Valence Of Ions Research Articles

Charging Metal-Organic Framework Membranes by Incorporating Crown Ethers to Capture Cations for Ion Sieving.

Protein channels on the biofilm conditionally manipulate ion transport via regulating the distribution of charge residues, making analogous processes on artificial membranes a hot spot and challenge. Here, we employ metal-organic frameworks (MOFs) membrane with charge-adjustable subnano-channel to selectively govern ion transport. Various valent ions are binded with crown ethers embedded in the MOF cavity, which act as charged guest to regulate the channels' charge state from the negativity to positivity. Compared with the negatively charged channel, the positive counterpart obviously enhances Li+ /Mg2+ selectivity, which benefit from the reinforcement of the electrostatic repulsion between ions and the channel. Meanwhile, theoretical calculations reveal that Mg2+ transport through the more positively charged channel needed to overcome higher entrance energy barrier than that of Li+ . This work provides a subtle strategy for ion-selective transport upon regulating the charge state of insulating membrane, which paves the way for the application like seawater desalination and lithium extraction from salt lakes.

Preparation, Chromatic Properties Analysis and Proportioning Optimization of Co-Cr-Fe-Based Black Pigment.

The utilization of Co-Cr-Fe-based black pigments bears considerable significance within the realm of commercial ceramic pigments, owing to their distinctive spinel structure, remarkable high-temperature stability, and exceptional chromatic attributes. This study delves into the synthesis of diverse black pigment configurations by employing the co-precipitation method, leveraging the interplay of these three metallic oxides. This investigation encompasses a comprehensive scrutiny of ion valences, crystal structures and parameters, colorimetric properties, and their interrelationships. The methodology integrates the response surface methodology (RSM) framework, using theoretical formulations to navigate the material ratios and elucidating the associations between the resultant compositions and color coordinate values, aligned with the CIE-Lab* colorimetric methodology. The derived predictive models yielded an optimized black pigment composition, characterized by heightened black intensity and a refined formulation.

CO to formaldehyde transformation study on pristine and Au-modified BaTiO3(001) through DFT calculations.

BaTiO3 is one of the most important ferroelectric oxides in electronic applications. Also, it has attractive properties for catalysis that could be used for reducing contamination levels, especially carbon monoxide, CO. CO is one of the main gaseous pollutants generally released from the combustion of fossil fuel. In this work, the CO transformation on pristine and Au-modified BaTiO3 perovskite for H2CO obtention is studied. The CO adsorption and hydrogenation on pristine BaTiO3 leads to formaldehyde synthesis as the most stable product through two possible routes. Furthermore, hydrogenation stages are less probable on pristine BaTiO3. On Au-modified BaTiO3 formaldehyde is the principal product too but Au adatom generates H2CO competition with HCOH. After BaTiO3 modification with Au unpaired electrons were generated. These unpaired electrons are related to the adatom reactivity. According to the obtained results, pristine and Au-modified BaTiO3 can adsorb and hydrogenate CO generating formaldehyde as the principal product. BaTiO3 modifications with Au increase the reactivity of the perovskite in the CO hydrogenation reactions. CO hydrogenation process on Au suggests that further hydrogenation stages beyond formaldehyde are possible. The study was performed through ab initio calculations using the periodic spin-polarized Density Functional Theory (DFT) as implemented in Quantum ESPRESSO. DFT calculations were carried out using the Plane Wave self-consistent field (PWscf). Spin density difference allows us to identify reactive regions related to dangling bonds and unpaired electrons. A plane wave basis set was used to represent the electron states. Vanderbilt pseudopotentials with nonlinear core correction were used to model the ionic cores and valence electrons interaction. Exchange-correlation energies were treated within the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) parameterization.

Model-Based Optimization of Multi-Stage Nanofiltration Using the Solution-Diffusion–Electromigration Model

Nanofiltration is well suited to separate monovalent ions from multivalent ions, such as the separation of Li+ and Mg2+ from seawater, a potential lithium source for the production of lithium-ion batteries. To the best of our knowledge, there is no existing work on the optimization of a multi-stage membrane plant that differentiates between different ions and that is based on a validated transport model. This study presents a method for modeling predefined membrane interconnections using discretization along the membrane length and across the membrane thickness. The solution-diffusion–electromigration model was used as the transport model in a fundamental membrane flowsheet, and the model was employed to optimize a given flowsheet with a flexible objective function. The methodology was evaluated for three distinct separation tasks, and optimized operating points were found. These show that permeances and feed concentrations might cause negative rejections and positive rejections (especially for bivalent ions) depending on the ions’ properties and fluxes, thereby allowing for a favorable separation between the ions of different valence at optimized conditions. In an application-based case study for the separation of Li+ and Mg2+ from seawater, the method showed that under optimal conditions, the mol-based ratio of Mg2+/Li+ can be reduced from 2383 to 2.8 in three membrane stages.

Experimental investigation of the erodibility of soda saline-alkali soil under freeze-thaw cycle from a microscopic view

Soda saline-alkali soil, dominated by NaHCO3, has complex engineering properties that change with external water, heat, and salt, making it prone to water erosion. By destroying soil microstructure, freeze-thaw (F-T) action can potentially enhance soil erodibility and provide water erosion material. Therefore, this work examined the freeze-thaw erosive properties and microstructural evolution mechanisms of soda saline-alkali soil. Disintegration tests and a series of microscopic tests examined the impacts of freeze-thaw cycles (N = 0, 1, 5, 10, 30, 60) and soluble salt content (η = 0.4 %, 0.8 %, 1.2 %, 1.6 %, 2.0 %) on the soil erodibility index (disintegration rate). The results demonstrated that F-T action continued to weaken the disintegration resistance of the saline soil. Moreover, this trend relatively stabilized after 10 F-T cycles.Soluble salt content had a two-phase impact on the saline soil disintegration. Increased salt content below 0.8 % improved erosion resistance, but salt content above 0.8 % accelerated the soil erosion. According to the Gouy-Chapman diffuse double layer (DDL) theory, the variation in the thickness of DDL induced by higher sodium ion contents and lower sodium ionic valence were deemed as the main causes. When the salt content increased from 0.8 % to 2.0 %, the disintegration rate increased by 49.40–71.43 %. Microscopic results showed that sequential F-T cycles decreased intra-aggregate pores (<4 μm) and increased inter-aggregate pores (>4 μm). This mechanism was attributed to the unfrozen water migration and ice segregation due to the cryo-suction process during the freezing process. Correlation analysis indicated that soil microstructure with a bimodal characteristic dominated the erodibility index. The effect of F-T action on soil erodibility was more significant than the soluble salt content, with both impacted saline soil erodibility by affecting pore distribution characteristics and soil aggregate formation, respectively. These findings may assist soda saline-alkali soil salinity prevention and control of saline soil erosion in seasonally frozen regions globally.

Production, purification, and characterization of cold-active lipase from the psychrotroph Pseudomonas sp. A6

Cold-active lipases are presently employed extensively in the detergent, chemical intermediate, fine chemical, food, and pharmaceutical industries. Seven cold-adaptive bacteria were isolated from the Mediterranean Sea near Alexandria, Egypt, and tested for their ability to produce cold-active lipase, with the highest activity at 10 °C. The most potent isolate was Pseudomonas sp. A6. To determine the most important variables, the bacterium was exposed to a necessary medium component and environmental factor screening using a single factor-at-a-time approach, followed by a multifactorial Plackett-Burman design strategy. After purification and characterization, the optimal activity levels for the cold-active lipase were figured out. Inoculation of Pseudomonas A6 under near optimum conditions using medium consisting of (g/L) peptone 7.14; soybean oil 7.5% (v/v); K2HPO4, 0.4; MgSO4, 0.1; glucose 2; pH 8; and temperature 10 °C led to a maximum lipase activity anticipated to be 23.36 U/mL. Purified lipase showed the best activity and thermal stability at a pH of 8 and a temperature of 10 °C. The Pseudomonas A6 lipase tolerated the monovalent ions, while greater valence ions did not.

Synthesis and luminescence properties of Cr2O3-CaO-GeO2 glass and glass ceramics for broadband NIR-LEDs

We report the fabrication of novel 0.1Cr2O3-25CaO-75GeO2 glass and glass ceramics with wideband NIR luminescence and the annealing temperature dependence of the photoluminescence (PL) properties for applications as NIR phosphors. The anisotropic growth of Ca2Ge7O16 nanocrystals in the annealing samples was confirmed. Annealing-induced variations in the body colors and diffuse reflectance spectra suggest that change in the valence of Cr ions and their coordination environments. Broadband luminescence of 700–1300 nm attributed to the 4T2 → 4A2 transition of Cr3+ was observed for the as-made glass. The peak wavelength is shifted from 860 to 780 nm, and line-shaped 2E → 4A2 emission appears due to the crystallization of Ca2Ge7O16 by heat treatment. The PL quantum yield reaches the maximum at 0.19 when the sample is annealed at 775 °C, and the dependence on annealing temperature can be understood by the change in the PL lifetimes and diffuse reflectance spectra.

Optimized electrical transport properties of La0.7Ca0.18Sr0.12MnO3 film by adjusting sintering temperature

Perovskite manganites Lax(Ca1-ySry)1-xMnO3 have conspicuous electrical transport properties used for the application of uncooled bolometers. Thus, considerable attention has paid to the researches on electrical transport properties of Lax(Ca1-ySry)1-xMnO3. Temperature coefficient of resistivity (TCR) and the corresponding peak temperature (Tk) are crucial parameters for uncooled bolometers. Optimal La0.7Ca0.18Sr0.12MnO3 (LCSMO) films with highly oriented growth were prepared on (00l) LaAlO3 substrate at different sintering temperature (Ts) using a facile sol-gel spin coating method. Based on the analysis of microstructure, ionic valence, surface morphology and electrical transport properties, LCSMO films exhibit high crystallinity and large room-temperature TCR at higher Ts. Theoretical Curie temperature and the coupling of the electron lattice weaken gradually with the increase in Ts, which is the dominant factor for the optimization of electrical transport properties. Additionally, the results suggest that the active energy and theoretical Curie temperature play a crucial role in adjusting TCR and Tk. With the increase in Ts, the former increases while the latter decreased, resulting in a high TCR value (12.10%/K) at room temperature (297.38 K). The peak TCR value of LCSMO sintered at 1673 K is about 25% higher than that of the film sintered at 1473 K. The resulting LCSMO films demonstrate great potential for application in uncooled bolometers. Further theoretical basis on the effects of Ts on electrical transport properties was provided.

Optimizing and extending ion dielectric polarizability database for microwave frequencies using machine learning methods

Permittivity at microwave frequencies determines the practical applications of microwave dielectric ceramics. The accuracy and universality of the permittivity prediction by Clausius–Mossotti equation depends on the dielectric polarizability (αD) database. The most influential αD database put forward by Shannon is facing three challenges in the 5 G era: (1) Few data, (2) Simplistic relation and (3) Low frequency (kHz–MHz) oriented. Here, we optimized and extended the Shannon’s database for microwave frequencies by the four-stage multiple linear regression and support vector machine model. In comparison with the conventional database, the optimized and extended databases achieved higher accuracy and expanded the amount of data from 60 to more than 900. Besides, we analyzed the relationships between αD and ion characteristics, including ionic radius (IR), atomic number (N), valence state (V) and coordination number (CN). We found that the positive cubic law of “αD ~ IR3” discussed in Shannon’s work was valid for the IR changed by the N, but invalid for the change caused by the CN.

The effect of cations and epigallocatechin gallate on in vitro salivary lubrication

Ionic valency influences oral processing by changing salivary behavior and merits more attention since little is known. In this study, the influence of three ionic valences (monovalent, divalent and trivalent), ionic strength and epigallocatechin gallate (EGCG) on lubricating properties of saliva were investigated. Tribological measurements were used to characterize the lubrication response of KCl, MgCl2, FeCl3, and AlCl3 in combination with EGCG to the ex vivo salivary pellicle. KCl at 150 mM ionic strength provided extra lubrication via hydration lubrication. Contrarily, trivalent salts aggregated together with the salivary mucins via ionic cross-link interactions, which led to a decrease in salivary lubrication. FeCl3 and AlCl3 affected the salivary lubrication differently, which was attributed to changes in the pH. Finally, in presence of EGCG, FeCl3 interacted with EGCG via chelating interactions, preventing salivary protein aggregation. This resulted in less desorption of the salivary film, retaining the lubrication ability of salivary proteins.

Research of Water Absorption and Release Mechanism of Superabsorbent Polymer in Cement Paste.

The water absorption and release properties of superabsorbent polymers' (SAP) internal curing agent are affected by many factors, such as solution properties, the ambient temperature and humidity and the particle size of SAP, which determine the curing effect and the durability of cement concrete structures directly. In this paper, the variation rule of the water absorbing capacity of SAP in simulated cement paste under different solutions and environmental conditions was studied. Based on microscopic image technology, the dynamic swelling behavior of the SAP particles was explored. The water release performance of SAP in cement paste was analyzed by both the tracer method and the negative pressure method. The results show that the water absorption of SAP in cement paste varied from 27 to 33 times. The ionic valence had a significant effect on the water absorption capacity of SAP, which suggests that the larger the ionic radius, the lower the absorption of SAP. The higher the temperature of the solution, the greater the water absorption rate of SAP. While the SAP particle size was less than 40-80 mesh, a slight 'agglomeration effect' was prone to occur, but the absorption state of SAP was more stable. Based on the swelling kinetic equation of SAP and the time-dependent swelling morphology of SAP in cement paste, a swelling kinetic model was established. The water release performance of SAP was less affected by the capillary negative pressures, and it would not release the water prematurely during the plastic stage, which was conducive to the continuous internal curing process of hardened paste in the later stage.

Trace doping realizing superior electrochemical performance in P2-type Na0.50Li0.08Mn0.60Co0.16Ni0.16O2 cathode for sodium-ion batteries

P2-type layered oxides are receiving significant interest due to their superior structure and intrinsic performances. There are strenuous attempts to balance the structure stability, phase transition as well as desirable electrochemical performances by inducing anion/cation ions, changing morphology, adjusting valence, etc. In this work, several same-period elements of Sc, Ti, V, Cr, Fe, Cu and Zn are doped into Na0.50Li0.08Mn0.60Co0.16Ni0.16O2 cathodes, which are manipulated by ions radii and valence state, further studied by operando X-ray powder diffraction patterns (XRD). As a result, the Cu2+ doped cathode performed higher rate capacities (as high as 86 mAh/g even at 10 C) and more stable structures (capacity retention of ∼89.4% for 100 cycles), which owing to the synergistic effect among the tightened TMO2 layer, enlarged d-spacing, reduce OO electrostatic repulsion, ameliorate lattice distortion as well as mitigate ordering of Na+/vacancy.

Modulating the chiral nematic structure of cellulose nanocrystal suspensions with electrolytes

HypothesisThe iridescent optical properties of films made of cellulose nanocrystals (CNC) are controlled by the pitch and range of the chiral nematic structures. These are further tuned with the addition of electrolyte. ExperimentsElectrolyte type, valency and concentration were varied. The bulk CNC suspension properties were investigated by combining rheology, polarised optical photography and microscopy, while the spacing between crystals was determined using SAXS. FindingsThe addition of electrolyte to a CNC suspension containing chiral nematic structures first causes the nematic pitch to increase indicating the suspension has a weaker structure. Further increases in electrolyte concentration cause aggregation and complete breakdown of the chiral nematic structures. The univalent species cause larger changes to the chiral nematic structure with the onset and magnitude of structure breakdown occurring at lower ionic strengths compared with the divalent species. Cation size influences the chiral nematic structure with the order of influence being K+ > Na+ ≈ Ca2+ > Mg2+, which corresponds from the largest to smallest cation. This work demonstrates that both ion valency, concentration and species play a significant role in controlling the chiral nematic structures of CNC suspensions and will be a vital step in the development of CNC liquid crystals, optical materials and sensors.

Lead-free medium-entropy (Na0.47(1-x)Bi0.47(1-x)Ba0.06(1-x)Sr0.7xNd0.2x)TiO3 relaxor ceramics with robust energy-storage performance

High-entropy engineering is becoming a new strategy in dielectric energy storage capacitors. However, high-entropy strategy alone is insufficient to produce good energy storage performance, as the polarization intensity is greatly reduced by the highly disordered state. We, herein, propose an “entropy engineering + polyphase” strategy and highlight that materials with medium entropy values, no necessity of high entropy values, can yield good energy storage performance under condition that polyphases are introduced in the materials. To illustrate the effectiveness of this strategy, the medium-entropy ceramics (Na0.47(1-x)Bi0.47(1-x)Ba0.06(1-x)Sr0.7xNd0.2x)TiO3 with x = 0.1, 0.2, 0.3, 0.4, and 0.5 were designed by doping ions with different ionic radii and valence states at the A-site. Investigations on the energy storage performance reveal that the sample of x = 0.4, with the maximum entropy value of 1.39R, has the largest recyclable energy storage density Wrec = 8.71 J/cm3 with a high efficiency η = 88.5%. The sample also shows excellent thermal stability of dielectric constant (Δε′/ε25oC′≤ ±15%) over a temperature range of −61–144 °C. The excellent performance is due to the introduction of multiphase in the medium entropy ceramics, which effectively refines the grain and domain sizes, leading to a high polarization intensity (44.23 μC/cm2) and excellent energy storage performance. This work shows that “entropy engineering + polyphase” is an effective strategy for excellent energy storage performance and paves a way of developing new energy storage materials by entropy engineering.

Effect of sulfonation time on physicochemical, osteogenic, antibacterial properties and biocompatibility of carbon fiber reinforced polyether ether ketone

The carbon fiber reinforced polyetheretherketone (CFR-PEEK) has been increasingly used in orthopedics dentistry due to its excellent biocompatibility and mechanical properties. However, the biological inertness and poor antibacterial activity limit its clinical applications. This paper focused on the performances of CFR-PEEK with porous morphology that were exposed to different sulfonation periods (1, 3, 5, and 10 min, corresponding to CP-S1, CP-S3, CP-S5, and CP-S10, respectively). Residual sulfuric acid was removed by acetone rinsing, NaOH immersion, and hydrothermal treatment before in vitro and in vivo studies. The results showed some significant difference in the physicochemical properties, including energy dispersive X-ray spectroscopy (EDS) map of sulfur atoms, X-ray photoelectron spectroscopy (XPS) of valences of sulfur ions, Fourier transformation infrared spectroscopy (FTIR), hydrophilicity, hardness, and elastic modulus among CP-S3, CP-S5, and CP-S10. However, CP-S5 and CP-S10 were more effective in promoting the proliferation, adhesion, and osteogenic differentiation of seeded bone mesenchymal stem cells (BMSCs) and growth inhibition of S. aureus and P. gingivalis compared with other groups. Furthermore, the CP-S5 and CP-S10 samples achieved better cranial bone repair than the non-sulfonation group in a rat model. Therefore, it can be inferred that both 5 and 10 min are viable sulfonation durations for 30% CFR-PEEK. These findings provide a theoretical basis for developing CFR-PEEK for clinical applications.

Insights into structure, local site symmetry, and energy transfer for regulating luminescent properties of SrLaLiTeO6: Dy/Eu and its application in wLEDs

A series of spectrally tunable Dy3+/Eu3+-coactivated double perovskites SrLaLiTeO6 (SLLT) were synthesized via solid-state ceramic route under air condition. Considering differences of ionic radius and valences among the dopants and host cations, Dy3+/Eu3+ are all inclined to enter La site, though slight occupations in Sr site cannot be completely ruled out. Dy shows narrow band emissions in blue (B) to yellow (Y) region, which is stemmed from magnetic (4F9/2 → 6H15/2) and electric (4F9/2 → 6H13/2) dipole transitions, respectively. Eu3+ exhibits orange-red (O–R) emissions, with two dominant peaks located at ∼ 593 and 617 nm from magnetic (5D0 → 7F1) and electric (5D0 → 7F2) dipole transitions, which could be used as compensation for the red-emitting portion in pc-wLEDs via energy transfer (ET) from Dy to Eu to overcome the disadvantage of low excitation efficiency. The substitutional local site symmetry could be regularly modified along with severely impacting on Y/B and R/O ratios for Dy and Eu emission colors via simply modifying the doping contents, due to changes in bond lengths and Coulomb potentials from interconnected octahedrons [LiO6] and [TeO6] around the dopants. The fabricated pc-wLED via combining a commercial n-UV LED chip with the SLLT: Dy/Eu, exhibited splendid EL performance, with the CIE coordinate is calculated to be (0.3690, 0.3539), CCT of 3232 K, and CRI (Ra) of 86.5. Altogether, it manifests that the stable SLLT: Eu and SLLT: Dy/Eu are potentially good candidates for applications as red and white phosphors, respectively in indoor plant growth LED and pc-wLEDs.

Enhanced energy storage properties in Nb-doped (Na0.5Bi0.5)TiO3-SrTiO3 lead-free relaxor ferroelectric ceramics

In this article, optimized energy-storage density obtained at low electric field and accompanied with high efficiencies was achieved simultaneously by donor-doping Nb5+ into 0.65(Na1/2Bi1/2)TiO3–0.35SrTiO3 system. The donor addition of Nb5+ may force Ti4+ to become Ti3+ due to the imbalance of ion valence after the Nb5+ substitution of Ti4+, leading to the formation of Ti3+-Nb5+ ion pair. The self-built electric field generated by Ti3+-Nb5+ ion pair is conducive to obtain slim P-E loops with high P max and negligible P r. Accordingly, a high recoverable energy densities of 1.04 J/cm3 with a high energy efficiencies of 86.7% was achieved under 82 kV/cm at x = 0.25 mol.% due to the enhanced E b and P max-Pr values. This work provides a promising approach for designing high-performance lead-free energy storage ceramics under low electric fields.

Structure and spectroscopic properties of Er3+ doped LiNbO3 thin film grown by e-beam evaporation

Er3+ doped LiNbO3 (Er: LN) single crystal films with varied doping levels of Er3+ were grown on z-cut LiTaO3 bulk single crystals by using e-beam evaporation method. The crystallographic orientation, fluorescence properties, ions valence states, Er3+ concentration and Li2O content of films were studied. The main phase of the obtained films is determined to be LN from X-ray diffraction and Raman scattering studies, and the films are found to be orienting along (006). Enhancement in the visible and near-infrared luminescence is observed as the doping concentration of Er3+ is increased. The Li2O content of films is determined using the optical birefringence method and found to be at a constant value of 48.8 mol%, which is consistent with the Raman results. XPS results show that the Er concentration in the films is lower than that in the polycrystalline powder since e-beam evaporation has a low efficiency for heavier Er3+. Fluorescence intensity ratios estimated at different measurement temperatures suggest that the Er: LN films have excellent temperature sensitivity, which shows the potential of the films for optical thermometry applications.

Novel Phenomenon of Scintillation Performances with the Component Variation in the Mg Co-/Nondoped GAGG:Ce Crystal

Gd3Al2Ga3O12:Ce (GAGG:Ce) shows potential application in the next-generation positron emission tomography material due to its high light yield and excellent energy resolution. The main method currently available to accelerate the scintillation decay time of GAGG:Ce is mainly through the codoping of low valence ions such as Mg2+, which partially converts Ce3+ to Ce4+ through a charge compensation mechanism. However, there is no clear and reasonable explanation for the deterioration of light yield by codoping with Mg2+ in GAGG:Ce. Therefore, further study of the Mg2+ codoping GAGG:Ce crystal is of great importance for improving the scintillation properties of GAGG:Ce. In this study, two sets of GAGG crystal samples containing different Ce concentrations without or with 0.5 atom % of Mg2+ ion codoping were grown by the micropulling down method. The optimal Ce concentration decreases after Mg2+ codoping, whereas the light yield degenerates significantly. This novel phenomenon suggests that the reduction of light yield after Mg2+ codoping is not only due to the reduction of the luminescence center but also the formation of {Ce3+–Mg2+} and {Ce4+–Mg2+} associates affects the luminescence emission. This work can provide a novel and significant view for high-performance codoped GAGG:Ce component design and performance modification.

Influence of natural organic matters on fate of polystyrene nanoplastics in porous media

Natural organic matters (NOMs) are widely present in aqueous environments. The effect of NOMs on the fate of nanoplastics that are gradually receiving widespread attention in porous media needs to be noticed, but relevant research is lacking. To fill this gap, the present study focused on elucidating the influence of NOMs and metal cations with varying concentrations upon the transport, long-term release, and particle fracture of polystyrene nanoplastics (PS-NPs) in saturated porous media. The adsorption, transport, long-term release, and particle fracture tests were conducted. A mathematical model and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory were used in this research. NOMs could adsorb onto PS-NPs leading to a reduction in the PS-NPs' zeta potential and an increase in the energy barrier and steric hindrance between PS-NPs and quartz sand, ultimately facilitating the transport of PS-NPs through porous media. On the other hand, an increase in concentration and valence of metal ions enhanced the PS-NPs' zeta potential, resulting in PS-NPs' aggregation and increased size when NOMs were present. This reduced the energy barrier between porous media and PS-NPs, resulting in increased blocking and straining, allowing decreased PS-NPs' transport. Long-term release tests demonstrated release ability and mobilities of PS-NPs decreased as the enhanced NOM concentration, addition of metal cations, and decreased valence of metal ions, in agreement with the transport test findings. In the research about particle fracture, NOMs were found to inhibit the fracture of PS-NPs by adsorbing on their surface to protect them from fracture. Metal cations and increased metal cation valence promoted the fracture of released PS-NPs when NOMs were present by promoting NOM aggregation and thus hindering the protection of NOMs for the nanoplastics.