Good Mechanical Properties Research Articles

Layer-by-Layer Construction of Antibacterial and Anticoagulant Blood Contacting Materials.

Vascular transplantation is a common treatment for Cardiovascular disease (CVD). However, the mismatch of mechanical, structural, or microenvironmental properties of materials limits the clinical application. Therefore, the functional construction of artificial vessels or other blood contact materials remains an urgent challenge. In this paper, the composite nanofibers of polycaprolactone (PCL) with dopamine and polyethylenimine (PEI) coating are first prepared, which are further self-assembled by anticoagulant hirudin (rH) and antimicrobial peptide (AMP) of HHC36 through layer-by-layer (LBL) method. The results of FTIR and XPS analysis show that hirudin and AMP are successfully loaded on PEI-PDA/PCL nanofibers and the hydrophilicity is improved. They also show good mechanical properties that the ultimate tensile strength and elongation at break are better than natural blood vessels. The antibacterial results show that the antibacterial effect is still 93% against E. coli on the fifth day because of the stable and continuous release of HHC36 and rH. The performance of anticoagulant activity also exhibited the same results, which APTT is even 9.7s longer in the experimental group than the control group on the fifth day. The novel materials would be effectively solve the formation of thrombosis around artificial blood vessel grafts and the treatment of inflammation.

A Single Component, Single Layer Flexile Foam Evaporator with the Higher Efficiency for Water Generation.

One of the greenest and promising ways to solve the problem of freshwater crisis is surface solar steam generation from seawater. A great number of photothermal materials with multi-component and multi-layered delicate yet complex structures often suffer from either low evaporation rate or high energy loss. Here, we present a single component foam evaporator with steam generation rate of up to 4.32kg m-2 h-1 under 1 sun irradiation. The evaporator is constructed from an aniline oligomer as a single light-absorbing component, covalent linked with polyethylene glycol to form a monolithic polymer foam. Floating on the seawater, the foam has absorbance of 99.5% over the entire solar spectral range and low thermal conductivity (0.0077W K-1m-1) that effectively retains heat in the material and at the interface. After 3 months of continuous outdoor natural sunlight irradiation, the evaporator maintains a stable and durable evaporation rate. Moreover, the materials have good mechanical properties (7.48MPa young's modulus and 57.38% elongation at break) and excellent chemical resistance in 10 common organic solvents and aqueous solutions of pH = 1 to 14. This study provides a new system and strategy for desalination, steam power generation, treatment of polluted water and sewage, etc. This article is protected by copyright. All rights reserved.

Sulfonated cobalt phthalocyanine/NH2-MIL-125 heterojunction modified electrospun nanofiber membrane for emulsion separation and PMS-photocatalysis synergistic degradation

Membrane technology for wastewater remediation has generated significant interest, however, the single functionality, dull wettability and easy fouling property of the membrane hinder its practical application. Herein, a self-cleaning and multi-use superwetting nanofiber membrane was prepared by electrospinning and subsequent spraying technique. The sulfonated cobalt phthalocyanine/NH2-MIL-125 (CoPcS/NMIL) heterojunction was uniformly enrobed over polyethylene terephthalate (PET) electrospun membrane derived from waste PET bottles. The unique CoPcS/NMIL heterojunction exhibited a dual driving effect in photocatalytic activity and membrane wettability. Therefore, the fabricated CoPcS/NMIL@PET composite membrane demonstrated its capability to address complex water pollution issues effectively. The composite membrane exhibited notable flux permeation ability (538–3180 L m−2 h−1) and achieved excellent separation efficiency of over 99 % for diverse oil-in-water emulsions under the gravity filtration condition. Notably, the membrane can efficiently deal with stubborn high-viscosity crude oil fouling profiting from the photocatalytic self-cleaning function. A high flux recovery ratio of 93.6 % and a low irreversible fouling resistance ratio of 6.4 % can be obtained after 30 min of visible light irradiation. Impressively, CoPcS/NMIL@PET membrane exhibited enhanced permeation flux, separation efficiency and self-cleaning capacity compared to NMIL@PET membrane. Meanwhile, the CoPcS/NMIL@PET-activated peroxomonosulfate (PMS) system exhibited extremely high degradation performance for RhB under visible light with the degradation efficiency of 98 % within 10 min, suggesting its potential in the rapid purification of water-soluble organic pollutants. In addition, the CoPcS/NMIL@PET membrane has good chemical stability and mechanical properties for potential long-term use. Moreover, the demulsification mechanism in oil-water separation and PMS-photocatalysis synergetic mechanism over the fabricated CoPcS/NMIL@PET membrane were also investigated in detail. The research offers a promising approach for the design and fabrication of novel nanofiber membranes that incorporate photosensitizers and MOFs functional surfaces to address the challenges associated with such wastewater treatment.

High-entropy carbide (ZrNbTiCrV)C ceramic composite coating possessing good mechanical properties and wear resistance

High entropy carbide ceramics possess high hardness but suffer from low toughness and densification challenges. A dense (ZrNbTiCrV)C composite coating was fabricated through spraying ZrO2-Nb2O5-TiO2-Cr2O3-V2O5-Al-SiC powders, which was subsequently compared to a (ZrNbTiCrV)C coating produced from binary carbides. Incorporating the V element facilitated the densification and element diffusion. The coating obtained via spraying ZrO2-Nb2O5-TiO2-Cr2O3-V2O5-Al-SiC powders exhibited superior mechanical properties and wear resistance, particularly achieving a 17.2 % increase in fracture toughness and a 73.3 % reduction in wear rate compared to the coating derived from binary carbides. These improved properties were attributed to fine-grained particles and a low porosity of 1.56 %. Wear resistance was also enhanced through rolling friction and the formation of a protective oxide film.

Solving the dilemma between reprocessability and mechanical properties faced by recyclable bio-based polyurethane foam through confining imine bonds in the hard domains

Introducing dynamic covalent bonds (DCBs) into polyurethane (PU) foams can solve the problem of their poor recyclability. However, a dilemma arises between reprocessability and mechanical robustness because of the low bond energies of DCBs. In this work, an aromatic diol (VAN-AM) containing imine bonds is synthesized to serve as the polyol together with castor oil. A series of bio-based polyurethane foams (BPUFs) with tunable bio-based carbon content, apparent density, cell properties and mechanical properties are prepared by adjusting the proportions of VAN-AM and castor oil. Benefiting from the molecular rigidity of VAN-AM, the dynamic imine bonds are enriched in the hard domains of PU. This allows for the kinetic control of the dynamicity of the PU networks. When the foams work at ambient temperature, which is much lower than the glass transition temperature of PU (113 ºC), the frozen segments of the hard domains inhibit the dynamic behavior of the imine bonds even if the latter may be somewhat activated (their triggering temperature ≈ 50 ºC). Consequently, the good mechanical properties of BPUFs can be maintained during service. At higher temperatures (> 113 ºC) or swollen state, the segmental mobility in the hard domains and dynamicity of imine bonds are greatly enhanced. Recycling of BPUFs is enabled as evidenced by hot-pressing the crushed foams into the compact sheets under mild conditions. The findings would facilitate the rational design of crosslinked polymeric foams with both high reprocessability and mechanical performance.

Construction of biodegradable superhydrophilic/underwater superoleophobic materials with CNF (cellulose nanofiber) fence-like attached on the surface for efficient oil/water emulsion separation

Superhydrophilic/underwater superoleophobic materials for the separation of oil-water emulsions by filtration have received much attention in order to solve the pollution problem of oil-water emulsion. In this paper, a fence-like structure on the surface of CNF/KGM (Konjac Glucomannan) materials by a simple method using CNF instead of metal nanowires was successfully developed based on the hydrogen bonding of KGM and CNF. The resulted organic CNF/KGM materials surface has outstanding superhydrophilic (WCA = 0°) in air and superoleophobicity (OCA≥151°) in water, which could separate oil-water mixtures with high separation efficiency above 99.14 % under the pressure of the emulsion itself. The material shows good mechanical properties because of the addition of CNF and has outstanding anti-fouling property and reusability. More importantly, the material can be completely biodegraded after buried in soil for 4 weeks since both of KGM and CNF are organic substances. Therefore, it may have a broad application prospect in the separation of oil-water emulsion because of its outstanding separation properties, simply preparation method and biodegradability.

Thermoplastic polyimide with good comprehensive performance based on carbazole groups and short flexible linkages

AbstractThermoplastic polyimides (TPIs) can meet the requirements of advanced electronic packaging such as flexible copper clad laminate (FCCL) applied under extreme conditions, attributed to their excellent thermal stability, mechanical properties, electrical insulation and chemical resistance. With the increasing demands for electronic devices, such as applications in high‐frequency communication, it is highly desirable to develop high‐performance TPI with good thermoplasticity, thermal stability, mechanical properties and dielectric properties. However, there is a trade‐off between thermoplasticity and other properties. Herein, we introduce an effective strategy to afford TPIs with good performance by copolymerization of a diamine monomer consisted of a coplanar aromatic carbazole group and a short flexible linkage methylene group. On the one hand, short flexible linkages help improve the flexibility of polymer chains and are not too much to enable small‐scale molecular motions below Tg. On the other hand, coplanar aromatic donor groups benefit to strong charge transfer complex (CTC) interaction and π‐π stacking interaction. Based on this strategy, the resultant TPI possesses good thermoplasticity with a proper Tg of 348 °C. Meanwhile, it preserves a low coefficient thermal expansion of 48 ppm K−1, low dielectric constant/dielectric loss factor of 3.27/0.0073 at 10 GHz, and tensile strength of ca. 78 MPa.

Carbon nanotube filled rubber nanocomposites

Rubber (elastomer) based polymer nanocomposites have attracted wide range of attention from industries and other fields due to its exceptionally good mechanical, thermal and electrical properties. One of the promising candidates of this category is CNT filled rubber nanocomposites. This review throws light on the historical trajectory of development of CNT filled rubber nanocomposites. Various fabrication methods, detailed explanation of reinforcement mechanism in CNT/rubber nanocomposites and the relationship between the structure and properties are reviewed. The next part of the review discusses about the morphological and interface characteristics. An attempt to investigate the versatile mechanical, thermal, and electrical properties also included in the review. The final part of the review includes the applications of CNT filled rubber nanocomposites. Major applications in fields like electronics, sustainable biomedical and EMI shielding are discussed in detail. The review also focuses on the key challenges that arises while incorporating CNTs into rubber matrices.

DESIGN AND OPTIMIZATION OF ESCITALOPRAM OXALATE ORAL DISSOLVING FILMS BY RESPONSE SURFACE METHODOLOGY

Objective: To develop and optimise the oral dissolving films of escitalopram oxalate by response surface methodology. Methods: Oral dissolving film compositions were optimized by central composite design. The films are prepared by solvent casting method. Initially, different polymers were screened and based on the results polyvinyl alcohol was selected as polymer, propylene glycol was selected as plasticizer. Concentration of polymer and concentration of plasticizer were fixed as independent variables; tensile strength, percent elongation, elastic modulus and amount dissolved up to 5 min (%D5 min) were taken as responses. Results: The prepared films exhibited good surface characteristics. The thickness, uniformity of weight, surface pH and drug content are within acceptable range. The mechanical properties like tensile strength, folding endurance, percent elongation and elastic modulus were determined. The statistical analysis showed that polymer concentration has a positive effect on disintegration time and the plasticizer concentration has a significant effect on folding endurance. The prepared film relesases nearly 95% at the end of 5 min. The design space was used to optimize the quantities of polymer and plasticizer. The comparison of checkpoint experiment batch responses are corelating with the predicted responses. Conclusion: Escitalopram oxalate oral dissolving films was successfully designed and optimized by response surface method. It was concluded that the prepared films exhibit good mechanical properties and maximum release within 10 min.

An adaptive biodegradable zinc alloy with bidirectional regulation of bone homeostasis for treating fractures and aged bone defects

Healing of fractures or bone defects is significantly hindered by overactivated osteoclasts and inhibited osteogenesis in patients with abnormal bone metabolism. Current clinical approaches using titanium alloys or stainless steel provide mechanical support but have no biological effects on bone regeneration. Therefore, designing and fabricating degradable metal materials with sufficient mechanical strength and bidirectional regulation of both osteoblasts and osteoclasts is a substantial challenge. Here, this study first reported an adaptive biodegradable Zn-0.8 Mg alloy with bidirectional regulation of bone homeostasis, which promotes osteogenic differentiation by activating the Pi3k/Akt pathway and inhibits osteoclast differentiation by inhibiting the GRB2/ERK pathway. The anti-osteolytic ability of the Zn-0.8 Mg alloy was verified in a mouse calvarial osteolysis model and its suitability for internal fracture fixation with high-strength screws was confirmed in the rabbit femoral condyle fracture model. Furthermore, in an aged postmenopausal rat femoral condyle defect model, 3D printed Zn-0.8 Mg scaffolds promoted excellent bone regeneration through adaptive structures with good mechanical properties and bidirectionally regulated bone metabolism, enabling personalized bone defect repair. These findings demonstrate the substantial potential of the Zn-0.8 Mg alloy for treating fractures or bone defects in patients with aberrant bone metabolism.

Interpenetrating network based on soybean protein isolate and carboxymethyl chitosan: Investigation of intermolecular reaction mechanism, physicochemical stability and in vitro release properties of the hydrogel

In this study, interpenetrating network (IPN) hydrogels were constructed from soybean protein isolate (SPI) and carboxymethyl chitosan (CMCS) using TGase and genipin (GP) as cross-linking agents. And the influence of IPN formation on the physicochemical properties of hydrogels was illuminated. Multispectral analyses showed that there was a strong interaction between SPI and CMCS, which also promoted the increase of disulfide bonds and hydrophobic interactions in the hydrogels. The IPN was the densest when the addtion of SPI and CMCS were 10% and 3%, respectively. Meanwhile, this structure endowed the hydrogels with good mechanical properties and allowed them to exhibit thixotropy in rheological tests. The LF-NMR results showed that the IPN had a strong binding ability with water molecules and could effectively maintain the water in the hydrogel after freeze-thaw. Moreover, SPI-CMCS IPN hydrogels were pH responsive. This enabled it to adjust its own structure when pH changed, and to achieve controlled release of bioactives during simulated in vitro digestion. Overall, the results of this study showed that the IPN network formed by SPI and CMCS can effectively improve the performance of hydrogel. These results demonstrated the potential of SPI and CMCS as hydrogel synthesizers and provided a theoretical basis for the application of SPI-CMCS IPN hydrogel.

Self‐healing waterborne polyurethane elastomers based on synergistic hydrogen, disulfide and borate bonding for composite conductors

AbstractAs a functional material, polyurethane elastomers have found different applications in a variety of fields such as flexible electronics and smart coatings, but due to the damage during use, they are often endowed with self‐healing properties. However, conventional intrinsically self‐healing polyurethanes often don't balance excellent mechanical and self‐healing properties, so it has become crucial to prepare polyurethane elastomers with excellent self‐healing properties and high mechanical properties. In this study, a self‐healing waterborne polyurethane elastomers (IP‐DTDAx‐BAy‐WPU‐n) was synthesized based on 4, 4‐diaminodiphenyl sulfide (DTDA) boronic acid (BA). The disulfide bond has high motility at low temperatures and induces molecular‐level healing at the damaged interface, contributing to good repair under mild conditions. The borate ester bond limits intermolecular chain slippage and improves the mechanical properties as a dynamic cross‐linking point, while its dynamic reversible effect can synergistically improve the self‐healing ability. The results show that the synthesized elastomer films have good mechanical properties (strength 23.21 MPa, elongation at break 1259.08%, toughness 83.28 MJ m−3), good elastic recovery and self‐healing properties (93%). Furthermore, a composite conductors (IP‐DTDAx‐BAy‐WPU/AgNWs) with self‐healing properties was prepared by compositing AgNWs nanowires with polyurethane elastomers, which laid the foundation for its application in flexible electronic devices and wearable sensing devices.

Corrosion and fretting-corrosion behavior of Zr-Nb alloy under aqueous LiOH solution

Zirconium alloys are the key materials for nuclear reactor’s core components due to low neutron cross-section and good mechanical and corrosion properties. During operation in nuclear reactor, some core components (exposed to the corrosive environment of coolant water having LiOH) may undergo corrosion and fretting-corrosion. This work presents a novel experimental approach for investigating the Zr-2.5 Nb alloy's corrosion and in-situ fretting-corrosion response. The corrosion analysis was performed using Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization, to study the effect of LiOH concentration in water and exposure duration. It is observed that the corrosion rate increases with increasing the concentration of LiOH in water and decreases with increasing the exposure duration. The fretting-corrosion tests were performed between SS-410 and Zr-2.5 Nb in aqueous LiOH solution. The results reveal that the contact resistance and coefficient of friction (COF) decrease with increasing concentration of LiOH in the solution. The present work highlights the scientific understanding of corrosion and fretting-corrosion phenomena in zirconium alloy and elucidates key mechanisms and factors governing the degradation behavior which can help in preventing the failure of the components.

A review of the emerging approaches for developing multi‐scale filler‐reinforced epoxy nanocomposites with enhanced impact performance

AbstractFiber‐reinforced polymer composites (FRPCs) are utilized for myriad applications owing to their exceptional characteristics like high specific strength and stiffness. However, the low‐to‐moderate impact strength of these materials is a major constraint restricting their usage in fields requiring high‐impact performance. To ensure the reliable performance of FRPCs throughout the intended life span, a combination of good static mechanical properties and high impact resistance is crucial. Recent advancements in this field have yielded a breakthrough by developing novel materials that overcome this limitation. This groundbreaking achievement was realized by processing epoxy‐based GFRPs containing a synergistic blend of surface‐modified nano‐clay and compatibilized polymeric fiber micro‐reinforcement. This review provides an overview of advancements in the development of FRPCs, starting from the single‐filler to multi‐scale filler‐reinforced materials. The review elaborates on the effect of reinforcement of various thermoplastic fibers (polyethylene, para‐aramid, and spandex) on the mechanical performance of FRPCs. The necessity of filler compatibilization to enhance interfacial bonding constituents is also discussed. It can be concluded that the choice of surface treatment for a given thermoplastic fiber is governed by its chemical composition, the functional groups to be added on its surface through a specific compatibilization treatment, and the chemical nature of other constituents of the composite system with which the treated fiber surface interacts. Further, the greater the elasticity and ductility of the reinforced thermoplastic fiber, the higher the impact strength of the resulting epoxy‐based GFRPs. Finally, the review brings forth the potential opportunities for future research in this area.Highlights Discussed recent advancements in epoxy‐based GFRPs with multi‐scale filler reinforcement. Multi‐scale filler‐reinforced epoxy‐based GFRPs have myriad applications in aviation, automobile, marine, sports, etc. Nano‐/micro‐fillers in their pristine state degrade the mechanical performance of epoxy‐based GFRPs. Filler compatibilization is essential for achieving superior mechanical performance in epoxy‐based GFRPs. Reinforcing compatibilized soft/ductile thermoplastic fibers resulted in a notable increase in impact strength while maintaining tensile properties.

A Flexible and Mechanical Robust All-Solid-State Polymer Electrolyte with Microphase Separated Structure for Lithium-Ion Battery.

Polyethylene oxide (PEO)-based electrolytes are the most widely used solid polymer electrolyte (SPE) due to their high safety, excellent ability to dissociate lithium salts, low cost, and ease of preparation. However, low ionic conductivity and narrow electrochemical stability window limit their potential for further development. "Polymer-in-salt" electrolytes exhibit superior electrochemical performance; however, the high lithium salt concentration makes the SPE mechanically fragile when facing lithium dendrites. Therefore, preparing an SPE that can withstand a high concentration of lithium salt while still maintaining good mechanical properties has become a valuable challenge. In this study, a macroscopically homogeneous but nanoscopically phase-separated polymer matrix was designed as an electrolyte that can withstand a high concentration of lithium salt while retaining good mechanical properties, and this study investigated changes in the Li+ solvation structure within the electrolyte and analyzed the reasons for the simultaneous achievement of good ionic conductivity (1.02 × 10-3 S cm-1 at 60 °C) and mechanical properties (7 MPa at room temperature). The formation of large ion clusters at the phase interface and selective enrichment of lithium salt in specific regions are found to play crucial roles, and the critical current density (CCD) can reach a value of 2.2 mA cm-2. This work demonstrates a promising design approach for polymer electrolytes that achieves an optimal balance between SPE conductivity and mechanical properties through microstructure control.

A novel red fluorescent and dynamic nanocomposite hydrogel based on chitosan and alginate doped with inclusion complex of carbon dots

Red fluorescent hydrogels possessing injectable and self-healing properties have widespread potential in biomedical field. It is still a challenge to achieve a biomacromolecules based dynamic hydrogels simultaneously combining with excellent red fluorescence, good mechanical properties, and biocompatibility. Here we firstly exploited hydrophilic inclusion complex of (R-CDs@α-CD) derived from red fluorescent carbon dots (R-CDs) and α-cyclodextrin (α-CD), and then achieved a red fluorescent and dynamic polysaccharide R-CDs@α-CD/CEC-l-OSA hydrogel. The nanocomposite hydrogel can be fabricated through controlling dopant of red fluorescent R-CDs@α-CD into dynamic polymer networks, taking dynamic crosslinked N-carboxyethyl chitosan (CEC) and oxidized sodium alginate (OSA) as an example. The versatile hydrogel simultaneously combines the features of injection, biocompatibility, and augmented mechanical properties and self-healing behavior, especially in rapid self-recovery even after integration. The R-CDs@α-CD uniformly dispersed into dynamic hydrogel played the role of killing two birds with one stone, that is, endowing red fluorescence as a hydrophilic fluorescent substance, and improving mechanical and self-healing properties as a dynamic nano-crosslinker, via providing hydrogen bonds as reversible crosslinkings. The novel red fluorescent and dynamic hydrogel based on polysaccharides hold promise for using as biomaterials in biomedical field.

Optimising fundamental knitting parameters for wearable triboelectric nanogenerators

During the past decade, Triboelectric Nanogenerators (TENG) have demonstrated their potential as an energy harvesting and self-powered sensing technology for future wearable applications. Among various TENG architectures, knitted textile TENGs have become increasingly popular in recent times, as they provide advantages such as high electrical outputs, very good mechanical properties and excellent wearability. However, there is still a lack of understanding on how to engineer the knitting parameters to maximize the electrical output generation of knitted textile TENGs. Herein, for the first time, we bridge this gap by mapping the relationship between basic knit parameters and the fundamental TENG parameters which govern their electrical outputs. In this work, the loop length, yarn count, number of yarns per loop and the loop structure of a knitted textile TENG are empirically varied and its impact on the charge, current and voltage outputs is studied. The observed output trends are then analysed in-depth using the distance-dependent electric field theory, thus, explaining the root causes of the observed output trends. Consequently, several new strategies on the design and optimisation of more efficient knitted textile TENGs are uncovered. Further, the impact of these optimisation strategies on the wearable properties of the knitted textile TENGs is studied, paving the way for practically applicable textile TENG designs with balanced electrical output generation and long-term wearability.

Schiff base derivative flame-retardant endowing epoxy resin with toughness, transparency, and high flame retardancy

In this study, a novel phosphorus-containing flame retardant, SMAE, was prepared through a nucleophilic addition of N,N'-bis(salicylidene)ethylenediamine (SAED) and phenyl hypophosphite. SMAE can dissolve well in epoxy resin and provides molecular-level flame retardancy. By using SMAE as a co-curing agent and DDM to cure epoxy resin, EP/SMAE composites with excellent flame retardancy and good mechanical properties were obtained. As the dosage gradually increases, the limited oxygen index (LOI) values continue to rise. At a 5 % dosage, the Limiting Oxygen Index (LOI) value can reach 39.7 % and meet the UL 94 V-0 standard. It is observed that SMAE mainly exerts a blowing-out effect in EP. In addition, the use of SMAE as a co-curing agent can improve the impact strength of EP. The impact strength of 5 % SMAE/EP can reach 14.15 kJ/m2, which is 25 % higher than that of pure EP.

Nanoprecipitate strengthened, alumina forming austenitic stainless steels for elevated temperature applications

Low cost stainless steels (SS) with high performance, especially with good mechanical properties and oxidation resistance at high temperature, are continuous pursuit for manufacture industry. To achieve good combination of mechanical properties, oxidation resistance and cost, nanoprecipitate strengthened alumina forming austenitic (NSAFA) SS have been developed by removing expensive elements such as Nb and Ta, lowering Ni concentration in Fe–26Ni–15Cr-1.5Mo-(2.8–3.5)Al-(1–2.35)Ti (wt.%) alloys. Microstructure investigation demonstrates that NSAFA SS are strengthened by L12 structured (Ni, Fe)3(Al, Ti) γ′ nanoprecipitates with area fraction around 25%–40%. Oxidation experiments (750 °C/480 h) in air demonstrates that all the NSAFA steels have alumina forming ability. In addition, it is found that Al and Ti are all necessary for γ′ nanoprecipitates, but additional Al and Ti facilitate formation of the Ni2AlTi phase. To ensure high volume fraction of γ′ nanoprecipitates and reduce Ni2AlTi phase, 2.8–3.0 wt% Al and 1.8–2.35 wt% Ti are preferred. Benefit from the high volume fraction of γ′ nanoprecipitates, yield strength of NSAFA steels is much higher than that of Fe-base superalloy (e.g., A286) and can compare to some Ni-base superalloys (e.g., Hayners 282 & Inconel 740H).

Fabrication of g-C3N4 films with enhanced mechanical and charge transfer properties by electrophoretic deposition and subsequent citric acid modification

A low-cost 2D metal-free material based on a graphitic carbon nitride (g-C3N4) film functionalized with a citric acid molecule has been successfully fabricated by Electrophoretic Deposition (EPD) and thermal techniques, aiming to evaluate its suitability for optoelectronic devices. The thickness-controlled g-C3N4 film having a good mechanical property was successfully performed. The chemical stability and photostability of the citric-modified g-C3N4 films deposited on indium tin oxide (ITO) glass were investigated. New chemical links were clarified such that it could possibly become a bridge for enhancing charge transport. The modified samples exhibited a significant increase in their photocurrent response, reaching 25 μA/cm2 at a thickness of about 20 μm. Electrochemical impedance spectra (EIS) verified the enhanced conductivity, efficient charge transfer, and reduced electron-hole recombination rate. This research revealed a facile synthetic route and environmentally benign materials, thereby suggesting promising prospects for their application in the optoelectronic field.