Interfacial Adhesion Performance Research Articles

Optimizing epoxy asphalt tack coat formulations for improved adhesion and working performance of ultrathin wearing course

Insufficient adhesion between ultrathin wearing courses (UTWCs) and substrate layers can result in pavement distress. Epoxy asphalt exhibits potential as a tack coat due to its high bonding strength and thermal stability. However, its rapid curing may pose challenges to construction schedules. This study aimed to optimize the formulations of epoxy asphalt tack coats (EATCs) to enhance the interfacial adhesion and working performance of UTWCs. The adhesion of EATCs was evaluated through rotational viscosity and tensile tests. Design parameters were optimized using analysis of variance and microscopic tests. Road performance was assessed via interlayer shear and tensile testing on three pavement structures. The results indicated that the curing agent strongly influenced the properties and curing kinetics of EATCs. Formulations containing complex polysebacic polyanhydride (CPSPA-EA) exhibited superior bonding while meeting construction schedules. Microscopic analysis of CPSPA-EA revealed a stable crosslinked network formed at 30% binder dosage. The amount of spraying significantly impacted the adhesion in UTWC structures. The optimal spraying amounts were 0.60 kg/m2 for asphalt concrete (AC-13), 0.55 kg/m2 for stone matrix asphalt (SMA-13), and 0.40 kg/m2 for cement concrete substrate layers. These findings presented an optimization framework for designing EATCs to enhance UTWCs working and long-term performance through balanced tack formulations and application parameters.

Designing multifunctional, 3D cross-linked network binder for actual use in high performance lithium ion batteries silicon based anodes

Binders have been proved to be an economical and effective approach for accelerating the industrial application of silicon based anodes. Herein, a 3D network binder (H-PAN-g-ECH) with multifunctional groups, is constructed by crosslinking polyacrylonitrile (PAN) hydrolysate (H-PAN) with epichlorohydrin (ECH). Strong polar groups carboxylate (-COO-) and amide (-CONH2) obtained from hydrolysis of PAN as well as the original cyanide (-CN) enhance the adhesive ability of H-PAN-g-ECH to not only active material but also current collector, and thus sustain the structure integrity of the electrode. In addition, the network structure proposed by linking H-PAN with short-chain molecules endows H-PAN-g-ECH with facilitated Li-ion transmission and improved mechanical property to accommodate the great volume variation of Si during cycling. The as-prepared H-PAN-g-ECH possesses multiple interfacial adhesion and robust mechanical performance, which improves the electrochemical property of silicon anode with high areal capacity. In combination with good processability, H-PAN-g-ECH is verified to be a superior binder in use of practical Si based anodes.

Investigation of nanoscale interfacial bonding properties in foamed asphalt cold recycled mixtures under chloride salt erosion

Salt-induced erosion from de-icing salts in Northern China and sea salt in Eastern coastal areas significantly compromises asphalt pavement integrity. A selection was made of four different types of foamed asphalt with different levels of water content, two types of aged asphalt, and three typical minerals (α-quartz, calcite, and bauxite), in addition to three chloride salt solutions (NaCl, CaCl2, MgCl2). It was found that (1) in dry conditions, the moisture level of foamed asphalt noticeably influences the adhesive performance at the juncture between asphalt and aggregates. Unlike acidic minerals, the bond strength between alkaline and neutral minerals and foamed asphalt increases as the water content of the foamed asphalt rises; (2) chloride salt solutions presence and increased levels significantly reduced the bond strength between asphalt and aggregates, particularly impacting neutral and alkaline minerals (in the presence of 10 % NaCl solution, the work of adhesion was reduced by 83.82 % and 87.48 %, respectively); (3) the influence of diverse chloride salts on the interfacial adhesive performance of asphalt mixtures varied, with the three chloride salts reducing the asphalt-aggregate interfacial adhesion work by 44.52 %, 21.90 %, and 34.94 %, respectively. (4) the investigation determined that the mineral composition considerably influences the hygroscopic sensitivity of asphalt mixtures. Minerals of an acidic nature exhibit superior moisture resistance when juxtaposed with alkaline counterparts, recommending the adoption of acidic aggregates in scenarios demanding elevated mixture stability.

Variation of SARA fractions of crumb rubber modified asphalt binder-aggregate interface system and its correlation with adhesion properties

The incorporation of rubber powder leads to a high degree of complexity in the CRMA binder-aggregate interfacial properties, which directly affects the interfacial adhesion performance. The objective of this study is to investigate the variation of SARA fractions of CRMA binder during the adhesion process and to explore the intrinsic relationship between the components and the adhesion properties. To this end, the staged extraction tests were performed to extract CRMA binder layers on the aggregate surface. After each extraction, the binder layer was evaluated in terms of its SARA fraction contents and molecular weight distribution. Additionally, the pull-off tensile strength (POTS) was used to assess the adhesion of the binder-aggregate interface through the binder bond strength (BBS) test. Finally, the correlation between the SARA fractions of CRMA binder and interface adhesion of CRMA binder-aggregate system was analyzed. The results showed that the CR tends to absorb the lighter components of base asphalt, the variations in SARA fractions and molecular weight distribution during the aggregate adhesion to CRMA binders occurred mainly in the third and fourth elution layers. Pen 70 CRMA binder and limestone show the best adhesion properties among all the binder and aggregate types. The increase in CR size and the decrease in CR dosage are favorable for the adhesion of CRMA binders to aggregates. Furthermore, asphaltenes and resins are positively correlated with adhesion, while aromatics and saturants are negatively correlated with adhesion. The correlation between SARA content and adhesion varied depending on the aggregate type.

An integrated, multi-functional intrinsic responsive foldable protective layer for space station solar panels

The functionalized foldable protective layer proficiently alleviates the potential detriment endured by space station solar panels due to prolonged and uninterrupted exposure to the environment. Soft actuators demonstrate significant value in foldable protective layers due to their intrinsic response characteristics and programmability. However, current soft actuators still struggle to meet the requirements of work stability and scene applicability in the space environment. A PMT (Polydimethylsiloxane (PDMS)/Multi-walled carbon nanotubes (MWCNTs)-Thermoplastic polyimides (TPI)) soft actuator was proposed to address this issue in this paper. The PMT soft actuators exhibit strong interlayer interfacial adhesion, stable physical and chemical performance, and excellent mechanical performance. Notably, the PMT soft actuators can sense thermal, electric fields, infrared light, and mechanical force simultaneously with only one active layer. Furthermore, analytical models were calibrated to provide predictions, and the thermal and photoelectric actuation processes of PMT soft actuators with different structures and application scenes were predicted accurately. The experimental results validated the application value of PMT actuators as foldable protective layers for space station solar panels. The preparation, testing, application, and model construction of the PMT system provide new research ideas and development opportunities for the practical application of functional polymers in intelligent sensing and actuation systems.

The Role of Surface Treatment and Coupling Agents for Adhesion between Stainless Steel (SUS) and Polyamide (PA) of Heterojunction Bilayer Composites.

The growing demand for lightweight and durable materials in industries, such as the automotive, aerospace, and electronics industries, has spurred the development of heterojunction bilayer composites, combining the structural integrity of metals with the versatility of polymers. This study addresses the critical interface between stainless steel (SUS) and polyamide 66 (PA66), focusing on the pivotal role of surface treatments and various silane coupling agents in enhancing the adhesion strength of heterojunction SUS/PA66 bilayer composites. Through systematic surface modifications-highlighted by scanning electron microscopy, atomic force microscopy, and contact angle analyses-the study assessed the impact of increasing the surface area, roughness, and energy of SUS. X-ray photoelectron spectroscopy evaluations confirmed the strategic selection of specific silane coupling agents. Although some coupling agents barely influenced the mechanics, notably, aminopropyl triethoxysilane (A1S) and 3-glycidyl oxypropyl trimethoxysilane (ES) significantly enhanced the mechanical properties of the heterojunction bilayer composites, evidenced by the improved lap shear strength, elongation at break, and toughness. These advancements were attributed to the interfacial interactions at the metal-polymer interface. This research underscored the significance of targeted surface treatment and the judicious selection of coupling agents in optimizing the interfacial adhesion and overall performance of metal-polymer composites, offering valuable insights for the fabrication of materials where reduced weight and enhanced durability are paramount.

Role of particle gradation of clay–sand mixtures on the interfacial adhesion performance of polymer coatings

Abstract The interface performance between clay–sand mixtures and concrete structures is governed by the mixture's composition and its physical properties. Moisture content and particle-size distribution play important roles in deciding the mixture's arrangement of soil particles, porosity, hydraulic conductivity and behaviour under various mechanical loadings. Application of a polymer interfacial coating can improve the bond performance between soils and concrete mainly via interfacial friction/mechanical interlocking. The present work analyses the development of interfacial strength between clay–sand mixtures and a polymer coating with changes in particle gradation. The multi-scale mechanisms at the interface are investigated, giving primary attention to soil porosity. A 50:50 clay–sand mixture exhibited a greater interfacial adhesive performance compared to other soil mixtures. In addition, the moisture-controlled pores and gradation-controlled pores demonstrated differences in macroscale interfacial strength. Both mercury intrusion porosimetry (MIP) and 129Xe nuclear magnetic resonance (NMR) were utilized to detect the pore structure of the mixtures. 129Xe-NMR revealed the pore distribution of the mixtures as ranging from macropores to nanopores, and MIP complemented the pore information by determining the critical pore entry diameter in the macropore regime. Mesopores dominated with increasing fine sand content until a threshold value was reached; thereafter, merging of pores occurred and macropores dominated.

Carbon nanotube composites fabricated through filament winding process for battery preheating application

AbstractCarbon nanotube (CNT) polymer composites have broad application prospects in thermal management as electrothermal heaters. Nevertheless, challenge remains in achieving high electrical conductivity for the composites due to the contradiction between CNTs and insulated polymers. To address this issue, herein, innovative use of interface strategy approach by constructing synergistic nanomaterial networks on carboxyl CNTs yarn winding composites for improving the interfacial adhesion and electrical performance. In the work, carboxyl CNTs yarn/CNTs‐graphene oxide (GO) polyvinyl alcohol (PVA) composites (C‐CY‐HP‐C) were proposed and manufactured via filament winding process. The as‐constructed C‐CY‐HP‐C demonstrated a remarkable interfacial shear strength of 2057.16 N mm−1, which was 53.59% higher than that of control CNTs yarn/PVA winding composites. In addition, the C‐CY‐HP‐C achieved an attractive electrical conductivity of 346.39 S cm−1 owing to the electronic transmission channels were formed. Notably, the superior electrical conductivity facilitated a rapid‐response of electrothermal performance for the C‐CY‐HP‐C. It reached a steady‐state temperature of 229.9°C within 10 s when the voltage was 1.2 V. Concurrently, it exhibited an impressive heating rate of 10.8°C min−1 at an ambient temperature of −20°C as the battery surface heater. These findings shed light on the development of technique for battery preheating system based on CNTs yarn/polymer composites.

A novel one-step eco-friendly dipping system for PA66 fiber/rubber composites with excellent interfacial adhesion and its adhesion mechanism

Fiber-reinforced rubber composites (FRRC) are widely used in tires, hoses, conveyor belts and other fields. Currently, the industry heavily relies on the resorcinol-formaldehyde-latex (RFL) system to enhance interfacial adhesion performance of FRRC; however, both resorcinol (R) and formaldehyde (F) pose significant risks to human health and the environment. Thus, some two-step RF-free dipping systems have been developed to replace RFL system. Nevertheless, these complex two-step systems face challenges during industrialization. In this study, we proposed a novel one-step eco-friendly dipping system (PCGL) for polyamide66 (PA66)fibers. By using the new system, a solid transition bridge between PA66 fiber and rubber matrix can be formed, due to the bonding between PA66 and isocyanate, the interaction among polyacrylic acid resin, isocyanate and epoxy, the catalytic effect of triethanolamine, as well as the co-crosslinking of styrene-butadiene-vinyl-pyridine latex and rubber. The interfacial adhesion performance of PA66 fiber/rubber composites treated by PCGL with optimized ratio of epoxy groups/isocyanate groups can reach more than 90% of RFL level, meeting industry requirements for high interfacial bonding performance, while maintaining strength and safety of composites. The mechanism of largely enhanced interfacial adhesion was revealed through the analysis of modulus transition and co-crosslinking at the composite interface.

Revisiting bitumen-clay interaction using molecular dynamics: The role of surfactants

Clay has been extensively applied in the research field of modified bitumen to impart excellent anti-aging properties. However, the tendency of agglomeration and nonuniform dispersion in bitumen compromises its modification effect. Surface functionalization of clay holds promise for addressing this issue by enhancing the bitumen-clay interfacial bonding strength to overcome clay self-aggregation, but it requires a profound understanding of bitumen-clay interactions. To explore the interaction mechanisms between diverse surface functionalized clay (also named organoclay) with bitumen at the molecular level and screen out the best one, this study selected four types of surfactants: cetyltrimethylammonium bromide (CTAB), benzethonium chloride (Byssonium), polyquaternary ammonium salt-11 (PolyQAC-11), and CTAB/3-aminopropyltriethoxysilane (CTAB/APS), for surface functionalization of clay (Expanded vermiculite, EVMT). Molecular dynamics simulations were employed to determine the distribution patterns and diffusion characteristics of bitumen molecules, and the interaction energy of bitumen and clay, as well as the uniaxial tensile performance of the bitumen-clay interface. The results show that variations in types and loadings of surfactants cause distinct distribution patterns of bitumen subfractions at diverse bitumen-organoclay interfaces. Additionally, Byssonium-EVMT and PolyQAC-11-EVMT display a preference for adsorbing aromatics and resins. The introduction of surfactants significantly reduces the diffusion rates of various bitumen subfractions within the interfacial system. In terms of interaction energy, the compatibility of different clay with bitumen can be ranked as follows: Byssonium-EVMT > Na + -EVMT ≈ PolyQAC-11-EVMT > OVEMT > APS-OEVMT. The findings from tensile simulations agree well with the judgments derived from interaction energy, suggesting that Byssonium-EVMT is the optimal choice for surface functionalization, owing to its outstanding interfacial adhesion performance. This study advances the understanding of compatibility between bitumen and clay, providing theoretical insights for the development of clay-modified bitumen with improved compatibility.

Tailoring interfacial adhesion and mechanical performance of biocomposites based on poly(lactic acid)/rice straw by using maleic anhydride through reactive extrusion process

AbstractIn this study, all‐green biocomposites based on poly(lactic acid) (PLA)/rice straw (RS) as an agricultural waste were prepared, and the physical, structural, and mechanical properties of these biocomposites were enhanced by alkali‐pulping of RS and chemical grafting of PLA onto the lignocellulosic fiber. The reactive compatibilizers of maleic anhydride grafted PLA (PLA‐g‐MA) were obtained through a reactive extrusion process at different processing conditions. The probable chemical reactions between the functional groups of PLA‐g‐MA with hydroxyl groups of RS pulp as well as the end groups of PLA chains can effectively improve the interfacial adhesion between the filler and matrix. However, the findings confirm the great importance of PLA‐g‐MA chemical structure in controlling the biocomposite performance. By choosing proper processing conditions for preparing PLA‐g‐MA and incorporating this compatibilizer into the PLA/treated RS biocomposite, Young modulus, tensile strength, impact strength, and tensile toughness of the PLA/RS biocomposite increased by 101%, 156%, 96%, and 327%, respectively.

Lightweight polyethylene terephthalate bead foams with good interfacial adhesion and thermal insulation performance fabricated by supercritical carbon dioxide secondary foaming strategy

AbstractThis paper reported the novel supercritical carbon dioxide (scCO2) secondary foaming and molding strategy to prepare the thermal‐insulation polyethylene terephthalate (PET) bead foam part with good interfacial adhesion and high expansion ratio. The incorporation of porous structure could effectively enhance the blowing agent solubility and fabricate the system viscosity difference, which contributed to the expansion and further welding of the expanded PET beads. Under the optimum foaming conditions, PET bead foam parts with excellent comprehensive performance were successfully prepared by molding method in the confined space via scCO2 secondary foaming, and the corresponding welding mechanism of PET beads was further investigated. The obtained foam parts possessed good tensile and compressive properties, reaching 1.03 and 1.27 MPa (at 20% strain) respectively. Besides, the foam part exhibited the low thermal conductivity of 0.060 Wm−1 K−1, which confirmed the improvement of thermal insulation performance owing to the high expansion ratio.

High erosion resistance thermoplastic polyurethanes composites fabricated via intercalation reinforced interfacial interaction

AbstractThe weak interface and poor dispersion of carbon nanofillers in polymer matrix composites lead to a significant decrease in their performance, restricting the development of polymer nanocomposites. In this work, a highly facile strategy has been developed to improve the interfacial adhesion performance between graphene nanoplates (GNP) and thermoplastic polyurethanes (TPU) matrix via self‐polymerization of dopamine. Then, single‐walled carbon nanotubes (CNT), as reinforcing agent, were introduced into surface modified GNP solution to prepare the corresponding ternary composites. Scanning electron microscope images show that GNP and CNT formed 3‐D interconnecting network‐like architecture. The sample modified with three layers of nonwoven fabric decorated with 1.0 mg/mL nanomaterial exhibit a tensile strength 35% higher than that of the virgin TPU. Consequently, compared with virgin TPU, the erosion resistance and thermal conductivity are enhanced by 78% and 45%, respectively.

Polyetherimide nanocomposites filled with in‐situ synthesised bismaleimide‐DDE@CCTO hybrid nanofibers enabling improved dielectric and interfacial performance

AbstractMost current research of nanocomposite dielectrics for modern electronic devices and electric equipment usually focuses more on dielectric properties while in some extent ignoring the interfacial adhesion characteristics. However, the poor interfacial adhesion frequently results in serious dielectric field distortion, which would in return impair the dielectric performance enhancement. As such, how to simultaneously achieve the excellent dielectric properties and interfacial adhesion performance in organic‐inorganic nanocomposite system is worth in‐depth investigation. To realise this aim, novel hybrid nanofibers are neatly fabricated using in situ copolymerisation reaction of bismaleimide and diamino‐diphenyl ether monomers on the CCTO nanofiller surface via covalent bond connections. The resulting nanocomposites achieve high dielectric constant (9.3) and low dielectric loss (0.0185) at 1 kHz. The BMI‐DDE@CCTO/PEI yields a high discharge energy density (3.09 J/cm3) at moderate electric field (200 MV/m). Noticeably, the nanocomposites enable stable dielectric performance over a wide temperature range from room temperature to 150°C. Moreover, the binding energy for BMI‐DDE and PEI is 1052 kJ/mol according to DFT calculation. As such, the authors speculate this interesting study would inspire the broad researchers devoting to investigating bismaleimide‐coated high‐aspect‐ratio nanofillers and their dielectric materials for collaboratively improved dielectric and interfacial performance.

Evaluation of the interface adhesion mechanism between SBS asphalt and aggregates under UV aging through molecular dynamics

The bonding characteristics between asphalt and aggregates have an important role in influencing the strength of asphalt mixtures. To clarify the bonding mechanism at the interface between SBS asphalt and aggregates under UV aging conditions, this research developed molecular models of the interface between SBS asphalt and representative aggregates including quartz (granite), augite (basalt), and calcite (limestone). Subsequently, dynamic simulations were performed on the interface models to assess the adhesive properties. Adhesion work was employed to assess the interfacial adhesion performance between SBS-modified asphalt and various types of aggregates. The results demonstrated that SBS asphalt exhibited significantly higher adhesive work with alkaline aggregates, following the order of limestone > basalt > granite in terms of adhesive strength. The dominant contributor to adhesive work was van der Waals interactions, with electrostatic interactions playing a crucial role in influencing variations in adhesive work among different aggregates. After the aging-induced fracture of SBS materials, there was a noticeable increase in the gap between them and the aggregates, resulting in a significant reduction in the adhesion effectiveness between SBS and aggregates. Aged asphaltene and colloid exhibited heightened polarity, resulting in enhanced electrostatic interactions between asphalt and aggregates, thus reducing adsorption distances and elevating adhesive work. This research provides comprehensive evaluation of the bonding mechanism between asphalt and aggregate under UV aging conditions at the molecular level, and provides guidance for the design of durable asphalt pavements.

Effect of coating thickness on interfacial adhesion and mechanical properties of Cr-coated zircaloy

The tensile failure behavior of the Cr-coated zircaloy (Zr-4) was investigated. The effect of the coating thickness on the interfacial adhesion of the samples was studied by observing the real-time process of tensile. The interfacial adhesion of the Cr coating was quantitatively evaluated using finite element analysis and shear strength theory. In addition, the crack propagation behavior of the Cr-coated samples was investigated. Results showed that the interfacial shear strength and the interfacial adhesion performance decreased with the increase of the coating thickness. However, the protective effect on the substrate increased with the increase of the coating thickness. Furthermore, the path of the crack propagation at the interface between the coating and the substrate also changed as the coating thickness increased. The cracks at the interface of the thinner coating expanded easily into the substrate, causing the local damage. The cracks of the thicker coating were more likely to propagate along the interface, resulting in the adhesive failure.

Micro-characterization of the adhesion properties and mechanisms at the asphalt-silica aggregate interface under combined thermal-oxygen aging and chloride salt erosion

In this investigation, various Atomic Force Microscopy (AFM) probes were used to characterize changes in the adhesion properties of aged asphalt under different concentrations of chloride salt. The characterization included analyzing the surface morphology, roughness parameters, height-height correlation function (HHCF), and force-distance curves of the asphalt. Additionally, Molecular Dynamics (MD) simulation was employed to reveal the underlying mechanisms that govern changes in adhesion properties between aged asphalt and aggregate when subjected to chloride salt erosion. Interfacial erosion and internal erosion models were constructed to facilitate a comprehensive analysis from multiple perspectives. The results demonstrate that chloride salts interact with the interface between asphalt and silica aggregates, engaging in competitive adsorption with the asphalt. The strength of this competitive adsorption is influenced by the constituents of the asphalt and the concentration gradient of chloride salts both within and outside the asphalt matrix. Under this concentration gradient, polar components are attracted to the asphalt surface by chloride ions, forming triangular adsorption structures with water molecules and aggregates such as asphaltene. Components with lower polarity exhibit distinct distributions and diffusion states due to variations in molecular weight and spatial configuration. As the concentration of chloride salts increases, the concentration gradient intensifies, resulting in enhanced transformations, migrations, and dissolutions of asphalt components. Consequently, the micro-morphology of the asphalt tends to smoothen, the HHCF undergoes significant modifications, roughness decreases, and the adhesion performance between asphalt and aggregate weakens. Moreover, at higher concentrations, the formation of precipitated chloride salt crystals disrupts the continuity of the asphalt, further compromising interfacial adhesion performance. This study is expected to provide theoretical guidance for the modification of asphalt and the improvement of asphalt pavement lifespan in complex service environments.

Experimental study of interfacial adhesion performance of prefabricated UHPC-NC diagonal shear groove

The reinforced lining of the tunnel was carried out using a prefabricated composite structure consisting of Ultra-High Performance Concrete (UHPC) and Normal Concrete (NC), utilizing a semi-post-pouring method. The bond performance between UHPC and NC is crucial for enhancing the overall stability and safety of the tunnel. To investigate the influence of interface construction on the bond performance at the UHPC-NC interface, inclined shear tests were conducted with variations in groove density, groove morphology, groove aspect ratio, and interface angle. The results revealed four different failure modes of the grooved specimens, with over 80% exhibiting failure at the interface between UHPC and NC. The average interface bond strength of the grooved specimens was found to be 5.8 times higher than that of the untreated interface group, indicating a significant improvement in the bond performance of the UHPC-NC interface due to the presence of grooves. When the volume loss ratio was below 0.09, the interface bond strength of the UHPC-NC interface increased with an increase in groove density. The interface bond strength of the 60° trapezoidal grooves was 80% higher than that of the right-angle grooves, while the interface bond strength of the 40° trapezoidal grooves was 28% higher than that of the right-angle grooves. Furthermore, the interface bond strength decreased as the angle between the interface and the horizontal plane increased. The precast inclined shear grooves exhibited a bond-slip curve that consisted of an initial slow-rise stage, an elastic rise stage, a yield stage, and a failure descent stage, with some specimens not exhibiting a distinct yield stage. In this study, a bond-slip model for the precast UHPC-NC inclined shear grooves was proposed, and recommendations for bond stiffness were provided.

Polycaprolactone/hydroxyapatite coating on spark generated Mg surfaces to promote anticorrosion and interfacial adhesion strength

Surface coatings have been widely accepted to tailor the degradation rate of Mg alloys for bioimplant applications. Nevertheless, poor adhesion strength resulting in debonding and delamination compromises their corrosion resistance. In the present study, Polycaprolactone/Hydroxyapatite (PCL/HA) coatings have been developed on different textured Mg surfaces obtained under optimized low discharge energy (LDE) and high discharge energy (HDE) conditions of wire electric discharge machining (WEDM). Since discharge energy influences the surface texture of WEDMed Mg alloy, coating on LDE treated surface (LDEedcoated) and coating on the fine-polished surface (Polcoated) showed homogeneous and defect-free coating morphology with contact angles (CA) of 87.85°, 94.05° with simulated body Fluid (SBF) while coating on HDE treated surface (HDEedcoated) displayed spatial defects, lowering the CA. On the LDEedcoated sample, physical anchoring, H2 bonding, and electrostatic interactions combinedly improved the coating's adhesion strength to 9.91 N, 4.5 times higher than the polished counterpart. LDEedcoated samples significantly suppressed the Icorr to 9.74 × 10−9 A/cm2, resulting in 75 % and 99.8 % higher corrosion inhibition efficiency (ηc) after 24 h compared to Polcoated and HDEedcoated samples. After 7 days of in-vitro immersion, the hydrogen evolution rate (HER) of the LDEedcoated sample (0.034 mL/cm2/day) was nearly 2.8 and 35 times lower than Polcoated and HDEedcoated samples, respectively. Superior anticorrosion performance and Ca-P rich apatite growth on LDEedcoated samples significantly improved the cellular viability of L929 cells. WEDM treatments at LDE settings offer a facile method for the preparation of 'substrate-anchored' coating systems with enhanced interfacial adhesion and anticorrosion performance on Mg alloys for clinical translation.

Adjusting the interfacial adhesion via surface modification to prepare high-performance fibers

Ultra-high molecular weight polyethylene (UHMWPE) fiber is a new kind of high-performance fiber. Due to its excellent physical and chemical characteristics, it is widely used in various fields. However, the surface UHMWPE fiber is smooth and demonstrates no-polar groups. The weak interfacial adhesion between fiber and resin seriously restricts the applications of UHMWPE fiber. Therefore, the surface modification treatments of UHMWPE fiber are used to improve the interfacial adhesion strength. The modified method by adding nanomaterials elucidates the easy fabrication, advanced equipment and proper technology. Thus, the progress of UHMWPE nanocomposite fibers prepared via adding various nanofillers are reviewed. Meanwhile, the effects of other various methods on surface modification are also reviewed. This work advances the various design strategies about nano technologies on improving interfacial adhesion performance via treatment methodologies.