mineral flotation behavior was studied, and the mechanism of SLC was further studied through ion dissolution tests, contact angle tests, infrared spectrum tests, and density functional theory (DFT) calculation. The adsorption of SLC on the mineral electrode increased the charge transfer resistance on the surface of the mineral electrode and hindered the resistance transfer; therefore, it could weaken the galvanic corrosion between galena and pyrite. SLC could selectively depress pyrite at low alkalinity. CaOH+ promoted the adsorption of SLC on the pyrite surface. When the pH of the slurry was adjusted by lime, SLC was more easily adsorbed on the pyrite surface, which hindered the adsorption of the collector on the surface of pyrite.

Picosecond laser processing super-wetting surfaces with hierarchical structures for passive driving of microfluidics

Hierarchical surfaces with superhydrophilicity have potential applications such as collecting water, liquid transport, and rapid heat transfer, but the fabrication and characterization methods still face challenges. In this paper, hierarchical surfaces with multi-level structures are designed and processed on glass substrates by ultrafast laser writing techniques. The contact angle test results indicate that all processed glass surfaces exhibit superhydrophilicity. To differentiate the hydrophilicity of surfaces with a contact angle approaching 0˚ (CA→0˚), we establish an anti-gravity wetting method characterized by fixed-area wetting time. Compared with laser-roughened glass surfaces, the complete wetting times of surfaces with a three-level-Ⅰ structure were shortened by 51.08 times. The roughness factor of the roughened glass surface increases to r=2.92, confirming the Wenzel model's prediction of enhanced hydrophilicity on rough surfaces. The introduction of sub-millimeter open microgrooves on the roughened surface significantly enhances the ability to transport liquids against gravity through capillary action. Ultimately, the tertiary hierarchical surface achieves the shortest anti-gravity wetting time, indicating the strongest wettability. Microchannels with super-wetting bottom surfaces are constructed and achieve passive rapid driving of microfluidics.

A Universal Interfacial Reconstruction Strategy Based on Converting Residual Alkali for Sodium Layered Oxide Cathodes: Marvelous Air Stability, Reversible Anion Redox, and Practical Full Cell.

Mn-based layered oxide cathodes have attracted widespread attention due to high capacity and low cost, however, poor air stability, irreversible phase transitions, and slow kinetics inhibit their practical application. Here, we propose a universal interfacial reconstruction strategy based on converting residual alkali to tunnel phase Na0.44MnO2 for addressing the above mentioned issue simultaneously, using O3 NaNi0.4Fe0.2Mn0.4O2@2 mol % Na0.44MnO2 (NaNFM@NMO) as the prototype material. The optimized material exhibits an initial capacity and energy density comparable with lithium-ion batteries. The reversible anionic redox behavior and charge compensation mechanism of NaNFM@NMO were analyzed and verified by soft X-ray absorption spectrum and in situ X-ray absorption spectrum. Due to the intrinsic stability of the tunnel structure, excellent air stability and highly reversible structure evolution of the NaNFM@NMO cathode material are achieved, which are confirmed by contact angle test, rigorous aging test, and in situ X-ray diffraction. More importantly, the NaNFM@NMO cathode demonstrates a great match with the nonpresodiated hard carbon anode and shows excellent electrochemical performance of the full cell. Additionally, such a strategy could be also applied to modify P2-type cathodes, showing superior universality and good prospects in industrialized production. Overall, the proposed strategy could improve air stability while remaining interfacial and bulk stable simultaneously and will open up a whole new field for the optimization of other electrode materials.

Preparation and performance study of heparinized multi‐walled carbon nanotube/cellulose acetate hemodialysis membrane

AbstractCurrently, the incidence of kidney failure is increasing worldwide. Hemodialysis is the main method for the treatment of kidney diseases, and the continuous development of new hemodialysis membranes is the key to improve the treatment effect and the quality of life of patients. In this study, heparinized multi‐walled carbon nanotube/cellulose acetate (Hep/MWCNTs@CA) membranes were prepared by non‐solvent induced phase separation (NIPS). The morphology and pore structure of Hep/MWCNTs@CA membranes were characterized by scanning electron microscopy (SEM). The elongation at break and tensile strength of the membranes were characterized by a mechanical property universal tester. The results showed that mechanical properties of 0.1 wt% MWCNTs enhanced the membrane is best. The water contact angle test confirmed that MWCNTs can improve the membrane hydrophilicity, and combined with the adsorption test results for proteins, it was found that the hydrophilicity can reduce the adsorption of proteins to the composite membrane and improve the blood compatibility of the material. The dialysis performance of urea and lysozyme was tested by a self‐made simulated hemodialysis device, and the clearance rates of urea and lysozyme were 84% and 47.2%, respectively, which showed that the interfacial gap between MWCNTs and CA matrix can make the composite membrane retain a high retention rate of macromolecular proteins (92.3%) and further improved the clearance rate of small and medium molecular toxins. In addition, the good blood compatibility and biocompatible properties of the materials were confirmed by hemolysis, recalcification and cytotoxicity tests on Hep/MWCNTs@CA membranes. In conclusion, the prepared Hep/MWCNTs@CA holds great potential for application in the field of hemodialysis.

Flotation separation of pyrite and carbonate minerals from a carlin-type gold deposit in Guizhou by a new combined collector and its adsorption mechanism

Flotation is the most common method for effective separation of pyrite and carbonate minerals from Carlin-type gold deposits. The effect of conventional xanthate collector on flotation of a Carlin-type gold mine in Guizhou province is poor, and it can not effectively remove carbonate minerals. In this paper, butyl xanthoxanthate and benzohydroxamic acid (BHA) were used as a new combined collector for the flotation separation of a Carlintype gold mine in Guizhou Province. The flotation behavior of pyrite and its adsorption mechanism on pyrite surface were discussed in detail through pure mineral flotation test, actual ore flotation test, contact Angle test, infrared spectrum analysis and XPS analysis. The results showed that the collection capacity of butyl xanthoxime combined with benzohydroxamic acid was obviously stronger than that of BHA or butyl xanthoxime alone. The optimal ratio of pyrite flotation with combined collector is 3, and the recovery rate of pyrite flotation is 37%, which is higher than that of pyrite flotation recovery of 30.5% when benzohydroxamic acid is used alone and 28.5% when butyl xanthate is used alone. The contact Angle test, infrared spectrum and XPS analysis showed that the combined collector of butyl xanthate and benzohydroxamic acid (BHA) produced strong chemical adsorption on the surface of pyrite. Bha can increase the adsorption capacity of butyl xanthate on the surface of pyrite, which is conducive to the flotation recovery of pyrite.

Hydrophobic Modification of Halloysite Nanotubes Loaded with a Small Amount of Tungsten Oxide for Efficient Oxidative Desulfurization.

Transition metal oxides can be used as efficient multiphase catalysts in the field of catalysis. In this study, a hydrophobic halloysite nanotube (HNT) catalyst was designed and prepared with a low loading. Tungsten oxide was immobilized on the inner surface of the HNT, through electrostatic adsorption and calcination. Furthermore, a dual-functional W/HMT/M catalyst was prepared by hydrophobic modification of the outer surface of HNT through a harmless and nontoxic method. The catalyst was applied in the oxidative desulfurization (ODS) of dibenzothiophene (DBT), and characterized by inductively coupled plasma (ICP), contact angle tests, and other methods. Systematic characterization further confirmed that W/HNT/M has a low loading (0.48 wt %) and a relatively high contact angle of 92.6°. Oxidative desulfurization experiments demonstrated that the high contact angle corresponds to good hydrophobicity. The low loading and high activity of the catalyst enabled it to achieve a removal efficiency of 100% for DBT under conditions of 60 °C and an O/S = 4. The hydrophobic surface of HNT allowed better dispersion in the oil phase, while its hydrophilic inner cavity could adsorb H2O2 and the converted dibenzothiophene sulfoxide, thereby reducing the subsequent extraction steps after oxidative desulfurization and enhancing the reaction environment for reactants and active oxygen. W/HNT/M maintained high activity for at least 5 cycles. Additionally, the potential mechanism of the catalyst in the aqueous ODS reaction was proposed. This study demonstrates that HNT-supported metal oxides have desulfurization potential and provides ideas for improving ODS catalytic activity of the ODS through low loading, high activity, and unique hydrophobicity design.

Investigation of the synergistic effects of SiO2 and Al2O3 nanoparticles with SDS and CTAB surfactants on the stability and improving phase behavior of water-oil emulsions

The stability of emulsions is a significant challenge across various industries, including food, pharmaceutical, and petroleum. Surface-active agents utilized for enhanced oil recovery often exhibit inadequate performance under reservoir conditions with high salinity, presenting a critical barrier to effective emulsion stabilization. Furthermore, due to the extreme hydrophilic or hydrophobic nature of nanoparticles (NPs), they are not effective in stabilizing emulsions on their own. To address this limitation, a minimal quantity of surfactant was introduced into the NPs to improve their wettability and achieve dual wettability. This research has examined the synergistic effects of SiO₂ and Al₂O₃ NPs combined with sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) surfactants on water-oil emulsion stability. This approach enhances emulsion stability by combining the stabilizing effects of both the NPs and the surfactants, an aspect that has not been previously addressed in phase behavior studies through the examination of the interactions and surface behavior of surfactant-nanoparticle complexes at the oil-water interface. Several experiments, including phase behavior, FT-IR, zeta potential, contact angle, and interfacial tension (IFT) tests, were performed to evaluate the interaction of surfactants with NPs. The results demonstrate that combining NPs with surfactants, especially those with opposite charges, significantly reduces IFT to the order of 10−6 mN/m, which can overcome capillary pressure, and enhances optimal salinity levels even up to 75000 ppm. Interactions between CTAB-SiO₂ and SDS-Al₂O₃ notably improve the hydrophobicity of NPs, resulting in IFT reductions of 11.4 and 7 mN/m, respectively, compared to NPs alone.

Study on the Effectiveness of Okra as an Environmentally Friendly and Economical Lubricant for Drilling Fluid

With the gradual improvement and implementation of unconventional wells drilling and environmental regulations, there is an urgent need for high-performance and more environmentally friendly lubricants for water-based drilling fluids (WD). Developing green oilfield chemicals from natural products is a shortcut. In this work, Abelmoschus esculentus (L.) Moench/okra has been studied as the lubricant in WD. The green drilling fluid lubricant developed demonstrates excellent lubrication performance, as well as good filtration loss reduction and inhibition of bentonite hydration expansion. The results show that with the addition of 2.5% okra slurry to water-based drilling fluid, the coefficient of friction decreased by 51.68%, the apparent viscosity (AV) increased by 51.32%, the plastic viscosity (PV) increased by 42.99%, and the fluid loss decreased by 39.88%. Moreover, through TGA, SEM, FT-IR, particle distribution tests, and contact angle tests, the lubrication mechanism of okra slurry was discussed. Finally, the economic feasibility of using okra as an environmentally friendly lubricant for drilling fluids was analyzed. This work combines agricultural products with industrial production, which not only solves industrial problems but also enhances the added value of agricultural products, providing a reference for the coordinated development of industry and agriculture.

Facile fabrication of porous fluorinated polyurethane membranes for organic solvent adsorption based on thiol-ene click reaction within high internal phase emulsions

Porous fluorinated polyurethane membranes show tremendous application potential in organic solvent adsorption. However, the solubilization of fluorinated monomers remain the main obstacle during their polymerization. In this work, we launched a new strategy combining high internal phase emulsion with thiol-ene click chemistry for the facile fabrication of porous fluorinated polyurethane membranes for efficient solvent adsorption. The successful construction of high internal phase emulsions and the effective formation of the designed polymer were confirmed by FTIR, SEM, EDS, XRD, XPS, MIP, and TG/DSC analysis. Contact angle and adsorption capacity tests were also carried out to further illustrate the hydrophobic property and adsorption performance. Results demonstrated that fluorinated polyurethane membranes could be successful synthesized through the in-situ thiol-ene click reaction within high internal phase emulsions. The resulting polymer presented abundant porous structure, excellent thermal stability, good hydrophobic property, and competitive adsorption capacity for several solvents, especially dichloromethane. Furthermore, the structure and properties of the prepared membranes can be effectively altered by regulating the ratio of fluorinated monomer and polyurethane prepolymer. This work presents a facial avenue for designing porous fluorinated polyurethane membranes with a remarkable application potential in solvent adsorption.

Water invasion and residual gas distribution in partially filled fractures via phase-field method

Water invasion is a significant factor affecting the conductivity of fractures in coal seams. The partially contact characteristics of deep coal seam fractures are pronounced, and surface wettability varies significantly. However, there is a limited understanding of how water invasion behavior in partially filled fractures affects the gas produced by these fractures. In this study, a high-temperature and high-pressure contact angle testing device was employed to assess the wettability of coal seams under in situ conditions. The geometry of partially filled fractures was reconstructed using random functions, while the phase field method was employed to calculate the interactions at the two-phase interface during water invasion. The results indicate that the deep coal seams in the Ordos Basin demonstrate weak air-wetting properties under in situ conditions. The partially contact characteristics of the filled fractures in the deep coal seams categorize the fractures into distinct pore and throat regions. The variations in connectivity levels lead to the gas exhibiting uninvaded, clustered, and fully invaded characteristics following water invasion. The change in gas saturation during water invasion is more sensitive to larger values of lgCa and higher cos(θ). A larger displacement pressure difference and a smaller contact angle enable the invasion fluid to penetrate smaller throats, resulting in a higher number of clusters of residual gas and a smaller cluster radius. The results enhance our understanding of water invasion behavior, and the variability of fracture surface properties and gas-water two-phase flow in deep coal seams deserves further investigation.

A high-strength, environmental-friendly, and multifunctional soy protein adhesive inspired by biomineralization

Soy protein is an economical and eco-friendly adhesive material that offers significant potential for the development of bio-based adhesives. However, they have poor water resistance, low bonding strength, mold-susceptibility, and deterioration, which are serious challenges to the widespread application of soy protein adhesives in plywood. This work was inspired by the biomineralization phenomenon and the preparation of a novel soy protein adhesive (SPI-RGT-AgNPs). The SPI-RGT-AgNPs adhesive exhibited excellent viscosity, residual rate, and moisture absorption performance compared with the original soy protein isolate (SPI) adhesive, with an increase from 37° (SPI) to 81° (SPI-10RGT-10AgNPs) in water contact angle testing. The dry and wet adhesion strengths reached 2.49 MPa and 1.43 MPa, 193 % and 117 % higher than SPI adhesive, respectively. Molecular docking simulations were used to verify that the introduction of modifiers significantly improved the stability and crosslinking strength of the adhesive. The best ratio of the SPI-RGT-AgNP adhesive was confirmed using the response surface methodology (RSM). Simultaneously, SPI-RGT-AgNPs adhesive also showed excellent anti-mildew and anti-microbial efficiencies to Escherichia coli (98.18 %) and Staphylococcus aureus (99.33 %). In addition, a life-cycle assessment was used to explore the pollution emissions from the adhesives. As compared to formaldehyde-based adhesives, the SPI-RGT-AgNP adhesive had lower energy consumption and pollution emissions. Therefore, this study prepared a novel high-strength and multifunctional soy protein adhesive, guiding the production of multifunctional and green adhesives.

Study on the Adhesion Performance of Biochar-Modified Asphalt Based on Surface Free Energy and Atomic Force Microscopy

To investigate the effect of biochar on the adhesion performance of asphalt, the macroscopic and microscopic adhesion performance of 70# base asphalt, SBS-modified asphalt (SBSMA), sludge-based biochar-modified asphalt, and waste wood-based biochar-modified asphalt (WWBMA) were tested using atomic force microscopy (AFM) and contact angle tests, respectively. The impact of these two testing methods on the evaluation of adhesion performance was also analyzed. Research results indicated that biochar increased the number of bee-like structures on the asphalt surface while significantly reducing their average area. This improves the distribution of asphalt adhesion by reducing the adhesion difference between bee-like structured areas and non-bee-like structured areas while simultaneously enhancing the overall adhesion of the asphalt surface. Surface free energy (SFE) theory analysis indicates a linear correlation between the SFE obtained from the contact angle test and the atomic force microscopy test. Biochar significantly increases the SFE of asphalt and its components, thereby increasing the work of adhesion between asphalt and aggregate and reducing the work of debonding. Consequently, it improves the bonding performance between asphalt and aggregate, as well as its resistance to moisture damage.

Novel synergistic mechanism of oxalic acid -CMC at the solid-liquid interface: For selective depression of talc from chalcopyrite

Flotation separation of chalcopyrite and talc is challenging due to their surface hydrophobicity, requiring a selective depressant for talc to achieve high-quality copper concentrate. This study is the first to use oxalic acid (OA) and carboxymethyl cellulose (CMC) as combined depressants for talc, and investigated the depression mechanism through flotation tests and various analysis techniques. Mixed minerals-flotation results showed that with 60+60 mg/L OA+CMC, talc was strongly depressed (10.16% recovery) with slight chalcopyrite (86.54% recovery) impact. The selective depression effect of OA+CMC was further verified through actual ore flotation experiments. Contact angle and zeta potential test indicated that OA+CMC significantly increased the hydrophobicity difference between talc and chalcopyrite surfaces. Adsorption capacity and atomic force microscope(AFM) results further confirmed that OA promotes CMC adsorption on talc surface, forming a dense CMC layer, whereas CMC adsorption on chalcopyrite was relatively low. Scanning electron microscope energy spectrum spectroscopy (SEM-EDS), fourier transform infrared spectroscopy(FTIR), and molecular dynamics (MD) results indicate that the synergistic depression mechanism of OA and CMC involves the formation of multiple adsorption layers at the solid-liquid interface, leading to an increased presence of hydrophilic groups on the talc surface, which results in its depression.

Research of Optical Properties and Biocompatibility in Different Zones of Multilayered Translucent Zirconia on Hydrothermal Aging.

We assessed the changes in optical properties and biocompatibility of transition zones in multilayered translucent monolithic zirconia exposed to prolonged hydrothermal aging and compared the results to those with different yttrium oxide contents. Four types of zirconia blocks from IPS e.max ZirCAD were used: 3Y-TZP e.max ZirCAD LT (ZL), 4Y-TZP e.max ZirCAD MT (ZM), 5Y-TZP e.max ZirCAD MT Multi (ZT), and 3Y/5Y-TZP e.max ZirCAD Prime (ZP). A total of 120 specimens (15.0 mm diameter and 1.5 mm height) were fabricated and divided into three groups (n = 10). The aging process for the specimens was conducted in an autoclave set to 134 °C and 0.2 MPa, with durations of 0 h (control), 5 h (first aged), and 10 h (second aged). The optical properties and biocompatibility were analyzed, followed by a statistical analysis of the data (α = 0.05). Before and after aging, ZL and ZP exhibited the lowest color changes. ZT exhibited the highest average transmittance and translucency parameter values, while ZL had the lowest. The water contact angle test showed the highest value in ZM and lowest in ZL across all the aging stages. ZL, ZM, and ZP showed a considerable decrease in the water contact angle; however, ZT did not. A cell counting kit-8 assay showed ZL had the highest value, while ZM had the lowest. A filamentous actin test exhibited the highest value in ZL and lowest in ZM. In the vinculin analysis, ZL and ZT exhibited the lowest values, whereas ZM and ZP had the highest. 3Y/5Y-TZP exhibited a balanced performance across critical parameters, such as color stability, translucency, and biocompatibility, aligning with 3Y-TZP. While 5Y-TZP demonstrated superior translucency, it confirmed the lowest color stability, whereas 3Y-TZP achieved the highest biocompatibility. These properties provide clinicians with a reliable material option that ensures superior esthetic outcomes and long-term prognosis, ultimately contributing to improved patient satisfaction and clinical longevity.