Effect Of Dissolution Research Articles

The Mesoscopic Damage Mechanism of Jointed Sandstone Subjected to the Action of Dry–Wet Alternating Cycles

The effect of the dry–wet cycle, characterized by periodic water level changes in the Three Gorges Reservoir, will severely degrade the bearing performance of rock formations. In order to explore the effect of the dry–wet cycle on the mesoscopic damage mechanism of jointed sandstone, a list of meso-experiments was carried out on sandstone subjected to dry–wet cycles. The pore structure, throat features and mesoscopic damage evolution of jointed sandstone with the action of the dry–wet cycle were analyzed using a-low-field nuclear magnetic resonance (NMR) technique. Subsequently, the impact on the mineral content of dry–wet cycles was studied by small angle X-ray scattering (SAXS). Based on this, the mesoscopic damage mechanism of sandstone subjected to dry–wet cycles was revealed. The results show that the effects of the drying–wetting cycle can promote the development of porous channels within sandstone, resulting in cumulative damage. Besides, with an increase in dry–wet cycles, the proportion of small pores and pore throats decreased, while the proportion of medium and large pores and pore throats increased. The combined effects of extrusion crush, tensile fracture, chemical reaction and dissolution of minerals inside the jointed sandstone contributed to the development of mesoscopic pores, resulting in the increase of porosity and permeability of rock samples under the dry–wet cycles. The results provide an important reference value for the stability evaluation of rock mass engineering under long-term dry–wet alternation.

Highly dispersed single-atom Fe and Fe3O4 clusters anchored hierarchical-pore carbon as efficient persulfate activation catalyst

The selective removal of Fe particles from carbonized Fe-MOFs presents an intriguing strategy for developing efficient peroxydisulfate (PDS) activators. It is commonly accepted that their outstanding performance is largely attributed to the high specific surface area/pore volume. However, our investigation into the structure–function relationship of these materials has revealed new insights. In this study, a highly dispersed single-atom Fe and Fe3O4 clusters anchored hierarchical-pore carbon (CM88-H) was obtained via post-acid treatment of carbonized MIL-88B (CM88). Various characterizations were comparatively conducted to highlight the beneficial effects of iron dissolution. The CM88-H/PDS system achieved a notable BPA degradation efficiency, with a reaction rate of 0.323 min−1, which is 3.94 times higher than that of the CM88/PDS system. DFT calculations indicate that the Fe3O4 clusters optimize the charge distribution around single-atom Fe, promoting favorable PDS adsorption and facilitating a higher oxidation state of CM88-H. As a result, BPA can be completely degraded within 10 min with 0.1 g/L CM88-H and 0.05 g/L PDS via both radical and non-radical pathways. The CM88-H/PDS/BPA system performs effectively under various conditions, with a general reduction in toxicity. Furthermore, the CM88-H/PDS system shows broad oxidation activity towards BPA substitutes and pollutants with high ionization potential (IP). Notably, the CM88-H sponge-based fixed-bed catalytic reactor demonstrated satisfactory BPA degradation, highlighting the promising application of CM88-H in water purification. This study provides a sustainable solution for water treatment and accelerates the practical application of powdered nanocatalysts to improve water quality.

The effect of burning on the dissolution behaviour and silicon and oxygen isotope composition of phytolith silica

Theδ30Si andδ18O values of opal-A precipitated in plants (silica phytoliths) have been shown to be useful for paleoenvironmental reconstructions. Here, the effects of burning and partial dissolution of phytoliths on their isotopic compositions and dissolution behaviour were examined. Phytoliths were heated to 700 °C and then dissolution experiments were conducted in batch reactors under a range of pH (4–8) and temperature (4–19 °C) conditions. Heating caused a −2.6 ‰ shift in phytolithδ18O values. NMR results suggest that heating reduces the number of surface vicinal silanols, which likely results in the formation of strained SiOSi bonds which incorporate oxygen from18O-depleted hydroxyl groups. During dissolution, theδ18O of burned phytoliths increased by up to 3.5 ‰ (average 1.8 ‰) until 15–45 % saturation was reached, and then adsorption of silica on the surface of the solid began to reducethe δ18O value of solid silica despite a net dissolution. The maximum increase in δ18O during dissolution of burned phytoliths is 1.8 ‰ smaller than previously observed for unburned silica subjected to partial dissolution under the same conditions. Heating did not cause a significant change inδ30Si values, and partial dissolution of burned phytoliths caused a slight increase inδ30Si values that was smaller in magnitude than for unburned phytoliths. Dissolution of burned phytoliths progressed more slowly than dissolution of fresh phytoliths in low pH and temperature conditions, but was faster than the dissolution of fresh phytoliths when pH > 6 and temperature = 19 °C. We propose that because fewer hydrolysis sites exist on the surface of burned phytoliths that the isolated silanols that remain after heating are difficult to deprotonate at low pH resulting in slower dissolution. However, at higher pH the breakage of strained SiOSi bonds in burned phytoliths may explain their higher dissolution rate relative to fresh phytoliths. We recommend caution in using theδ18O values of soil phytoliths in paleoclimate reconstructions as they can be altered during both heating and partial dissolution. For phytolith assemblages collected from archaeological hearths or grasslands prone to wildfires, the shift towards lowerδ18O values caused by heating would result in overestimations of temperature using paleothermometer equations. Care must be taken to identify alteration by dissolution or burning, which may not always be visually evident.

Atomic insights into the ductile–brittle competition of cracks under dissolution

Environmental effects can determine the ductile–brittle behavior of cracks at the atomic scale, but the underlying processes remain poorly understood and contentious. Here, we report the competition between ductile and brittle behaviors at crack tips induced by the prevalent environmental effect of dissolution. Our findings reveal that this competition is driven by two fundamental deformation mechanisms related to dissolution: crack blunting and defect accumulation. Through separate evaluations of dissolution-induced cleavage and dissolution-induced plasticity, we demonstrate that these deformation mechanisms not only dominate brittle fracture toughness but also lead to dislocation slip. We have developed a theoretical model to predict the ductile and brittle behavior of cracks under dissolution, and the theory aligns well with the simulation results and remains consistent with existing experimental trends. This work will broaden the microscopic understanding of ductile and brittle fracture of cracks in complex environments.

DEM simulations of particle dissolution effects on the passive earth pressure of retaining walls

Assessing passive earth pressure is fundamental in geotechnical engineering practice. Mineral dissolution in the soil can reduce the soil strength, causing an overestimation of passive earth pressure in design. In this study, the effect of dissolution on passive earth pressure on retaining walls is investigated by using discrete element method, taking into account three modes of motion: translation (mode T), rotation around the wall bottom (mode RB), and rotation around the wall top (mode RT). The simulations show that the particle dissolution results in a significant reduction in the passive earth pressure on retaining walls. The largest reductions of resultant force are about 73.5 % and 78.5 % in modes T and RT when wall displacement is minor. Nevertheless, when the wall displacement is large, the largest reduction in resultant force is approximately 74.7 % in mode RB. A detailed analysis is provided to explain this phenomenon. Dissolution also leads to weak force chains and an increase in soil porosity, thereby weakening wall-soil interactions. Dissolution has a significant effect on passive earth pressure of lower part's soil. This study suggests that reinforcing the lower part's soil and preventing seepage in this area can help mitigate the effects of dissolution on retaining walls.

Groundwater Geochemistry in the Karst-Fissure Aquifer System of the Qinglian River Basin, China

The Qinglian River plays a significant role in China’s national water conservation security patterns. To clarify the relationship between hydrogeochemical properties and groundwater quality in this karst-fissure aquifer system, drilling data, hydrochemical parameters, and δ2H and δ18O values of groundwater were analyzed. Multiple indications (Piper diagram, Gibbs diagram, Na+-normalized molar ratio diagram, chloro-alkaline index 1, mineral saturation index, and principal component analysis) were used to identify the primary sources of chemicals in the groundwater. Silicate weathering, oxidation of pyrite and chlorite, cation exchange reactions, and precipitation are the primary sources of dissolved chemicals in the igneous-fissure water. The most relevant parameters in the karst water are possibly from anthropogenic activities, and other chemicals are mostly derived from the dissolution of calcite and dolomite and cation exchange reactions. Notably, the chemical composition of the deep karst water from the karst basin is mainly influenced by the weathering of carbonate and cation exchange reactions and is less affected by human activities. The hydrogeochemical properties of groundwater in the karst hyporheic zone are influenced by the dissolution of carbonates and silicates, evaporation, and the promotion effect of dissolution of anorthite or Ca-containing minerals. Moreover, the smallest slope of the groundwater line from the karst hyporheic zone among all groundwater groups revealed that the mixing effects of evaporation, isotope exchange in water–rock interaction or deep groundwater recharge in the karst hyporheic zone are the strongest. The methods used in this study contribute to an improved understanding of the hydrogeochemical processes that occur in karst-fissure water systems and can be useful in zoning management and decision-making for groundwater resources.

Incorporating Er:YAP Microcrystals Into Tellurite Fiber Using Volumetric Interface Doping

AbstractIn this semi‐quantitative study, laser crystal microparticles which are potentially capable of generating mid‐infrared (MIR) light are incorporated into MIR transmitting optical fibers using a volumetric interface doping technique that combines interface doping with volumetric doping. Using confocal microscopy with a refractive index matching fluid, the Er:YAP microcrystals (MCs) inside the tellurite glass fiber are observed based on the detection of the green upconversion fluorescence emission of Er3+ ions, produced under excitation at 976 nm and localized at the central region within the fiber. The key outcome from this proof‐of‐concept study is that MC particles that are fused with the glass during the fiber drawing process survived heat treatment because the MC particles are exposed for a short time to a glass fluid with high viscosity of ≈105 Pa.s, which prevented the glass from exerting a dissolution effect. The survival of the MCs demonstrated the viability of the doping technique for fabricating fibers with exotic crystal‐glass combinations for applications including good refractive index matching across the pump and lasing bands of rare earth ions. This latter parameter provides significant particle size flexibility whilst minimizing additional loss from scattering especially at MIR wavelengths where the MC diameter‐to‐wavelength ratio becomes smaller.

Realistic Simulation of Dissolution Process on Rock Surface

Hydraulic dissolution, driven by carbon dioxide-rich precipitation and runoff, leads to the gradual breakdown and removal of soluble rock materials, creating unique surface and subsurface features. Dissolution is a complex process that is related to numerous factors, and the complete simulation of its process is a challenging problem. On the basis of deep investigation of the theories of geology and rock geomorphology, this paper puts forward a method for simulating the dissolution phenomenon on a rock surface. Around the movement of water, this method carries out dissolution calculations, including processes such as droplet dissolution, water flow, dissolution, deposition, and evaporation. It also considers the lateral dissolution effect of centrifugal force when water flows through bends, achieving a comprehensive simulation of the dissolution process. This method can realistically simulate various typical karst landforms such as karst pits, karst ditches, and stone forests, with interactive simulation efficiency.

Step flow mechanism in dissolutive wetting Cu/Ni systems

The Cu-Ni system is a typical dissolutive system due to its mutual dissolution across a wide range of temperatures and compositions. We characterized the effects of Ni dissolution on the wetting behavior of liquid Cu by combining high-temperature wetting experiments, in-situ observation of spreading and solidification, microstructure analysis of the quenched droplets, and computational fluid dynamic (CFD) simulations. In the very early moment, at 1100 °C, when the Cu droplet is brought in contact with the Ni substrate, it oscillates due to capillarity and is dampened by inertial effects, while the significant Ni dissolution at 1150 °C largely reduced the initial oscillations. Later, a peculiar spreading behavior is observed and we propose to describe it through a 4-step mechanism: pinning of the contact line by a newly formed solid solution layer at the interface acting as a physical barrier, driving of liquid towards the solidified edge due to a Ni-concentration induced Marangoni flow, forming of a precursor film ahead of the solidified edge caused by the strong Cu-Ni interactions and Marangoni flow, and finally depinning due to overflow as a result of liquid accumulation at the solidified edge. The formation of a solid solution layer is confirmed by in-situ observation and quenching. The Ni-concentration induced Marangoni flow is characterized experimentally and further investigated by CFD simulations. The proposed step flow mechanism can be potentially relevant to other dissolutive wetting systems (e.g. Bi/Sn, Ag/Cu and Cu/Fe systems), which are crucial for high-temperature processing techniques.

The roles of celestine and barite in modulating strontium and barium water column concentrations in the northeast Pacific Ocean

The water column distributions of the alkaline earth metals strontium (Sr) and barium (Ba) were studied along a transect from Hawaii to Alaska. Despite similarity in the chemical properties of Sr and Ba, we find that changes in their concentrations along the transect are governed by different chemical and biological processes, meaning that these elements can be treated as independent variables in modern and ancient environments. Alaskan margin sediments are a particularly important source of dissolved Ba to the North Pacific, likely through a combination of saline submarine groundwater discharge and reductive dissolution of manganese (Mn) oxides. Abyssal North Pacific sediments are also a source of Ba to the bottom waters but a sink for Sr. We find that over 90 % of the water column variability in Sr concentrations is driven by precipitation and dissolution of the celestine (SrSO4) skeletons of Acantharia. However, the high Ba content of Acantharia celestine accounts for only 5–8 % of the global ocean variability in Ba concentrations in the water column. Similarly, the effects of barite (BaSO4) precipitation and/or dissolution on the marine Sr cycle is negligible, accounting for <1 % of the water column concentration structure for Sr and ∼3 % of the sedimentary Sr burial. The Sr-Ba-PO4 concentration distributions in the North Pacific are inconsistent with significant export of barite to the deep ocean and sediment. This suggests most of the barite formed at intermediate depths dissolves at similar horizons to its formation. The Ba content of phytoplankton organic matter is too low to constitute a major source for particulate Ba in the mesopelagic North Pacific, which suggests Ba is concentrated in marine aggregates by heterotrophic micro-organisms.

Corrosion fatigue crack propagation behaviour in different micro-regions of steel/aluminum laser-MIG hybrid fusion-brazed joints

Evaluating corrosion fatigue crack propagation (CFCP) behaviour in different micro-regions of steel/aluminium welded joints is crucial for ensuring the safety and reliability of these joints in service environments. However, the CFCP behaviour of steel/aluminum welded joints has rarely been studied. This study explores the CFCP behaviour of steel/aluminium laser-metal inert gas hybrid fusion-brazed joints in different micro-regions under a simulated corrosive environment (3.5wt.% NaCl solution) at room temperature. A self-made 5 KN electronic servo testing machine was used to apply a sinusoidal wave load (stress ratio R = 0.1, frequency = 0.5Hz) to single-edge notched tensile specimens. The notches were located at the weld, heat-affected zone (HAZ) and steel/aluminium interface (abbreviated as interface). The fatigue crack propagation rate (da/dN) of different micro-regions in steel/aluminium welded joints followed the order of interface > weld > HAZ under corrosive environment and air conditions. Compared with air, the corrosive environment triggered a markedly higher da/dN, irrespective of notch location at the weld, HAZ or interface. This accelerated da/dN resulted from the combined effects of anodic dissolution, chloride ions and galvanic corrosion. The electron backscatter diffraction results indicated that compared with the weld and HAZ specimens, the HAZ specimen exhibited lower da/dN, attributed to its small grains, higher proportion of high-angle grain boundaries and increased geometrically necessary dislocation density. Fatigue striations were clearly observed on the weld and HAZ fracture surfaces, while a brittle fracture pattern was observed on the corrosion fatigue fracture surface for the interface.

Permeability evolution of sandstone caprock transverse fractures during intermittent CO2 injection in coal-bearing strata

The caprock of coal-bearing strata plays a critical role in CO2 geological storage, with the presence of fractures posing a heightened risk of CO2 leakage. The cyclic effects of CO2 injection and in situ stress influence the permeability of caprock fractures. However, the combined impact of CO2 and in situ stress on fracture permeability remains uncertain. This study conducted cyclic seepage experiments under varying amplitude stresses on fractured sandstone samples soaked in ScCO2 for different times (0, 15, 30, and 60 days). The microstructural characteristics of the fractured sandstone surfaces were analyzed using scanning electron microscopy and x-ray diffraction. The experimental results indicated that soaking in ScCO2 reduces sandstone fracture permeability, but the extent of this reduction is nonlinearly related to the soaking time. During the stress cycling process, due to the effect of plastic deformation, the permeability of sandstone fractures decreases with increasing cyclic amplitude and remains relatively constant with decreasing cyclic amplitude. At the same cyclic amplitude, the permeability of sandstone fractures initially increases and then decreases with prolonged soaking time. The impact of ScCO2 and stress cycling on the permeability of sandstone fractures is the result of a series of combined chemical–mechanical effects. The combined effects of chemical dissolution and mechanical degradation significantly influence the permeability of sandstone fractures, and this impact is notably time-dependent. During short-term soaking, geochemically induced changes in the surface structure of fractures cause fluctuations in permeability, while in long-term soaking, the combined chemical–mechanical effects promote a reduction in fracture permeability.

Patterns of spatiotemporal variations in the hydrochemistry and controlling factors of bedrock aquifers in the northern region of the Linhuan mining area

Systematically studying the hydrochemical evolution of bedrock groundwater in mining areas during mining process is crucial for effective groundwater resource management and coal mine production. The spatiotemporal characteristics and hydrochemical evolution patterns of the Permian fractured sandstone aquifer (PA) and the Carboniferous Taiyuan Formation limestone aquifer (CTA), both of which are directly associated with coal mining in the northern Linhuan mining area, China, were investigated using multivariate statistical analyses, hydrochemical graphical methods, ion ratio analysis, and a conceptual model. 72 groundwater samples, collected before and after mining, were classified into four groups by hierarchical cluster analysis (HCA). Principal component analysis (PCA) and ion ratio analysis indicated that water-rock interactions involve mineral dissolution (carbonates, gypsum, dolomite, silicates), cation exchange, and common ion effects. Hydrochemical evolution is influenced by bedrock paleotopography, aquifer hydraulic conductivity, and mining drainage. Paletopographic differences significantly influence water-rock interactions and spatial variability in hydrochemistry, with ion concentrations in groundwater increasing as paleotopographic elevation decreases. The pattern of hydraulic conductivity reflects the control exerted by variations in aquifer characteristics on mineral dissolution, leading to minor changes in hydrochemical characteristics. Mining activities disrupt the aquifer's reducing environment, resulting in a significant increase in groundwater SO42− concentration. These findings provide insights and a solid theoretical foundation for studying the hydrochemical variations patterns of groundwater and these control mechanisms in the hidden coal fields of North China.

The dual role of dissolution at a crack tip

The scientific literature is rife with conflicting reports regarding the effect of dissolution on fracture. The complexity arises, in part, due to dissolution often being intertwined with various other mechanisms such as hydrogen embrittlement and the formation of debris behind an advancing crack, which can obfuscate the sole contribution of dissolution. Here, we report on the effect of dissolution when acting in isolation via the utilization of an efficient atomistic-based multiscale modeling technique and a specialized interatomic potential. Our results reveal a dual role of dissolution on crack behavior, introducing an additional layer of complexity to the mechanistic basis of environmental effects. This finding, while challenging for engineering prognosis, provides a route for engineering improved materials. Recognizing and navigating this duality could be pivotal to precluding potentially disastrous consequences in a broad array of engineering applications, from harnessing earth’s energy resources to aerospace technologies.

Nanoemulsion-based transdermal delivery of third-generation steroidal and non-steroidal aromatase inhibitors in preclinical models.

Aromatase inhibitors are effective in treating hormone receptor-positive breast cancer, particularly in postmenopausal women. However, the challenges of inconsistent dissolution, variable absorption and side effects with oral administration persist. To address these issues, transdermal delivery has emerged as a viable alternative. In our study, we have developed nanoemulsion-based transdermal creams containing third-generation aromatase inhibitors Exemestane (EXE) or Letrozole (LE) and evaluated their toxicity, anti-tumour effects and androgenic potency using preclinical models including Bama minipigs, DMBA-induced breast cancer rats and orchidectomized male rats. The results of our study are significant, suggesting that both creams effectively penetrated the skin, demonstrating an impressive anti-breast cancer effect. Importantly, EXE cream had no organ toxicity at the tested dose, providing a reassuring safety profile for its use. In contrast, LE cream displayed reversible toxicity from drug molecule itself in animals at the given dose, dissipating after 3 weeks of withdrawal and recovery. This study establishes a solid foundation for the safe clinical use of third-generation aromatase inhibitors. It highlights transdermal creams as a promising drug delivery carrier for administering them.

Comprehensive analysis of lignin dimer dissolution microscopic mechanism in different aromatic-based deep eutectic solvent

Aromatic-based deep eutectic solvent (DES) is a novel kind of DES that can dissolve lignin efficiently. Density functional (DFT) calculation, molecular dynamics (MD) simulation and multivariate analysis were used to investigate the interaction mechanism of five aromatic-based DES on two lignin dimer models. The effects of dissolution temperature and the type of aromatic hydrogen bond donor (HBD) on the breaking bonds between β-O-4 and 5–5 substructural units or interacting with different functional groups on lignin were investigated. With the introduction of DES, the electrostatic interaction between Cl- and lignin was obvious, while the van der Waals interaction between HBD, Ch+ and lignin was obvious. Among all the aromatic-based DES, choline chloride/p-hydroxybenzoic acid (ChCl/PB) is considered to have efficient dissolution effect. In the process of lignin dissolution, γ-OH was the preferred site for PB and Cl- acting on the lignin dimer (β-O-4), and the proportion of hydrogen bonding with γ-OH is 40 %. It was distributed around the lignin dimer (β-O-4) at 0.28–0.32 nm, and the total interaction energy was −4041.1452 kJ/mol. This study provided novel insights and theoretical basis for the preparation of renewable DES using aromatic components.

Effects of kaolinite and montmorillonite calcined clays on the sulfate balance, early hydration, and artificial pore solution of limestone calcined clay cements (LC3)

This study investigated the physicochemical effects of kaolinite (CK) and montmorillonite (CM) calcined clays on the sulfate balance, early hydration, and artificial pore solution of limestone calcined clay cement (LC3). The effects of fineness, clay dissolution, and ion-adsorption capacity were evaluated by isothermal calorimetry, compressive strength, ICP-OES, and zeta potential within 72 h, respectively. Increasing the fineness of both calcined clays did not significantly affect the sulfate depletion kinetics or the compressive strength and the adsorption of Ca2+ ions onto the calcined clay’s surface is not the main factor responsible for differences in sulfate demand. The higher dissolution of ions Al in CK provided an intensified and accelerated formation of ettringite that competes for the available sulfate. We demonstrate that the chemical effects have a significant impact on the sulfate balance of LC3, revealing the lesser impact of alternative clays like montmorillonite compared to metakaolin (MK) which can minimize the problem of accelerated sulfate depletion of LC3 mixes with MK.

Mechanical behaviour of granular materials undergoing grain dissolution

Geotechnical engineering projects are often at risk from threats related to mineral dissolution and loss of particles that constitute the matrix of the geomaterial. Moreover, the impact of climate change can exacerbate these risks by accelerating the physical processes. To address such challenges, it is a pre-requisite to understand and quantify the effect of mineral dissolution on geomechanical behaviour. A general theoretical approach to mechanical consequences of geomaterials experiencing mineral dissolution was first proposed. Following, a series of oedometer tests were conducted using mixtures of salt and sand with various salt contents to observe and characterise the effect of dissolution on the mechanical behaviour of granular materials. The dissolution of salt crystals was performed in three different stress states to observe the stress-dependent response of the material. The effect of dissolution was dependent both on the amount of dissolved salt particles and the applied stress state. The laboratory experiments and the discussion followed shares insights into the effect of grain dissolution on the mechanical behaviour of granular materials and proved the potential of the framework presented in this paper. Finally, the paper ends by discussing the engineering implications bearing in mind the climate change we are facing today.

Understanding the mechanisms behind the antibacterial activity of magnesium hydroxide nanoparticles against sulfate-reducing bacteria in sediments

Nanomaterials, with their small size, surface characteristics, and antibacterial properties, are extensively employed across environmental, energy, biomedical, agricultural, and other industries. This study examined the antibacterial efficacy of magnesium hydroxide (Mg(OH)2) nanoparticles (NPs) against sulfate-reducing bacteria (SRB) within sediments. The inhibitory effects of two types of Mg(OH)2 NPs with distinct particle sizes (20.3 and 29.6 nm) and concentrations (0–10.0 mg/mL) were examined under optimal treatment conditions. The antibacterial mechanisms of Mg(OH)2 NPs through direct contact and dissolution effects were determined. The results revealed a correlation between the concentration, particle size, and inhibitory activity, with the smallest NPs (20.3 nm) at the highest concentration (10.0 mg/mL) substantially reducing SRB counts from 8.77 ± 0.18 to 6.48 ± 0.13 log10 colony forming units/mL after 6 h treatment. Treatment with high concentrations of Mg(OH)2 NPs induced cellular damage, reduced intracellular lactate dehydrogenase activity, and elevated intracellular catalase activity and H2O2 content, suggesting that the contact effect of NPs stimulated SRB. This leads to oxidative stress response and structural damage to the cell membrane, which has emerged as the primary driver of the antibacterial action of Mg(OH)2 NPs. This study presents a novel nanomaterial that can inhibit and control SRB in natural sedimentary environments.

High strain rate behavior of polycaprolactone reinforced with aramid nanofiber for insight into dynamic behavior

AbstractSelf-healing materials are repairable and extend product lifetimes but are limited in application due to their mechanical properties such as low yield strength. Here, we examined the dynamic mechanical performance of an elastomeric polymer composite containing aramid nanofibers. These studies provided an economically feasible foundation to understand the reinforcement concentration and resultant mechanical properties that would result should aramid nanofibers be used to reinforce a self-healing polymer that requires complex synthesis methods and expensive reactants. The elastomeric polymer used was polycaprolactone containing various weight percent aramid nanofibers. Dynamic mechanical testing of these samples was performed using a split-Hopkinson pressure bar system that enabled quantification of polymer softening and aramid nanofiber reinforcement. Dynamic flow stress and strain rates were also calculated with these data. Crystallinity and thermal softening effects of solvent dissolution of polycaprolactone are explored to further characterize the performance of aramid nanofibers as a fiber in composite materials. Graphical abstract