Physical Barrier Effect Research Articles

Bio‐inspired graphene oxide/epoxy coating with ordered stacking for anticorrosion/wear protection of Mg alloy

AbstractThe random arrangement of graphene oxide (GO) nanosheets within the organic coating forms a conductive network, thereby accelerating galvanic corrosion and exacerbating metal deterioration. Inspired by ordered layered structure of natural nacre, this study has successfully fabricated a biomimetic GO/epoxy coating on Mg alloy to prevent corrosion and reduce wear. By polymerizing polyaniline (PANI) and dopamine (PDA) on the GO, GO/PANI/PDA sheets with good dispersibility and impermeability are obtained. Subsequently, the bio‐inspired coating (I‐GO/PANI/PDA‐WEP) with “nacre‐like” structure is prepared via alternately spraying GO/PANI/PDA layers with epoxy layers. The anisotropic electrical conductivity of the coating is derived from the ordered distribution of GO/PANI/PDA layers to the Mg substrate, which can conduct electricity more efficiently in‐plane while suppressing longitudinal electron transport. The enhanced physical barrier effect by the “nacre‐like” structure and the electron suppression effect can improve anticorrosion performance. The coating reduces the corrosion rate by 6.3 × 105 times in comparison to Mg alloy. Moreover, this coating shows excellent wear resistance, which protects Mg alloy from friction and wear with a reduction in wear rate by approximately 96%. This bio‐inspired approach offers a unique strategy for fabricating GO composite coatings with exceptional performance.Highlights The corrosion/wear resistance of I‐GO/PANI/PDA has greatly improved. GO/PANI/PDA coating exhibits excellent anisotropic conductivity. Galvanic corrosion is inhibited due to the addition of GO/PANI/PDA. “Nacre‐like” structure shows high labyrinth effect. The ordered orientation of GO/PANI/PDA suppresses out‐plane electron transport.

Effects of interlayer-modified layered double hydroxides with organic corrosion inhibiting ions on the properties of cement-based materials and reinforcement corrosion in chloride environment

Developing novel, environmentally friendly, and efficient corrosion inhibitors is of great significance for improving the durability of marine concrete against chloride ion erosion. This paper aims to explore the potential of layered double hydroxides (LDHs) as nanocontainers, incorporating organic corrosion inhibitors between LDHs layers to synergistically enhance their effectiveness. In this study, Mg/Al-pAB-LDH was synthesized through the interlayer modification of LDHs with an organic corrosion inhibitor, p-aminobenzoic acid (pAB), employing a calcination-rehydration method. Chloride ion (Cl−) adsorption behavior was quantitatively and qualitatively analyzed and the effect on mortar properties was investigated. The corrosion resistance of steel bars in the mortar was assessed under chloride salt simulated concrete pore solution (SCPs) and chloride salt wet-dry cycles via electrochemical tests and microscopic characterization of Mg/Al-pAB-LDH. The results demonstrate that Mg/Al-pAB-LDH efficiently captures Cl− and releases corrosion-inhibiting ions pAB, with the adsorption process conforming to pseudo-second-order kinetics and Langmuir adsorption isotherm. Mg/Al-pAB-LDH enhances the pore structure of mortar, effectively improving mechanical properties and resistance to chloride ion penetration, with the optimal effect observed at a 4 % addition rate. Mg/Al-pAB-LDH demonstrates outstanding corrosion resistance to steel bars in both SCPs and mortar. In SCPs, it serves as a corrosion inhibitor by adsorbing Cl− and releasing pAB, whereas in mortar, it functions as a corrosion inhibitor by enhancing the physical barrier effect of mortar, adsorbing Cl−, and releasing pAB. This study demonstrates the promising potential of utilizing Mg/Al-pAB-LDH as a novel corrosion inhibitor to mitigate the corrosion of steel bars in marine concrete.

Flexible and Recyclable Bio-Based Polyester Composite Films with Outstanding Mechanical and Gas Barrier Properties Using Leaf-Shaped CNT@BNNS Covalent Heterojunction.

With the depletion of petroleum resources, the development of sustainable alternatives for plastic substitutes has grown in importance. It is urgently desirable yet challenging to design high-performance polyesters with extensive mechanical and prominent gas barrier properties. This work uses bio-based PBF polyester as a matrix, "leaf-shaped" carbon nanotube@boron nitride nano-sheet (CNT@BNNS) covalent hetero-junctions as functional fillers, to fabricate CNT@BNNS/PBF (denoted as CBNP) composite films through an "in-situ polymerizing and hot-pressing" strategy. The covalent CNT "stem" suppresses the re-stacking of BNNS "leaf", endowing hetero-structured CNT@BNNS illustrates superior stress transfer and physical barrier effect. The covalently hetero structure and high orientation degree of CNT@BNNS greatly improve the comprehensive performance of the CBNP composites, including excellent mechanical (strength of 76MPa, modulus of 2.3GPa, toughness of 85MJm-3, elongation at break of 193%) and gas barrier (O2 of 0.015 barrer, and H2O of 1.1 × 10-14g cm cm-2s-1Pa-1) properties that are much higher than for pure PBF or other-type polyesters, and most engineering plastics. Moreover, the CBNP composites also boast easy recyclability, overcoming the tradeoff between high performance and easy recycling of traditional plastics, which makes the polyester composite competitive as a plastic substitute.

Study on the microstructure and impermeability of calcium aluminate cement containing metakaolin for development of high-performance marine engineering materials

To provide a high-performance marine engineering material, the microstructure and impermeability of calcium aluminate cement (CAC) containing metakaolin (MK) were studied. The chloride penetration resistance of the CAC-MK and Portland cement (PC) mortars was assessed based on physical and chemical barrier effects. The results show that the alumina in MK is more easily dissolved than silica, which inhibits the transformation of CAH10 and prevents microstructural deterioration. Adding 7.5% and 15.0% MK reduces the volume of large pores in the 3-day-old CAC paste by 49.8% and 69.1% while increasing the volume of pores smaller than 50 nm by 175.6% and 242.5%, respectively. Moreover, the microstructure of MK-containing CAC pastes becomes denser with age when cured at 40 °C, enhancing the mechanical strength and water penetration resistance. The CAC mortar containing MK exhibits better resistance to chloride attack than PC mortar, due to the stronger chloride binding capacity and migration resistance.

A novel high corrosion-resistant and superhydrophobic MAO-30/PA/VTES composite coating on Cu[sbnd]15Fe alloy for long-term corrosion protection

The copper (Cu) alloys are prone to severe corrosion in marine environments. In this work, we successfully develop a novel high corrosion-resistant and superhydrophobic MAO-30/PA/VTES composite coating on Cu15Fe alloy for long-term corrosion protection. The composite coating, with a corrosion rate of 0.00001 mm/y and a water contact angle of 152.7°, presents significant advantages over most Cu alloys modification methods to date. Benefiting from the modification with phytic acid (PA) and vinyltriethoxysilane (VTES), the corrosion current density of the composite coating remains 2.14 × 10−10 A·cm−2 even after 168 h of immersion in 0.6 M NaCl, which is four orders of magnitude lower than Cu15Fe substrate (5.68 × 10−6 A·cm−2). The exceptional long-term corrosion resistance of the composite coating is attributed to the physical barrier effect of the micro-arc oxidation (MAO) layer, the superhydrophobic characteristics and sealing effect of the PA/VTES film layer, and the chelating effect of the phytic acid. Developing the composite coating introduces a new approach to protecting Cu alloys from corrosion in marine environments.

The effect of polyvinyl chloride and polyethylene terephthalate on the mechanical properties of butyl rubber (IIR)-based thermoplastic elastomer using semi-efficient vulcanisation system and a nano zinc oxide as activator

Thermoplastic elastomers (TPEs), a class of materials bridging the gap between rubber and thermoplastics, have revolutionised diverse fields with their unique properties and applications. This study highlights the critical importance of compatibility between plastics, polyvinyl chloride (PVC), polyethylene terephthalate (PET), and butyl rubber (isobutylene-isoprene rubber, IIR) components in TPEs for optimal performance. Several TPEs were prepared with different amounts of plastics. Subsequently, the TPEs were cured, and curing and mechanical properties, and correspondent thermal stability and solvent resistance were measured. It revealed that the thermal stability of TPEs, containing PVC, PET and IIR, was influenced by the type and quantity of each plastic, affecting degradation temperatures. PVC and PET exhibited distinct effects on the curing behaviour of IIR-based TPEs, impacting scorch time and optimum cure time differently. The incorporation of PVC and PET enhanced the organic solvent resistance of the TPEs, attributed to physical barrier effects, enhanced crosslinking, increased crystallinity, and specific interfacial interactions. Tensile strength and elongation at break generally decreased with the addition of plastics, reflecting incompatible interactions and increased crystallinity. Meanwhile, hardness increased due to the rigid structure and filler effects of plastics. Achieving an optimal TPE formulation involves balancing these competing effects.

Effectiveness of different mixed physical barriers in controlling seawater intrusion in homogeneous and layered coastal aquifers

The intrusion of salt water into coastal regions threatens water resources, especially in arid and semi-arid regions. It damages large quantities of fresh water in these regions, and the productivity of the freshwater abstraction wells declines. Management of seawater intrusion (SWI) is therefore needed to improve fresh groundwater in these regions. This study investigated 12 different configurations of mixed physical subsurface barriers (MPBs) to control SWI in homogeneous and heterogeneous layered aquifers. The effectiveness of different MPB locations and configurations was tested, including (i) a barrier wall on the landward side and the subsurface dams on the seaward side, (ii) a barrier wall on the seaward side and a subsurface dam on the landward side, and (iii) the barrier wall was placed above the subsurface dam, both with different permeabilities. All simulations were based on the SEAWAT code. The numerical model was validated against experimental data. The results showed that a permeable cut-off wall above an impermeable subterranean dam (case MPB-3) with different permeabilities resulted in a reduction of the seawater wedge of 91% and 92% for homogeneous and heterogeneous layered aquifers, respectively. When the barrier wall was placed on the land side and the dam on the seaside (case MPB-1), the reduction of the seawater wedge reached 83% and 85% for homogeneous and heterogeneous layered aquifers, respectively. In contrast, when the dam was placed on the land side and the wall on the seaside (case MPB-2), the saltwater wedge was reduced by 73% for both homogeneous and heterogeneous layered aquifers. In addition, a case study was conducted on the Biscayne aquifer, southeast Florida, USA, with homogeneous conditions. Seawater intrusion was reduced by 36% and 44% in case MPB-1, 41% and 38% in case MPB-2, and 43% and 46% in case MPB-3. These seawater intrusion control methods offer numerous benefits, including improving freshwater storage, effectively controlling salinity during droughts, and potentially improving contaminant management.

A self-growing “Polysulfide-Phobic” interface constructed by in-situ gelation of organic bentonite interlayer to suppress shuttle effect in lithium-sulfur batteries

The shuttle effect of polysulfides hinders the long-term operation of lithium-sulfur batteries (LSBs). As the secondary current collector, the conductive interlayer can achieve induced fixation of polysulfide within a certain range, but the mechanism of action is limited by bearing saturation of the interlayer on polysulfide. In this work, the limited gelation of organic bentonite (OB) in the electrolyte is utilized to construct an in-situ gel-type physical barrier. During the initial discharge activation stage, the gel layer gradually evolves into a "Polysulfide-Phobic" repulsive layer by trapping free Lithium-polysulfides (LiPSs). Due to the strong repulsion between the "Polysulfide-Phobic" layer and free polysulfide anions, the spatial distribution of LiPSs in the positive electrode region is changed. In addition, the physical barrier effect of the gel interlayer and the chemisorbed action on LiPSs ensure the stability of the "Polysulfide-Phobic" layer during the discharge stage, while the low electronic conductivity avoids the risk of oxidation decomposition of the interface during the charging stage, which is verified by in-situ Raman. The Cells with OB interlayers show excellent cycle stability (515.5 mAh g−1 after 300 cycles) under high loading conditions (5 mg cm−2, E/S ≈ 7.5 μL mg−1). This strategy of sacrificing initial efficiency to build an electrostatic repulsion layer in exchange for long-term stability is profitable, providing a new approach to addressing the shuttle effect.

Corrosion-resistant superhydrophobic composite coating with mechanochemical durability

It is important to improve the corrosion resistance of magnesium alloy for expanding its application field. Poor durability seriously restricts the practical application of superhydrophobic anti-corrosion coatings. Here, a durable superhydrophobic anti-corrosion coating was prepared on AZ31 Mg substrate via a facile one-step spraying approach. The microscale glass fibers (GF) and nanoscale hydrophobic SiO2 particles were integrated into the epoxy resin (ER) to construct superhydrophobic composite coating (ER/GF-SiO2). Benefitting from the air cushion and physical barrier effect of superhydrophobic coating, the ER/GF-SiO2 coating exhibits good reinforced protectives properties. Compared with the AZ31, the corrosion current density of superhydrophobic coating decreased by three orders of magnitude and the low-frequency impedance modulus decreased by one order of magnitude. The ER/GF-SiO2 coating still maintained a high protective efficiency (89.44 %) after immersion in 3.5 wt% NaCl solutions for 13 d. The ER/GF-SiO2 coating shown good mechanochemical durability. The superhydrophobicity can be maintained after 40 m of sandpaper abrasion, 30 min of water impact, 20 min of sand impact, and 80 cycles tape-peeling. Furthermore, the high bond strength of the coating-substrate was verified by energetic analysis of molecular dynamics simulation at a microscopic level. The facile and effective preparation process provides an effective strategy for large-scale industrial production of durable superhydrophobic coating.

Novel nanoparticle composed by Ovalbumin-OSA modified pectin-rutin for improving the stability of Monascus pigments

To improve the resistance of Monascus pigments (MPs) to adverse environmental factors, a nanoparticle carrier was constructed using ovalbumin, rutin and pectin modified by octenyl succinic anhydride. According to the determination of particle size, ζ-potential and microstructure, the composite nanoparticles exhibited the "core-shell" structure. Specifically, the ovalbumin core was encapsulated by the modified pectin adsorbed with rutin. Spectroscopic analysis demonstrated that electrostatic interactions, hydrogen bonding and hydrophobic interactions between wall materials and MPs were the main driving forces to form composite nanoparticles. The stabilities of light, thermal and storage of MPs were significantly enhanced after encapsulation due to the physical barrier effect of the wall materials against external disturbances and the multiple functions of rutin, including free radical scavenging, absorption of partial UV and scatter light, and possible co-pigmentation effects with MPs. Moreover, the composite nanoparticles exhibited higher inhibition activity against pancreatic lipase and antioxidant activity compared with those of free MPs. The results provided an ideal way to develop new MPs products, which had long-lasting and stable performance during food processing and storage.

Phytic acid-doped polypyrrole/graphene oxide nanofillers for the preparation of self-healing anticorrosion coatings with the synergistic physical barrier, passivation and chelating effect

The corrosion protection of organic coatings for metal substrates is generally limited because of the unavoidable coating micropores and cracks, even the coating anticorrosion function will lose when it is damaged. Although the addition of nanofillers into the organic coating matrix can effectively address the above issues, it is challenging to facilely and wholesale construct surface-modified nanofillers with synergistic anticorrosion ability of physical barrier, passivation and chelating effect. In this study, we develop a simple one-pot approach for preparing polypyrrole (PPy) modified graphene oxide (GO) nanofillers with the doping of phytic acid (Ph) (namely GO-PPy@Ph nanoparticles) and then incorporating them into epoxy resin (EP) coating system to form the anticorrosion nanocomposite coatings. The research results display that the GO-PPy@Ph nanoparticles can uniformly disperse in the EP coatings to improve their anti-penetrant ability against corrosive media. And the introduction of GO-PPy@Ph nanoparticles effectively enhances the coating adhesion strength and mechanical performance. Moreover, the anticorrosion tests show that the impedance modulus at 0.01 Hz of GO-PPy@Ph coating after 60-day immersion in 3.5 wt% NaCl solution remains at about 1010 Ω cm2. The dramatical anticorrosive performance of the GO-PPy@Ph coating with self-healing performance is attributed to the synergistic protection of impermeable GO-PPy@Ph nanosheets, passivation function of PPy and metal chelation effect of Ph. This study provides an effective and universal avenue to construct multifunctional nanofillers with the synergistic anticorrosion of high physical barrier, passivation and metal chelating effects for developing anticorrosive nanocomposite coatings with high performances, which have highly attractive potential in the commercialization applications of metal corrosion protection.

A novel UV-curable amphiphobic coating with dynamic air-layer copolymer brush offering stable dual-functional anti-scaling and anti-corrosion properties

Scale deposition and metal corrosion, especially in the petroleum industry, have always been serious issues that seriously affect economic efficiency and safety. However, conventional anti-scaling strategies including mechanical descaling and chemical detergents are energy-consuming and environmentally damaging, which can't achieve efficient and long-term protection. Based on mechanical descaling and chemical detergents, and anti-corrosion strategies based on filler are inadequate to realize efficient protection. Herein, this work reports a novel UV-curable polymer coating with long-term anti-scaling and anti-corrosion properties. The excellent anti-scaling capability was achieved by inhibiting interfacial nucleation and reducing interfacial adhesion work of scaling products. Significantly, the anti-scaling capability of the designed coating mainly originates from two aspects: inhibiting interfacial nucleation and reducing interfacial adhesion work of scaling. Compared with pure polyurethane acrylic coating (0 % FGSS), the 20 % FGSS coating shows significantly improved scaling repellence even after a 240 h dynamic scaling test while maintaining a fairly low theoretical adhesion work (≈0.1 mN/m). This outstanding anti-corrosion capability of the FGSS coating mainly originates from two aspects: the physical barrier effect of the air layer and low surface energy resistance barriers with dynamic FGSS brushes. The physical barrier effect of the air layer and the low surface energy resistance barriers also lead to outstanding anti-corrosion property (with the |Z|0.01 Hz value maintained at 108 Ω·cm2). This study presents a simple and effective design and fabricated strategy, paving a new pathway for developing UV-cured coatings with unique anti-corrosion and anti-scaling properties. This facile and effective UV-curable polymer coating shows great potential in metal protection and paves a new pathway for the development of long-term functional protection coatings.

Chloride Ions-Responsive Intelligent Coatings for the Active Protection of Degradable Biomedical Mg Alloys.

In this work, the hydroxyapatite (HA) microspheres are utilized as carriers for 8-hydroxyquinoline (8-HQ) inhibitors with a sodium alginate-silver nitrate layer (Ag-SA) added to confer chloride-responsive properties. These 8-HQ@Ag-SA-HA microspheres are subsequently integrated into poly(lactic acid) (PLA) coatings to produce biocompatible coatings. The resulting 8-HQ@Ag-SA-HA microsphere exhibits a spherical structure with a diameter of 3.16 μm. Thermogravimetric analysis indicates that the encapsulated 8-HQ inhibitors are approximately 11.83 wt %. Furthermore, the incorporation of these microspheres fills the micropores within the PLA coating, leading to a denser coating surface, enhanced wettability (contact angle value = 88°), and improved adhesion strength, thereby reinforcing the physical barrier effect. Corrosion tests reveal that the coatings exhibit increased resistance to corrosion in simulated body fluid (SBF) solutions. The released 8-HQ inhibitors in response to chloride ions form a protective layer of Mg(HQ)2, providing the coatings with self-healing properties and ensuring their durability in the SBF environment. Additionally, the cell test demonstrates a significant presence of MG-63 cells, accompanied by a low hemolysis rate of 3.81%, confirming the exceptional biocompatibility of the coatings. These findings offer valuable insights into the development of stimuli-responsive biocompatible coatings for effectively protecting Mg alloys.

Self-crosslinking hyaluronic acid hydrogel as an enteroprotective agent for the treatment of inflammatory bowel disease

The pathological changes in inflammatory bowel disease (IBD) include the disruption of intestinal barrier function and the infiltration of pathogenic microbes. The application of an artificial protective barrier at the site of inflammation can prevent bacterial infiltration, promote epithelial cell migration, and accelerate wound healing. In this study, dopamine-modified hyaluronic acid (HA-DA) was developed as a bioadhesive self-cross-linkable hydrogel, which acted as an enteroprotective agent to promote the healing of inflamed intestinal tissue. The adhesion strength HA-DA to mouse colon was 3.81-fold higher than HA. Moreover, HA-DA promoted Caco-2 cell proliferation and migration as well as had a strong physical barrier effect after gelation. After oral administration, the HA-DA reduced weight loss and attenuated impaired goblet cell function in mice with dextran sodium sulfate-induced IBD. In addition, HA-DA promoted restoration of the epithelial barrier by the upregulation of tight junction proteins. The results reported herein substantiated that self-cross-linkable hydrogel-based enteroprotective agents are a promising approach for the treatment of IBD.

Utilizing the oxidation defects of black phosphorus to reduce and stabilize copper(I) molybdate to achieve flame retardancy and smoke suppression in polycarbonate composites

Promising phosphorus-based flame retardants reduce thermal hazards while increasing non-thermal hazards. This work utilizes the oxidative defects of black phosphorus, which can synchronously reduce and stabilize copper(I) molybdate while introducing surface modification with sodium alginate in an environmentally friendly ball milling process to enhance dispersibility. First, the T5% and Tmax of PC/BP@CM@SA (2 wt%) increase by 9.5 °C and 8 °C, respectively, under nitrogen. Second, UL-94 V0 was achieved, and the peak heat release rate, total heat release, and total smoke release decreased by 44.0 %, 22.1 %, and 17.0 %, respectively. Compared with that of the neat sample, the height of the char layer doubled, while its graphitization degree decreased from 2.38 to 2.14. In short, this is largely attributable to the catalytic action and physical barrier effect of BP@CM@SA. This study provides a way to balance the reduction in thermal hazards and increase in non-thermal hazards of phosphorus-based flame retardants such as black phosphorus.

Comparative study on the flame retardancy, pyrolysis behavior, and flame retardant pathways of black phosphorus in polyurethane and polypropylene

Black phosphorus nanosheets (BPns) have gained widespread attention in the field of flame retardancy due to their highly efficient flame-retardant properties achieved with a low addition rate (e.g., 0.4%). However, the pyrolysis pathways of BP in polymers have not yet been elucidated. This work systematically studies the flame retardancy and pyrolysis behavior of BP in oxygen-containing (polyurethane, PU) and oxygen-free (polypropylene, PP) polymers, distinguishing between the gas-phase and the condensed-phase flame retardant effect of BP. Through slow heating and staged heating methods, the condensed phase and gas phase pyrolysis products of BP in PU and PP at different temperatures are compared in detail. The distinct flame retardant pathways of BP in PU and PP are revealed. The results indicate that the oxidation of BP commences with its reaction with atmospheric oxygen, implying that the condensed-phase flame-retardant effect of BP primarily occurs at the polymer surface. In PP, BP mainly functions as a gas-phase flame retardant. In the condensed phase, BP generates phosphate derivatives that cover the substrate surface, providing solely a physical barrier effect. In PU, while BP demonstrates an outstanding gas-phase flame-retardant effect, it also accelerates the early dehydration carbonization of alcohols within the substrate, resulting in the formation of phosphate ester compounds (P–O–C structure) to bolster the thermal stability of residual carbon. Additionally, the side reactions of BP during catalytic carbonization will decrease the thermal stability of ester bonds in PU. This work lays a theoretical foundation for the development and application of BP-based flame retardant systems.

Enhancing the protective performance of anti-impact, corrosion resistant and flame retardant polyurea coatings using bio-based supramolecular decorated montmorillonite

Developing bio-based nano-additives for enhancing mechanical strength, corrosion resistance, and flame retardancy in polyurea (PUA) coatings at low loading levels is crucial for human well-being and environmental preservation. In this study, montmorillonite (MMT) was first exfoliated by ball milling with the aid of chitosan, and then further co-assembled with phytic acid and urea to form a nanohybrid (CPN@MMT). The resulting CPN@MMT nanohybrid exhibited good compatibility and dispersibility within matrix and endowed PUA composites with improved anti-impact, corrosion resistant and flame retardant properties. Remarkably, the addition of CPN@MMT improved the mechanical and impact protection properties of PUA coatings. Electrochemical and salt spray tests confirmed that the excellent anti-corrosion performance of PUA composite coating stemmed from the dispersed nano-sheets forming a protective nano-barrier. CPN@MMT in the PUA matrix formed a compact char layer, reducing heat release and smoke by inhibiting heat diffusion and volatile gas evaporation, as evidenced by cone calorimeter and TG-FTIR tests. The enhanced fire safety was primarily attributed to the physical barrier, catalytic charring and dilution effect of CPN@MMT. Hence, a green and feasible method was developed to create bio-based nano-additive in PUA coatings with anti-impact, corrosion resistant and flame retardant performance.

Sonication-mediated modulation of macronutrient structure and digestibility in chickpea

Ultrasound processing is an emerging green technology that has the potential for wider application in the food processing industry. While the effects of ultrasonication on isolated macromolecules such as protein and starch have been reported, the effects of physical barriers on sonication on these macro-molecules, for example inside whole seed, tissue or cotyledon cells, have mostly been overlooked. Intact chickpea cells were subjected to sonication with different ultrasound processing times, and the effects of sonication on the starch and protein structure and digestibility were studied. The digestibility of these macronutrients significantly increased with the extension of processing time, which, however was not due to the molecular degradation of starch or protein but related to damage to cell wall macro-structure with increasing sonication time, leading to enhanced enzyme accessibility. Through this study, it is demonstrated that ultrasound processing has least effect on whole food structure, for example, whole seeds but can modulate the nutrient bioavailability without changing the properties of the macronutrients in seed fractions e.g. intact cells, offering new scientific knowledge on effect of ultrasound in whole foods at various length scales.

Boosting the initial coulombic efficiency for SiO anodes through component controlling and microcrystalline size limiting regulated by carbon layer

Silicon-based anode materials are attracting considerable attention due to their high specific capacity for further improving the energy density of lithium-ion batteries (LIBs). Among them, silicon monoxide (SiO) has a good balance between high specific capacity and cycling lifespan, which is increasingly valuable in the market of lithium-ion batteries. However, its poor initial coulombic efficiency (ICE) severely impedes the commercialization of SiO. Although prelithiation and surface carbon coating are considered effective methods to reduce irreversible consumption during the initial lithiation process, the synergistic relationship between prelithiation and carbon coating has not yet been confirmed. Herein, we used LiH as solid-phase prelithiation reagent and acetylene as carbon source for carbon coating to improve the ICE as well as cyclic stability of SiO anode. Results show that the process sequence of pre-lithiation and carbon coating has a significant impact on regulating the internal lithium silicate components and the microcrystalline size of silicon and lithium silicates. A prioritizing carbon layer coating subsequent to prelithiation can achieve physical barrier effect, effectively regulating the prelithiation reaction process to refine the internal silicon and lithium silicate crystal material, and avoiding the formation of lithium-poor Li2Si2O5 phase. The obtained SOC-P sample exhibits a superior ICE of 88.1 % and a stable irreversible capacity of 842.9 mAh/g after 200 cycles. This work provides practical reference idea for solving the low initial efficiency issue of SiO anode material.

Fire-retardant anti-microbial robust wood nanocomposite capable of fire-warning by graded-penetration impregnation

Wood, renowned for its sustainability, specific strength, and thermal insulation, stands as a highly sought-after sustainable structural material. However, the inherent flammability, decay susceptibility, and inadequate mechanical strength hinder its practical applications in high-rise buildings. Here, we report a groundbreaking solution to fabricate multi-functional fire-retardant wood (M-FRW) through a coupled delignification/impregnation procedure followed by densification treatment. The GO/BA created a hybridized network on the M-FRW surface, while BA molecules penetrated the wood cell. As-created M-FRW exhibits a superior flame retardancy due to the physical barrier and catalytic charring effect of GO/BA, as reflected by an ultrahigh limiting oxygen index value of >75 % and an 85 % reduction in the peak of heat release rate compared to natural wood. Furthermore, the GO/BA layer of M-FRW has a sensitive fire alarm response and ultralong alarm time (∼11280 s). More impressively, M-FRW exhibits an exceptional ability to inhibit decay fungi, mold fungi, and common bacteria due to the superimposed anti-microbial effect of GO and BA. Additionally, M-FRW shows desirable mechanical and thermal insulation properties. This work provides a facile strategy to fabricate a multi-functional advanced wood nanocomposite, making them hold great potential for various engineering applications, such as intelligent buildings.