Charge Shielding Effect Research Articles

NaCl-Responsive Ultrashort Peptide to Trigger Self-Assembly of TPE-Capped Supramolecular Hydrogelator.

With the advantages of less invasiveness and better shape adaptability, in situ-forming hydrogels are desired biomaterials as scaffolds, drug carriers, and so on. Herein, a negatively charged NaCl-responsive ultrashort peptide sequence (EEH) is reported whose electrostatic repulsion can be reduced through the charge-shielding effect. Under physiological conditions, its AIEgen-capped amphiphile TPE-GEEH of low concentration (1 mg/mL) presents NaCl-triggered morphological transformation from micelle to closely packed fiber with enhanced emission, which can be applied to biosense sodium ion (Na+) with high sensitivity and quick response. At a slightly acidic pH, 10 mg/mL TPE-GEEH undergoes sol-gel transition upon addition of NaCl (100 mM) with improved mechanical properties, which should be useful to develop an in situ-forming hydrogel. Overall, our report provides a simple strategy to construct NaCl-responsive assemblies for potential application in biosensors and drug delivery system.

Effects of mono- and divalent-ions and their strength on foaming properties of infant formula protein model system

Metal ions may affect the foaming properties of infant formula products that including milk protein during reconstitution. In this study, an infant formula protein model system (IFPMS) composed of both whey protein and casein was constructed, and the effect of mono (Na+, K+) and divalent (Mg2+, Ca2+) ions and their strength (0–100 mM) on foaming properties was investigated. The mono ions had no significantly impact on foaming capacity (FC), MgCl2 slightly increase FC and reaching a maximum of 116.09 ± 7.46% at 25 mM, whereas CaCl2 significantly decreased FC from 105.78 ± 7.42% to 83.14 ± 6.75% as 0–25 mM (p < 0.05). Foam stability (FS) was significantly improved as all salts above 10 mM (p < 0.05). The dramatically decreased net charge and larger protein aggregates (>25 mM) of IFPMS with divalent ions indicating their stronger charge-shielding effect, which caused slow adsorption of protein and increased surface tension. Multiple spectral results confirmed that salts enhanced protein interactions via inter-molecular and form a viscoelastic layer to stabilize foam. Absorbed protein and SDS-PAGE analysis revealed that MgCl2 promoted protein adsorption, while CaCl2 reduced casein in the foam phase. Correlation analysis further implied that the FC showed highly significant positive with absorbed protein, solubility, and β-turn (p ≤ 0.01), and FS was significantly correlated with secondary structure and viscosity (p ≤ 0.05). This study may provide useful information for an in-depth understanding of the foaming properties of infant formula.

Chloride-salt separation type nanofiltration membranes for efficient crude salt refinement

Application of unrefined crude salt not only leads to a serious equipment scaling and a low product quality, but also increases operational risks and poses health hazards. Therefore, it is essential to refine crude salt prior to its use. However, traditional methods of crude salt refinement are energy-intensive and probably produce additional chemical by-products. In this work, membrane technology was used to accomplish the refinement of crude salt due to its unique characteristics, such as environmentally friendly and lower energy consumption. To improve the separation performance, the membranes were fabricated by simply adjusting the aqueous monomer concentration. For single-salt feed, the membrane (M10) prepared with a high ratio of 10 exhibited excellent salt rejection due to the formation of a thicker and denser PA layer. And it owned a superior MgCl2/NaCl selectivity of ∼22.0, demonstrating that the membrane can achieve outstanding selectivity for mono-/divalent ions. The selectivity of Mg2+/Na+ increased to ∼23.5 for bi-salt feed and further improved to 66.2 for multi-salt feed due to the stronger charge shielding effect. Most importantly, the membrane was also successfully applied in the refinement of crude salt. When using crude salt (NaCl 30 g/L, purity 0.90) as feed, the M10 exhibited both excellent retention of bivalent ions and permeation of univalent ions, resulting in the corresponding Mg2+/Na+ selectivity up to ∼251.6 and the tremendous enhancement in the Na + purity of ∼0.997. This work offers a feasible strategy for crude salt refinement, and could expand to some other potential applications such as resource utilization in the salinization industry and zero-liquid discharge of industrial wastewater.

A Schottky heterojunction with spatially separated active sites for piezo-photocatalytic dual-channel hydrogen peroxide generation

Mechanical and solar energy-driven piezo-photocatalysis has drawn growing attention for H2O2 synthesis and related applications. However, most reported works focused on single pathway and ignored simultaneous oxygen reduction and water oxidation for H2O2 generation. Herein, Au-ZnO Schottky heterojunction is constructed for piezo-photocatalytic H2O2 synthesis via dual-channel pathway (simultaneous oxygen reduction and water oxidation). Experimental results and density functional theory calculations illustrated that the reduction and oxidation reactions predominantly take place at Au and ZnO sites, respectively. The spatially separated active sites avoid site competition, and enable a synergistic effect of oxidation and reduction. Furthermore, Au nanoparticles not only provide hot electrons via surface plasmon resonance effect, but also form Schottky junctions with ZnO to decrease the charge shielding effect. As a result, a H2O2 generation of 186 μM in pure water (30 min) is achieved by the optimal sample. This study provides a strategy for the construction of piezo-photocatalysts from the perspective of spatially separated redox sites for efficient H2O2 synthesis.

Microbially Inspired Calcium Carbonate Precipitation Pathway Integrated Polyelectrolyte Capsules (MICPC) for Biomolecules Release.

Complexation between oppositely charged polyelectrolytes offers a facile single-step strategy for assembling functional micro-nano carriers for efficient drug and vaccine delivery. However, the stability of the delivery system within the physiological environment is compromised due to the swelling of the polyelectrolyte complex, driven by the charge shielding effect, and consequently leads to uncontrollable burst release, thereby limiting its potential applications. In a pioneering approach, cellular pathway-inspired calcium carbonate precipitation pathways are developed that are integrated into polyelectrolyte capsules (MICPC). These innovative capsules are fabricated at the interface of all-aqueous microfluidic droplets, resulting in a precisely controllable and sustained release profile in physiological conditions. Unlike single-step polyelectrolyte assembly capsules which always perform rapid burst release, the MICPC exhibits a sustainable and tunable release pattern, releasing biomolecules at an average rate of 3-10% per day. Remarkably, the degree of control over MICPC's release kinetics can be finely tuned by adjusting the quantity of synthesized calcium carbonate particles within the polyelectrolyte complex. This groundbreaking work not only deepens the insights into polyelectrolyte complexation but also significantly enhances the overall stability of these complexes, opening up new avenues for expanding the range of applications involving polyelectrolyte complex-related materials.

Preliminary study of dual annular multiple-beam cathode for V-band coaxial transit-time oscillator

Since the research toward high-power millimeter-wave generator becomes a tendency in high-power microwave, overmoded structure with the high-order mode has been a considerable interest because of its potential to increase power handling capacity (PHC). To expand the PHC of V-band transit-time oscillator and excite higher mode TM03, a dual annular multiple-beam cathode has been proposed. In the geometric structure of the dual annular multiple-beam diode, cathode rods around two concentric circles are uniformly placed on cathode base, and each circle has several graphite rods. Because of space charge shielding effect and fluctuation of electron beam, explosive emission current of inner and outer cathode circles is difficult to be balanced, and the electron beam transmission rate is not very high. To solve those two problems, the relative length (ΔL) and the relative radius (Δr) between the inner and outer cathode circles are optimized to obtain balanced currents of inner and outer beams and a good transmission rate. In this paper, the preliminary study of a dual annular multiple-beam cathode is carried out by optimizing the cathode structure. When ΔL and Δr are equal to 2.5 and 4 mm, respectively, the dual annular multiple-beams cathode can provide 2.71 kA uniform intense relativistic electron beams under 421 kV, and the magnetic field is 1.2T. As a simulation result, explosively emitted and the 95.2% of total beam current transmission rate can be reached.

Bimolecular photoinduced symmetry-breaking charge separation of perylene in solution

Photoinduced symmetry-breaking charge separation (SB-CS) results in the generation of charge carriers through electron transfer between two identical molecules, after photoexcitation of one of them. It is usually studied in systems where the two reacting moieties are covalently linked. Examples of photoinduced bimolecular SB-CS with organic molecules yielding free ions remain scarce due to solubility or aggregation issues at the high concentrations needed to study this diffusion-assisted process. Here we investigate the excited-state dynamics of perylene (Pe) at high concentrations in solvents of varying polarity. Transient absorption spectroscopy on the subnanosecond to microsecond timescales reveal that self-quenching of Pe in the lowest singlet excited state leads to excimer formation in all solvents used. Additionally, bimolecular SB-CS, resulting in the generation of free ions, occurs concurrently to excimer formation in polar media, with a relative efficiency that increases with the polarity of the solvent. Moreover, we show that SB-CS is most efficient in room-temperature ionic liquids due to a charge-shielding effect leading to a larger escape of ions and due to the high viscosity that disfavours excimer formation.Graphical abstract

Potassium-Based Dual-Ion Batteries Operating at -60 °C Enabled By Co-Intercalation Anode Chemistry.

Battery performance at subzero is restricted by sluggish interfacial kinetics. To resolve this issue, potassium-based dual-ion batteries (K-DIBs) based on the polytriphenylamine (PTPAn) cathode with anion storage chemistry and the hydrogen titanate (HTO) anode with K+ /solvent co-intercalation mechanism are constructed. Both the PTPAn cathode and the HTO anode do not undergo the desolvation process, which can effectively accelerate the interfacial kinetics at subzero. As revealed by theoretical calculations and experimental analysis, the strong K+ /solvent binding energy in the dilute electrolyte, the charge shielding effect of the crystal water, and the uniform SEI layer with high content of the flexible organic species synergically promote HTO to undergo K+ /solvent co-intercalation behavior. The special co-intercalation mechanism and anion storage chemistry enable HTO||PTPAn K-DIBs with superior rate performance and cycle durability, maintaining a capacity retention of 94.1% after 6000 cycles at -40 °C and 91% after 1000 cycles at -60 °C. These results provide a step forward for achieving high-performance energy storage devices at low temperatures.

Water-in-water Pickering emulsion: A fascinating microculture apparatus for embedding and cultivation of Lactobacillus helveticus

Currently, the cultivation of lactic acid bacteria is mainly carried out by improving the fermentation process and culture conditions, which was difficult to ensure the survival quantity and culture efficiency. The primary purpose of this work was to construct water-in-water (W/W) Pickering emulsion as a microculture for probiotics. The W/W Pickering emulsion consisting of maltodextrin (MD) and hydroxypropylmethylcellulose (HPMC) was constructed by using microcrystal celluloses (MCC) as the Pickering stabilizers. The effects of MCC concentration, NaCl concentration, MRS broth concentration, and pH value on the formation and stability of W/W Pickering emulsion have been investigated. The stability of W/W Pickering emulsions was driven by the electrostatic repulsion provided by the MCC. The stability of the emulsion was reduced by increasing NaCl and MRS broth concentrations, primarily because their charge shielding effect weakened the electrostatic repulsion between the MCC particles. The W/W Pickering emulsion had higher stability in a weakly acidic environment. The results from another trial revealed that Lactobacillus helveticus CICC 22,536 had little influence on the stability of the W/W Pickering emulsion when it was encapsulated in the emulsion. Moreover, Lactobacillus helveticus was able to be cultured in the emulsion, and the numbers of Lactobacillus helveticus after being cultured for 16 h were increased to 1.1 × 109 CFU/mL. These findings indicated that the W/W Pickering emulsion provided a new approach and an attractive platform for the cultivation of probiotic bacteria.

Regulated the Swelling Properties of Poly(acrylamide‐co‐acrylic acid) Hydrogel by Changing the Charge Density

AbstractHydrogels can swell without dissolving in water and are widely used in water treatment and biomedicine. The swelling rate of hydrogels is closely related to the network structure and charge density of hydrogels, but there are few detailed studies in this area. In this work, poly(acrylamide‐co‐acrylic acid) anionic hydrogel with acrylic acid (AA) as anionic monomer is prepared. By changing the monomer ratio, or changing the pH value of hydrogels, the internal charge density can be adjusted, and then the swelling rate can be controlled. With the increase of AA monomer content, the content of carboxylate in hydrogel increases, resulting in higher charge density. A high charge density corresponds to a high swelling rate. On the other hand, the swelling rate is closely related to the pH value, which is because the concentration of proton affects the ionization of carboxylic acid, which leads to the change of charge density. It is worth noting when pH increases to 10, the charge shielding effect of the counter‐ion (Na+) gradually increases, thus limiting the swelling of the hydrogel and reducing the swelling rate. This work has reference value for the practical application of hydrogels.

Shielding effect enables fast ion transfer through nanoporous membrane for highly energy-efficient electrodialysis

A key to sustainable management of saline organic-rich wastewaters is to precisely fractionate organic components and inorganic salts (NaCl) as individual resources. Conventional nanofiltration and electrodialysis processes suffer from membrane fouling and compromise the fractionation efficacy. Here we develop a thin-film composite nanoporous membrane via co-deposition of dopamine and polyethyleneimine as a highly anion-conducting membrane. Experimental results and molecular dynamics simulations show that co-deposition of dopamine and polyethyleneimine effectively tailors the membrane surface properties, intensifying the charge shielding effect and enabling fast anion transfer for highly efficient electrodialysis. The resulting nanoporous membrane exhibits unprecedented electrodialytic fractionation of organics and NaCl with negligible membrane fouling, dramatically outperforming state-of-the-art anion exchange membranes. Our study sheds light on facile design of high-performance anion-conducting membranes and associated new mass transport mechanisms in electrodialytic separation, paving the way for sustainable management of complex waste streams.

A rapid removal of Phaeocystis globosa from seawater by peroxymonosulfate enhanced cellulose nanocrystals coagulation

Cellulose nanocrystals (CNC) are recognized as promising bio-based flocculants for controlling harmful algal blooms (HABs). Due to the charge shielding effect in seawater and the strong mobility of algae cells, CNC can’t effectively remove Phaeocystis globosa from seawater. To solve this problem, peroxymonosulfate (PMS) was used to enhance the coagulation of CNC for rapidly removal of P. globosa. The results showed that 91.7% of Chl-a, 95.2% of OD680, and 97.2% of turbidity of P. globosa were reduced within 3 h with the use of 200 mg L−1 of CNC and 20 mg L−1 of PMS. The removal of P. globosa was consisted of inactivation and flocculation. Notably, electron paramagnetic resonance (EPR) spectrums and quenching experiments revealed that the inactivation of P. globosa was dominated by PMS oxidation and 1O2. Subsequently, CNC entrained inactivated algal cells to settle to the bottom to achieve efficient removal of P. globosa. The content of total organic carbon (TOC) and chemical oxygen demand (COD) decreased significantly, indicating that a low emission risk of algal cell effluent was produced in the CNC-PMS system. In view of the excellent performance on P. globosa removal, we believe that the CNC-PMS system has great potential for HABs treatments.

Liquid–Solid Triboelectric Probes for Real‐Time Monitoring of Sucrose Fluid Status

AbstractTriboelectric probes have rapidly developed as an efficient tool for understanding contact electrification at liquid–solid interfaces. However, the liquid–solid electrification process is susceptible to interference from chemical components in mixed solutions, severely limiting the potential applications of triboelectric probes in various liquid environments. This study for the first time reports a triboelectric probe capable of sucrose solution concentration sensing, finding that the dissolution of sucrose destroys the hydrogen bond network between water molecules and forms sucrose–water hydrogen bonds, which alters the fluid mechanics characteristics of the solution and enhances its conductivity, thereby reducing the droplet size and causing an ion charge shielding effect that significantly affects the electron transfer in liquid–solid contact electrification. Owing to the feedback of the triboelectric probe on the sucrose concentration gradient‐type sensing electrical signals, efficient sensing of sucrose solution was achieved (sensitivity of −0.0038%−1, response time of 90 ms). The triboelectric probe is also used as a wireless smart terminal to enable real‐time detection of sucrose solution. This work contributes to the understanding of the structure–function relationship between micro hydrogen bonding and macro performance, and provides a promising solution for building sustainable intelligent sensors.

Effect of Metal Ions and Suspended Particles on Streamer Propagation

Metal contamination in insulating oil is one of the main threats to the safe and reliable operation of oil-immersed equipment such as on-load tap changers. The mechanism analysis of metal ions’ influence on the discharge process of insulating oil is rarely involved in previous studies. Herein, the generation mechanism of metal ions and suspended particles is summarized first for subsequent modeling. Numerical models are constructed to simulate the streamer propagation in oil, considering the effect of two forms of metal contaminant. The dissociation source term of ionic compounds is introduced into the charge continuity equation to elucidate the impact of metal ions on streamer propagation. The results reveal that adding metal ions increases the overall speed of the streamer and decreases the maximum field intensity at the head of the steamer compared to pure oil conditions. Excessive ion concentration hinders the streamer’s development by creating the space charge shielding effect. Charge accumulation on the surface of suspended metal particles is the leading cause for the branching or turning of the streamer channel. The size, quantity of the metal particles, and the landing location will significantly affect the streamer propagation characteristics, e.g., the landing location on the surface of the metal particle will determine whether the subsequent branching streamer head can further develop. The results contribute to a better understanding of the influence of ionic and particulate metal contaminants on the microscopic discharge process in insulating oil.

Chitosan particles modulate the properties of cellulose nanocrystals through interparticle interactions: Effect of concentration

The physical and chemical properties of cellulose nanocrystals (CNC) were regulated by physical crosslinking with chitosan particles (CSp). At a fixed concentration (0.5 wt%) of CNC, varying CSp concentration (0.02–0.5 wt%) influenced the morphologies and chemical properties of the obtained complex particles (CNC-CSp). The results of Fourier transform infrared spectroscopy (FTIR) and zeta potential confirmed the electrostatic and hydrogen bonding interactions between CSp and CNC. At a low CSp concentration (0.02–0.05 wt%), the charge shielding effect induced the formation of particle aggregation networks, thus showing increased viscosity, turbidity and size (153.4–2605.7 nm). At a higher CSp concentration (0.1–0.5 wt%), the hydrogen bonding interaction promoted CSp adsorption onto the surface of CNC, thus facilitating the dispersion of CNC-CSp due to electrostatic repulsion caused by surface-adsorbed CSp. In addition, CSp improved the thermal stability, hydrophobicity (41.87–60.02°) and rheological properties of CNC. Compared with CNC, CNC-CSp displayed a better emulsifying ability and emulsion stability, in which CSp could play a dual role (i.e., charge regulator and stabilizer). This study suggests that introducing CSp can improve the properties and application potentials of CNC as food colloids.

Water-in-water Pickering emulsion stabilized by cellulose nanocrystals as space-confined encapsulating systems: From establishment to stability

The development of new water-in-water (W/W) emulsion systems and the improvement of the long-term stability of emulsions could create opportunities for studying interfacial bionic systems and microencapsulation applications. In this study, the new W/W emulsion systems were constructed from hydroxypropyl methylcellulose (HPMC) and maltodextrin (MD). The effects of cellulose nanocrystals (CNC) and environmental factors (ionic strength and pH) on the stability of W/W Pickering emulsions were investigated. The stabilizing effect was observed at contents of CNC as low as 0.025 wt%. The W/W Pickering emulsion showed no phase separation within 30 days when the CNC concentration was above 0.025 wt%, indicating that the emulsions were stable during the observation period. The stability of W/W Pickering emulsions was driven by the electrostatic repulsion provided by the CNC adsorbed at the droplet interface, which decreased with increasing NaCl concentration. This was attributed to the charge-shielding effect of NaCl weakening the electrostatic repulsion of the CNCs at the emulsion droplet interface. Lactobacillus helveticus cells were encapsulated in the W/W Pickering emulsion. These results revealed that the developed W/W Pickering emulsions have potential applications in protecting the activity of probiotic bacteria and investigating the behavior of cells in restricted spaces.

Water-Stabilized Vanadyl Phosphate Monohydrate Ultrathin Nanosheets toward High Voltage Al-Ion Batteries.

Al ion batteries (AIBs) are attracting considerable attention owing to high volumetric capacity, low cost, and high safety. However, the strong electrostatic interaction between Al3+ and host lattice leads to discontented cycling life and inferior rate capability. Herein, a new strategy of employing water molecules contained VOPO4 ·H2 O to boost Al3+ migration via the charge shielding effect of water is reported. It is revealed that VOPO4 ·H2 O with water lubrication effect and smaller steric hindrance owns high capacity and fast Al3+ diffusion, while the loss of unstable water upon cycling leads to a rapid performance degradation. To address this problem, ultrathin VOPO4 ·H2 O@MXene nanosheets are fabricated via the formed TiOV bond between VOPO4 ·H2 O and MXene. The MXene aided exfoliation results in enhanced VOwater bond strength between H2 O and VOPO4 that endows the obtained composite with strong water holding ability, contributing to the extraordinary cycling stability. Consequently, the VOPO4 ·H2 O@MXene delivers a high discharge potential of 1.8V and maintains discharge capacities of 410 and 374.8 mAh g-1 after 420 and 2000 cycles at the current densities of 0.5 and 1.0 A g-1 , respectively. This work provides a new understanding of water-contained AIBs cathodes and vital guidance for developing high-performance AIBs.

The effect of high‐pressure homogenization on rabbit myofibrillar proteins in dilute sodium chloride solutions: weak ionic shielding promotes the depolymerisation

SummaryThe study attempts to determine the effect of ionic strength on the structure and solubility of rabbit myofibrillar proteins (MPs) and improves MPs dissolution in low salt medium. There was a significant effect of ionic strength on the structure and dissolution characteristics of MPs in low salt medium range (0–200 mM NaCl), increased ionic strength led to MPs aggregation and reduced solubility (P &lt; 0.05), while decreased ionic strength weakened charge shielding effect, resulted in stronger electrostatic repulsion and weaker hydrophobic interaction between molecules, thus promoting MPs structural swell and separation between filaments. The modification effect of HPH on the MPs also depended on the ionic strength. Upon HPH, due to the difference in charge shielding effect and hydrophobic interactions, there was a progressive improvement in MPs solubility (from 23.51% to 85.25%) and dispersion stability at 0 mM salt medium (I = 0.0217) while limited increase in solubility at medium higher than 13 mM (from 4.39% to 7.20% at 20 mM). Decreasing ionic strength promoted the depolymerisation of HPH on MPs, inhibited the myosin assembly into filaments after HPH. The modification of ionic strength on the surface charge and hydrophobicity of MPs were further amplified, also contributed to the improved solubility and dispersion stability.

Hydrovoltaic Nanogenerators for Self-Powered Sweat Electrolyte Analysis.

Human sweat comprises various electrolytes that are health status indicators. Conventional potentiometric electrolyte sensors require an electrical power source, which is expensive, bulky, and requires a complex architecture. Herein, this work demonstrates an electric nanogenerator fabricated using silicon nanowire (SiNW) arrays comprising modified carbon nanoparticles. The SiNWarrays platform is demonstrated as an effective self-powered sensor for sweat electrolyte analysis. It has been shown that an evaporation-induced water flow in nanochannels can yield an open-circuit voltage (Voc ) of 0.45V and a short-circuit current of 10.2µA at room temperature as a result of overlapped electric double layers. The electrolyte in the water flow results in a Voc decrease due to the charge shielding effect. The Voc is inversely proportional to the electrolyte concentration. The fabricated hydrovoltaic device shows the capability for sensing electrolytes in human sweat, which is useful in evaluating the hydration status of volunteers following intense physical exercise. The device depicts a novel response mechanism compared to conventional electrochemical sensors. Furthermore, the hydrovoltaic device shows a maximum output power of 1.42 µW, and as such has been successfully shown to drive various electronic devices including light-emitting diodes, a calculator, and an electronic timer.

Effects of soil grain size and solution chemistry on the transport of biochar nanoparticles

Biochar nanoparticles (BC-NP) have attracted significant attention because of their unique environmental behavior, some of which could potentially limit large-scale field application of biochar. Accurate prediction of the fate and transportability of BC-NP in soil matrix is the key to evaluating their environmental influence. This study investigated the effects of soil grain size and environmentally relevant solution chemistry, such as ionic strength (cation concentration, 0.1 mM–50 mM; cation type, Na+, and Ca2+), and humic acid (HA; 0–10 mg/L), on the transport behavior of BC-NP via systematic column experiments. The transportability of BC-NP in the soil-packed column decreased with decreasing soil grain size and was inversely proportional to soil clay content. At low cation concentrations (0.1–1.0 mM), a considerable proportion of BC-NP (15.95%–67.17%) penetrated the soil columns. Compared with Na+, Ca2+ inhibited the transportability of BC-NP in the soil through a charge shielding effect. With increasing HA concentration, the transportability of BC-NP increased, likely due to an enhanced repulsion force between BC-NP and soil particles. However, at a high HA concentration (10 mg/L), Ca2+ bridging reduced the transportability of BC-NP in the soil. Breakthrough curves of BC-NP were explained by the two-site kinetic retention model. The antagonistic effects of ionic strength and HA indicated that the transport behavior of BC-NP in the soil was governed by competitive effects of some environmental factors, including soil grain size, environmental solution chemistry, and natural organic matter content.