High Hydrostatic Pressure Exacerbates Bladder Fibrosis through Activating Piezo1.

OBJECTIVE: Bladder outlet obstruction (BOO) results in significant fibrosis in the chronic stage and elevated bladder pressure. Piezo1 is a type of mechanosensitive (MS) channel that directly responds to mechanical stimuli. To identify new targets for intervention in the treatment of BOO-induced fibrosis, this study investigated the impact of high hydrostatic pressure (HHP) on Piezo1 activity and the progression of bladder fibrosis. METHODS: Immunofluorescence staining was conducted to assess the protein abundance of Piezo1 in fibroblasts from obstructed rat bladders. Bladder fibroblasts were cultured under normal atmospheric conditions (0 cmH2O) or exposed to HHP (50 cmH2O or 100 cmH2O). Agonists or inhibitors of Piezo1, YAP1, and ROCK1 were used to determine the underlying mechanism. RESULTS: The Piezo1 protein levels in fibroblasts from the obstructed bladder exhibited an elevation compared to the control group. HHP significantly promoted the expression of various pro-fibrotic factors and induced proliferation of fibroblasts. Additionally, the protein expression levels of Piezo1, YAP1, ROCK1 were elevated, and calcium influx was increased as the pressure increased. These effects were attenuated by the Piezo1 inhibitor Dooku1. The Piezo1 activator Yoda1 induced the expression of pro-fibrotic factors and the proliferation of fibroblasts, and elevated the protein levels of YAP1 and ROCK1 under normal atmospheric conditions in vitro. However, these effects could be partially inhibited by YAP1 or ROCK inhibitors. CONCLUSION: The study suggests that HHP may exacerbate bladder fibrosis through activating Piezo1.

Carbon coated Na3+xV2-xCux(PO4)3@C cathode for high-performance sodium ion batteries.

Na3V2(PO4)3 is considered as one of the most promising cathodes for sodium ion batteries owing to its fast Na+ diffusion, good structural stability and high working potential. However, its practical application is limited by its low intrinsic electronic conductivity. Herein, a carbon coated Cu2+-doped Na3V2(PO4)3 cathode was prepared. The carbon coating not only improve its apparent conductivity, but also inhibit crystal growth and prevent agglomeration of particles. Moreover, Cu2+ doping contributes to an enhanced intrinsic conductivity and decreased Na+ diffusion energy barrier, remarkably boosting its charge transfer kinetics. Based on the structure characterizations, electrochemical performances tests, charge transfer kinetics analyses and theoretical calculations, it's proved that such an elaborate design ensures the excellent rate performances (116.9 mA h g-1 at 0.1C; 92.6 mA h g-1 at 10C) and distinguished cycling lifespan (95.8 % retention after 300 cycles at 1C; 84.8 % retention after 3300 cycles at 10C). Besides, a two-phase reaction mechanism is also confirmed via in-situ XRD. This research is expected to promote the development of Na3V2(PO4)3-based sodium ion batteries with high energy/power density and excellent cycling lifespan.

Pinpointing the Cl Coordination Effect on Mn-N3-Cl Moiety Toward Boosting Reaction Kinetics and Suppressing Shuttle Effect in Li-S Batteries.

Single atom catalysts (SACs) are highly favored in Li-S batteries due to their excellent performance in promoting the conversion of lithium polysulfides (LiPSs) and inhibiting their shuttling. However, the intricate and interrelated microstructures pose a challenge in deciphering the correlation between the chemical environment surrounding the active site and its catalytic activity. Here, a novel SAC featuring a distinctive Mn-N3-Cl moiety anchored on B, N co-doped carbon nanotubes (MnN3Cl@BNC) is synthesized. Subsequently, the selective removal of the Cl ligands while inheriting other microstructures is performed to elucidate the effect of Cl coordination on catalytic activity. The Cl coordination effectively enhances the electron cloud density of the Mn-N3-Cl moiety, reducing the band gap and increasing the adsorption capacity and redox kinetics of LiPSs. As a modified separator for Li-S batteries, MnN3Cl@BNC exhibits high capacities of 1384.1 and 743 mAh g-1 at 0.1 and 3C, with a decay rate of only 0.06% per cycle over 700 cycles at 1 C, which is much better than that of MnN3OH@BNC. This study reveals that Cl coordination positively contributes to improving the catalytic activity of the Mn-N3-Cl moiety, providing a fresh perspective for the design of high-performance SACs.

A crosslinked network polypyrrole coated cobalt doped Fe2O3@carbon cloth flexible anode material for quasi-solid asymmetric supercapacitors.

Iron(III) oxide (Fe2O3) exhibits a substantial theoretical specific capacitance and a broad operational voltage window, making it a prospective anode material. The crystal structure of Fe2O3 was altered through cobalt doping, and its electronic conductivity was improved by supporting it with carbon cloth (Co-Fe2O3@CC). Subsequently, a crosslinked network of polypyrrole (PPy) was synthesized onto Co-Fe2O3@CC via an ice-water bath, resulting in the formation of PPy/Co-Fe2O3@CC. This PPy nano-crosslinked network not only established three-dimensional electron transport pathways on the Fe2O3 surface but also amplified the composite material's specific surface area to 45.229 m2 g-1, thereby promoting its electrochemical performance. At a current density of 2 mA cm-2, PPy/Co-Fe2O3@CC displayed an area specific capacitance of 704 mF cm-2, a value 2.2 times higher than that of Co-Fe2O3@CC. The assembled PPy/Co-Fe2O3@CC//Ni-MnO2@CC asymmetric supercapacitor demonstrated an energy density of 1.41 mW h cm-3 at a power density of 54 mW cm-3, making the synthesized electrode material a promising candidate for flexible supercapacitors.

Edge Coordination of Ni Single Atoms on Hard Carbon Promotes the Potassium Storage and Reversibility.

Hard carbon is the most promising anode for potassium-ion batteries (PIBs) due to its low cost and abundance, but its limited storage capacity remains a major challenge. Herein, edge coordination of metal single atoms is proved to be an effective strategy for promoting potassium storage in hard carbon for the first time, taking B, N co-doped hard carbon nanotubes anchored by edge Ni-N4 -B atomic sites (Ni@BNHC) as an example. It is revealed that edge Ni-N4 -B can provide active sites for interlayer adsorption of K+ and that Ni atoms can facilitate the reversibility of K+ storage on N and B atoms. Furthermore, an unprecedentedly reversible K+ storage capacity of 694 mAh g-1 at 0.05 A g-1 is realized by introducing commercial carbon nanotubes. This work provides a new perspective for the application of single-atom engineering and the design of high-performance carbon anodes for PIBs.

PPy-Coated Mo3S4/CoMo2S4 Nanotube-like Heterostructure for High-Performance Lithium Storage.

Heterostructured materials show great potential to enhance the specific capacity, rate performance and cycling lifespan of lithium-ion batteries owing to their unique interfaces, robust architectures, and synergistic effects. Herein, a polypyrrole (PPy)-coated nanotube-like Mo3S4/CoMo2S4 heterostructure is prepared by the hydrothermal and subsequent in situ polymerization methods. The well-designed nanotube-like structure is beneficial to relieve the serious volume changes and facilitate the infiltration of electrolytes during the charge/discharge process. The Mo3S4/CoMo2S4 heterostructure could effectively enhance the electrical conductivity and Li+ transport kinetics owing to the refined energy band structure and the internal electric field at the heterostructure interface. Moreover, the conductive PPy-coated layer could inhibit the obvious volume expansion like a firm armor and further avoid the pulverization of the active material and aggregation of generated products. Benefiting from the synergistic effects of the well-designed heterostructure and PPy-coated nanotube-like architecture, the prepared Mo3S4/CoMo2S4 heterostructure delivers high reversible capacity (1251.3 mAh g-1 at 300 mA g-1), superior rate performance (340.3 mAh g-1 at 5.0 A g-1) and excellent cycling lifespan (744.1 mAh g-1 after 600 cycles at a current density of 2.0 A g-1). Such a design concept provides a promising strategy towards heterostructure materials to enhance their lithium storage performances and boost their practical applications.

Heteroatom-doped carbon materials derived from covalent triazine framework@MOFs for the oxygen reduction reaction.

Heteroatom-doped carbon catalysts are ideal to promote the kinetic process of the oxygen reduction reaction (ORR) due to their high energy conversion efficiency. Here, we report a series of catalysts obtained from CTF@MOF-x (x = 15, 24, 33 wt%) by pyrolysis methods, in which CTFs served as C and N sources, and Ni-MOFs served as Ni and S sources. A CTF was supported on the surface of a MOF to prevent the collapse and aggregation of the CTF during pyrolysis. The electrocatalyst exhibited enhanced ORR activity in an alkaline medium, with Eonset and E1/2 values being comparable to those of 20 wt% commercial Pt/C, and showed excellent durability and methanol resistance. This work provides new opportunities for CTF-derived carbon-based electrocatalysts to achieve high ORR performance.

Cobalt-Nickel Phosphate Composites for the All-Phosphate Asymmetric Supercapacitor and Oxygen Evolution Reaction.

Recently, design of cost-effective multifunctional electromaterials for supercapacitors and oxygen evolution reaction (OER) and enhancing their functionalities have become an emphasis in energy storage and conversion. Herein, a series of cheap and functional phosphate composites with different ratios of cobalt and nickel are synthesized using a simple polyalcohol refluxing method, and their excellent capacity and OER properties are systematically studied. Notably, owing to the different major role of Co and Ni elements in the phosphate composites for capacity and OER, the optimal electroconductibility, structural adjustment, electrochemical active sites, and activities for capacity and OER are obtained from the composites with the different ratios of Co/Ni. In addition, using high-capacity BiPO4 (BPO) as the negative electrodes, the new type of all-phosphate asymmetric supercapacitor (CNPO-40//BPO) shows a high energy density and reaches 36.84 W h kg-1 at a power density of 254.52 W kg-1. Its cyclic stability is also more excellent than that of the CNPO-40//AC device using commercial activated carbon as the negative electrodes. This study is beneficial to the more in-depth research on efficient dual-function electromaterials in capacity and OER and provides a high-efficient way to improve the practicality of asymmetric supercapacitors using the high-capacity Bi-based electromaterials as the negative electrodes.

Promising High-Performance Supercapacitor Electrode Materials from MnO2 Nanosheets@Bamboo Leaf Carbon.

MnO2@bamboo leaf (BL) carbon composites have been prepared by a hydrothermal method, wherein, the BL porous carbon structure was based on BLs. The MnO2@BL composites were characterized by SEM, TEM, XRD, Raman, XPS, and TGA. The electrochemical properties of the composites were investigated in a three-electrode system using 1 M Na2SO4 aqueous solution as an asymmetric supercapacitor electrolyte. Electrochemical measurements showed that the MnO2@BL composites can be applied in asymmetric supercapacitors and exhibited a good cycling stability with a capacitance retention ratio of 85.3% after 5000 cycles (at 0.5 A g-1). The MnO2@BL composites were promising materials for application in supercapacitors.

Metal Cation-Assisted Synthesis of Amorphous B, N Co-Doped Carbon Nanotubes for Superior Sodium Storage.

Nearly inexhaustible sodium sources on earth make sodium ion batteries (SIBs) the best candidate for large-scale energy storage. However, the main obstacles faced by SIBs are the low rate performance and poor cycle stability caused by the large size of Na+ ions. Herein, a universal strategy for synthesizing amorphous metals encapsulated into amorphous B, N co-doped carbon (a-M@a-BCN; M = Co, Ni, Mn) nanotubes by metal cation-assisted carbonization is explored. The methodology allows tailoring the structures (e.g., length, wall thickness, and metals doping) of a-M@a-BCN nannotubes at the molecular level. Furthermore, the amorphous metal sulfide encapsulated into a-BCN (a-MSx @a-BCN; MSx : CoS, Ni3 S2 , MnS) nanotubes are obtained by one-step sulfidation process. The a-M@a-BCN and a-MSx @a-BCN possess the larger interlayer spacing (0.40 nm) amorphous carbon nanotube rich in heteroatoms active sites, making them exhibit excellent Na+ ions diffusion kinetics and capacitive storage behavior. As SIBs anodes, they show high capacity, excellent rate performance, and long cycle stability.

Anion-regulated selective growth ultrafine copper templates in carbon nanosheets network toward highly efficient gas capture.

Controlling micropore size is the core for synthesizing highly efficient adsorbents for gas adsorption and separation engineering. Porous carbon prepared by traditional methods usually lacks competitiveness due to the random micropore size or complex process. Herein, we report a novel strategy for synthesizing nitrogen doped carbons nanosheets (Cu-NDPCs) with unimodal ultra-micropore based on the metal-organic covalency and the anion regulated in situ copper template. The thickness of single Cu-NDPCs is about 4.2 nm. In the presence of Cl-, the porosity of Cu-NDPCs can be tuned at 4.1-4.8 Å by adjusting the pyrolysis temperature. Among them, Cu-NDPC-800 has unique carbon nanosheets networks structure, ultrahigh surface area (2150 m2 g-1), large micropore volume (0.92 cm3 g-1) and abundant surface N doping (5.33%). As an adsorbent, it exhibits superhigh C2H2, C2H6, C3H8 and CO2 uptakes (6.7, 7.0, 11.4 and 4.4 mmol g-1) and corresponding x/CH4 or CO2/N2 IAST selectivities (12.9, 17.8, 468.6, 4.3 and 17.1) under ambient conditions. Meanwhile, the Cu-NDPC-800 possesses excellent cyclic stability.

Fabrication of Pd3@Beta for catalytic combustion of VOCs by efficient Pd3 cluster and seed-directed hydrothermal syntheses.

Subnanometric Pd clusters confined within zeolite crystals was fabricated using zeolitic seeds with premade [Pd3Cl(PPh2)2(PPh3)3]+ clusters under hydrothermal conditions. Characterization of the Pd3@Beta catalysts indicate that the Pd clusters confined in the channels of Beta zeolite exhibit better dispersion and stronger interaction with the zeolite support, leading to stabilized Pd species after heat treatment by high temperature. In the model reaction of toluene combustion, the Pd3@Beta outperforms both zeolite-supported Pd nanoparticles prepared by conventional impregnation of Pd3/Beta and Pd/Beta. Temperatures for achieving toluene conversion of 5%, 50% and 98% of Pd3@Beta are 136, 169 and 187 °C at SV = 60 000 mL g-1 h-1, respectively. Pd3@Beta could also maintain the catalytic reaction for more than 100 h at 230 °C without losing its activity, an important issue for practical applications. The metal-containing zeolitic seed directed synthesis of metal clusters inside zeolites endows the catalysts with excellent catalytic activity and high metal stability, thus providing potential avenues for the development of metal-encapsulated catalysts for VOCs removal.

Patchy Templated Synthesis of Macroporous Colloidal Hollow Spheres and Their Application as Catalytic Microreactors.

Porous colloidal hollow spheres have been applied to diversified fields over the past few decades. However, developing simple and efficient methods to prepare such porous hollow spheres with macro pores remains a challenge. To address this problem, we present a patchy templated synthesis route, which can be used to prepare such colloidal hollow spheres that have macro pores through the shells. This was achieved by using patchy poly(styrene-co-sodium styrenesulfonate) spheres as the template and poly(allylamine hydrochloride) as binding molecules. SiO2 can site-selectively only grow on one kind of patch, resulting in the formation of porous hollow spheres. The pore sizes can be tuned from ∼50 to 400 nm. The resulting porous hollow spheres have a Janus character so that Au nanoparticles can only be attached to the interior surfaces in situ, which can be used as catalytic microreactors and show the catalytic performance of pore size dependence.

High Specific Capacitance Electrode Material for Supercapacitors Based on Resin-Derived Nitrogen-Doped Porous Carbons.

Carbon-based materials, as electrodes for supercapacitors, have attracted tremendous attention. Therefore, nitrogen-doped porous carbons (NPCs) were prepared through a facile carbonization/activation strategy by treating different mass ratios of melamine-urea-formaldehyde resin and KOH. It is clearly demonstrated that because of the introduction of KOH, the resulting NPCs were shown to have increased specific surface area and a rich pore structure, and the best sample possessed a large specific surface area of 2248 m2 g-1 and high N content, which contributed to the good electrochemical performance for supercapacitors. Accordingly, a three-electrode system assembles NPCs as an electrode using aqueous KOH solution; the specific capacitance was 341 F g-1 under the current density of 1 A g-1 and retained a specific capacitance of almost 92% after 5000 cycles. The maximum energy output for a symmetrical solid-state supercapacitor with NPCs as the electrode material was 9.60 W h kg-1 at 1 A g-1. NPCs have promising applications on high-performance supercapacitors and other energy-storage devices.

Role of surface functionalities of nanoplastics on their transport in seawater-saturated sea sand.

The transport and retention of nanoplastics (NP, 200 nm nanopolystyrene) functionalized with surface carboxyl (NPC), sulfonic (NPS), low-density amino (negatively charged, NPA-), and high-density amino (positively charged, NPA+) groups in seawater-saturated sand with/without humic acid were examined to explore the role of NP surface functionalities. The mass percentages of NP recovered from the effluent (Meff) with a salinity of 35 practical salinity units (PSU) were ranked as follows: NPC (19.69%) > NPS (16.37%) > NPA+ (13.33%) > NPA- (9.78%). The homoaggregation of NPS and NPA- was observed in seawater. The transport of NPA- exhibited a ripening phenomenon (i.e., a decrease in the transport rate with time) due to the high attraction of NP with previously deposited NP, whereas monodispersed NPA+ presented a low Meff value because of the electrostatic attraction between NPA+ and negatively charged sand. Retention experiments showed that the majority of NPC, NPS and NPA+ accumulated in a monolayer on the sand surface, whereas NPA- accumulated in multiple layers. Suwannee River humic acid (SRHA) could remarkably improve the transportability of NPC, NPS, and NPA- by increasing steric repulsion. The strong attraction between NPA+ and the deposited NPA+ in the presence of SRHA triggered the weak ripening phenomenon. As seawater salinity decreased from 35 PSU to 3.5 PSU, the increase in electrostatic repulsion of NP-NP and NP-sand enhanced the transport of NPC, NPS, and NPA-, and the ripening of NPA- breakthrough curves disappeared. In deionized water, NPC, NPS, and NPA- achieved complete column breakthrough because the electrostatic repulsion between NP and sand intensified. However, the Meff values of NPA+ in 3.5 PSU seawater and deionized water presented limited increments of 15.49% and 23.67%, respectively. These results indicated that the fate of NP in sandy marine environments were strongly affected by NP surface functionalities, seawater salinity, and coexisting SRHA.

Removal of Cr(III) from aqueous solution by silica-gel/PAMAM dendrimer hybrid materials.

Water pollution caused by Cr(III) is a serious environmental problem which bring adverse effect to environmental protection and public safety. Efficient removal of Cr(III) from aqueous solution is important for the remediation of Cr(III) pollution. Herein, a series of silica-gel/polyamidoamine (PAMAM) dendrimer hybrid materials (SG-G0~SG-G4.0) were used for the removal of Cr(III) from aqueous solution. The factors that affect the adsorption were extensively studied and the adsorption mechanism was demonstrated based on the experimental results and density functional theory (DFT) calculation. Result demonstrates the adsorption capacity of ester-terminated silica-gel/PAMAM dendrimers follow the order of SG-G2.5 > SG-G3.5 > SG-G1.5 > SG-G0.5, while that of amino-terminated ones decrease in the order of SG-G2.0 > SG-G4.0 > SG-G3.0 > SG-G1.0 > SG-G0. The highest adsorption is achieved at pH 4.0 for both ester- and amino-terminated materials. Adsorption kinetic indicates the adsorption equilibrium can be reached at about 240 and 180 min for amino- and ester-terminated hybrids, respectively. Adsorption kinetic can be well fitted by pseudo-second-order kinetic model with film diffusion process as the rate-limiting step. Adsorption isotherm follows Langmuir model with monolayer adsorption behavior. Fourier transform infrared spectra (FTIR) indicate the adsorption of Cr(III) by PAMAM dendrimer mainly involve the participation of N-H and C=O groups. DFT calculation demonstrates the uptake of Cr(III) by ester-terminated adsorbents mainly involves carbonyl oxygen and secondary amine nitrogen atoms to form tetra-coordinated chelate, while that of amino-terminated one tends to form hexa-coordinated chelates by carbonyl oxygen, primary and secondary amine nitrogen atoms.

Ultra-thin iron phosphate nanosheets for high efficient U(VI) adsorption.

In this study, the ultra-thin iron phosphate Fe7(PO4)6 nanosheets (FP1) with fine-controlled morphology, has been designed as a new two-dimensional (2D) material for uranium adsorption. Due to its unique high accessible 2D structure, atom-dispersed phosphate/iron anchor groups and high specific surface area (27.77 m2⋅g-1), FP1 shows an extreme-high U(VI) adsorption capacity (704.23 mg·g-1 at 298 K, pH = 5.0 ± 0.1), which is about 27 times of conventional 3D Fe7(PO4)6 (24.51 mg·g-1 -sample FP2) and higher than most 2D absorbent materials, showing a great value in the treatment of radioactive wastewater. According to the adsorption results, the sorption between U(VI) and FP1 is spontaneous and endothermic, and can be conformed to single molecular layer adsorption. Based on the analyses of FESEM, EDS, Mapping, FT-IR and XRD after adsorption, the possibile adsorption mechanism can be described as a Monolayer Surface Complexation and Stacking mode (MSCS-Mode). Additionally, the research not only provide a novel preparing method for 2D phosphate materials but also pave a new pathway to study other two-dimensional adsorption materials.

Cotransport of nanoplastics (NPs) with fullerene (C60) in saturated sand: Effect of NPs/C60 ratio and seawater salinity.

Nanoplastics (NPs) have been identified as newly emerging particulate contaminants. In marine environments, the interaction between NPs and other engineered nanoparticles remains unknown. This study investigated the cotransport of NPs with fullerene (C60) in seawater-saturated columns packed with natural sand as affected by the mass concentration ratio of NPs/C60 and the hydrochemical characteristics. In seawater with 35 practical salinity units (PSU), NPs could remarkably enhance C60 dispersion with a NPs/C60 ratio of 1. NPs behaved as a vehicle to facilitate C60 transport by decreasing colloidal ζ-potential and forming stable primary heteroaggregates. As the NPs/C60 ratio decreased to 1/3, NPs mobility was progressively restrained because of the formation of large secondary aggregates. When the ratio continuously decreased to 1/10, the stability and transport of colloids were governed by C60 rather than NPs. Under this condition, the transport trend of binary suspensions was similar to that of single C60 suspension, which was characterized by a ripening phenomenon. Seawater salinity is another key factor affecting the stability and associated transport of NPs and C60. In seawater with 3.5 PSU, NPs and C60 (1:1) in binary suspension exhibited colloidal dispersion, which was driven by a high-energy barrier. Thus, the profiles of the cotransport and retention of NPs/C60 resembled those of single NPs suspension. This work demonstrated that the cotransport of NPs/C60 strongly depended on their mass concentration ratios and seawater salinity.

Low-temperature organic phase change material microcapsules for asphalt pavement: preparation, characterisation and application.

Low-temperature phase change material (PCM) is a material that stores additional heat at elevated temperatures and releases energy when the temperature is below the limit. A way to solve the low-temperature disaster of asphalt pavement is desired to be developed. In this article, a two-component organic low-temperature PCM was encapsulated by melamine-urea-formaldehyde resin and finally reinforced with polypropylene. The reinforced PCM microcapsules were mixed with 70# SBS (Styrene-Butadiene-Styrene) modified asphalt in SMA-10 (Stone Matrix Asphalt-10) to form aggregates. The results showed that after adding 6.0% (w/w) reinforced PCM microcapsules, there was a significant delay compared to a blank sample with a maximum temperature difference of 1.8 °C when the temperature dropped to 0 °C, which proved that this method has a good potential in resisting low-temperature disasters on asphalt pavement and deserves further improvement.

Size-dependent transport and retention of micron-sized plastic spheres in natural sand saturated with seawater.

A series of one-dimensional column experiments were conducted to investigate the transport and retention of micron-sized plastic spheres (MPs) with diameters of 0.1-2.0 µm in seawater-saturated sand. In seawater with salinity of 35 PSU (practical salinity units), the mass percentages recovered from the effluent (Meff) of the larger MPs increased from 13.6% to 41.3%, as MP size decreased from 2.0 µm to 0.8 µm. This occurred because of the gradual reduction of physical straining effect of MPs in the pores between sands. The smaller MPs (0.6, 0.4, and 0.1 µm) showed the stronger inhibition of MPs mobility, with Meff values of 11.5%, 11.9%, and 9.8%, respectively. This was due to the lower energy barriers (from 108 kBT to 16 kBT) between the smaller MPs and the sand surface, when compared with the larger MPs (from 296 kBT to 161 kBT). In particular, the aggregation of MPs (0.6 or 0.4 µm) triggered a progressive decrease in MP concentration in the effluent. Retention experiments showed that the vertical migration distance of most MP colloids was 0-4 cm at the inlet of column. For 0.6 or 0.4 µm MPs, the particles were concentrated over a 0-2 cm vertical distance. Moreover, the salinity (35-3.5 PSU) did not affect the transport of the larger MPs (2.0-0.8 µm). However, as seawater salinity decreased from 35 PSU to 17.5 or 3.5 PSU, the aggregation of the smaller MPs (0.6-0.1 µm) was dramatically inhibited or completely prevented. Meanwhile, ripening of the sand surface by the MPs (0.6 and 0.4 µm) no longer occurred. By contrast, all MPs in deionized water (0 PSU) achieved complete column breakthroughs because of the strong repulsive energy barrier (from 218 kBT to 4192 kBT) between the MPs and the sand surface. Consequently, we find that the transport and retention of MPs in sandy marine environment strongly relies on both the MP size and the salinity levels.