Low Surface Tension Research Articles

Directional rebound of compound droplets on asymmetric self-grown tilted mushroom-like micropillars for anti-bacterial and anti-icing applications

Directional liquid bouncing is of great significance for a variety of biological and industrial applications. Although surface engineering through 3D printing or self-assembly enables water droplets to rebound directionally, directional bouncing of compound droplets still poses a challenge due to their low surface tension. Moreover, preparation of superamphiphobic surfaces in an efficient and simple manner to accomplish this mission remains to be studied. Here, a tilted stepped mushroom-like micropillar surface (TSMMs), whose structural morphology can be created and tailored by a facile and direct femtosecond laser-induced asymmetric self-growing strategy, is designed to enable the oblique quasi-pancake bouncing of a low surface tension droplet (γ = 32 mN/m). Oblique quasi-pancake bouncing can not only reduce the droplet contact time (7 ms) but also effectively control the direction of droplet bouncing (the horizontal distance of 2.4 mm). Accompanying mechanistic analysis provides an in-depth understanding of the structure-droplet motion relationship. Finally, we demonstrate the applications of TSMMs in antibacterial and anti-icing scenarios. This work advances the investigation of directed droplet transportation, and paves new avenues in the fields of advanced biomedical and other industrial materials.

Self-assembly behavior of fluorinated amphiphilic copolymer in aqueous solution and its properties in the solid film state

Owing to the high electronegativity of fluorine atoms, incorporation of fluorinated moieties in a polymer can confer unique properties such as low surface energy and self-assembling ability in solution. In this study, a series of amphiphilic copolymers were prepared by radical polymerization using three monomers: 2-((2,3,3,3- tetrafluoro- 2- (1,1,2,3,3,3- hexafluoro −2- (perfluoroethoxy) propoxy) propanoyl)oxy) ethyl acrylate (FHEMA), maleic anhydride (MAH), and acrylic acid (AA). The PFHEMA block provided low surface tension, and the MAH and AA blocks (containing carboxyl) increased solubility. The properties of the polymer (PFHEMA-co-PMAH-co-PAA) can be regulated by changing the PFHEMA length. Characterization by Fourier-transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) indicated successful polymerization (FHA01 and FHA02). When the FHEMA/MAH/AA molar ratio was 3:8:9 (FAA02), the surface tension of the hydrolyzed amphiphilic copolymers FAA02 at 300 mg·mL−1 in aqueous solution was 15.76 mN·m−1, the lowest value due to a higher fluorine content than FAA01. FAA02 self-assembled in water to form pH-sensitive micelles with diameters greater than 140 nm. For the FAA02 film, both the F/C ratio and arrangement of fluorine-containing side chains decreased with increasing film depth. Thus, this type of fluorine-containing low surface free energy material can be developed into a high performance coating material.

Surface activity of protein extracts from seed oil by-products and wettability of developed bioplastics

Protein concentrates, extracted from the by-products of Hemp (Cannabis sativa), Cardoon (Cynara cardunculus), and Argan (Argania spinosa L.) oilseeds after oil extraction, were utilized to produce sustainable and eco-friendly protein-based bioplastics. The surface wettability and roughness of these bioplastics were investigated due to the pivotal role of these parameters in their application in food packaging sector. Advancing contact angle value revealed that Argan protein-based bioplastic is the most hydrophobic (θ > 90°) while Cardoon protein-based film is the most hydrophilic (θ < 40°). These results are then supported by the roughness of wet film surfaces and their swelling ratio, where Cardoon-based bioplastics and Argan-based bioplastics have also the lowest and the highest roughness average, respectively. The measured hydrophilicity of the produced bioplastics motivates a detailed investigation of the surface activity of protein concentrates used for film formation which can determine the packaging by coating. Adsorption/desorption kinetics, surface tension and dilatational rheology are reported at two different pHs values (10 and 12). The three protein concentrates are surface active and develop stable adsorbed layers at the air-water interface after 1 h. Cardoon proteins showed the same final surface tension (>45 mN m−1) at both pHs, while Argan and Hemp proteins displayed lower values than Cardoon, especially at pH 12 (<40 mN m−1), indicative of higher surface activity. Finally, Argan protein adsorbed more irreversibly, followed by Hemp protein while Cardoon protein provides the largest partial desorption from the surface. Combined analysis of the data features a correlation between the higher advancing contact angle of Hemp protein-based bioplastic and higher hydrophobicity, less swelling, faster adsorption kinetics, lower surface tension and more irreversible adsorption of protein. These apply for Hemp and Cardoon protein concentrates and their driven bioplastics while the presence of free oil in Argan protein concentrate and its bioplastic hinders the correlation between different phenomena. The new interconnections highlighted between film properties and surface adsorption could potentially be employed in food packaging and coating technology.

Non-fluorinated durable water repellent and stain resistant coating

Fluorinated materials have been broadly used in the industry of water repellent and stain resistance. Because fluorinated materials have low surface tension, and the coatings could easily be manufactured as water-repellent and stain-resistant, fluorinated materials dominate the market for breathable waterproof textiles. However, these materials had substantial health hazards because of the toxicity of fluorinated materials. Moreover, many governments also regulate fluorinated materials for health reasons. As a result, non-fluorinated materials replacing fluorinated materials have become a trend in the industry. As a result, many companies are actively looking for solutions for non-fluorinated water-repellent and stain-resistant materials. This literature review will give a comprehensive understanding of water-repellent properties, materials surfaces, and stain-resistance properties, materials, and surfaces.Moreover, this review would also include reviews of natural water repellent and stain repellent. Furthermore, this review will also talk about the theories behind the materials. Additionally, the fabrication process limitation and future outlook will be discussed in this review.

Hydrogen Production by Methane Pyrolysis in Molten Cu-Ni-Sn Alloys

Hydrogen is an essential vector for transitioning today’s energy system. As a fuel or reactant in critical industrial sectors such as transportation and metallurgy, H2 can diversify the energy mix and supply and provide an opportunity to mitigate greenhouse-gas emissions. The pyrolysis of methane in liquid catalysts represents a promising alternative to producing hydrogen, as its energy demand is comparable to steam methane reforming, and no CO2 is produced in the base reaction. In this work, methane pyrolysis experiments were conducted using a graphite crucible filled with liquid ternary Cu-Ni-Sn alloys at 1160.0 °C. A statistical design of experiments allowed the generation of a model equation that predicts the achievable conversion rates in the ranges of the experiments. Furthermore, the experimental results are evaluated considering densities as well as surface tensions and viscosities in the investigated system, calculated with Butler and KRP equations, respectively. The highest methane conversion rate of 40.15% was achieved utilizing a melt of pure copper. The findings show that a combination of high catalytic activity with a high density and a low viscosity and surface tension of the melt results in a higher hydrogen yield. Furthermore, the autocatalytic effect of pyrolysis carbon is measured.

Self-Aggregation, Antimicrobial Activity and Cytotoxicity of Ester-Bonded Gemini Quaternary Ammonium Salts: The Role of the Spacer.

Five ester-bonded gemini quaternary ammonium surfactants C12-En-C12 (n = 2, 4, 6), with a flexible spacer group, and C12-Bm-C12 (m = 1, 2), with rigid benzene spacers, were synthesized via a two-step reaction and analyzed. Furthermore, the effects of the spacer structure, spacer length and polymerization degree on the self-aggregation, antimicrobial activity and cytotoxicity of C12-En-C12 and C12-Bm-C12 and their corresponding monomer N-dodecyl-N,N,N-trimethyl ammonium chloride DTAC were investigated. The results showed that C12-En-C12 and C12-Bm-C12 had markedly lower critical micellar concentration (CMC) values and lower surface tension than DTAC. Moreover, the CMC values of C12-En-C12 and C12-Bm-C12 decreased with increasing spacer length. In the case of equivalent chain length, the rigidity and steric hindrance of phenylene and 1,4-benzenediyl resulted in larger CMC values for C12-Bm-C12 than for C12-En-C12. The antibacterial ability of C12-En-C12 and C12-Bm-C12 was assessed using Escherichia coli (E. coli) and Staphylococcus albus (S. aureus) based on minimum inhibitory concentrations (MICs). Furthermore, C12-En-C12 and C12-Bm-C12 exhibited higher antimicrobial activity than DTAC and had stronger function toward S. aureus than E. coli. The antimicrobial activity was enhanced by increasing the spacer chain length and decreased with the increased rigidity of the spacers. The cytotoxic effects of C12-En-C12 and C12-Bm-C12 in cultured Hela cells were evaluated by the standard CCK8 method based on half-maximal inhibitory concentration (IC50). The cytotoxicity of C12-En-C12 and C12-Bm-C12 was significantly lower than alkanediyl-α,ω-bis(dimethyldodecylammonium) bromide surfactants and DTAC. The spacer structure and the spacer length could induce significant cytotoxic effects on Hela cells. These findings indicate that the five ester-bonded GQASs have stronger antibacterial activity and lower toxicity profile, and thus can be used in the pharmaceutical industry.

Numerical investigation of the gravity effect on two-phase flow and heat transfer of neon condensation inside horizontal tubes

The condensation flow and heat transfer characteristics of cryogenic neon inside horizontal tubes with diameters of 1 mm and 2 mm were numerically investigated. The mass flux ranged from 20 to 187 kg/(m2·s) for gravity levels includes zero gravity, Lunar gravity, Martian gravity, and Earth gravity. The effects of gravity on the condensation flow pattern, local condensate film distribution, and local and global heat transfer were analyzed in detail. The gravity effect on the condensation heat transfer showed three states, including enhancement, deterioration and gravity-independence, which were mainly determined by the mass flux and vapor quality. Under normal gravity, the condensation heat transfer coefficients increased with increasing mass flux and decreasing tube diameter. Under low mass flux, the cryogenic neon underwent enhanced condensation heat transfer under zero gravity and reduced gravity in the high vapor quality region but deteriorated condensation heat transfer in the low vapor quality region. By increasing the mass flux, the gravity effect was effectively suppressed, which resulted in gravity-independent behavior of condensation heat transfer in the high vapor quality region. The gravity effect significantly affected the liquid film distribution in the condensation process, with a more uniform distribution of the liquid film appearing along the circumferential direction as the gravity level decreased. However, due to the low surface tension of the deep cryogenic fluid, the condensation interface was more prone to flow instability under reduced gravity levels.

The core-shell structured aqueous dispersions of the siloxane-grafted polyurethane copolymers with high transparency

We have synthesized the siloxane-grafted polyurethane copolymers aqueous dispersions by semi-continuous emulsion polymerization. The mono-methacryloxypropyl terminated polydimethylsiloxane was used to react with the acrylate-terminated waterborne polyurethane, which served as seed emulsions. It is obtained that the as-synthesized copolymer dispersions are stable and have small particle sizes ranging from 77 nm to 120 nm, and they possess core-shell structures. Moreover, the results show that the prepared films exhibit high transparency and hydrophobic surface. Moreover, the enrichment of siloxane and the heterogeneous structure on the film surface was studied. The results of Raman spectra disclose that the intensities of siloxane on the surface change over time during the film formation. These results are correlated to the pressure difference of droplets and low surface tension of siloxane segments. The as-synthesized dispersions promise to be applied in the displayer coatings.

Molecular simulation and experimental validation for surface tension of new Low-GWP refrigerant mixtures R32/CF3I and R1123/CF3I

This study demonstrated a new procedure for measuring surface tension using molecular dynamics (MD) simulations. The surface tension was measured by the differential capillary rise method for refrigerant mixtures R1123/CF3I and R32/CF3I, which have a low global warming potential. The information of the saturated density in the low-temperature region, which was necessary for data reduction, was supplemented by an MD simulation, which was validated using accurate measurement data near the critical point. The surface tension calculated from the pressure tensor obtained by the MD simulation deviated considerably. However, the surface tension obtained from the simulated density and composition in the vapor and liquid phases by the parachor method was in agreement with the measured values within the measurement uncertainty ranges from 0.15 mNm−1 to 0.35 mNm−1. The simulated density distribution showed positive surface activity at the vapor–liquid interface, indicating that R32 and R1123, with smaller polarities, tended to aggregate on the liquid surface. This helps interpret the empirically postulated decrease in the surface tension of the mixtures due to the concentration of substances with lower surface tension at the vapor–liquid interface.

Hyper-Production of Biosurfactant by Pseudomonas guguanensis Strain Iraqi ZG.K.M through Random Mutagenesis

Background: With growing environmental concern, interest was increased in research anddevelopment of environmentally friendly substances. Microbial surfactants are nontoxic andbiodegradable bioproducts that are widely used in medical, pharmaceutical, agricultural,industrial, food, cosmetics, and refinery applications. However, the main challenges in theproduction of biosurfactants are the high production cost and the limited yield. The improvementof biosurfactant production depend on many strategies, such as the use of low-cost raw materials,adjusting medium and growth conditions, and the selection of hype-producing strains.Objective: The study was conducted to obtain Pseudomonas guguanensis strain Iraqi ZG.K.Mmutant with higher biosurfactant production, through random mutagenesis.Materials and Methods: Chemical mutagen (acridine orange) in different concentrations andthe physical mutagen (UV irradiation) were used for the production of random mutagenesis inPseudomonas guguanensis strain Iraqi ZG.K.M. The biosurfactant hype-producing strain wasselected depending on CTAB test, E 24 %, and the measurement of surface tension.Results: A clear indication of the efficiency of UV light in producing biosurfactant mutant. Inwhich, a higher E 24 % (78%) and the lowest surface tension (33 mN/m) were recorded withZUVM2 mutant.Conclusion : UV light can successfully used to mutagenize Pseudomonas guguanensis strainIraqi ZG.K.M to obtain hyper-producer mutants of biosurfactant that used in many applications.

Esterification of acetic acid with isobutanol catalyzed by ionic liquid n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate: Experimental and kinetic study

As an important organic, isobutyl acetate (IbAc) has been widely used in industries because of its good biodegradability, low surface tension, and other properties. The industrial production of IbAc is usually catalyzed by sulfuric acid. However, the use of sulfuric acid has the drawbacks of causing considerable corrosion to equipment and being difficult to be separated. In this work, n-sulfopropyl-3-methylpyridinium trifluoromethanesulfonate ([HSO3-PMPY][CF3SO3]) Brönsted acidic ionic liquid (BAIL) was used as the catalyst and the catalytic activity, solubility, and corrosiveness were evaluated for the esterification of acetic acid with isobutanol. The reaction kinetics and chemical equilibrium were systemically studied. Compared to conventional acid catalysts, [HSO3-PMPY][CF3SO3] showed higher catalytic activity, more excellent reusability, more favorable phase separation, and non-corrosiveness. Three kinetic equations based on ideal homogeneous (IH), non-ideal homogeneous (NIH), and modified non-ideal homogeneous (NIH-M) models were established and correlated with the experimental data to determine the parameters and errors. The NIH-M model exhibited the best agreement with the experimental data, owing to its prediction considering the non-ideality and the self-catalysis effect of acetic acid in this system. Besides, the error of NIH-M model fitting was mainly caused by the difference in solubility between [HSO3-PMPY][CF3SO3] with reactants and products in the reaction system. Furthermore, the applicability of the NIH-M model was investigated by simulating the esterification of acetic acid with three short-chain alcohols (ethanol, n-butanol, and isobutanol) catalyzed by BAILs. The NIH-M model displayed an acceptable simulation for this type of acetic acid esterification reaction catalyzed by BAILs at different ranges of the BAILs concentration and temperature. This study confirmed the industrial prospects of [HSO3-PMPY][CF3SO3] in isobutyl acetate production and the applicability of the NIH-M kinetic model in the esterification of acetic acid.

Improving waterproof-breathable capability of degradable macroporous film/hemp hydroentangled nonwovens composite membranes by porous structure and surface wettability modification

Due to recent serious COVID-19 pandemic, medical protective materials with outstanding microbial barrier and liquid barrier property have attracted much attention. However, the crucial issue of improving the waterproof-breathable capability and degradable properties of medical protective material is still challenging. In this research, poly(butyleneadipate-co-terephthalate) (PBAT)/hemp@silica-polyvinylsilsesquioxane (SiO2-PVSQ) composite membranes with good moisture permeability and waterproof property were fabricated. Firstly, hemp and cotton fibers were mixed and hemp/cotton hydroentangled nonwovens were produced to endow the membranes with outstanding water vapor penetration and mechanical properties. Then, degradable PBAT macroporous membranes were prepared by non-solvent induced phase separation (NIPS) method, and combined with hemp/cotton hydroentangled nonwovens to endow the composite membranes with waterproof property. Finally, SiO2 particles were hydrophobically modified by vinyltrimethoxysilane (VTMOS) and grafted on the surface of PBAT/hemp composite membranes. The waterproof property of composite membranes was further improved by hierarchical rough structure and low surface tension hydrophobic groups on the membrane surface. The prepared PBAT/hemp@SiO2-PVSQ composite membranes showed excellent tensile strength with high moisture permeability, good waterproof and water contact angle of 139.5°, indicating promising candidates for the new generation comfort and degradable medical protective textiles.

Synthesis and Characterization of Hydrophobic and Low Surface Tension Polyurethane

Polyurethane is a common polymeric coating, providing abrasion resistance, chemical durability, and flexibility to surfaces in the biomedical, marine, and food processing industries with great promise for future materials due to its tunable chemistry. There exists a large body of research focused on modifying polyurethane with additional functionalities, such as antimicrobial, non-fouling, anticorrosive action, or high heat resistance. However, there remains a need for the characterization and surface analysis of fluoro-modified polyurethanes synthesized with commercially available fluorinated polyol. In this work, we have synthesized traditional solvent-borne polyurethane, conventionally found in food processing facilities, boat hulls, and floor coatings, with polyurethane containing 1%, 2%, and 3% perfluoropolyether (PFPE). Polyurethane formation was confirmed by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, with the urethane band forming at 1730 cm−1 and the absence of free isocyanate stretching from 2275–2250 cm−1. X-ray photoelectron spectroscopy (XPS) was used to confirm perfluoropolyether polymerization with an increase in the atomic percentage of fluorine. Wettability and hydrophobicity were determined using a dynamic water contact angle with significant differences in advancing the water contact angle with the inclusion of perfluoropolyether blocks (PU–co–1PFPE 131.5° ± 8.0, PU–co–2PFPE 130.9° ± 5.8, and PU–co–3PFPE 128.8° ± 5.2) compared to the control polyurethane (93.6° ± 3.6). The surface orientation of fluorine supported the reduced critical surface tensions of polyurethane modified with PFPE (12.54 mN m−1 for PU–co–3PFPE compared to 17.19 mN m−1 for unmodified polyurethane). This work has demonstrated the tunable chemical qualities of polyurethane by presenting its ability to incorporate fluoropolymer surface characteristics, including low critical surface tension and high hydrophobicity.

Surface tension and viscosity of binary ionic liquid mixtures from high vacuum up to pressures of 10 MPa

In the present study, we investigated the surface tension and viscosity of binary ionic liquid (IL) mixtures at or close to saturation conditions from high vacuum conditions up to elevated pressures. We studied four different mixtures of 1,3-bis(2-(2-methoxyethoxy)ethyl)imida-zolium iodide ([(mPEG2)2Im]I) and 1-methyl-3-octylimidazolium hexafluorophosphate ([C8C1Im][PF6]) with [C8C1Im][PF6] mole contents between (4.6 and 49.8) mol%. Argon (Ar) gas of relatively low solubility was used to vary the applied pressure between (0.1 and 10) MPa. For temperatures from (303 to 363) K, the surface tension obtained by the pendant-drop (PD) method was used to determine the saturated liquid viscosity from surface light scattering (SLS). These studies are complemented by additional PD measurements under ultraclean high vacuum (HV) conditions in a second setup. At about 0.1 MPa, the surface tension and viscosity of the IL mixtures show negative deviations from a linear mixing rule based on the molar bulk composition, which is more pronounced at lower temperatures. The surface tension values at 0.1 MPa and under HV agree with each other and lie closer to the values of [C8C1Im][PF6] that has a distinctly lower surface tension than [(mPEG2)2Im]I and is surface-active. For the equimolar IL mixture at 303 K, an increase in the pressure up to 10 MPa has a negligible influence on the viscosity, while it causes a distinct reduction in the surface tension compared to the value at 0.1 MPa. The pressure-dependent relative change for the viscosity of the ternary mixtures of the two ILs and Ar corresponds well to the mean values of the positive and negative relative changes observed for the two binary [(mPEG2)2Im]I-Ar and [C8C1Im][PF6]-Ar subsystems, respectively. For the surface tension, the absolute changes at a given pressure are very similar regardless of the IL bulk composition, suggesting a similar weak Ar enrichment at the gas–liquid interface.

Smart NiAl-LHDs-based superwetting Janus membrane based on charge demulsification for efficient separation of multiple emulsions and mixtures via multi-strategy synergy

In recent years, there has been an urgent need to remove low surface tension oil from oily wastewater due to the increasing industrial oily wastewater and the frequent occurrence of oil pollution incidents. Among these, emulsion separation in particular has become a global challenge. In previous studies, double layer hydroxides have been found to have hydroxide-rich surface and good hydrophilicity. Surprisingly, it is positively charged underwater, which is able to exert charge on oil-in-water emulsions containing anionic surfactants and thus demulsify them for efficient separation. Inspired by this, we prepared NiAl-LDHs on stainless steel mesh (SSM) by hydrothermal method, and then prepared Janus membrane by spraying method that can easily achieve on-demand separation of oil-in-water and water-in-oil emulsions, heavy oil/water and light oil/water mixtures. What's more, the prepared membrane maintains excellent performance after 10 cycles of emulsion separation and 25 cycles of oil–water separation. It maintains high hydrophobicity even after 50 impacts of sand and exhibits high repellency to acidic and alkaline droplets, so it can function in various harsh environments. The novel materials prepared in this work that can be used for charge demulsification and the proposed combination of multiple separation strategies have unlimited potential in the future of emulsion separation.

Synthesis and Characterization of Antimicrobial Hydrophobic Polyurethane.

Food borne illness remains a major threat to public health despite new governmental guidelines and industry standards. Cross-contamination of both pathogenic and spoilage bacteria from the manufacturing environment can promote consumer illness and food spoilage. While there is guidance in cleaning and sanitation procedures, manufacturing facilities can develop bacterial harborage sites in hard-to-reach areas. New technologies to eliminate these harborage sites include chemically modified coatings that can improve surface characteristics or incorporate embedded antibacterial compounds. In this article we synthesize a 16 carbon length quaternary ammonium bromide (C16QAB) modified polyurethane and perfluoropolyether (PFPE) copolymer coating with low surface energy and bactericidal properties. The introduction of PFPE to the polyurethane coatings lowered the critical surface tension from 18.07 mN m-1 in unmodified polyurethane to 13.14 mN m-1 in modified polyurethane. C16QAB + PFPE polyurethane was bactericidal against Listeria monocytogenes (>6 log reduction) and Salmonella enterica (>3 log reduction) after just eight hours of contact. The combination of low surface tension from the perfluoropolyether and antimicrobial from the quaternary ammonium bromide produced a multifunctional polyurethane coating suitable for coating on non-food contact food production surfaces to prevent survival and persistence of pathogenic and spoilage organisms.

Optimizing the size distribution of zinc borosilicate glass powder by organic solvent and tetradecylphosphonic based wet milling

Zinc borosilicate glass are crucial adhesive medium in modern electronic industry. However, it is still hard to prepare the zinc borosilicate glass with uniform particle size distribution. Herein, narrow particle size distribution and reduced hemispherical point temperature of zinc borosilicate glass was obtained by choosing low polarity, viscosity and surface tension organic solvent as well as surface modifier in the wet ball milling method. It is found that xylene, ethanol and isopropyl alcohol are good liquid medium for wet ball milling. Moreover, tetradecylphosphonic acid (TDPA) as a surface modifier could effectively reduce the formation of surface hydroxyl group in glass powder by the nucleophilic substitution reaction of the phosphonic acid group, showing superb anti-aggregation properties. Therefore, this work provides a general method for controlling particle size distribution of glass powder.

Molecular Mechanism Study on the Effect of Microstructural Differences of Octylphenol Polyoxyethylene Ether (OPEO) Surfactants on the Wettability of Anthracite.

Inhalable coal dust poses a serious threat to coal mining safety, air quality, and the health of miners. Therefore, the development of efficient dust suppressants is crucial for addressing this issue. This study evaluated the ability of three high-surface-active OPEO-type nonionic surfactants (OP4, OP9, and OP13) to improve the wetting properties of anthracite via extensive experiments and a molecular simulation and determined the micro-mechanism of different wetting properties. The surface tension results show that OP4 has the lowest surface tension (27.182 mN/m). Contact angle tests and wetting kinetics models suggest that OP4 exhibits the strongest wetting improvement ability on raw coal with the smallest contact angle (20.1°) and the fastest wetting rate. In addition, FTIR and XPS experimental results also reveal that OP4-treated coal surfaces introduce the most hydrophilic elements and groups. UV spectroscopy testing shows that OP4 has the highest adsorption capacity on the coal surface, reaching 133.45 mg/g. The surfactant is adsorbed on the surface and pores of anthracite, while the strong adsorption ability of OP4 results in the least amount of N2 adsorption (8.408 cm3/g) but the largest specific surface area (1.673 m2/g). In addition, the filling behavior and aggregation behavior of surfactants on the anthracite coal surface were observed using SEM. The MD simulation results indicate that OPEO reagents with overly long hydrophilic chains would produce spatial effects on the coal surface. Under the influence of the π-π interaction between the hydrophobic benzene ring and the coal surface, OPEO reagents with fewer ethylene oxide quantities are more prone to adsorb onto the coal surface. Therefore, after the adsorption of OP4, both the polarity and the water molecule adhesion ability of the coal surface are greatly enhanced, which helps to suppress dust production. These results provide important references and a foundation for future designs of efficient compound dust suppressant systems.

A high adhesion co-assembly based on myclobutanil and tannic acid for sustainable plant disease management.

Pesticides are irreplaceable inputs for protecting crops from pests and improving crop yield and quality. Self-assembly nanotechnology is a promising strategy by which to develop novel nano-formulations for pesticides. Nano-formulations improve the effective utilization of pesticides and reduce risks to the environment because of their eco-friendly preparation, high drug loading, and desirable physicochemical properties. Here, to enhance the utilization efficiency of myclobutanil (MYC) and develop a novel nano-formulation, carrier-free co-assembled nanoparticles (MT NPs) based on MYC and tannic acid (TA) were prepared by noncovalent molecular interactions using a green preparation process without any additives. The results showed that the prepared spherical nanoparticles had good stability in neutral and acidic aqueous solutions, low surface tension (40.53 mN m-1 ), high rainfastness, and good maximum retention values on plant leaves. Release of active ingredients from MT NPs could be regulated by altering the molar ratio of subassemblies in the co-assembly and the pH of the environment. Antifungal experiments demonstrated that MT NPs had better activities against Alternaria alternata and Fusarium graminearum [half-maximal effective concentration (EC50 ) = 6.40 and 77.08 mg/L] compared with free MYC (EC50 = 11.46 and 124.82 mg/L), TA (EC50 = 251.19 and 503.81 mg/L), and an MYC + TA mixture (EC50 = 9.62 and 136.21 mg/L). These results suggested that MYC and TA incorporated in the co-assembled nanoparticles had a synergistic antifungal activity. The results of a genotoxicity assessment indicated that MT NPs could reduce the genotoxicity of MYC to plant cells. Co-assembled MT NPs with synergistic antifungal activity have outstanding potential for the management of plant diseases. © 2023 Society of Chemical Industry.

Development of spray dried functional milk protein concentrate containing whey proteins as fibrils

Fibrillated milk protein concentrate (MPC) was produced by selective fibrillation of whey proteins and spray dried to extend shelf life. The fibrillated MPC powder was characterized for whey protein fibrils and functionality. Observations from Thioflavin T fluorescence value, transmission electron microscopy, gel electrophoresis, rheology, and turbidity confirmed the presence of fibrils in fibrillated MPC. However, fibrils in reconstituted fibrillated MPC were thinner compared with the fibrils before spray drying. Aggregation of fibrils was also seen in fibrillated MPC dispersions. Further, rheological analysis of reconstituted fibrillated MPC at different total solids levels showed that reconstituted fibrillated MPC has significantly higher viscosity, consistency index, and shear thinning behavior compared with control. Reconstituted fibrillated MPC also showed significantly lower surface tension and interfacial tension, with higher emulsification capacity, foaming capacity, and foam stability. Fibrillated MPC powder can be used as a functional ingredient in dairy and food formulations.