Materials For Advanced Applications Research Articles

Three failure modes of High-Strength Steel (HSS) perfobond connector embedded in UHPC

The application of advanced high-performance materials, such as High-Strength Steel (HSS) and Ultra-High Performance Concrete (UHPC), provides innovative concepts for structural designs. To implement lighter, longer-span, and more durable structures, composite structures consisting of HSS and UHPC have been paid more attention recently since their combination might fully develop the superiority of each. Although perfobond connectors (PBLs) were reported to have excellent behavior, most studies focused on the PBLs with conventional materials and dimensions. The failure modes of PBLs with a smaller size embedded in UHPC are unclear. Besides, the current interface design methods are for ordinary composite structures, which could cause an unconservative design for HSS-UHPC composite structures. In this study, the push-out tests of HSS-UHPC PBLs with varying plate thickness and strength were performed. The fracture of perfobond plates, the fracture of perforated rebars accompanied by the yielding of hole walls, and the rebar fracture without hole wall yielding were found as the three failure modes. The failure mode significantly affected the shear strength and slip capacity, and the shear stiffness increased with the plate thickness. Then, the FE models that considered the fracture of perfobond plates and perforated rebars were established and validated. 90 numerical models with different hole diameters, plate thicknesses, and steel grades were built to investigate the transition conditions between the failure modes. Lastly, a shear capacity equation for PBLs considering the varying failure modes was proposed, which matched well with the parametric study results.

Interface strengthening and high-value recycling of epoxy resin/carbon fiber fabric composites

Thermoset epoxy resin/carbon fiber fabric (EP/CF) composites are used increasingly in the fields of automotive, aerospace, and wind power, but the large difficulty in interfacial strengthening and high-value recycling of CF hinders their wide applications in advanced sustainable materials. Here, thiol-terminated hyperbranched polyimides (DSPI-n) were synthesized by a newly designed imide monomer and then were covalently grafted onto the surface of pristine carbon fiber fabric (PCF) by a thiol-ene click reaction to produce thiol-functionalized carbon fiber fabric (TCF). Then, the degradable imide skeleton hyperbranched epoxy resin (DIHE-n) was synthesized from DSPI-n by a click reaction to prepare the DIHE-n/TCF composites. Compared with the DIHE-n/PCF composites, the tensile strength, interlaminar shear strength, and interfacial shear strength of the DIHE-n/TCF composites were distinctly increased, explained by an interfacial strengthening mechanism, being attributed to a synergistic effect of the wide interface layer, strong load transfer capacity of the deformable hyperbranched topological structure, and mechanical interlock of double crosslinked structure. Moreover, the prepared composites can be completely degraded under mild conditions and the carbon fiber fabric can be intactly recycled. This study offers a new approach for the preparation of recyclable and high-performance EP/CF composites.

From the Mexican glass industry to the smart fabric: applications of advanced materials in window design

El presente trabajo de investigación pretende entender cómo el desarrollo tecnológico ha impactado el diseño y funcionalidad de una ventana tradicional. Se analiza la situación de la industria del vidrio como fuente original de este producto, y se enfatiza el papel del surgimiento de los materiales avanzados en el diseño de ventanas inteligentes dentro del ámbito arquitectónico y diseño de productos. Se incluyen ejemplos de ventanas comercializadas actualmente, así como un panorama en la industria mexicana y de investigación.

Novel bilayer coating on gentamicin-loaded titanium nanotube for orthopedic implants applications

Fabricating a multifunctional orthopedic implant which prevents post-surgery infection is highly desirable in advanced materials applications. However, designing an antimicrobial implant, which simultaneously promotes a sustained drug release and satisfactory cell proliferation, remains a challenge. The current study presents a drug-loaded surface-modified titanium nanotube (TNT) implant with different surface chemistry which was developed to investigate the effect of surface coating on drug release, antimicrobial activity, and cell proliferation. Accordingly, sodium alginate and chitosan were coated on the surface of TNT implants with different coating orders through layer-by-layer assembly. The coatings' swelling ratio and degradation rate were around 613% and 75%, respectively. The drug release results showed that surface-coatings prolonged the releasing profile for about 4 weeks. Chitosan coated TNTs demonstrated greater inhibition zone at 16.33mm compared with the other samples where no inhibition zone was observed. However, chitosan and alginate coated TNTs exhibited smaller inhibition zones at 48.56mm and 43.28mm, respectively, compared to bare TNT, which can be attributed to the coatings preventing the antibiotic burst release. Higher viability of cultured osteoblast cells was observed for chitosan-coated TNT as the top layer compared to the bare TNT at 12.18%, indicating improved bioactivity of TNT implants when the chitosan has the most contact with cells. Coupled with the cell viability assay, molecular dynamics (MD) simulations were carried out by placing collagen and fibronectin near the considered substrates. In agreement with cell viability results, MD simulations also indicated that chitosan had the highest adsorption energy approximately 60Kcal/mol. In summary, the proposed bilayer chitosan-coated drug-loaded TNT implant with chitosan and sodium alginate coating as the top and the bottom layers, respectively, can be a potential candidate for orthopedic applications in the light of its bacterial biofilm prevention, better osteoconductivity, and providing an adequate drug release profile.

Removal of Naphthalene, Fluorene and Phenanthrene by Recyclable Oil Palm Leaves’ Waste Activated Carbon Supported Nano Zerovalent Iron (N-OPLAC) Composite in Wastewater

Despite keen interest in the development of efficient materials for the removal of polycyclic aromatic hydrocarbons (PAHs) in wastewater, the application of advanced composite materials is still unexplored and needs attention. Therefore, this study focused on the synthesis of the composite of oil palm leaves’ waste activated-carbon (OPLAC) and nano zerovalent iron (NZVI) at Fe:OPLAC = 1:1 (N-OPLAC-1) and 1:2 (N-OPLAC-2). The composite with enhanced surface properties was applied for removal of three PAHs including naphthalene (NAP), fluorene (FLU) and phenanthrene (PHE) in wastewater at various pH, dosages, contact time and initial concentration in batch testing. The PAHs’ removal parameters were optimized using design expert software. The PAHs’ removal efficiency was evaluated in produced water at optimized parameters. The results showed that the N-OPLAC-2 had superior surface properties compared to N-OPLAC-1. The removal of NAP, FLU and PHE was heterogenous, favorable and involved chemisorption proved by Freundlich isotherm and pseudo-second-order kinetic models using N-OPLAC-2. The optimum parameters were as follows: pH of 3, dosage and contact time of 122 mg/L and 49 min, respectively. The application of N-OPLAC-2 in produced water was favorable for removal of NAP, FLU and PHE and showed up to 90% removal efficiency, and higher stability up to 3 cycles. It can be concluded that the NZVI-OPLAC composite was successfully synthesized in this study and the materials showed good removal efficiency for three PAHs (NAP, FLU and PHE) in wastewater.

Chitosan as a Canvas for Studies of Macromolecular Controls on CaCO3 Biological Crystallization.

A mechanistic understanding of how macromolecules, typically as an organic matrix, nucleate and grow crystals to produce functional biomineral structures remains elusive. Advances in structural biology indicate that polysaccharides (e.g., chitin) and negatively charged proteoglycans (due to carboxyl, sulfate, and phosphate groups) are ubiquitous in biocrystallization settings and play greater roles than currently recognized. This review highlights studies of CaCO3 crystallization onto chitinous materials and demonstrates that a broader understanding of macromolecular controls on mineralization has not emerged. With recent advances in biopolymer chemistry, it is now possible to prepare chitosan-based hydrogels with tailored functional group compositions. By deploying these characterized compounds in hypothesis-based studies of nucleation rate, quantitative relationships between energy barrier to crystallization, macromolecule composition, and solvent structuring can be determined. This foundational knowledge will help researchers understand composition-structure-function controls on mineralization in living systems and tune the designs of new materials for advanced applications.

Challenges and Future Roadmaps in Heterogeneous Electro-Fenton Process for Wastewater Treatment.

The efficiency of heterogeneous electro-Fenton technology on the degradation of recalcitrant organic pollutants in wastewater is glaringly obvious. This green technology can be effectively harnessed for addressing ever-increasing water-related challenges. Due to its outstanding performance, eco-friendliness, easy automation, and operability over a wide range of pH, it has garnered significant attention from different wastewater treatment research communities. This review paper briefly discusses the principal mechanism of the electro-Fenton process, the crucial properties of a highly efficient heterogeneous catalyst, the heterogeneous electro-Fenton system enabled with Fe-functionalized cathodic materials, and its essential operating parameters. Moreover, the authors comprehensively explored the major challenges that prevent the commercialization of the electro-Fenton process and propose future research pathways to countervail those disconcerting challenges. Synthesizing heterogeneous catalysts by application of advanced materials for maximizing their reusability and stability, the full realization of H2O2 activation mechanism, conduction of life-cycle assessment to explore environmental footprints and potential adverse effects of side-products, scale-up from lab-scale to industrial scale, and better reactor design, fabrication of electrodes with state-of-the-art technologies, using the electro-Fenton process for treatment of biological contaminants, application of different effective cells in the electro-Fenton process, hybridization of the electro-Fenton with other wastewater treatments technologies and full-scale analysis of economic costs are key recommendations which deserve considerable scholarly attention. Finally, it concludes that by implementing all the abovementioned gaps, the commercialization of electro-Fenton technology would be a realistic goal.

A Review of Electric Motors with Soft Magnetic Composite Cores for Electric Drives

Electric motors play a crucial role in modern industrial and domestic applications. With the trend of more and more electric drives, such as electric vehicles (EVs), the requirements for electric motors become higher and higher, e.g., high power density with good thermal dissipation and high reliability in harsh environments. Many efforts have been made to develop high performance electric motors, such as the application of advanced novel electromagnetic materials, modern control algorithms, advanced mathematical modeling, numerical computation, and artificial intelligence based optimization design techniques. Among many advanced magnetic materials, soft magnetic composite (SMC) appears very promising for developing novel electric motors, thanks to its many unique properties, such as magnetic and thermal isotropies, very low eddy current loss, and the prospect of low-cost mass production. This paper aims to present a comprehensive review about the application of SMC for developing various electric motors for electric drives, with emphasis on those with three-dimensional (3D) magnetic flux paths. The major techniques developed for designing the 3D flux SMC motors are also summarized, such as vectorial magnetic property characterization and system-level multi-discipline robust design optimization. Major challenges and possible future work in this area are also discussed.

Advanced Flexible Materials from Nanocellulose

AbstractWith the increase of environmental pollution and depletion of fossil fuel resources, the utilization of renewable biomass resources for developing functional materials or fine chemicals is of great value and has attracted considerable attention. Nanocellulose, as a well‐known renewable nanomaterial, is regarded as a promising nano building block for advanced functional materials owing to its unique structure and properties, as well as natural abundance. Typically, its high mechanical strength, structural flexibility, reinforcing capabilities, and tunable self‐assembly behavior makes it highly attractive to fabricate flexible materials for various applications. Herein, the recent progress in the design, properties, and applications of advanced flexible materials from nanocellulose is comprehensively summarized. The preparation and properties of nanocellulose are first briefly introduced and discuss its merits in fabricating flexible materials. Then, various advanced flexible materials from nanocellulose are introduced, and the critical role of nanocellulose in constructing flexible materials is highlighted based on its intrinsic properties. After that, their applications in energy storage, electronics, sensor, biomedical, thermally insulating, photonic devices, etc., are presented. At last, the outlook of the current challenges and future perspectives for developing nanocellulose‐derived flexible materials are discussed.

Synthesis of High Molecular Weight Polymers by Organocatalyzed Living Radical Polymerization and Self-Assembly Behavior.

A mild organocatalyzed living radical polymerization method is studied for high molecular weight polymers (HMWPs), yielding low-dispersity linear and star polymers (Đ = Mw /Mn = 1.03-1.28) up to Mn = 3.9 × 105 and monomer conversion = 80%, where Mn and Mw are the number- and weight-average molecular weights, respectively. Even at high degrees of polymerization (DPs > 2000), this technique still features excellent control over molecular weights and Đ values, indicating the living character. The macroinitiators prepared at DP = 2000 are subsequently used for block polymerizations at high DPs (>2000) with functional methacrylates, yielding linear A-B diblock, linear B-A-B triblock, and 3-arm star A-B diblock copolymers, suggesting the excellent block efficiency of macroinitiators synthesized at a high DP value (=2000). This mild organocatalyzed living radical polymerization technique can enhance the livingness of propagation radicals and kinetic chain length at high monomer conversions for monomers with moderate propagation rate coefficients (kp s), reduce the persistent radical effect as much as possible, and hence enable HMWPs without the presence of metal catalyst, exogenous initiator, or harsh equipment. The obtained amphiphilic block copolymers present unique microphase separation behavior, and hold great potential in advanced materials applications, for example, thermosensitive nanocarriers.

Impacts of Temperature and Time on Direct Nitridation of Aluminium Powders for Preparation of AlN Reinforcement

Aluminium nitride (AlN) is an important technical ceramic with outstanding strength and thermal conductivity that has important applications for advanced heat sink materials and as a reinforcement for metal-based composites. In this study, we report a novel, straightforward and low-cost method to prepare AlN powder using a vacuum tube furnace for the direct nitridation of loose aluminium powder at low temperatures (down to 500 ∘C) under flowing high-purity nitrogen. Small amounts of magnesium powder (1 wt.%), combined with aluminium, promote nitridation. Here, we characterise the effects of time (up to 12 h) and temperature (490 to 560 ∘C) on nitridation with the aim to establish an effective regimen for the controlled synthesis of an aluminium nitride reinforcement powder for the production of metal matrix composites. The extent of nitridation and the morphology of the reaction products were assessed using scanning electron microscopy and X-ray diffraction analyses. AlN was detected for all nitriding temperatures ≥ 500 ∘C, with the highest yields of 80% to 85% obtained at 530 ∘C for times ≥ 1 h. At this temperature, nitridation proceeded rapidly, and there was extensive agglomeration of the reaction products making it difficult to reprocess into powder. At lower temperatures around 510 ∘C, a relatively high proportion of AlN was attained (>73% after 6 h) while retaining excellent friability so that it could be manually reprocessed to powder. The synthesised reinforcement consisted of micro- or nano-crystalline AlN comingled with metallic aluminium. The ratio of AlN and metallic aluminium can be readily controlled by varying the nitriding temperature. This provides a flexible and accessible method for the production of AlN-reinforcement powders suited to the production of metal matrix composites.

Multiscale modeling of laminated thin-shell structures with Direct FE[formula omitted

Shell finite element is computationally efficient and thereby favored in large-scale structural analysis. With the application of advanced materials, understanding the relation between micro-heterogeneities and structural behavior is important. To this end, we propose a multiscale method in the current contribution for modeling thin-walled fiber reinforced composite laminates with Mindlin–Reissner shell theory and Direct FE2. By exploiting the length scales in layered structure together with a shell formulation degenerated from continuum solid element, both in-plane and through-thickness periodicity can be assumed. A single-fiber unit cell attached to each Gauss point is employed as a representative volume element (RVE) rather than a through-thickness microstructure. In this way, the scale transitions are naturally dealt with using a first-order homogenization framework, in which the downscaling of transverse shear strain, commonly troublesome for the through-thickness RVE, is straightforward. The other merit inherited from Direct FE2 is that the two-scale problem is formulated in a single finite element analysis wherein the macro and micro DOFs are coupled based on the downscaling kinematics. It avoids the upscaling of the macroscopic stresses and tangents in the conventional nested FE2 scheme, which is challenging in the case of complex microstructural response. The developed method is then verified through several benchmarking examples, including a flat plate and two curve shells. Isotropic materials and composite laminates with homogeneous and heterogeneous RVEs have been examined. Two examples with plasticity and cohesive cracks are further presented to showcase its potential in modeling damage propagation in composite structures.

An efficient approach to extract nanocrystalline cellulose from sisal fibers: Structural, morphological, thermal and antibacterial analysis

Nanocellulose has been proposed by many researchers as a suitable bio-reinforcement material for the development of sustainable bio-nanocomposites in advanced applications due to its excellent properties. Conventional techniques for extracting nanocellulose from plant biomass are time-consuming and involve chemical wastage. This study aims to extract nanocellulose using simple processes with minimal consumption of chemicals in a minimum time. In the present work, cellulose nanocrystalline has been extracted from sisal fibers efficiently by chemical treatment assisted with steam explosion and mechanical grinding. The morphology of extracted sisal cellulose nanocrystalline (CNC-S) was analyzed by FESEM, whereas the DLS, TEM and AFM confirmed its nanosize. The average aspect ratio and zeta potential (ζ) of CNC-S were measured as 7.4 and −14.3 mV, respectively. The XRD analysis indicated that the crystallinity of the fibers considerably improved from 48.74 % for untreated fibers (UT-S) to 74.28 % for CNC-S. The chemical structure of the fibers was changed as hemicellulose and lignin were found to be eliminated after the chemical treatment which FTIR confirmed. From TGA-DTG results, it was observed that CNC-S has good thermal stability. It was also noticed that CNC-S did not show any antibacterial properties against E. coli and S. aureus due to the complete removal of lignin. This study suggests that the present extraction process can be considered as an efficient process to convert fibers into high performance nanocellulose to be used as potential reinforcing material in advanced applications.

Photo‐controllable Luminescence from Radicals Leading to Ratiometric Emission Switching via Dynamic Intermolecular Coupling

AbstractThe development of photoinduced luminescent radicals with dynamic emission color is still challenging. Herein we report a novel molecular radical system (TBIQ) that shows photo‐controllable luminescence, leading to a wide range of ratiometric color changes via light excitation. The conjugated skeleton of TBIQ is decorated with steric‐demanding tertiary butyl groups that enable appropriate intermolecular interaction to make dynamic intermolecular coupling possible for controllable behaviors. We reveal that the helicenic pseudo‐planar conformation of TBIQ experiences a planarization process after light excitation, leading to more compactly stacked supermolecules and thus generating radicals via intermolecular charge transfer. The photo‐controllable luminescent radical system is employed for a high‐level information encryption application. This study may offer unique insight into molecular dynamic motion for optical manufacturing and broaden the scope of smart‐responsive materials for advanced applications.

Interplay of Dual-Proton Transfer Relay to Achieve Full-Color Panel Luminescence in Excited-State Intramolecular Proton Transfer (ESIPT) Fluorophores.

A new design was applied for the facile synthesis of pure organic photoluminescent molecules with dual excited-state intramolecular proton transfer (ESIPT) sites. In this novel class of emitters, full-color panel emission from blue, green, and yellow to red, including white light, can be achieved in different solvents as modulated by the enol-keto(1st)-keto(2nd) tautomer emissions. A comprehensive transient photophysical study verifies that keto(1st) and keto(2nd) have a precursor (<0.8 ps)-successor (∼20 ps)-relayed absorbance relationship, and then a fast equilibrium between the two is established, resulting in dual emissions in the nanosecond scale (∼1900 ps). Through the research on copper ions' selective PL response, the dual-ESIPT mechanism was further verified; in addition, the study of solid-state PL changes upon the stimulus of organic vapor manifests the potential application sensitivity of the molecules as dual-ESIPT sensors. Theoretical results including reaction potential energy surface analyses manifest the fact that dual-proton transfer goes along a sequential route with a smaller energy barrier, firmly supporting the experimental results. An intrinsic system that undergoes intramolecular double proton relayed transfer is thus established for the achievement of much broadened optical responses and full-color display, providing reference for the design and application of advanced dual-ESIPT optical materials.

Zirconia nanocomposites and their applications as transparent advanced optical materials with high refractive index

AbstractPolymer nanocomposites, prepared by incorporating functional nanoparticles (NPs) into a polymer matrix, have advantages of utilizing functionalities of polymers and NPs. Among them, transparent high‐refractive‐index polymer nanocomposites (THPNs), prepared by incorporating highly refractive NPs into polymer matrices, are advantageous for effectively manipulating light. This review focuses on the introduction of fabrication of THPN prepared by incorporating inorganic‐oxide NPs, especially zirconia (ZrO2), and its characteristics as an optical material. ZrO2 NPs have a high refractive index and high transmittance in visible light regions with high and narrow optical bandgap energy. Since ZrO2 NPs are harmless to humans and physically and chemically stable, they are suitable for applications of advanced optical materials for display and energy devices. Various fabrication methods of THPN with ZrO2 NPs and surface modifications of ZrO2 NPs to prevent agglomeration are introduced. Principles and specific applications, which THPN could work with and for, are introduced as well.

Date Palm Cellulose Nanocrystals (CNCs)/Polyamide Composites: Tailoring Morphological, Mechanical, and Thermal Properties

In the present study, polyamide (PA) was successfully reinforced with cellulose nanocrystal (CNC) prepared from date palm leaves using two different techniques, electrospinning and the solution casting method, and a comparative study of these two systems was performed. The morphological, thermal, wetting, and mechanical properties of the nanocomposites were analyzed for CNC content between 0 and 5 wt%. Morphological analyses showed different roughness in the fractured surface of neat PA and its nanocomposites after the addition of CNC. The modified composite is found to have a smooth surface without cracks and showed increased roughness with greater hydrophilicity and thermal stability. The nano-indentation results showed that the highest hardness was obtained at 5% CNC loading for the solution cast composite samples, which could be related to the relatively good CNC dispersion with good filler matrix bonding as evidenced by the morphological characterization. We also observed that the electrospinning technique produced nanocomposites of better thermo-physical properties than the solution cast method. The results point to the prospect of the development of nanocomposite films using date-palm-leaf-derived CNC incorporated in PA for high-performance and advanced material applications such as membranes.

The influence of advanced materials on the analytical performance of semiconductor-based gas sensors.

Chemiresistive gas sensors are metal oxide-based sensors that have received significant attention in different fields. Ambient gas sensors are especially important in the fabrication of wearable probes for the real-time detection of biomarkers in human body samples. Usually, room temperature sensors are affordable due to their low power consumption, resulting in simple instrumentation and maintenance. To fabricate versatile gas sensors, i.e. sensitive, selective, ambient temperature operating gas sensors, and improve the sensing performance of the traditionally used sensor, new materials play an important role. In other words, new advanced materials are essential for designing and fabricating new gas sensors. Hence, in this review, the application and impact of new advanced materials in the fabrication of reliable gas sensors are discussed in detail. Special emphasis is given to the effect of new materials in the fabrication of room-temperature operating systems. Finally, future research outlook and possible challenges that may be encountered by reliable gas sensors are also explained.

(Controlled) Free radical (co)polymerization of multivinyl monomers: strategies, topological structures and biomedical applications.

Free radical (co)polymerization (FRP/FRcP) of multivinyl monomers (MVMs) has emerged as a powerful strategy for the synthesis of chemically and topologically complex polymers due to its unique reaction kinetics, which enables the preparation of polymers with multiple functional groups and novel macromolecular structures. However, conventional FRP/FRcP of MVMs inevitably leads to insoluble crosslinked materials. Therefore, the development of advanced strategies for the controlled polymerization of MVMs is essential for the preparation of chemically and topologically complex polymers. In this review, we introduce the gelation mechanism of conventional FRP of MVMs and present the strategies of controlled polymerization of MVMs for the preparation of chemically and topologically complex polymers. We also discuss polymers with unique topologies synthesized by controlled polymerization of MVMs, such as crosslinked networks, (hyper)branched, star, cyclic, and single-chain cyclized/knotted structures. Finally, biomedical applications of various advanced polymeric materials prepared by controlled polymerization of MVMs are highlighted and the challenges is this field are discussed.

A densely packed air-stable free-standing film with FeP nanoparticles@C@P-doped reduced graphene oxide for sodium-ion batteries.

Developing a facile strategy which enhances the structural stability and air/moisture stability of transition metal phosphides for practical applications is important but challenging. Herein, we designed a densely packed free-standing film consisting of carbon-coated FeP nanoparticles anchored on P-doped graphene (FeP@C@PG film) through solventless thermal decomposition and the roll-press method. Phytic acid serves a multifunctional role as both a phosphorus source to prepare ultrafine FeP nanoparticles and a protective layer to improve air stability along with hydrophobic graphene and maximize the utilization of phosphide. This structure can enhance electron/ion transport kinetics, allowing for full utilization of active materials, and buffer large volume expansions while preventing pulverization/aggregation during cycling. Noticeably, the densely packed structure can greatly enhance oxidation resistance by effectively blocking the penetration of air/moisture. Therefore, the FeP@C@PG film delivers a stable reversible capacity of 536.6 mA h g-1 after 1000 cycles at 1 A g-1 with good capacity retention, an excellent rate capability of 440.7 mA h g-1 at 5 A g-1, and excellent oxidation stability at 80 °C in air. Furthermore, a pouch-type full-cell exhibits excellent rate/cycling performance and bendability. This study provides a new direction for the rational design and practical applications of advanced P-based materials used in alkali metal-ion batteries.