The study, published in the journal Environmental Geochemistry and Health by a team led by Hongyang Wang of Liaoning University together with colleagues from Northeastern University and Inner Mongolia Yitai Guanglian Coal Chemical, addresses a stubborn technical bottleneck. Coal seam water injection, in which water is pumped into a seam ahead of mining to pre-wet the coal, has long been a frontline dust control strategy. But conventional water struggles to infiltrate the pore and fracture networks of deep coal, especially when mixed metallic substances within the coal matrix block penetration. The result is uneven wetting, dry zones that shatter into inhalable dust during extraction, and suppression rates that fall far short of what occupational health standards demand.

The researchers’ solution is a composite formulation built from three widely available components: sodium gluconate, abbreviated SG, fatty alcohol polyoxyethylene ether known as AEO-3, and sodium fatty alcohol polyoxyethylene ether sulfate, or AES. Each ingredient plays a distinct role. Sodium gluconate, a chelating agent, is capable of binding the metallic substances dispersed in the coal, thereby clearing obstacles that would otherwise impede water movement through the coal’s internal pore structure. AEO-3, a nonionic surfactant, and AES, an anionic surfactant, work in combination to lower the surface tension of the injection solution and reduce the contact angle at the water-coal interface, two of the most important physical parameters governing how readily a liquid spreads across and soaks into a hydrophobic solid surface.

Coal is notoriously water-repellent. Its surface is dominated by hydrophobic carbon structures with relatively few oxygen-containing functional groups, the chemical handles to which water molecules can attach. The SAA formulation changes this chemistry. According to the team’s laboratory characterization, treatment with the agent increased the number of oxygen-containing functional groups on the coal surface, giving water more anchoring points and improving wettability at the molecular scale. At the same time, the surfactants promoted agglomeration of micron-sized coal dust particles, causing individual fine grains to clump into larger, heavier particles that settle out of the air more readily. The effect on particle size distribution was quantifiable: the median particle size, known as the D50 value, increased by 22.58 percent compared with untreated dust.

To test how these microscopic changes translate into real dust control performance, the team constructed a custom dust-suppression simulation system in the laboratory. The apparatus allowed them to generate airborne coal dust under controlled conditions and measure how effectively different spray solutions captured it. When SAA-treated water was used, the effective dust-suppression rate reached 71.50 percent. That figure is 2.17 times the performance of traditional water-mist dust suppression, meaning the formulated agent more than doubled the capture efficiency achievable with plain water alone. For an industrial process where even marginal gains in suppression translate into measurably lower respirable dust exposures for miners, a performance margin of this size is significant.

The most consequential part of the study, however, took place underground. The researchers carried out on-site dust suppression tests at the 3-802 working face of a production coal mine, injecting SAA-treated water into the seam using standard water injection equipment. Before injection, dust sampling established baseline conditions. After treatment, the average coal dust particle size at the face had risen to 2.53 times its pre-injection value, confirming that the agglomeration effect observed in the laboratory survived the journey from bench to bordeline. Larger particles mean less respirable dust, faster settling and cleaner air at the point where miners actually work.

Monitoring across multiple underground measurement points showed total dust suppression rates ranging from 60 to 84 percent, a broad but consistently strong performance envelope that reflects the natural variability of ventilation, mining activity and seam conditions across a working face. Beyond improving air quality, the treatment appeared to influence the mechanical behavior of the coal itself. The team reports that SAA water injection reduced the tendency of the coal to fracture and generate dust, a property linked in earlier research to burst liability, the dangerous propensity of some deep coal seams to fail suddenly and violently. By softening this tendency, the agent may offer a secondary safety benefit against rock bursts and coal bursts, phenomena that remain among the most feared hazards in deep mining.

What distinguishes this work from many prior surfactant studies, the authors argue, is the full chain of evidence it assembles. Laboratory mechanism analysis, surface chemistry characterization, particle size measurement, simulation chamber testing and underground field trials are all presented in a single integrated study, closing the gap that so often separates promising bench chemistry from deployable engineering practice. The funding came from the National Natural Science Foundation of China under grant 52427805, and the work involved authors from Liaoning University’s School of Environmental Sciences, Northeastern University’s School of Resources and Civil Engineering, and Inner Mongolia Yitai Guanglian Coal Chemical, a collaboration that pairs academic environmental science with direct industrial access.

The implications extend beyond a single mine. Deep coal mining is expanding in major producing nations, and occupational dust exposure remains a leading cause of preventable disease among miners, including coal workers’ pneumoconiosis, an incurable and often fatal lung condition. The health burden of coal dust has been documented extensively in the occupational health literature, and regulators continue to tighten permissible exposure limits. Technologies that make existing controls, such as water injection and water sprays, substantially more effective without requiring wholesale redesign of mining equipment are therefore valuable. The SAA formulation uses relatively inexpensive, commercially available chemicals, which the authors suggest positions it for practical engineering application.

Challenges remain before widespread adoption. Field performance will need to be validated across seams of different rank, metamorphic grade and mineralogy, since the wetting behavior of coal varies considerably with its chemical composition. Long-term dosing, environmental discharge and cost at scale will also require scrutiny. Nevertheless, the reported numbers give the approach credibility: a doubling of mist suppression efficiency in the lab, suppression rates of up to 84 percent underground, and a measurable reduction in fracturing tendency all point toward a wetting agent that does more than tweak surface tension. By combining chelation, nonionic and anionic surfactant synergy, and verified field performance, the SAA study offers deep coal mines a concrete new tool in the long-running fight against dust, and offers miners something even more precious: cleaner air at the coal face.

Subject of Research: A composite SAA wetting agent for enhancing coal seam water injection and dust suppression in deep coal mining

Article Title: High-efficiency ‘SAA’ wetting agent for coal mine dust control: from preparation and mechanism to field application

Article References: Wang, H., Zhao, T., Wang, H., Wang, H., Leng, Y., Pan, Y., Xu, L., & Zhu, Y. (2026). High-efficiency ‘SAA’ wetting agent for coal mine dust control: from preparation and mechanism to field application. Environmental Geochemistry and Health, 48(15), Article 600. https://doi.org/10.1007/s10653-026-03491-3

Image Credits: AI Generated

DOI: 10.1007/s10653-026-03491-3

Keywords: coal mining, dust suppression, wetting agent, coal seam water injection, surfactants, deep mining, occupational health, coal dust, sodium gluconate, wettability, Environmental Geochemistry and Health, rock burst

The research team, led by Guangpei Lin of Wuhan University of Science and Technology together with colleagues at the Guangdong Academy of Sciences, Jinan University and City University of Hong Kong, used laser direct energy deposition, or LDED, to fabricate composite coatings in which varying amounts of diamond powder were blended into FeCoCrNi high-entropy alloy feedstock. LDED is an additive manufacturing technique in which a focused laser beam melts powder as it is fed through a nozzle, building up dense metallic layers layer by layer. Because FeCoCrNi is a canonical high-entropy alloy, containing near-equal atomic fractions of iron, cobalt, chromium and nickel, it offers an unusually robust and ductile matrix in which to embed brittle reinforcement particles.

Embedding diamond in metal is notoriously difficult. Diamond is the hardest known bulk material, giving it enormous potential as a wear-resistant reinforcement, but it is also thermodynamically unstable at the temperatures reached in a laser melt pool. At high temperature and in contact with certain molten metals, diamond can graphitize, converting from its prized cubic crystal structure into soft graphite, which destroys its load-bearing capacity. Worse, many metals do not wet diamond well, meaning the molten alloy fails to bond to the particle surface and leaves gaps that act as ready-made crack starters under mechanical load.

The new study reveals that the FeCoCrNi system overcomes both obstacles through a fortunate combination of physics and chemistry. During deposition, the diamond particles, being far less dense than the surrounding molten alloy, experience buoyancy forces. At the same time, steep temperature gradients across the melt pool drive Marangoni convection, a circulating flow generated by surface tension differences that stirs the liquid metal. Acting together, these forces preferentially transport the diamond particles upward, enriching them at the coating surface. This is a significant advantage: the very region of the coating that experiences the most severe sliding contact and abrasion in service is precisely the region that ends up with the highest concentration of the superhard phase.

Wettability, the ability of the melt to spread over and adhere to the diamond surface, proved equally important. The researchers found that the compositional compatibility between cobalt-rich coating material and the FeCoCrNi substrate improved wetting of the diamond by the melt, allowing the liquid alloy to embrace the particles closely rather than leaving deleterious voids around them. Good wetting is a prerequisite for strong interfaces in any metal-matrix composite, because load applied to the coating must transfer efficiently from the ductile alloy into the stiff, hard particles for those particles to shield the surface from wear.

The decisive chemical trick, however, involves chromium. As the melt pool solidifies, chromium atoms from the alloy react in situ with carbon atoms at the diamond surface, forming a thin chromium carbide layer at the particle-matrix interface. This carbide layer performs two critical functions simultaneously. First, it acts as a diffusion barrier and chemical buffer that suppresses the graphitization damage that would otherwise degrade the diamond during the thermal cycle. Second, it creates a strong, adherent bridge between particle and matrix, enhancing the interfacial bond strength so that the diamond can fully exploit its load-bearing reinforcement role. The diamonds also promote the formation of additional carbides in their vicinity, further raising the hardness of the surrounding matrix.

The team systematically varied the diamond content and found a clear optimum. At 20 percent diamond, the coating exhibited the best combination of microstructure, interfacial bonding and tribological performance. In wear testing, this optimal coating reduced wear loss by 16.2 percent and wear volume by 40.5 percent relative to a pure FeCoCrNi coating produced under the same conditions. Detailed examination of worn surfaces showed that the diamond-rich surface layer shields the underlying material, shifting the dominant wear mechanism to relatively benign abrasive wear. Under impact loads and compressive stresses, some diamond particles do flake out of the surface, leaving small pits, but the overall damage remains far milder than in the unreinforced alloy.

Just as instructive is what happens when the diamond content departs from the optimum. Excessive diamond loading disrupts the continuity of the metallic matrix and weakens interfacial bonding, so particles detach early during sliding. Once freed, these detached particles roll between the coating and the counterface as third-body abrasives, gouging the surface and accelerating material removal, a self-defeating outcome that the moderate, 20 percent formulation avoids. Moderate loading keeps the matrix continuous, maintains stable bonding and prevents the early particle detachment that would seed third-body abrasion. The result is a coating in which each diamond particle remains anchored, load-bearing and protective throughout its service life.

The implications extend across industries in which surface wear dictates component lifetimes: mining tools, drilling and cutting equipment, forming dies, pumps and aerospace actuators all depend on hard coatings, and laser direct energy deposition is already attractive for repairing and resurfacing expensive parts in place. By showing that a high-content diamond reinforcement can survive additive manufacturing and deliver measurable tribological gains in a ductile high-entropy alloy, the study offers a practical recipe for next-generation protective coatings. The work also contributes fundamental insight into how buoyancy and Marangoni convection can be harnessed, rather than merely tolerated, to position reinforcement particles where they are most useful, and how a single reactive alloying element, chromium, can be recruited to protect a fragile superhard phase from thermal destruction during processing.

The research was supported by the National Natural Science Foundation of China, the Guangdong Provincial Key R&D Program, the Advanced Materials National Science and Technology Major Project, the Guangdong Basic and Applied Basic Research Foundation, the Guangdong-Hong Kong Joint Laboratory of Modern Surface Engineering Technology and several provincial and municipal programs. Correspondence for the study is handled by Zhaobing Cai of Wuhan University of Science and Technology and Bingwen Lu of the Guangdong Academy of Sciences. As additive manufacturing continues to mature from prototyping into production of demanding engineering components, strategies that unite process physics with interface chemistry, as demonstrated here, are likely to define the next wave of wear-resistant surface engineering.

Subject of Research: Diamond-reinforced FeCoCrNi high-entropy alloy coatings fabricated by laser direct energy deposition

Article Title: High-content superhard diamond enhances hardness and wear resistance in LDED FeCoCrNi high-entropy alloy

Article References: Lin, G., Cai, Z., Gu, L., Dong, Z., Feng, L., Huang, X., Dai, S., Zhang, P., Yan, X., & Lu, B. (2026). High-content superhard diamond enhances hardness and wear resistance in LDED FeCoCrNi high-entropy alloy. Journal of Materials Science. https://doi.org/10.1007/s10853-026-13720-w

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13720-w

Keywords: high-entropy alloy, diamond composite, laser direct energy deposition, wear resistance, hardness, chromium carbide, Marangoni convection, wettability, abrasive wear, FeCoCrNi, coatings, tribology

The material at the heart of the study is the insoluble rice bran natural complex, or IRBNC, a composite left behind when soluble proteins and bioactive polysaccharides are extracted from defatted rice bran. Roughly half of the defatted bran ends up in this residue, in which tightly bound proteins, insoluble polysaccharides, and phenolic compounds form networks so robust that conventional separation techniques struggle to dismantle them. Rather than fighting this recalcitrance, the researchers embraced it. Because plant-derived natural complexes are assembled in situ during plant growth through cross-linking of proteins, polysaccharides, and polyphenols, they possess a structural integrity and richness of intermolecular interactions that artificially blended systems cannot match. The problem was that their particle sizes were uneven and their surface chemistry unoptimized for interfacial work.

Earlier work by the same group had shown that mechanical pretreatment could partially improve the wettability of IRBNC particles, and that the green tea catechin EGCG could markedly enhance their emulsion-stabilizing capacity. But a critical question remained open: were EGCG’s benefits unique to its particular structure, or did they depend on generalizable features such as the number of phenolic hydroxyl groups and the presence of a galloyl moiety? To answer this, the team selected three representative catechin monomers—epicatechin (EC), epigallocatechin (EGC), and epicatechin gallate (ECG)—which differ systematically in hydroxyl count and galloylation, and conjugated each of them to IRBNC at three dosages: 25, 50, and 100 milligrams of catechin per gram of complex.

The evidence for genuine interaction was unambiguous. Bound phenol content rose with catechin dosage, although binding efficiency fell at higher loadings, indicating that the complex surfaces saturate at around 25 milligrams per gram. Free amino and sulfhydryl groups in the proteins declined steadily, consistent with quinone-mediated covalent reactions under the alkaline conditions used for conjugation, alongside extensive hydrogen bonding. Infrared spectroscopy showed attenuated hydroxyl and carbonyl bands, while X-ray diffraction revealed that the semi-crystalline cellulose signature of the complex broadened and weakened, signaling a shift toward a more amorphous, flexible architecture. Protein secondary structure analysis confirmed partial unfolding, with ordered alpha-helices and beta-sheets giving way to more disordered conformations that favor interfacial adsorption.

Wettability emerged as the decisive parameter. Native IRBNC particles, with a water contact angle of roughly 127 degrees, are so hydrophobic that they resist stable positioning at oil–water interfaces. Catechin modification progressively introduced hydrophilic hydroxyl groups, pushing the contact angle toward the golden value of 90 degrees at which particles anchor most effectively. ECG-modified particles reached 91.05 degrees at just 25 milligrams per gram, while EGC required 50 milligrams per gram to approach the same range. Interfacial tension measurements confirmed the functional payoff: equilibrium tension at the oil–water boundary dropped from 20.43 to 16.19 millinewtons per meter after modification, reflecting faster and denser particle adsorption and stronger interfacial film formation.

When the modified particles were used to prepare oil-in-water Pickering emulsions, the benefits carried through. Droplet sizes shrank to around 46 to 49 micrometers at optimal dosages, compared with large, heterogeneous droplets stabilized by unmodified IRBNC. Confocal microscopy visualized continuous fluorescent shells of protein and polysaccharide encasing the oil droplets, evidence of compact interfacial layers built from the reorganized complexes. Rheological testing showed enhanced viscoelasticity, with storage moduli exceeding loss moduli across the tested frequency range, indicating emulsions with a robust, elastic network character rather than a fragile suspension of isolated droplets.

Oxidative stability improved in parallel. During 30 days of accelerated storage at 45 degrees Celsius, emulsions stabilized by moderately modified particles accumulated fewer lipid hydroperoxides and lower levels of thiobarbituric acid reactive substances, the markers of primary and secondary oxidation respectively. The researchers attribute this dual protection to the synergistic action of catechin antioxidant chemistry—phenolic hydroxyls scavenging free radicals—and the physical barrier formed by particle-laden interfaces, which restricts oxygen diffusion and shields lipid substrates from pro-oxidants. ECG, with its galloyl group and highest hydroxyl density, delivered the strongest suppression of both oxidation markers.

The study also carries a clear warning about dosage. At excessive catechin concentrations of 50 to 100 milligrams per gram, particles over-crosslinked and aggregated, wettability overshot into excessive hydrophilicity, and emulsion stability deteriorated—droplets coarsened, creaming intensified, and oxidation markers climbed. This structure–dosage–function triangle means that each catechin demands its own optimal loading: 25 milligrams per gram for EC and ECG, and 50 for EGC. The galloyl-bearing ECG proved the most efficient overall performer, achieving tight interfacial packing and superior stability at low dosage, whereas the smaller EC adsorbed rapidly but formed weaker films.

Beyond the immediate numbers, the work establishes a rational design principle for natural Pickering stabilizers: molecular features of polyphenols—hydroxyl density and galloyl substitution—can be used as tunable levers to restructure insoluble plant complexes for interfacial duty. Given the enormous global stream of rice bran waste, the approach offers a route to convert a low-value by-product into functional ingredients for beverages, sauces, encapsulated nutrients, and delivery systems for lipophilic bioactives. The authors note that advanced molecular and interfacial characterization will be needed to fully resolve the interaction pathways and assembly mechanisms at oil–water interfaces, but the demonstration that a tea molecule’s architecture can dictate the fate of a rice milling residue is a striking example of structure-guided food materials engineering.

Subject of Research: Structure-dependent interfacial modification of insoluble rice bran natural complexes by catechin monomers for Pickering emulsion stabilization

Article Title: Enhancing Pickering emulsion stabilization of insoluble rice bran natural complexes: Structure-dependent interfacial regulation by catechin monomers

Article References: Cui, H., Li, H., Yu, E., Wu, X., Lin, L., & Wu, W. (2026). Enhancing Pickering emulsion stabilization of insoluble rice bran natural complexes: Structure-dependent interfacial regulation by catechin monomers. Current Research in Food Science, 13, Article 101554. https://doi.org/10.1016/j.crfs.2026.101554

Image Credits: AI Generated

DOI: 10.1016/j.crfs.2026.101554

Keywords: Pickering emulsion, rice bran, catechins, EGCG, ECG, interfacial regulation, wettability, lipid oxidation, protein-polysaccharide complex, food-grade stabilizer, tea polyphenols, emulsion stability