Interface Interaction Research Articles

Deciphering the enigmatic PilY1 of Acidithiobacillus thiooxidans: An in silico analysis

Thirty years since the first report on the PilY1 protein in bacteria, only the C-terminal domain has been crystallized; there is no study in which the N-terminal domain, let alone the complete protein, has been crystallized. In our laboratory, we are interested in characterizing the Type IV Pili (T4P) of Acidithiobacillus thiooxidans. We performed an in silico characterization of PilY1 and other pilins of the T4P of this acidophilic bacterium. In silico characterization is crucial for understanding how proteins adapt and function under extreme conditions. By analyzing the primary and secondary structures of proteins through computational methods, researchers can gain valuable insights into protein stability, key structural features, and unique amino acid compositions that contribute to resilience in harsh environments. Here, it is presented a description of the particularities of At. thiooxidans PilY1 through predictor software and homology data. Our results suggest that PilY1 from At. thiooxidans may have the same role as has been described for other PilY1 associated with T4P in neutrophilic bacteria; also, its C-terminal interacts (interface interaction) with the minor pilins PilX, PilW and PilV. The N-terminal region comprises domains such as the vWA and the MIDAS, involved in signaling, ligand-binding, and protein-protein interaction. In fact, the vWA domain has intrinsically disordered regions that enable it to maintain its structure over a wide pH range, not only at extreme acidity to which At. thiooxidans is adapted. The results obtained helped us design the correct methodology for its heterologous expression. This allowed us partially experimentally characterize it by obtaining the N-terminal domain recombinantly and evaluating its acid stability through fluorescence spectroscopy. The data suggest that it remains stable across pH changes. This work thus provides guidance for the characterization of extracellular proteins from extremophilic organisms.

Advancing Dental Implant Design: A Comprehensive Study of Machining Parameters, Corrosion Behavior, and Microstructural Evaluation.

In this research, we investigate the impact of varying machining parameters [depth of cutting (mm) and spindle rotation speed (rpm)] on the microstructure and electrochemical behavior of Ti6Al4V-ELI dental implants. This comprehensive study employs an approach, leveraging potentiodynamic methods and electrochemical impedance spectroscopy, to analyze corrosion behavior in a phosphate-buffered saline solution. To further deepen our understanding of corrosion kinetics, we used an alternating current circuit model, based on a simple Randles equivalent circuit. This model elucidates the corrosion interface interactions of the Ti6Al4-V-ELI alloy implant within the PBS solution. In addition, our research delves into the microstructural implications of different machining parameters, utilizing scanning electron microscopy and X-ray diffraction (XRD) techniques to reveal significant phase changes. The changes in texture were examined qualitatively by comparing the intensities of the peaks of the XRD pattern. A detailed correlation analysis further links the machining parameters with the corrosion properties of dental implants, offering a comprehensive perspective rarely explored in the existing literature. The results obtained for the three samples showed that the corrosion resistance would be higher by increasing the machining depth and the spindle rotation and that the corrosion current would be lower. As a result, a lower corrosion rate was obtained. Finally, experimental results from electrochemical analyses are compared and discussed.

Ferroelectricity‐Induced Surface Ferromagnetism in Core–Shell Magnetoelectric Nanoparticles

Magnetoelectric nanoparticles (NPs) present an important class of nanomaterials with a wide interest in piezocatalytic and biomedical applications. Herein, the results of magnetoelectric and magnetization measurements performed on core–shell NPs having magnetic core (MnFe2O4, MFO) and ferroelectric shell (Ba0.85Ca0.15Ti0.5Zr0.5O3, BCZT) synthesized by the microwave hydrothermal method are reported. Magnetic results are compared with the measurements on reference MFO NPs prepared under identical conditions. Detailed SQUID magnetometer measurements of the magnetization hysteresis loops M(H) down to 2 K reveal the existence of a clear exchange bias effect in pure MFO NPs attributed to the coexistence of ferromagnetic and antiferromagnetic short‐range interactions. When the magnetic core is covered by the thin ferroelectric BCZT shell, it is observed that 1) the shell suppresses the apparent bias effect and 2) induces an “extra” ferromagnetic magnetization at T < 20 K. The results indicate that this “extra” ferromagnetism has a 2D character and it is most likely related to the interface interactions between the MFO core and BCZT shell. Ferroelectric properties and strong magnetoelectric effect in core–shell NPs are revealed via piezoresponse force microscopy under magnetic field. The mechanisms of the observed effects are discussed.

Wood derived carbon embedded with shell-core CoP@CoFe for efficient oxygen evolution

Development of hybrid materials with specific architecture, interface, and multicomponent interactions demonstrates effective paradigm for pursuing high-performance energy conversion materials. Herein, using renewable and inexpensive wood-derived carbon as host, the shell-core CoP@CoFe particles are embedded on walls of carbonized wood channels (termed as CoP@CoFe/CW) to fabricate composite catalyst for electrocatalysis oxygen evolution reaction (OER). With benefits of the well distribution of CoP@CoFe particles, high conductivity of CW with channels, and good integration between them, highly exposed catalysis surface as well as rapid charge/mass transfer are achieved. The interface effect of shell-core hybrid activates the intrinsic OER efficiency of CoP@CoFe. Thus, the designed CoP@CoFe/CW yields excellent OER performance with ultralow overpotential of 120 mV (10 mA cm−2). This strategy of catalyst design based on eco-friendliness and renewable CW host may offer promising reference to explore composite materials with high conductivity and fast mass transfer for water electrolysis and other energy storage/conversion systems.

Fluorine atoms incorporation strengthens the strong metal-support interaction of PtNi@NFGC for enhanced methanol oxidation reaction performance under alkaline media

The regulatory mechanism of strong metal-support interaction (SMSI) is of great significance in improving the electrocatalytic performance for supported electrocatalysts. Here, PtNi alloy nanoparticles were deposited on N, F-codoped graphene-like carbon nanosheets (PtNi@NFGC) to construct a highly active interface for efficient methanol oxidation reaction (MOR), which solves the problems of high cost, poor activity and easy aggregation of Pt-based catalysts. Due to the high electrophilicity, F atoms doping into the carbon lattice can not only manipulate the electron structure and the state of the carbon skeleton, but also further trigger the stronger charge transfer between metal atoms and carbon support. Compared with single-doped PtNi@NGC, N, F-codoped PtNi@NFGC possesses a lower onset potential and methanol oxidation potential, higher methanol oxidation current and stronger CO tolerance. The results of the partial density of state (PDOS) simulation display that N, F-codoping promotes the electron transfer from Pt atoms to NFGC support, and leads to the d-band center shift upward, thus strengthening the oxidation degree of Pt active sites and increasing the composition of high-valent Ptx+. In-situ Raman analysis and density functional theory (DFT) results expound that F atoms embedding observably enhances the adsorption energy of Pt active centers to *OH intermediates, which not only significantly improves MOR catalytic activity, but also achieves efficient methanol dehydrogenation and alleviates CO poisoning. This customization of metal-support interface interaction by heteroatom doping strategy opens up opportunities for designing efficient supported catalysts.

II-Scheme Heterojunction Frameworks Based on Covalent Organic Frameworks and HKUST-1 for Boosting Photocatalytic Hydrogen Evolution.

Covalent organic frameworks (COFs) are one type of promising polymer semiconductors in solar-driven hydrogen production, but majority of COFs-based photocatalytic systems show low photocatalytic efficiency owing to lack of metal active sites. Herein, we reported II-Scheme heterojunction frameworks based on COF (TpPa-1) and metal-organic framework (HKUST-1) for highly efficient hydrogen production. The coordination bonding directed self-assembly of HKUST-1 on the surface of TpPa-1 endows the heterojunction frameworks (HKUST-1/TpPa-1) with strong interface interaction, optimized electronic structures and abundant redox active sites, thus remarkably boosting photocatalytic hydrogen evolution. The hydrogen evolution rate for optimal HKUST-1/TpPa-1 is as high as 10.50 mmol g-1 h-1, which is significantly enhanced when compared with that of their physical mixture (4.13 mmol g-1 h-1), TpPa-1 (0.013 mmol g-1 h-1) and Pt-based counterpart (6.70 mmol g-1 h-1). This work offers a facile approach to the construction of noble-metal-free II-Scheme heterojunctions based on framework materials for efficient solar energy conversion.

Fe3O4 Nanoparticles Embedded into Pyridinic-N-Rich Carbon Nanohoneycomb with Strong dx2-Pz Orbital Hybridization for High-Performance Electromagnetic Wave Absorption.

Carbon-based magnetic nanocomposites as promising lightweight electromagnetic wave (EMW) absorbents are expected to address critical issues caused by electromagnetic pollution. Herein, Fe3O4 nanoparticles embedded into a 3D N-rich porous carbon nanohoneycomb (Fe3O4@NC) were developed via the pyrolysis of an in-situ-polymerized compound of m-phenylenediamine initiated by FeCl2 in the presence of NaCl crystals as templates. Results demonstrate that Fe3O4@NC features highly dispersed Fe3O4 nanoparticles into an ultrahigh specific pyridinic-N doping carbon matrix, resulting in excellent impedance matching characteristics and electromagnetic wave absorbing capability with the biggest effective absorption bandwidth (EAB) of up to 7.1 GHz and the minimum reflective loss (RLmin) of up to -65.5 dB in the thin thickness of 2.5 and 2.3 mm, respectively, which also outperforms the majority of carbon-based absorbers reported. Meanwhile, its high absorption performance is further demonstrated by an ethylene propylene diene monomer wave absorbing patch filled with 8.0 wt % Fe3O4@NC, which can completely shield a 5G signal in a mobile phone. In addition, theory calculation reveals that there is a strongest dx2-Pz orbital hybridization interaction between Fe3O4 clusters and pyridinic-N dopants in the carbon network, compared with other kinds of N dopants, which can not only generate more dipoles of carbon networks but also increase net magnetic moments of Fe3O4, thereby leading to a coupling effect of efficient dielectric and magnetic losses. This work provides new insights into the precise design and synthesis of carbon-based magnetic composites with specific interface interactions and morphological effects for high-efficiency EMW absorption materials.

Two-dimensional bilayer ice in coexistence with three-dimensional ice without confinement

Icing plays an important role in various physical-chemical process. Although the formation of two-dimensional ice requires nanoscale confinement, two-dimensional bilayer ice in coexistence with three-dimensional ice without confinement remains poorly understood. Here, a critical value of a surface energy parameter is identified to characterize the liquid-solid interface interaction, above which two-dimensional and three-dimensional coexisting ice can surprisingly form on the surface. The two-dimensional ice growth mechanisms could be revealed by capturing the growth and merged of the metastable edge structures. The phase diagram about temperature and pressure vs energy parameters is predicted to distinguish liquid water, two-dimensional ice and three-dimensional ice. Furthermore, the deicing characteristics of coexisting ice demonstrate that the ice adhesion strength is linearly related to the ratio of ice-surface interaction energy to ice temperature. In addition, for gas-solid phase transition, the phase diagram about temperature and energy parameters is predicted to distinguish gas, liquid water, two-dimensional ice and three-dimensional ice. This work gives a perspective for studying the singular structure and dynamics of ice in nanoscale and provides a guide for future experimental realization of the coexisting ice.

First-principles study of the structure, magnetism, and electronic properties of the all-Heusler alloy Co2MnGe/CoTiMnGe(100) heterojunction.

Based on first-principles calculations in the density functional theory, we systematically investigated the possible interface structure, magnetism, and electronic properties of the all-Heusler alloy Co2MnGe/CoTiMnGe(100) heterojunction. The calculation indicated that the Co2MnGe Heusler alloy is a half-metal with a magnetic moment of 4.97μB. CoTiMnGe is a narrow-band gap semiconductor and may act as an ultra-sensitive photocatalyst. We cannot find an "ideal" spin-polarization of 100% in CoCo termination and MnGe termination. Due to the interface interaction, the direct magnetic hybridization or indirect RKKY exchange will be weakened, leading to an increase in the atomic magnetic moment of the interfacial layer. For eight possible heterojunction structures, the half-metallic gaps in the Co2MnGe bulk have been destroyed by the inevitable interface states. The spin-polarization value of 94.31% in the CoCo-TiGe-B heterojunction revealed that it is the most stable structure. It is feasible to search for high-performance magnetic tunnel junction by artificially constructing suitable all-Heusler alloy heterojunctions.

Visible light-enhanced interface interaction for PMS activation towards the removal of emerging organic pollutants: performance, mechanism and toxicity

The peroxymonosulfate (PMS)-based advanced oxidation process is considered as an effective way to remove emerging organic pollutants in the wastewater. However, the heterogeneous catalysts used for PMS activation suffers from low catalytic stability and PMS utilization efficiency. Herein, sulfur-doped cobalt ferrite loaded graphitic carbon nitride (S-CoFe2O4/CN) was firstly synthesized for PMS activation toward the sulfamethoxazole (SMX) removal. The S-CoFe2O4/CN possessed excellent PMS catalytic activity and photocatalytic activity. The first-order kinetic constant (k) of SMX degradation in the presence of visible light reached 0.3564 min−1 with high PMS utilization efficiency (78.3 %). Mechanism analysis elucidated that compared to the original CoFe2O4, sulfur doping created more oxygen vacancies, while visible light further promoted the regeneration of Co(II), Fe(II) and oxygen vacancy, the formation of high-valent iron oxo as well as the reduction of S2- oxidation. In addition, the visible light/S-CoFe2O4/CN/PMS system showed high resistance to inorganic ions, and superior catalytic stability. Both acute and chronic toxicity of treated SMX solution decreased. This study provides an effective system to remove emerging organic pollutants in the wastewater.

A vertically aligned flake like CuO/Co3O4 nanoparticle@g-C3N4 ternary nanocomposite: A heterojunction catalyst for efficient photo electrochemical water splitting

Efficient utilization of solar energy for the conversion of water into hydrogen via photoelectrochemical (PEC) water splitting holds tremendous promise for sustainable energy production. In this study, we report a novel vertically aligned flake-like CuO/Co3O4 nanoparticle@g-C3N4 sheets ternary nanocomposite as a heterojunction catalyst for enhancing PEC water splitting efficiency. The ternary nanocomposite was synthesized via a facile and scalable method, resulting in a unique structure with vertically aligned CuO/Co3O4 nanoparticles in tight interface interaction with g-C3N4 sheets. The resulting heterojunction exhibited enhanced light absorption, efficient charge separation, and improved charge transfer kinetics, leading to significantly enhanced PEC water splitting performance. The as-synthesized ternary nanocomposite, such as CuO/Co3O4@g-C3N4 nanocomposite, demonstrated superior PEC activity with an enhanced photocurrent density, i.e., 0.88 mA/cm2, which is higher than that of the pristine CuO (0.65 mA/cm2), Co3O4 (0.7 mA/cm2), and CuO-Co3O4 (0.77 mA/cm2) structures with linear sweep voltammetry under light irradiation. Additionally, the ternary nanocomposite exhibited excellent stability during 2 h PEC water splitting measurements under 1 h time interval chopped conditions. The remarkable performance of the vertically aligned CuO/Co3O4 nanoparticle@g-C3N4 ternary nanocomposite underscores its potential as a promising catalyst for efficient solar-driven hydrogen generation. This study not only provides insights into the design of advanced heterojunction catalysts but also contributes to the development of sustainable energy conversion technologies.

Rigid-flexible mediated Co-polyimide enabling stable silicon anode in lithium-ion batteries

Silicon is considered as a promising electrode materials for the next generation of lithium-ion batteries. However, it’s commercial applications are hindered by significant volume changes. In this study, copolyimide binders with adjustable rigidity and flexibility were synthesized through simple copolymerization. The rigid segments containing adenine groups (p-APA) provide excellent mechanical strength and interface interaction, while flexible segments containing siloxane bonds and alkane chains (DS-NH2) can buffer volume changes through enhanced mobility and topological entanglement of molecular segments. Optimizing the copolymerization ratio helps minimize damage to the silicon electrode structure and stabilizes solid electrolyte interphase (SEI) growth. Compared to the rigid polyimide binders, rigid-flexible coupling strategy improves cycling stability, remaining a capacity of 2170 mAh/g at 2 A/g after 200 cycles and exhibiting stable cycling for over 750 cycles with a capacity limitation of 1500 mAh/g. The high mass loading silicon anodes, micron-sized silicon oxide electrodes and the full cells also exhibit favorable electrochemical performance. This research provides valuable insights for designing high-performance aromatic polymer binders for high energy density lithium-ion batteries.

One-Step process of wrinkle microstructured iontronic pressure sensor with all fabric wearable electrode

The advancement of pressure sensors featuring high sensitivity, wide detection ranges, and linear response characteristics is important for advancing tactile sensing technologies for robots and human health monitoring. However, conventional preparation suffers from nonlinear signal output, non-environmental friendliness, and poor comfort, which affects the sensor’s ability to accurately detect different pressure levels, which is critical for subtle haptic feedback systems. To overcome these challenges, our research introduces a breakthrough in flexible capacitive pressure sensors by ingeniously integrating thermal stress-induced microstructured ionic gels with textile electrodes within a band-aid-like form factor. This method prevents the requirement for external templates or intricate manufacturing procedures, streamlining the production process while enhancing the sensor’s performance. The pivotal role of the ionic gel lies in its ability to form an efficient electric double layer (EDL), which adeptly transforms ion–electron interface interactions into measurable pressure-sensing outputs. Notably, this band-aid-based iontronic sensor showcases exceptional performance metrics. It exhibits an extraordinarily high sensitivity, reaching 5652.41 kPa−1, and demonstrates a broad pressure detection range (from 0-400 kPa). Additionally, the sensor responds rapidly to pressure changes, maintains robust long-term cycle stability, and boasts an impressively low detection threshold. Its potential applications, particularly in the precise monitoring of human muscle movements, open exciting new avenues for both health monitoring and the broader field of flexible electronic devices. This showcases the potential of everyday materials in advanced technological applications.

Molecular dynamics simulation of interfacial mechanical properties of crumb rubber concrete

Crumb rubber concrete is a new type of cement concrete made from waste rubber as partial aggregate. The mechanical properties and resistance to cracking of crumb rubber concrete are not only related to the mechanical properties of each constituent phase, but also closely related to the interface characteristics and interactions between the cement paste and rubber/aggregate. This article uses molecular dynamics simulation to analyze the two characteristic interfaces (coarse aggregate/cement paste, rubber/cement paste) in the micro and nano structures of crumb rubber concrete at the molecular scale. By simulating the indentation process, interfacial adhesion energy, and interfacial pull-out performance, the micro mechanical properties and mechanisms of different interfaces were further compared and analyzed. From the simulation results, it can be seen that the C-S-H/calcite interface is mainly composed of ion bonds, with the highest interaction force. The C-S-H/silica interface is mainly composed of hydrogen bonds, while the C-S-H/rubber interface is mainly composed of van der Waals force, with the lowest interaction force. The C-S-H/calcite interface has the highest adhesion energy, while the C-S-H/rubber interface has the lowest adhesion energy. In interface indentation simulation, calcite has the greatest impact on C-S-H, while rubber has the smallest impact on C-S-H.

Accelerated corrosion of FeCrAlTi coating by in situ proton irradiation in molten lead-bismuth eutectic

The synergistic effect of simultaneous proton irradiation and LBE corrosion on FeCrAlTi coating is investigated, and the surface morphology, elementary composition, microstructure and crystal structure of the formed oxide scale are systematically analyzed. The results reveal the accelerated LBE corrosion behavior of proton irradiated FeCrAlTi coating, which can be attributed to irradiation produced defects leading to enhanced diffusion, irradiation induced more porous oxide scale resulting in promoted short-circuit diffusion, and irradiation enhanced adsorption energy of O, Pb and Bi on coating surface contributing to intensive interface interaction.

Interface Design and Functional Optimization of Chinese Learning Apps Based on User Experience

This research paper investigates the interface design and functional optimization of Chinese learning apps through the lens of user experience. With the increasing popularity of Chinese language learning apps in the era of rapid mobile internet development, users' demands for enhanced interface design and interaction experience have grown significantly. The study aims to explore the influence of user feedback on the design and functionality of Chinese learning apps, proposing optimization strategies to improve user experience and learning outcomes. By conducting a comprehensive literature review, utilizing methods such as surveys and user interviews for data collection, and analyzing user feedback, this research identifies existing issues in the interface design and interaction experience of Chinese learning apps. The results present user opinions, feedback analysis, identified problems, improvement directions, and specific optimization strategies. The study discusses the potential impact of these optimization strategies on enhancing user experience and learning outcomes, compares findings with previous research, addresses limitations, and suggests future research directions. In conclusion, this research contributes to enriching the design theory of Chinese learning apps, offering practical optimization recommendations for developers, and supporting the continuous advancement of Chinese language learning apps.

Effect of alkali metal cations in alkaline iron battery electrodes

Abstract Rechargeable alkaline iron batteries (e.g. Ni-Fe and Fe-air) have been extensively studied recently as viable energy storage systems for renewable energy sources. However, inherent issues such as passivation of the iron and parasitic hydrogen evolution reaction (HER) on the electrode surface limit their full capability. Multiple approaches to improving iron electrode performance have been conducted, few of which focused on electrolyte composition. While alkali metal (AM) cations on the electrolyte do not directly participate in the electrochemical reactions, their intrinsic characteristics can dictate the performance of the electrode. Investigating the interface interactions and electrical double layer (EDL) structure can provide a deeper insight into the operation of iron electrodes in an alkaline solution. In this work, we investigated the effect of alkali metal cations (Li+, Na+, K+, Cs+) in the electrolyte solution in inhibiting passivation and HER on electrodeposited iron on carbon paper (Fe/CP) electrodes. The electrochemical measurements show that the iron redox and HER activities of the electrode increased with increasing cation size in the electrolyte. The non-covalent interactions between hydrated alkali metal cations and adsorbed OH species resulted to the formation of quasi-adsorbed clusters which can block active sites on the electrode surface. Furthermore, the concentration of these clusters decreases with increasing cation size which resulted to higher EDL capacitance and ECSA values of the electrode. The results of this work provide a better understanding of the surface reactions on iron electrodes and can help in developing novel techniques for suppressing passivation and parasitic HER on rechargeable alkaline iron batteries.

Study of pyrene-based covalent organic frameworks for efficient photocatalytic oxidation of low-concentration NO

This research presents the development of innovative pyrene-based COFs aimed at enhancing photocatalytic oxidation of low-concentration nitrogen oxide. By precisely modifying the structural length and incorporating additional functional groups into pyrene-based COFs, we identified TAPPy-DMTP-COF as the most effective performer. This COF, characterized by its shortest length and the presence of -OCH3 functional groups, demonstrated superior performance, likely due to reduced electron transfer resistance and the presence of additional oxygen active sites. Building on the potential of TAPPy-DMTP-COF, we developed a covalently linked Type-II heterostructure with g-C3N4. The resulting heterostructure, 40TAPPy-DMTP-COF/g-C3N4, with a 40 % mass fraction of TAPPy-DMTP-COF, was confirmed using SEM, XRD, and other techniques. It exhibited an exceptional photocatalytic efficiency of 45.8 % and NO3- selectivity of 97.4 %. This remarkable performance can be attributed to improved electron communication facilitated by chemical bonding, as confirmed by XPS results. Additionally, the optimized heterostructure interface not only improved electron transfer but also inhibited the recombination of electron-hole pairs. The growth of TAPPy-DMTP-COF on the surface of g-C3N4 significantly enhanced visible light absorption, as confirmed by UV–vis spectroscopy. This study not only underscores the importance of precise control over the structural features of pyrene-based COFs but also introduces a novel approach for enhancing NO oxidation. By constructing a covalently linked Type-II heterostructure, we have significantly enhanced the interface interaction within the heterostructure, leading to superior photocatalytic performance.

Microanalysis of behavior characteristics for asphalt binders on different mineral surfaces based on MD and SEM

To investigate the influence of different minerals on the behavior characteristics of asphalt binders at micro scale, molecular dynamics (MD) and scanning electron microscopy (SEM) were combined to study the interaction of asphalt binders and different mineral surfaces. Firstly, commonly used aggregates were analyzed by X-ray diffraction (XRD), and the main mineral categories were obtained, including quartz, albite, biotite and calcite. Secondly, the asphalt-mineral micro models were established by combining the reasonable asphalt micro model and mineral micro model, and the interface behavior characteristics were analyzed by MD simulation. Finally, the interface structure of asphalt and minerals was observed through SEM testing, which intuitively revealed the behavior characteristics of asphalt on different mineral surfaces. The results show that the relative concentration distribution of asphalt binders at the asphalt-mineral interface is relatively high, and it can be affected by mineral category, surface structure state and asphalt type. The transition zone of biotite, albite and asphalt interface is relatively wide, which means that the influence of biotite, albite and asphalt diffusion characteristics is relatively obvious, and the interface interaction ability is relatively strong. The study reveals the behavior characteristics of asphalt binders on different mineral surfaces, and provides a research basis for exploring the structural stability of asphalt-aggregate interface.

Construction of Fire Safe Thermoplastic Polyurethane/Reduced Graphene Oxide Hierarchical Composites with Electromagnetic Interference Shielding.

Incorporating outstanding flame retardancy and electromagnetic interference shielding effectiveness (EMI SE) into polymers is a pressing requirement for practical utilization. In this study, we first employed the principles of microencapsulation and electrostatic interaction-driven self-assembly to encapsulate polyethyleneimine (PEI) molecules and Ti3C2Tx nanosheets on the surface of ammonium polyphosphate (APP), forming a double-layer-encapsulated structure of ammonium polyphosphate (APP@PEI@Ti3C2Tx). Subsequently, flame-retardant thermoplastic polyurethane (TPU) composites were fabricated by melting the flame-retardant agent with TPU. Afterwards, by using air-assisted thermocompression technology, we combined a reduced graphene oxide (rGO) film with flame-retardant TPU composites to fabricate hierarchical TPU/APP@PEI@Ti3C2Tx/rGO composites. We systematically studied the combustion behavior, flame retardancy, and smoke-suppression performance of these composite materials, as well as the flame-retardant mechanism of the expansion system. The results indicated a significant improvement in the interface interaction between APP@PEI@Ti3C2Tx and the TPU matrix. Compared to pure TPU, the TPU/10APP@PEI@1TC composite exhibited reductions of 84.1%, 43.2%, 62.4%, and 85.2% in peak heat release rate, total heat release, total smoke release, and total carbon dioxide yield, respectively. The averaged EMI SE of hierarchical TPU/5APP@PEI@1TC/rGO also reached 15.53 dB in the X-band.