Solid-liquid Reaction Research Articles

Utilizing 2D layered structure Cu-g-C3N4 electrocatalyst for optimizing polysulfide conversion in wide-temperature Li-S batteries

Lithium-sulfur batteries (LSBs) as “post-lithium-ion battery” have gained a high level of visibility due to high energy density and specific capacity. Nevertheless, the commercial production of LSBs is hampered by the the most notorious trouble for shuttling effects of lithium polysulfides (LiPSs). To settle the inherent issues, copper-doped graphitic carbon nitride (Cu-g-C3N4) catalysts with two-dimensional lamellar structures are synthesized using a template method as coating materials for LSBs separators. The substrate material g-C3N4 has a high nitrogen content, which can augment the charge density and significantly enhance the affinity of the materials for LiPSs. Doping of copper atoms in the layered structure of g-C3N4 significantly increases the electrocatalytic activity by creating additional active sites and expediting the redox kinetics of LiPSs for simultaneous S reduction as well as Li2S oxidation. With in-situ UV–vis and theoretical calculations, the efficient activation of bidirectional reaction substantially enhances the rate of solid–liquid-solid reaction, especially solid–solid (Li2S2-Li2S) conversion. As a consequence, the cell with Cu-g-C3N4 shows a satisfied initial discharge capacity of 1469.36 mAh/g at 0.1C. In addition, a high areal capacity of 6.04 mAh/cm2 is achieved under a S loading of 5.10 mg/cm2. Most importantly, the cell with Cu-g-C3N4 maintains stable cycling performance over the scope of a broad temperature (0 °C and 60 °C). This work demonstrates that Cu-g-C3N4 catalysts can be realized for the design of low/high-temperature-resistant LSBs.

Novel strategy for depolymerization of avermectin fermentation residue to value-added amino acid product.

Avermectin fermentation residue (AFR) is rich in proteins, which can be depolymerized to value-added amino acids for in-plant reuse. The hydrochloric acid (HCl) hydrolysis is performed and investigated under different conditions, including HCl concentration, solid-liquid ratio, temperature, and time. The hydrolysis degree (HD) of 67.7% can be achieved. The empirical correlation of HD is established with a good practicability to control the HD and predict the experimental conditions. Solid-liquid reaction is confirmed to be dominant during the hydrolysis process. There are 17 kinds of amino acids in the hydrolysate, benefiting the reuse. Avermectin is not detected in the hydrolysate and AFR, and the mass of AFR is reduced by 53.8wt%. This work provides a novel strategy for the environmentally friendly treatment and meanwhile the resource recovery of AFR.

Modify the interface between ex-situ γ-Al2O3 and Al matrix via in-situ coating in an Al matrix composite

In this study, an Al matrix composite reinforced with both ex-situ and in-situ γ-Al2O3 particles was prepared through the liquid-solid reaction. Most of the in-situ γ-Al2O3 particles distribute along grain boundaries, while the ex-situ γ-Al2O3 particles were simultaneously coated by in-situ γ-Al2O3 with a thickness of several nanometers. This coating structure is supposed beneficial for enhancing the bonding strength between ex-situ γ-Al2O3 and the Al matrix. The ultimate tensile strength of the composite is tested to be 362 MPa at room temperature, while the strength can still be high to 205 MPa at 350 °C. This study sheds new insights to resolve the problem between ex-situ particles and the matrix in metal matrix composites.

Double-phase electrolyte enabling the long-lasting redox mediation in Li–O2 batteries

The achievement of practical Li–O2 batteries is impeded by their low discharge capacity, large charge overpotential, and short lifespan. In general, the use of electrolyte with a high-donor-number solvent such as dimethyl sulfoxide (DMSO) is able to drive the solution-mediated pathway, alleviating the premature passivation of cathode from the surface-mediated Li2O2 film growth, gaining large Li2O2 toroidal particles, and extending the discharge lifetime. However, direct electrochemical decomposition of Li2O2 toroidal products typically occurs at a high charge potential owing to the poor solid-solid contact between cathode catalysts and Li2O2 toroids. Besides, DMSO-based electrolytes are unstable to Li anode, leading to undesired parasitic reactions. To overcome above issues, herein, a double-phase electrolyte composed of 10-methylphenothiazine (MPT)-dissolved DMSO-based catholyte and octyltrimethoxysilane (TOOS)-based anolyte is designed taking advantages of the immiscibility of DMSO and TOOS solvents and the insolubility of MPT in TOOS. Benefiting from the rapid liquid-solid reaction between MPT+ and Li2O2 products, the blocked MPT shuttling in TOOS, and the good compatibility of TOOS-based electrolyte to Li anode, the assembled Li–O2 battery delivers a reduced charge overpotential and a robust cyclability over 250 cycles. This study provides a promising strategy for electrolyte design towards next-generation high-performance Li–O2 batteries.

Metastable Liquid Properties and Surface Flow Patterns of Ultrahigh Temperature Alloys Explored in Outer Space.

The metastable liquid properties and chemical bonds beyond 2000 K remain a huge challenge for ground-based research on liquid materials chemistry. We show the strong undercooling capability, metastable liquid properties and surface wave patterns of refractory Nb-Si and Zr-V binary alloys explored in space environment. The floating droplet of Nb82.7Si17.3 eutectic alloy superheated up to 2338 K exhibited an extreme undercooling of 437 K, approaching the 0.2TE threshold for homogeneous nucleation of liquid-solid reaction. The microgravity state endowed alloy droplets with nearly perfect sphericity and thus ensured the high accuracy to determine metastable undercooled liquid properties. A special kind of swirling flow was induced for liquid alloy owing to Marangoni convection, which resulted in the spiral microstructures on Zr64V36 alloy surface during liquid-solid phase transition. The coupled impacts of surface nucleation and surface flow brought in a novel olivary shape for these binary alloys. Furthermore, the chemical bonds and atomic structures of high temperature liquids were revealed to understand the liquid properties in outer space circumstances.

Investigation of hydrodynamic performance in a staggered multistage internal airlift loop reactor

The multistage internal airlift loop reactor (MIALR) has shown promising application prospects in gas–liquid–solid reaction systems. However, traditional MIALRs have a global circulation with strong interstage liquid-phase exchange. This paper proposes a staggered multistage internal airlift loop reactor (SMIALR) that incorporates special guide elements to create a staggered flow. Both experiments and computational fluid dynamics-population balance model simulations were conducted to investigate the hydrodynamic performances of MIALR and SMIALR. The results demonstrate that SMIALR exhibits a local circulation at each stage. Bubbles have a longer residence time in SMIALR, resulting in a 28.35%–55.54% increase in gas holdup and a 7.27%–13.69% increase in volumetric mass transfer coefficient. The gas–liquid mass transfer coefficient of SMIALR was improved by increasing the gas–liquid interfacial area. Additionally, the radial distribution of solids was found to be more uniform. This study offers insights for optimizing MIALR and provides a theoretical foundation for the design and scale-up of SMIALR.

Mechanism of solid–liquid reaction in magnesium smelting by silicothermic process

The reaction pathways and phase transitions during primary magnesium production via silicon reduction of CaO·MgO under vacuum conditions were examined using thermodynamic calculations, X-ray diffraction (XRD), electron probe microanalyzer scanning (EPMA), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analysis. The findings suggest that the actual chemical reaction involves Si interacting with CaO in dolime to form CaSi2, which subsequently serves as a reducing agent to reduce MgO, resulting in magnesium vapor. Solid–solid reactions occur in pellets at temperatures below 1028 °C, whereas solid–liquid reactions take place above this temperature. The solid–liquid reaction notably enhances the reaction rate. In addition, the limited hydration reactivity of the slag from the silicothermic process is attributable to the formation of large MgO particles through the solid–liquid reaction.

Study on the green extraction of corncob xylan by deep eutectic solvent

Corn as one of the world's major food crops, its by-product corn cob is also rich in resources. However, the unreasonable utilization of corn cob often causes the environmental pollution, waste of resources and other problems. As one of the most abundant polymers in nature, xylan is widely used in food, medicine, materials and other fields. Corn cob is rich in xylan, which is an ideal raw material for extracting xylan. However, the intractable lignin is covalently linked to xylan, which increases the difficulty of xylan extraction. It has been reported that the deep eutectic solvent (DES) could preferentially dissolve lignin in biomass, thereby dissolving the xylan. Then, the xylan in the extract was separated by ethanol precipitation method. The xylan precipitate was obtained after centrifugation, while the supernatant was retained. The components of the supernatant after ethanol precipitation were separated by the rotary evaporator. The ethanol, water and DES were collected for the subsequent extraction of corn cob xylan. In this study, a novel way was provided for the green production of corn cob xylan. The DES was used to extract xylan from corn cob which was used as the raw material. The effects of solid-liquid ratio, reaction time, reaction temperature and water content of DES on the extraction rate of corn cob xylan were investigated by the single factor test. Furthermore, the orthogonal test was designed to optimize the xylan extraction process. The structure of corn cob xylan was analyzed and verified. The results showed that the optimum extraction conditions of corn cob xylan were as follows: the ratio of corn cob to DES was 1 : 15 (g : mL), the extraction time was 3 h, the extraction temperature was 60 °C, and the water content of DES was 70%. Under these conditions, the extraction rate of xylan was 16.46%. The extracted corn cob xylan was distinctive triple helix of polysaccharide, which was similar to the structure of commercially available xylan. Xylan was effectively and workably extracted from corn cob by the DES method. This study provided a new approach for high value conversion of corn cob and the clean production of xylan.

Changing the potassium-based activation path to prepare coal-based porous carbon with more graphitic or graphene structures for high-performance organic supercapacitors

Graphitic porous carbon is becoming an excellent platform for high-performance supercapacitors due to its unique structural characteristics, especially the combination of high specific surface area and long-range ordered sp2 carbon framework, which can synergistically improve the ion transfer/storage capability and the structural stability during long-term cycling. However, the trade-off contradiction between porosity and graphitization of carbon materials is difficult to circumvent by traditional chemical or physical activation strategies. Herein, we changed the conventional potassium-based activation pathway by introducing a pre-carbonization process, thus transforming low-rank coal precursors into graphitic porous carbon with more graphite or graphene structures. Raman mapping characterization was introduced to comprehensively reveal the distribution of crystalline carbon within the obtained carbon materials, confirming that enhancing the structural maturity of carbon-based precursors by introducing a pre-carbonization process promotes the deep and uniform development of graphitized structures during the KOH activation process. Typical reaction intermediate characterization indicates that the reason for this structural transformation is due to a change in the primary form of potassium species under the changed activation pathways, leading to a solid-liquid phase reaction environment mediated by molten K2CO3. The obtained graphitic porous carbon possesses simultaneously a hierarchically porous structure with specific surface area of 2456 m2 g−1 and well-developed graphitic carbon crystalline by which the constructed organic supercapacitor delivers excellent capacitance and rate performance, along with a high energy-power density, and a lifespan exceeding 10,000 cycles. The elucidated potassium-based activation mechanism facilitates the easy adjustment of carbon porosity and crystalline structures to meet varying requirements in different application scenarios.

A switchable hydrogenation chemoselectivity of biomass platform compounds based on solvent regulation

Selective catalytic conversion of biomass-derived compounds to fuels and fine chemicals serves as a renewable energy pathway for the partial substitution of fossil resources, in which reaction pathway and selectivity control are key issues. Herein, we report a fully exposed Pt clusters immobilized on CoAl mixed metal oxides catalyst (denoted as Ptn/CoAl-MMOs), which exhibits prominent catalytic performance towards liquid phase hydrogenation reaction of furfural (FAL). Noteworthily, the hydrogenation chemoselectivity can be switched among four products via using four different solvents: tetrahydrofurfuryl alcohol (THFA; yield: 91.4%), furfuryl alcohol (FA; yield: 97.7%), 2-methylfuran (2-MF; yield: 92.1%) and furan (FU; yield: 90.8%) are obtained in ethanol, dioxane, isopropanol and n-hexane solvent, respectively. Experimental studies (in situ FT-IR and TPSR-Mass) combined with theoretical calculations (DFT) reveal that solvent molecules exert an essential influence on the adsorption configuration of FAL via changing the solvent-catalyst and/or substrate-catalyst interaction, which ultimately determines the hydrogenation pathway, key intermediate and final product. This work demonstrates a facile solvent-dependent product-switching strategy within one catalytic system, which opens up potential opportunities for tailoring hydrogenation selectivity in liquid-solid catalytic reactions towards biomass upgrading.

Photothermal catalytic hydrogen production coupled with thermoelectric waste heat utilization and thermal energy storage for continuous power generation

Photothermal catalytic water splitting is a potential way to produce renewable hydrogen. However, low-grade heat converted from solar energy in the photochemical process is inevitably dissipated to the environment and often wasted. Besides, the intermittency of solar energy causes the devices unable to work continuously. Here, a novel integrated solar to hydrogen-electricity and thermal storage system (STHET) is proposed to solve above problems. STHET consists of a photothermal catalytic system and a thermoelectric generator (TEG) system, which can realize hydrogen-electricity co-production and thermal self-storage. Photothermal effect in STHET is increased by recycling scattered light, leading to an enhancement of 22.7% in hydrogen production than the traditional system without TEG. Meanwhile, the maximum power of waste heat utilization by TEG is 193.53 μW. Furthermore, since strengthened heat exchange in STHET with forced cooling, the output power of TEG can improve to 1578.13 μW, and hydrogen production is reduced by only 1.4% than the traditional system without TEG. Additionally, STHET can continuously generate power using stored thermal by the liquid reaction system to achieve continuous working in the dark, in which 19% (maximum proportion) of the electrical energy output can be obtained at night. The heat exchange methods in STHET can be flexibly selected according to the requirement for hydrogen energy and electric power. As a conceptual model, STHET can also be promoted in other solid-liquid reaction systems.

Wide pH photocatalytic nitrate reduction at adaptive microenvironment-dominated liquid–liquid-solid trilayer reaction interfaces

Developing highly efficient photocatalysts with a wide pH application range is the key to achieving widespread practical application of photocatalytic denitrification. However, the current study neglects the limitations of diffusion and mass transfer efficiency in the reaction interfacial microenvironment on high activity and selectivity, resulting in the inability to achieve the ideal results. Herein, the photocatalytic NO3– reduction system with a microenvironment-dominated trilayer reaction interface of liquid (external liquid)-liquid (adaptive interfacial microenvironment)-solid (Br-Bi2WO6-x photocatalysts with different charge transfer mechanisms under acid/base conditions and hydrophilic surfaces) (LEL-LIM-S) was successfully constructed. The interfacial microenvironment in the system can self-adapt and adjust its ion composition according to the changes in the pH environment, which facilitates timely supplementation of NO3–/HCOO– required for the reaction from external liquid, thus maintaining the relative stability of the microenvironment and achieving an excellent NO3– removal rate of over 90 % in a wide pH range from 3 to 9. Meanwhile, the trilayer reaction interface of LEL-LIM-S collectively constitutes a unique carrier shuttle and molecular reaction channel from the catalyst interior to the surface contaminants. Highly selective NO3– to NH3 conversion (NH3 selectivity of 91.7 %, NH3 yield of 750 μmol g-1h−1) could be accomplished utilizing this channel.

Ethyl palmitate decarboxylation using colloidal SiO2- templated mesoporous Ni-ZrO2 catalysts

A series of 10 wt% NiO-xSiO2-ZrO2 (x = 0–30 wt%) catalysts were synthesized using a one-pot coprecipitation method with different of colloidal SiO2 contents, as a hard template, in order to imprint mesoporous cavities after a post-synthesis selective alkaline NaOH/H2O lixiviation. The final catalysts were characterized by XRD, HRTEM, textural measurements, 29Si-MAS NMR, FTIR, and XPS; the lixiviated, calcined and H2-reduced powders, were evaluated in the decarboxylation (DCO2) of ethyl palmitate as a liquid-solid phase model reaction at 300 °C, and 20 kg/cm2 H2 pressure. Optimal amount of colloidal SiO2 was 10 wt%. SiO2 effect (as colloid in fresh preparations and/or residual SiO2, after lixiviation) on ZrO2 is twofold. (i) to upgrade mesoporosity and (ii) to stabilize the porous structure. Residual SiO2 (from incomplete lixiviation) plays a beneficial role as examined by 29Si-NMR, being chemically bonded to ZrO2 and acting as props of the mesopores. Total pore volume and specific surface area values increased 5 and 6 times, respectively, when using a 30 wt% SiO2 in comparison with a non-silicated NiO-ZrO2 preparation. DCO2 of ethyl palmitate benefit from better mesoporosity and a great number of oxygen vacancies from Ni isomorphic substitution into cubic ZrO2 (as indicated by XPS); being at the origin of the reaction mechanism. For instance, a 10 wt% SiO2 NiO-ZrO2 catalyst is 1.6 times more selective (to n-pentadecane) and 1.2 times more active than a non-silicated NiO-ZrO2, yielding decarboxylated (i.e., deoxygenated) renewable linear hydrocarbons similar to those in a Diesel composition. However, DFT calculations indicate that adsorbed CO2 (as a formate species) desorbs, once fully hydrogenated, as methane regenerating the oxygen vacancies but consuming H2 as well, in agreement with the high methane concentration detected in gas phase.

Liquid-solid interfacial polymerization of thin-film composite nanofiltration membrane

Interfacial polymerization prepared polyamide (PA) nanofiltration membranes are widely used for desalination and wastewater recovery due to their lower operating pressure compared to reverse osmosis desalination and ease of scalability. The diffusion behavior of amine (PIP) and acyl chloride (TMC) monomers make a significant impact on PA structure and performance. In this paper, through freezing the aqueous amine reactive solution which turned the liquid–liquid reaction process into liquid–solid and regulated the amine monomer diffusion behavior, an ultra-thin, defect-free PA layer was achieved. The effect of PIP solution temperature in the range of −15 to 25 °C on membrane morphology, chemical composition and surface properties was investigated. The results indicated that PIP diffusion rate had a positive effect on the crosslinking degree of formed PA layer. However, frozen amine solution effectively inhibited the diffusion rate of PIP and hydrolysis of TMC which simultaneously improve the permeability and selectivity. The fabricated membrane by liquid–solid reaction process showed hydrophilic, dense and ultrathin PA layer with a high pure water permeance (23.7 L·m−2·h−1·bar−1) and good retention of salt (95.4 % for Na2SO4). Also, the good selectivity to divalent cation and anion, and excellent stability of the membrane prefigured its potential in application of various water treatment fields.

The enhancement of waste PET particles enzymatic degradation with a rotating packed bed reactor

Polyethylene terephthalate (PET) is widely used, and biodegradation of waste PET results in a residue-free process, generating recyclable products, thereby contributing to the advancement of a more recyclable plastics lifecycle. Extensive research has been conducted on the modification and evolution of enzyme for PET degradation. As a solid-liquid heterogeneous reactions of PET degradation, the slow diffusion rate of the enzyme from liquid to solid PET surface leading to a slow reaction rate. Enhancement of mass transfer would accelerate PET degradation. Rotating packed bed (RPB) is a mass transfer enhancement reactor, but shear strength generated by the enzyme molecule knocking on rotator of RPB leads to enzyme denaturation. To address this issue, shear strength resistance agents were introduced in this study. With the protection of β-cyclodextrin combined with kieselguhr, PET particle degradation rate of 95% was achieved under the optimum conditions in 24 h, which was improved by 30% compared to that in stirred tank reactor. The results of this work demonstrated that the mass transfer greatly influenced the PET biodegradation process. RPB combined with the function of shear strength resistance agents could greatly improve the efficiency of the biodegradation process. This study provides a reference for the scaling up of PET degradation, and holds significant promise in the broader context of combatting plastic pollution challenges and advancing sustainable solutions for plastic waste.

A novel process of gradient oxidation roasting-acid leaching for vanadium extraction from stone coal

Efficient green vanadium extraction is a research direction of stone coal. This study focuses on efficient green vanadium extraction of stone coal. A gradient oxidation roasting-acid leaching (GORA) process was proposed, which is additive-free and effectively improves the leaching efficiency with preliminary oxidation and further high-temperature reoxidation. The results of this study showed that 95.59 % of −0.074 mm particles were the most appropriate. The suitable roasting temperature and time for preliminary oxidation roasting were 650 °C and 0.5 h, respectively. A porous structure was formed with a specific surface of 2.61 m2/g, and a total pore volume of 0.0164 cm3/g. Further, the optimal conditions of high-temperature reoxidation roasting were 850 °C, 3 h, 35 % O2, and 600 ml/min. The best V2O5 leaching rate of the GORA was 68.89 %, which was 36.23 % higher than that of the raw ore. It was discovered that stone coal could withstand high temperatures without sintering after preliminary roasting. High-temperature reoxidation is a prerequisite for destroying the lattice of vanadium-bearing minerals and promoting vanadium release. Meanwhile, the loose and porous honeycomb particle products promoted subsequent gas–solid and liquid–solid reactions. Therefore, this study provides a novel and effective method for extracting vanadium from stone coal.

Integrated Circular Economy Model System for Direct Lithium Extraction: From Minerals to Batteries Utilizing Aluminum Hydroxide.

Aluminum hydroxide, an abundant mineral found in nature, exists in four polymorphs: gibbsite, bayerite, nordstrandite, and doyleite. Among these polymorphs gibbsite, bayerite, and commercially synthesized amorphous aluminum hydroxide have been investigated as sorbent materials for lithium extraction from sulfate solutions. The amorphous form of Al(OH)3 exhibits a reactivity higher than that of the naturally occurring crystalline polymorphs in terms of extracting Li+ ions. This study employed high-temperature oxide melt solution calorimetry to explore the energetics of the sorbent polymorphs. The enthalpic stability order was measured to be gibbsite > bayerite > amorphous Al(OH)3. The least stable form, amorphous Al(OH)3, undergoes a spontaneous reaction with lithium, resulting in the formation of a stable layered double hydroxide phase. Consequently, amorphous Al(OH)3 shows promise as a sorbent material for selectively extracting lithium from clay mineral leachate solutions. This research demonstrates the selective direct extraction of Li+ ions using amorphous aluminum hydroxide through a liquid-solid lithiation reaction, followed by acid-free delithiation and relithiation processes, achieving an extraction efficiency of 86%, and the maximum capacity was 37.86 mg·g-1 in a single step during lithiation. With high selectivity during lithiation and nearly complete recoverability of the sorbent material during delithiation, this method presents a circular economy model. Furthermore, a life cycle analysis was conducted to illustrate the environmental advantages of replacing the conventional soda ash-based precipitation process with this method, along with a simple operational cost analysis to evaluate reagent and fuel expenses.

Multivariate modeling of intrinsic kinetics for gas-solid heterogeneous photocatalytic reaction: A general method for different pollutant-photocatalyst systems

A reactor model that can interpret the effects of multiple variables on photocatalytic performance is crucial to bridging the gap between lab- and commercial-scale reactors. However, there is no explicit expression to simultaneously describe the relationships between reaction rate and operating parameters including initial concentration, flow rate, light intensity, relative humidity, and catalyst dosage. Therefore, this work presents a multivariate reactor model that extensively describes the effects of these quantities on reaction rate. First, the model is developed by resolving the Navier-Stokes equations coupled with the convection-diffusion equations and an improved reaction kinetics expression. Then, the particle swarm optimization (PSO) algorithm is integrated with the numerical simulation of velocity and concentration fields to determine intrinsic kinetic parameters. Subsequently, the multivariate model for NO degradation is experimentally validated. In addition, the versatility of the proposed modeling method is evidenced by the experimental data of different photocatalyst-pollutant systems from literature. The model predictions agree with experimental results well with the R2 values of 0.949–0.995. Furthermore, a CFD simulation is executed to understand the interactive effects of fluid flow, mass transfer, and kinetic reaction to guide reactor optimization. Finally, the model for NO removal using UiO-66-NH2 in the current study outperforms several reported NO removal models with the smallest RMSE of 2.57% and MAPE of 2.74%. It is concluded that the proposed modeling method could successfully predict the performance of different gas-solid or liquid-solid heterogeneous reactions.

Numerical study on the chemical and electrochemical coupling mechanisms for concrete under combined chloride-sulfate attack

Cementitious materials exposed to marine and saline environments are commonly threatened by a combined attack of sulfate and chloride ions. This study developed a numerical framework to investigate two combined coupling mechanisms of 1) coupled solid-liquid chemical reactions for competitive chloride-sulfate attack and 2) electrostatic multi-ion coupling effect on reactive-transport mechanisms. Various chemical reactions including sulfate attack with anhydrous calcium aluminates, secondary precipitation of expansive minerals, competitive binding, and calcium leaching have been quantified. The electrostatic potential caused by multi-ions coupling was solved according to constitutive electrochemical laws. After model validation, the chemical coupling mechanisms for solid-liquid reactions during competitive chloride-sulfate binding were investigated. On this foundation, the influence of electrostatic multi-ionic coupling effects on ionic transport and its interaction with chemical coupling were disclosed. It was found that neglecting multi-ions coupling effect would result in an underestimated chemical coupling strength in competitive chloride-sulfate binding.

The coating of ex–situ AlN particles with in–situ AlN nanolayers in an (AlN + AlB2)/Al composite

In this paper, an (AlN + AlB2)/Al composite was produced via liquid–solid reaction. Except for in–situ formed AlN and AlB2 phases, a nanolayer with the thickness of roughly 10 nm was found coating the ex–situ AlN. The nanolayer has the same crystal structure with ex–situ AlN, which is supposed beneficial for the combination between ex–situ AlN and Al matrix. The composite exhibits attractive ultimate tensile strength at 25 °C and 350 °C, which is 416 MPa and 242 MPa, respectively.