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Based on surface science, adsorption of mineral oil, water, gas products (typified by CO2 and CH4), and acids (typified by formic acid) on meta-aramid insulation paper has been investigated by molecular dynamics simulations. When the adsorption process finishes, the free volume fraction in the crystalline region is very small owing to the stable molecular arrangement of fiber. In addition, the number of pores on the surface of the meta-aramid fiber and the pore size are small, and the stable configuration of hydrogen bonds plays an important role, so it is difficult for the mineral oil and aging products to enter the meta-aramid crystalline region. The irregular arrangement of molecules in the amorphous region means that it is easier for the mineral oil and aging products to enter the amorphous region than the crystalline region, and the influence of these substances on the amorphous region is greater than that on the crystalline region. The order of the adsorption strengths of the four types of aging products on meta-aramid fiber is formic acid > water > CO2 > CH4. Therefore, it is necessary to monitor the acid and water contents in transformers with meta-aramid insulation paper as the solid insulation material. [ABSTRACT FROM AUTHOR]

Flexible graphene-based paper is promising for wide applications due to its outstanding electrical and thermal conductivities. Graphene flakes with large size are usually known as the key factor for improved paper performance. However, we find that a combination of flakes with large and small sizes is more favorable for both electrical and thermal conductivities than pure large flakes. In this work, flexible paper with enhanced electrical and thermal properties was fabricated by mixing graphene flakes with various size distributions. Large-size graphene (LSG) flakes play the role of a backbone structure, whereas small-size graphene (SSG) flakes fill the voids in the paper without disturbing the high orientation. The physical properties of the as-prepared graphene papers with contents of SSG varying from 0 to 100% have been investigated. It is found that the electrical and thermal conductivities of the paper with 25 wt% SSG are both around 140% higher than that of pure LSG paper. Our results indicate that the lightweight and flexible graphene-based paper has great potential for lateral heat dissipation applications requiring heat movement in a particular direction. [ABSTRACT FROM AUTHOR]

We present a theory giving the standard roughness metrics R a and R q of stochastic fibrous materials in terms of their porosity and the thickness of the constituent fibres. Our treatment shows also that R a and R q are linearly dependent on each other with gradient depending on the skewness of the surface depth profile. Comparison of our theory with experiments on laboratory-formed paper samples and with data from the literature for industrially manufactured paper and carbon fibre nonwovens for use in fuel cells is excellent. The theory has applicability to generic families of stochastic fibrous materials and has relevance, for example, to printing of devices on paper. [ABSTRACT FROM AUTHOR]

Starch is one of the most popular biodegradable polymers in nature, which is gaining increasing attention because of its abundant availability and low cost. However, starch film itself is very brittle and its barrier property is poor for many applications. Polyvinyl alcohol (PVA), a versatile polymer in paper industry, is used to improve the barrier property of starch film. In this study, painting paper with exceptional barrier properties against organic solvents is successfully prepared for art creation purpose by coating a thin layer of environmentally friendly starch/PVA film on its surface. The coated paper can resist the penetration of the ink from marker pens. Furthermore, the solvent resistance and mechanical flexibility of freestanding starch/PVA hybrid film were investigated in detail. It found that the excellent barrier properties of the coated painting paper against solvents are due to the superior solvent resistance and mechanical flexibility of starch/PVA hybrid film. Therefore, the biodegradable and cost-effective strategy in this study provides a promising approach to enhance the barrier property of painting paper against solvents, which can find potential applications in painting field. [ABSTRACT FROM AUTHOR]

Cellulose nanopaper consists of a dense fibrous self-binding network composed of cellulose nanofibres connected by physical entanglements, hydrogen bonding, etc. Compared with conventional printing paper, cellulose nanopaper has higher strength and modulus because of stronger fibres and inter-fibre bonding. The aim of this paper is to investigate the fracture properties of cellulose nanopaper using double edge notch tensile tests on samples with different notch lengths. It was found that strength is insensitive to notch length. A cohesive zone model was used to describe the fracture behaviour of notched cellulose nanopaper. Fracture energy was extracted from the cohesive zone model and divided into an energy component consumed by damage in the material and a component related to pull-out or bridging of nanofibres between crack surfaces which was not facilitated due to the limited fibre lengths for the case of nanopapers. For comparison, printing paper which has longer fibres than nanopaper was tested and modelled to demonstrate the importance of fibre length. Buckypaper, a fibrous network made of carbon nanotubes connected through van der Waals forces and physical entanglements, was also investigated to elaborate on the influence of inter-fibre connections. [ABSTRACT FROM AUTHOR]

We demonstrate in this paper that commercially available printing paper can reach very high fracture toughness, comparable to that of steel, simply due to a special arrangement of the paper sheets with respect to the crack. Fracture mechanics experiments are conducted on single sheets of paper as well as on multilayer specimens in crack divider and crack arrester configuration. It is demonstrated that an arrangement in crack arrester configuration leads to an increase of the fracture toughness by a factor ten. An explanation of the effect is given and the transferability to other materials is discussed. [ABSTRACT FROM AUTHOR]

Fiber length and fiber-to-fiber bonding effects on tensile strength and fracture toughness of kraft paper have experimentally been investigated. Laboratory sheets were made from kraft pulp, each with a distinct set of fiber lengths. Additionally, the fiber-fiber bond strength was improved by carboxymethyl (CMC) grafting. The tensile strength and work of fracture toughness results were compared to predictions from a shear-lag model which considers the fiber-fiber bond shear strength, the fiber tensile strength and fiber pull-out work. The tensile strength and fracture work for papers with weak fiber-fiber bonds increased with fiber length consistent with the shear-lag model. CMC-treated fibers provided strong fiber-fiber bonds. Papers made from such fibers displayed high strength and work of fracture independent of fiber length which indicates that the failure process is governed by fiber failures rather than bond failures. The fracture toughness, expressed as the critical value of the J-integral, increased strongly with fiber length for both untreated and CMC-treated papers. The results show that long fibers and CMC addition are extremely beneficial for improving the fracture toughness. [ABSTRACT FROM AUTHOR]

Carbon papers (CPs) have been fabricated using wet-laying carbon fibers (CFs) and polyacrylonitrile (PAN) fibers. Scanning electron microscopy revealed that the PAN fibers tightly interconnected the CF junctions with the pores between the fibers. The tensile strength of the carbon webs (CWs) increased as the fraction of PAN fibers used as the binder increased. The CW fabricated with 0.15 wt% PAN fibers had a tensile strength six times greater than that of the CW without PAN fibers. Moreover, by mixing the CFs with PAN fibers in water, the CFs separated from each other in the webs due to the interruption of hydrophobicity between the CFs. After mixing with PAN fibers, the CWs were carbonized at 1200 °C in the presence of a phenolic resin. The PAN fibers maintained their morphology due to their high carbon content after carbonization. The electrical resistivity of the CPs with high PAN fiber content was significantly lower than that of a CP without PAN fibers due to the interconnection of the CFs by the carbonized PAN fibers. [ABSTRACT FROM AUTHOR]

Facile and robust immobilization of metal nanoparticles onto porous supporting matrix is an important issue in heterogeneous catalysis. This study reports a facile procedure for the synthesis and immobilization of small catalytic active silver nanoparticles (AgNPs) on cellulose paper (CP), which possesses interconnected fibrous structure and can be employed as cost-effective supports. Amino groups were first introduced to CP, through a silane coupling technique, to provide stable anchoring centers for silver ions. Small-sized AgNPs without aggregation were facilely synthesized and stably immobilized onto the fiber surface of CP followed by NaBH reduction. The as-prepared AgNPs incorporating composites exhibited excellent catalytic activity for the reduction of 4-nitrophenol. The rate constant of the catalytic reaction was calculated to be 1.46 × 10 s. More importantly, these amino-modified paper-based composite catalysts can be easily recovered and reused for at least six cycles due to their enhanced mechanical and catalytic stability. [ABSTRACT FROM AUTHOR]

Paper is a widely used packaging material and is nowadays regaining importance, e.g., as bio-based and biodegradable material. Moreover, new technologies such as polymer-fiber composites, printed electronics and the deep drawing of paper are developing. The process stability and also the resulting quality of paper converting processes such as coating, metallization, printing, and the printing of electronics are highly affected by the hygroexpansion of paper. In order to reduce production instability and to choose and develop paper substrates with ideal characteristics, critical parameters need to be known. This paper offers an extensive overview of those parameters, starting at a molecular and microscopic level with the effect of the constituents and morphology of single fibers, before moving on to paper contents, chemical modifications and additives and finally concluding with paper production and fiber network modification. It was found that the major influences are single fiber sorption, inter-fiber contacts, microfibril angle, fiber morphology (length, width, curliness) and fiber orientation. This review gives new ideas and insights for technologists working in research, development and production optimization of paper-based products. [ABSTRACT FROM AUTHOR]

An analytical model is developed for the compression of coated substrates in a soft rolling nip formed between a hard roll and a soft covered roll. The coating layer, substrate, and soft cover are modeled as a stack of three layers that are compressed jointly while passing through the nip. Material models have been adopted separately for each of the three layers and were combined together according to the thickness of individual layers. In this study, the substrate is considered to be a viscoelastic–plastic material and is represented by a modified solid element while the coating layer is assumed to be elastic and the soft cover material is approximated by a standard Maxwell model. A strain function is derived for the compression of substrate in the nip that appears to be a parabolic function of time. Substrate compression in the nip and its subsequent relaxation are calculated by solving a set of differential equations that describe the coating, substrate, and soft cover deformations. This model is used to study the soft-nip calendering of coated papers. Examples of numerical modeling that demonstrate the paper deformation and stress profiles in the nip are presented. In addition, the effects of paper and cover properties as well as calendering parameters on the dynamics of paper compression are discussed. Finally, a comparison of the modeling results is made with the experimental data. [ABSTRACT FROM AUTHOR]

Smoothness is an important factor in consumer perception of tissue quality, with physical modification and chemical additions to the paper able to enhance tissue handle. Therefore objective measurement of the papers mechanical properties in developing new products and maintaining existing quality is vital. In this study the surface chemical composition of the softener treated paper is investigated using ToF-SIMS, and related to the surface frictional properties of the paper. [ABSTRACT FROM AUTHOR]

Thermal conductivity of paper coatings is increasingly important in the performance of many printing processes, including traditional heatset web offset and thermal papers, as well as digital processes, such as electrophotography. This work studies the extension of a Modified Lumped Parameter Model, previously used successfully to describe talc coatings, to model the thermal conductivity–coating structure relationships of calcium carbonate (gcc: 60 wt% < 2 μm) coatings. A series of compact tablets were used to provide experimental values of thermal diffusivity and conductivity. The samples studied covered a range of latex binder addition levels, namely 0–25 parts, based on 100 parts pigment, of 0.2 μm styrene acrylate latex. Combining the observed thermal properties with knowledge of the pore structure changes induced by the latex addition, it is possible to establish initial correlation with the model, in which the connectivity of the structure is increased at low latex dose illustrating the initial increase in effective thermal conductivity. The practically hard sphere properties of the latex used, combined with the broad size distribution of the gcc, produce a disruptive packing effect as the dose level increases, such that the conductivity reflects a competition between the increasing connectivity provided by the latex versus the increasing relative pore size in the network structure. It is recognized that the fixed pigment volume in the model unit cell diverts from a true representation of the residual porosity. At the highest latex dose levels, the intrinsically less conducting properties of the latex begin to dominate. [ABSTRACT FROM AUTHOR]

The effects of two kinds of wastewater (black liquor and paper regeneration wastewater) from paper industry as solvent on the hydrothermal liquefaction of plantation biomass were discussed in this study. For the solvent of eucalyptus, black liquor was not suitable because the oil yield was very low and the yield of water-soluble constituent was very high. There was little difference in the product yields between the liquefaction of eucalyptus with the paper regeneration wastewater (pH 9.5) and that with NaOH aqueous solution (pH 9.5). In comparison with the liquefaction with water, the decrease of residue yield and the increase of oil yield were observed on the liquefaction with the wastewater. During the liquefaction with water, it was anticipated that dehydration and polymerization between carboxylic and phenolic hydroxyl groups in the molecules of the eucalyptus occurred. On the other hand, carboxylic acid formed during the liquefaction of eucalyptus was considered to be neutralized with Na+ in NaOH aqueous solution or cations in the wastewater because the formation of carboxylate was observed in the water-soluble constituents derived from these liquefactions. Therefore, the residue yield decreased owing to the inhibition of the condensation reaction. Accordingly, possibility for the reduction of the amount of greenhouse gas (CO2) and paper regeneration wastewater, and the production of oil from eucalyptus was clarified on the liquefaction of plantation biomass (eucalyptus) with paper regeneration wastewater. [ABSTRACT FROM AUTHOR]

new type of paper with superhydrophobic surface was prepared by addition of modified nano-TiO to cellulose pulp. Nano-TiO powder was first dispersed with a high-speed homogenizer, followed by surface modification with the coupling agent, 3-(trimethoxysilyl) propyl methacrylate (MPS). The superhydrophobic and opaque paper was obtained by adding the modified nano-TiO to plant fiber to change its characteristics from hydrophilic to hydrophobic. The effects of the initial content of the coupling agent MPS used, on the weight percentage of MPS attached on the surface of nano-TiO were studied. The obtained paper was characterized by contact angle measurements and SEM. The results showed that the water contact angles for the modified paper ranged from 126.5 to 154.2°, and the sliding angle was <3°. Moreover, many well-dispersed nano-TiO protuberances were observed on the surface of the paper, which further confirmed that the obtained paper was superhydrophobic on account of its nanostructure. Comparative optical studies performed on the paper handsheets revealed a much higher opacity for the sample with the MPS-modified-TiO nanoparticles. [ABSTRACT FROM AUTHOR]

A novel high speed microcompression platen tester was developed in order to measure the out-of-plane compressive modulus of thin materials. The instrument is capable of subjecting a sample of thickness 20 μm or greater to a transverse compressive pulse over a time interval ranging from approximately 2 ms to several seconds, and can therefore be used to collect data under conditions representative of those in a high speed calender nip. In this study, free layers of coating formulations normally used to coat paper were prepared and tested using the microcompression platen tester described above. Tests were conducted at high speeds, with a pulse duration of 2 ms during the compressive stroke, and at 23 °C to simulate room temperature calendering conditions. The compressive modulus of the coating did not correlate strongly with the modulus of its constituent latex. Latex content, however, strongly affected coating compressive modulus. A sharp increase in the compressive modulus was observed at the coating critical pigment volume concentration (CPVC)—essentially the latex concentration at which the coating layer porosity is reduced to zero. Pigment size distribution and pigment morphology also affected the compressive modulus of coating in a manner consistent with packing theory. [ABSTRACT FROM AUTHOR]

ZnZrOx has been used in large quantities for the preparation of light olefins from CO2, but the relationship between structure and performance remains unclear at present. In this paper, ZnZrOx were prepared by co-precipitation method, and a series of oxides with different sizes were prepared by varying the calcination temperatures. Subsequently, these oxides were combined with SAPO-34 to create a composite bifunctional catalyst for the synthesis of light olefins by CO2 hydrogenation, in which the impact of nanocrystal size effect was examined. The catalytic performance significantly increased as the nanocrystal size reduced from 18 to 12 nm. However, when the nanocrystal size was further decreased to 8 nm, the catalytic performance decline. Characterizations revealed a gradual increase in the number of oxygen vacancies with decreasing nanocrystal size. However, the oxide with the smallest nanocrystal size, prepared by varied calcination temperatures, did not yield the optimal catalytic performance due to sintering occurring during the reaction process. The results show that the assumption that smaller nanocrystal sizes inherently equate to improved catalytic performance is not universally valid, and stability must be considered when the nanocrystal size is decreased. The bifunctional catalysts used in this paper for the prepared light olefins from CO2 in yield as high as 13.8%, which is higher than most previous reports. [ABSTRACT FROM AUTHOR]

The Journal of Materials Science has a tradition of publishing papers on Ceramic Materials. The editors of the journal have interdisciplinary interests, but they will focus on the traditional areas of ceramics and electronic materials in the first three editorials. The editors make the initial decision on whether a paper on ceramic/electronic materials will interest readers and meet the quality standards of the journal. The editorial provides brief biographies of the editors, including their areas of expertise and accomplishments in the field of materials science. [Extracted from the article]

Recently, papers with superhydrophobic surfaces and unique antibacterial and self-cleaning capabilities have attracted great attention due to its potential applications in cold chain logistics packaging. Therefore, a facile and versatile route to fabricate superhydrophobic and anti-bacterial adhesion dual-functional paper was reported. The approach was based on pufferfish-like structured ZIF-8 incorporated cellulose fibers. Specifically, cellulose fibers without any chemical pretreatment were used as templates for the in situ aqueous construction of pufferfish-like structured ZIF-8 with zinc nitrate as zinc source and dimethylimidazole as organic ligand. After paper-making and hydrophobicity treatment, the obtained paper possessed excellent superhydrophobic and anti-bacterial adhesion properties. These surfaces retained their water resistance after 30 finger-wipe cycles and 10 sandpaper abrasions. Moreover, the hydrophobic surface prepared also showed excellent anti-adhesion performance toward bacteria. This strategy route proposed here can significantly reduce or eliminate potential risks associated with various contamination. [ABSTRACT FROM AUTHOR]

As one of the most promising energy-storage devices, supercapacitors have drawn great research interests because of their outstanding electrochemical behavior. Carbon paper holds great prospect as an electrode material for supercapacitors since it is inexpensive and highly conductive. In this paper, the modified Hummer's method is employed as an effective strategy to produce activated carbon paper with rougher surfaces and increased specific surface areas. It is further observed that hydrophilic groups such as hydroxyl (-OH), carbonyl (>C=O), and carboxyl (-COOH) have been introduced into the surface of carbon paper over treatment and they serve as strong polar sites to absorb water molecules, leading to improved hydrophilicity. Thus, the as-treated carbon papers with both increased specific surface areas and improved surface hydrophilicity exhibited excellent capacitive characteristics. Moreover, the charge/discharge test over 2000 cycles shows their excellent long-term capacitive retention. [ABSTRACT FROM AUTHOR]

The paper uses X-ray diffraction (XRD) at different temperatures and both imaging and X-rays energy-dispersive spectroscopy (XEDS) in the SEM to examine changes that occur in this high-entropy oxide. The paper was handled by David Cann, one of our Editors whose own research emphasizes ceramics; it is entitled "Phase equilibria and metastability in the high-entropy A SB 6 sb B SB 2 sb O SB 17 sb oxide family with I A i = Zr, Hf and I B i = Nb, Ta." The paper is essentially a classical study of a ceramic material with the twist that these high-entropy ceramics had not been recognized as such until quite recently. [Extracted from the article]

The ability of the bacteria Gluconacetobacter sucrofermentans to produce high-quality cellulose is well known. This bacterial cellulose has unique properties, as the result of an ultrathin crosslinked structure. It is almost chemically pure (until 98% cellulose), has a high crystallinity, mechanical strength, elasticity and durability. It is compatible with plant cellulose and could be grown on a vegetal fibrous network what makes bacterial cellulose an excellent candidate to reinforce damaged papers. The objective of this work is to promote the production of bacterial cellulose on the surface of a variety of papers by the direct application of a culture of G. sucrofermentans and to test if this procedure could be an economic and feasible possibility in reinforcing papers or cellulosic surfaces. After 7 days of cultivation, G. sucrofermentans deposits a thin layer (ca. 10 µm) of bacterial cellulose on the papers surfaces. Microscopic observations have shown a heterogeneous covering of the surfaces, while the modified papers maintain their thickness and their basic weight. The treatment has not increased the papers mechanical properties, but maintains them after artificial aging. The changes in optical properties of the reinforced papers, such as opacity and colorimetric coordinates, are minor even after further aging. Air permeance is the paper characteristic that experiences more variations because the layers of bacterial cellulose inhibit the airflow through the papers. The changes in the static and dynamic contact angles suggest that the bacterial cellulose structure is more compact and make the surface more hydrophobic than the original paper surface. [ABSTRACT FROM AUTHOR]

Biogas-powered fuel cells that use low-quality biogas produced from organic waste hold a great promise for providing ultra-clean electric energy with on-site power generators. However, natural biogas contains a small amount of HS, which causes a rapid deactivation of steam-reforming metal catalysts, such as Ni. In this work, we successfully prepared two types of paper-structured catalyst, separately containing manganese oxides (MnO) and nickel/magnesium oxides (Ni/MgO), for desulfurization and methane-steam reforming, respectively. In the sequential desulfurization and methane-steam reforming, paper catalyst assembly, designed by stacking MnO papers upstream and Ni/MgO papers downstream in a dual-layered form, enabled continuous hydrogen production from simulated biogas containing ca. 2000 ppm HS impurities, whereas single-layered Ni/MgO papers immediately lost their catalytic activity due to the HS poisoning. This combination of flexible, stackable, and easy-to-handle paper-structured catalysts has the potential to improve the energy efficiency and to process economics of providing hydrogen to biogas-powered fuel-cell systems. [ABSTRACT FROM AUTHOR]

Cellulose insulation paper as a part of oil-paper insulation systems plays an important role in the reliability of converter transformers. The reliability of converter transformers equipped with traditional cellulose paper is adversely affected by space charge under DC voltage. The addition of nanoparticles into other dielectrics has been demonstrated to improve electrical performance. However, studies on the space charge behavior of cellulose paper reinforced with nanoparticles are rarely reported. This paper presents the results of a study aimed at elucidating the effect of nano-aluminum nitride (AlN) concentration on the space charge behavior of cellulose paper. Samples with various nano-AlN concentrations were fabricated and pretreated first. The micro-morphologies of prepared cellulose papers were observed using a field-emission scanning electron microscope. The space charge distribution was measured using a pulsed electroacoustic instrument. The results show the dependence of the charge injection as well as charge dissipation on the concentration of nano-AlN. The isothermal decay current method is used to obtain trap information. Based on the density and distribution of traps, the underlying mechanism of the effect of various concentrations on the space charge behavior is theoretically explained. [ABSTRACT FROM AUTHOR]

In-situ formation and integration of graphene into MoS2 interlayer spacing: expansion of interlayer spacing for superior hydrogen evolution reaction in acidic and alkaline electrolyte. The paper was handled by our Editor Mark Bissett and is entitled "In-situ formation and integration of graphene into MoS SB 2 sb interlayer spacing: expansion of interlayer spacing for superior hydrogen evolution reaction in acidic and alkaline electrolyte"; it is part of our "Energy materials" Topical Collection. The cover for the December 2022 issues of the Journal of Materials Science comes from the paper by Bui et al., which appeared in issue #40 from October 2022 [[1]]. [Extracted from the article]

This study presents a comparison of the mechanical and barrier properties of papers coated with microfibrillated cellulose (MFC) by two different coating processes: (i) bar coating and (ii) size press. Due to the high water content of MFC, water-treated papers were taken as references to highlight the effects of MFC on the properties of papers. Structural, mechanical and barrier properties of the ensued materials were performed respectively with SEM, tensile and stiffness testers, and air and oxygen permeability equipments. The properties of the water-treated papers were considerably damaged compared to those of the base paper that underlined the negative impact of both coating processes on the papers structure. With MFC, the air barrier and the bending stiffness were considerably improved (+90 and +50 % respectively), especially when the bar coating was used, i.e. with 7 g m of MFC. Size press was indeed not able to considerably improve papers properties as the MFC coat weight barely reached 4 g m resulting from ten successive MFC layers. [ABSTRACT FROM AUTHOR]

One of the effective ways to achieve drilling of Carbon fiber reinforced polymer (CFRP) materials is to use short pulse lasers. However, the existing cutting thermal damage, such as the heat-affected zone (HAZ), can weaken the CFRP mechanical properties. In this paper, a heterogeneous mesoscopic model of transient distribution of short pulse laser ablation heat flow is built to fully explore the formation and extension mechanism of thermal damage. The significant difference in laser interaction thermal effects between fibers and resin leads to the formation of HAZ with exposed fibers. The interface effect exists in the ablation process, which aggravates the matrix damage. The ablation of carbon fibers occurs within the duration of a single laser pulse, and the degree of ablation depends on the pulse energy. Under the coupling of the thermal conduction effect along the fiber axis and the thermal accumulation effect between pulses, the matrix damage extends significantly during the cooling stage. Large pulse repetition frequency increases heat accumulation between pulses and increases matrix damage. There is a new erosion mechanism in that the thermal accumulation behavior leads to the falling off of fragmented carbon fiber filaments. The accuracy of the model was verified through different pulse ablation tests, and the average error of ablation morphology is 11.28%. [ABSTRACT FROM AUTHOR]

As a new functional material, metal halide perovskites provide new possibilities for preparing gain media for nanosemiconductor lasers. This paper reviews the fabrication results of nanosemiconductor lasers based on metal halide perovskite materials. Firstly, three standard metal halide perovskite-based nanosemiconductor lasers are described: thin-film, nanowire, and quantum dot lasers. Under the corresponding gain structure of each laser, the appropriate gain dielectric material is discussed, and its application in the fabrication of nanosemiconductor lasers is discussed. On this basis, the effects of these gain structures and metal halide perovskite materials on the performance of nanosemiconductor lasers and related application progress are analyzed. Finally, the challenges and opportunities of nanosemiconductor lasers based on metal halide perovskite materials are summarized and the future development trend was discussed. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) metal halide perovskites feature several specific advantages over others 2D materials, such as facile wet chemical synthesis and layers exfoliation, high composition combination especially the choice of organic cations as well as 2D phase, excellent confinement for exciton. In this paper, we present a fundamental study of diaminonaphthalene lead iodide (DANPI) perovskite, a Dion–Jacobson 2D perovskite based on divalent cation organic spacer 1,5-diaminonaphthalene. We report its material synthesis, optical and structural characterization as well as DFT calculations. Hydro-iodic acid-based wet chemistry was used to prepare DANPI crystals and, by cast-capping, thin films as well. Both DANPI materials show a dominant emission peak at about 519 nm with a full width at half-maximum as small as 14 nm. This peak coincides with the absorption edge of the material at 510 nm (2.43 eV) which suggests an exciton-related recombination process. According to single-crystal X-ray diffraction measurements the crystal structure could be either monoclinic P21/c or tetragonal P4212. DFT calculations including spin–orbit coupling show that the DANPI band gap is direct, with a valence band of s-symmetry and a conduction band of p-symmetry. A dominant emission peak at about 519 nm with a full width at half-maximum as small as 14 nm. The crystal structure could be either monoclinic P21/c or tetragonal P4212. The DANPI band gap is direct, at 2.43 eV, with a valence band of s-symmetry and a conduction band of p-symmetry. Suggested Dexter electron exchange process for Wannier excitons to organic Frenkel excitons. [ABSTRACT FROM AUTHOR]

The alloy composition and sensitization behavior are crucial factors that cannot be overlooked in Al–Mg alloys. The effect of Zn addition on mechanical properties and sensitization behavior of 5083 alloy was investigated by tensile tests, weight loss experiments, and first-principles calculation in this paper. The results show that Zn can significantly improve the strength and sensitization behavior of the alloy. The tensile strength of the cold-rolled alloy increased from 459 to 498 MPa with the addition of 1.5%Zn. Furthermore, by incorporating 2.0% Zn, the mass loss of the cold-rolled alloy after sensitization at 170℃/1 h decreased from 49.3 mg·cm−2 to 19.5 mg·cm−2. First-principles calculations indicate that Mg clusters can only exist stably near grain boundaries, while Mg–Zn clusters can exist stably both within and at grain boundaries. This reduces the number of corrosive media at grain boundaries and weakens their continuity. Moreover, the energy barrier that T-phase precipitation needs to overcome during precipitation is lower than β-phase, which transforms the stabilization schedule of the alloy from 240℃/12 h without Zn to that 210℃/4 h with 2.0% Zn-containing. The synergistic effects of Zn content and sensitization on the properties of the alloy were revealed, which sheds some light for the design of the composition and processing method according to application scenarios. [ABSTRACT FROM AUTHOR]

The effect of the grain boundary (GB) misorientation on plastic deformation of Inconel 718 (IN718) alloy was investigated in this paper, using in-situ tensile experiment at 650 °C in combination with crystal plasticity finite element method (CPFEM). The results indicate that dislocations tend to accumulate at GBs to form stress concentration, but the degree of stress concentration does not necessarily increase with the increase of the GB misorientation. It is attributed to the slip transfer at the GBs, determined by the angle between the slip systems of the two adjacent grains. There is a significant uncertainty in the slip transfer for GB misorientation larger than 10°. However, the m α β ′ SF α + SF β criterion, which is a function of the Luster and Morris m α β ′ combining the Schmid factors of the two slip systems with the GB misorientation, has some statistical separation significance. Slip transfer tends to appear at GB misorientation less than 30° and m α β ′ SF α + SF β > 0.78 . This study clarifies the mechanism of the influence of GB misorientation on IN718 microplastic deformation and provides a new strategy to study the deformation behavior of superalloys. [ABSTRACT FROM AUTHOR]

This paper presents the nickel–cobalt nanoprickly particles (PNi2Co3) composited with graphene nanosheets (GNs) and carbon nanotubes (CNT), prepared via the one-pot hydrothermal method (PNi2Co3/GNs/CNT), as an efficacious nonprecious metal bifunctional electrocatalyst for both oxygen evolution and reduction reactions (OER/ORR). The study employs a comprehensive methodology, incorporating cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) analysis to characterize and assess the materials and electrochemical properties investigated in the article. The primary objective was to successfully prepare a bifunctional electrocatalyst, and the PNi2Co3/GNs/CNT material achieved this goal. It exhibited superior OER activity, durability, and resistance to crossover effects, by an overpotential (η) of 480 mV and a Tafel slope of 61 mV dec−1, significantly higher than those obtained for RuO2 nanoparticles (η = 970 mV, Tafel slope = 85 mV dec−1). A similar trend was observed for ORR, where the PNi2Co3/GNs/CNT displayed high activity with an n = 3.93, close to the activity of a Pt/C (20 wt%), commercial catalyst with n = 4. Careful analysis of the EIS results via suitable models, in conjunction with Tafel data, revealed that the enhanced activity originates mainly from two factors: (a) the large surface area of the Ni–Co nanoprickly alloy and graphene sheets, where the CNTs (as a spacer) helped graphene nanosheets to avoid restacking and decreasing the surface area, and (b) the synergistic effect between Ni–Co nanoprickly and carbon components (GNs and CNT) of the composite. [ABSTRACT FROM AUTHOR]

In this paper, EFKA FA 4663 (EFKA) dispersant was used for the first time in the alumina slurries tert-butyl alcohol-based freeze-casting and compared to the commonly used anionic dispersant citric acid (CA). The comparison of both dispersants was analyzed at the beginning of the process at different ultra-low freezing temperatures (− 170 to − 130 °C). The monoliths obtained with EFKA presented promising properties due to its stabilization of alumina particles by both electrostatic interactions and steric impediment, a considerable improvement when compared to the CA that promotes the stabilization of alumina particles only by electrostatic interaction. The use of different dispersants, as well as the control of freezing temperature, significantly influenced the microstructural properties of the monoliths. The monoliths exhibited prismatic pore geometry with high connectivity, forming a complex pore channel with total porosity up to 64.7%, and open porosity up to 48.5%. Results confirmed that the modification of the type of dispersant led to a difference in the grain size (up to 23.1%) and pore size (up to 30.5%) obtained in the materials. The monoliths produced with EFKA dispersant presented a considerable compressive strength resistance up to 11.7 MPa due to its dispersion mechanism that provided the thickening of the walls, confirming that the type of dispersion has a strong influence on the final properties of the materials. Therefore, the type of dispersant proved to be another parameter that allows the refinement of alumina monoliths properties, highlighting the use of EFKA as a promising alternative in the system studied. [ABSTRACT FROM AUTHOR]

This paper focuses on the effect of laser shock peening on the rotational bending fatigue life of S51740 stainless steel round bar specimens. The improvement of material properties by laser shock peening is investigated by combining simulation calculations and experiments. The main results are as follows: Finite element simulations yielded three sets of laser process parameters for the study (LPS-1, LSP-2, LSP-3). The fatigue test results show that laser impact strengthening can effectively improve the fatigue life of the material, and compared with the unenhanced specimens, 350% increase in fatigue life of LSP-2 specimens. EBSD analysis showed that the LSP-2 specimen performed the best. It was verified that the material properties of S51740 stainless steel were greatly improved when the laser process parameter was LSP-2. [ABSTRACT FROM AUTHOR]

The fashion and textile manufacturing sectors are increasingly focusing on innovative raw materials that are renewable and biodegradable. Such materials not only mitigate environmental impacts but also prevent resource depletion. Bacterial cellulose (BC) has emerged as a prime candidate, derivable from a variety of natural ingredients such as tea and coffee in addition to a sugar source in presence of the bacterial microorganisms. Numerous studies have established the potential of BC in future fashion, and some brands have already started to utilise BC as a sustainable raw material. The applications of BC ranges from basic clothing and accessories to wearable electronics. This paper discusses the scope of BC in fashion and textiles, positioning it as a sustainable alternative to conventional materials. We present a comprehensive scoping review, covering the unique properties of BC, the factors influencing its production, and its applications in textile, clothing, and footwear over the past decade. The advantages of BC in fashion are manifold: zero-waste manufacturing, reliance on renewable sources, diminished environmental pollution, and biodegradability. Furthermore, the use of BC aligns with United Nations Sustainable Development Goals 6, 7, 12, 13 and 15. However, there exist challenges pertaining to production costs, scalability, and quality, in addition to the imperative of harnessing food waste streams instead of contending for human food resources. Addressing these challenges is vital to cement BC's position as a pivotal sustainable material in future fashion. [ABSTRACT FROM AUTHOR]

In this study, four ZrNxOy coatings were deposited on the surface of Ti–45Nb alloy by multi-arc ion plating technology at different N/O ratios. The effects of oxygen content on the mechanical properties, wear resistance, electrochemical corrosion and tribocorrosion properties of the coatings were investigated separately. As the increasing of O2 ratio, the hardness value decreases from 30.2 to 9.7 GPa; the Young's modulus values decrease from 322.1 to 172.2 GPa. The H/E and H3/E2 values showed a decreasing trend with the increasing O2, which indicates a gradual decrease in the load-bearing capacity of the coatings. The critical load of these coatings in scratch test ranges from 12 N, 7.2 N, 5 N to 3N. In the friction test, both the TiNb alloy and coating exhibited predominantly abrasive and adhesive wear. The relatively low wear rate of the ZrN coating demonstrated its excellent wear resistance; however, the wear-resisting property of the ZrNxOy coating gradually decreases as the oxygen content increases, and ZrO2 coating showed the poorest wear resistance. On the contrary, the higher the oxygen content, the better the electrochemical corrosion resistance, and ZrO2 coating showed the excellent corrosion resistance. The results of tribocorrosion test show that the ZrNxOy coating has better wear resistance in simulated body fluid solution compared to Ti–Nb alloys. The experimental results and design concepts of the paper can provide a better understanding of the preparation of medical titanium alloy surface functional coatings with good comprehensive performance. [ABSTRACT FROM AUTHOR]

Many important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1%, dried until a constant weight was reached) and freeze-drying (FD, treated at − 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity. [ABSTRACT FROM AUTHOR]

In low- to middle-income communities, the lack of affordability of conventional sanitary products during menstrual cycles can cause psychological and health issues, ultimately affecting their quality of life. It is crucial to develop alternative products that are affordable and accessible to all while also promoting menstrual health and hygiene. Super absorbent polymers (SAPs) are a vital component in current disposable sanitary pads and nappies. However, these SAPs are often non-biodegradable and non-biocompatible. Therefore, the use of eco-friendly materials for the production of SAPs is gaining popularity in the hygiene industry, as it offers a means to reduce the carbon footprint and environmental impact associated with traditional SAPs made from non-renewable petroleum-based materials. SAPs made from polysaccharides often have naturally occurring antibacterial properties, making them appealing for commercial applications in sanitary products such as sanitary pads. In addition, the move toward reusable sanitary pads with antibacterial properties can significantly reduce waste generated by single-use products and prevent the growth of bacteria, improving the safety and hygiene of the product. Furthermore, computational modeling and artificial intelligence are now important tools in SAP synthesis, providing advantages such as predicting polymer properties, rationalizing synthesis pathways, and improving quality control. These tools can reduce synthesis costs by eliminating the need for trial-and-error approaches in polymer synthesis, ultimately promoting more affordable products for end users. Overall, these advancements in polymer synthesis and material design can help to create a more sustainable industry and promote menstrual hygiene and product accessibility to those who need it most. [ABSTRACT FROM AUTHOR]

Presently, special metallic materials (titanium and a number of its alloys, stainless steels, magnesium alloys, etc.) are extensively used for the manufacturing of many medical tools and devices and choosing the appropriate material is of vital importance as it determines the success and safety of the medical devices for their application. Recent years witnessed active research and development to improve the mechanical and functional properties of these biomaterials using their nanostructuring by means of severe plastic deformation (SPD) techniques. The specific nanostructural features induced by SPD processing in metallic biomaterials significantly contribute to their performance, which has been evidenced in a series of investigative activities conducted lately to improve existing metallic biomaterials and explore potential for their production capability. This paper presents a review of these works and considers the scientific principles of achieving a higher level of properties in the metallic biomaterials as well as related challenges and uncertainties, which forms the basis for the production of a new generation of medical implants with improved design and increased biofunctionality. [ABSTRACT FROM AUTHOR]

In this paper, the effect of deep cryogenic treatment (DCT) on the microstructure and properties of automotive 6063 aluminum alloy at different times was investigated with automotive 6063 aluminum alloy as the research object. The results show that under the conditions of deep cryogenic treatment, the lattice distortion occurs in the alloy matrix microstructure, and the resulting internal stress promotes the large proliferation of dislocations within the alloy and the increase of dislocation density; meanwhile, after the deep cryogenic treatment, the deformed grains are transformed into recrystallized and sub-crystals structural grains, the grains are refined, and the size of the grains is refined from the original 25.2 μm to 20.3 μm, with fine equiaxed crystals. Among them, the mechanical properties of the DCT36h specimen were the best, and its hardness, tensile strength, yield strength and elongation reached 142.44 HV, 328.32 MPa, 177.42 MPa, and 29.29%, which were 34.17%, 5.62%, 11.10%, and 32.77% higher than the original sample, respectively. We believe that the main mechanism for the increase in toughness is multiple reinforcement such as dislocation strengthening, grain refinement strengthening, precipitated phase strengthening and texture strengthening. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation is a sustainable and green desalination method with great prospects for development in today's severe water shortage problem. In this paper, a novel composite aerogel was prepared by hydrothermal method with sodium alginate (SA) and Cu2+ in the preparation process using reduced graphene oxide as photothermal material and cellulose nanofibers as substrate. The good hydrophilicity of nanocellulose makes the composite aerogel have strong capillary action and continuous water transport. The gel formed by ion exchange between SA and Cu2+ greatly improves dry and wet mechanical strength of the composite aerogel and ensures the stability of the evaporator for multiple recycling. Copper is doped by reduction of copper ion complexes and reduced graphene oxide have a synergistic effect to increase the photothermal response rate of the composite aerogel of 1.446 kg m−2 h−1 with evaporation efficiency of 84.87% under one standard solar irradiation. In addition, the purification of heavy metal ions, dye wastewater as well as acid and alkali solutions also has excellent results. It is expected that this study will provide some new ideas for the fields of seawater desalination and wastewater treatment. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrate (PHB) is a hydrophobic, biodegradable biopolymer, which can be a potential substitute for currently used synthesized polymers in the packaging industry. However, its utility is often limited by its brittleness and poor mechanical properties, mainly because of its through-thickness fractures. In this study, we laminate and crystallize PHB on glassine paper by hot-pressing and tune the crystallization conditions to minimize cracking. Glassine paper is impermeable to PHB granules and allows the formation of a distinguishable bilayer of PHB. It was found that glassine paper serves as a soft substrate, which increases the number of nucleation sites of the spherulites and prevents growth of the cracks in the neighboring PHB layer. Quenching the films to the crystallization temperature was found to minimize cracking enough to reduce the water vapor transmission rate to $$15$$ - $$25\,{\mathrm{g}}\,{\mathrm{m}}^{-2}\,{\mathrm{day}}^{-1}$$ , irrespective of the crystallization temperature; however, the mechanical properties improved only at the crystallization temperatures below 77 °C, perhaps due to the local stress in the existing cracks at higher crystallization temperatures. The optimum crystallization conditions were found to be quenching the film in an ice bath and crystallization at room temperature, by which we obtained mechanical strength and Young's modulus of $$80\,\text {MPa}$$ and $$2.5\,\text {GPa}$$ , respectively, and a water vapor transmission rate of $$20\,\text {g}\,\text {m}^{-2}\,\text {day}^{-1}$$ . Our results suggest a simple and cost-effective method to produce PHB films with enhanced mechanical and barrier properties. [ABSTRACT FROM AUTHOR]

The Journal of Materials Science is known for publishing papers on polymer materials. The journal has several editors who specialize in polymers, including Chris Cornelius, Steve Eichhorn, Jamie C. Grunlan, Dale Huber, Maude Jimenez, Greg Rutledge, Jean-François Gohy, and Mohammad Naraghi. These editors handle papers on a wide range of topics related to polymers, including composites, materials for the life sciences, coatings, electronic materials, chemical routes to materials, and ceramics. Each editor has their own area of expertise and has made significant contributions to the field. The journal is a valuable resource for researchers interested in polymeric materials and related topics. [Extracted from the article]

Bacterial cellulose (BC) is a pure biopolymer with abundant sources. BC has been used in wound dressings, artificial blood vessels, bone tissue engineering, and other applications because of its microporosity, superior water retention, thermal stability, and biocompatibility. The tensile strength of pure BC in wet state is weak, and the water holding capacity is above 90%, which limits its application. However, the mechanical properties of dehydrated BC are excellent at the expense of toughness, which is not enough to meet the demand of high additional-value materials, such as high strength flexible electronic device substrate, wearable electronic devices, vibration film for microphone and earphone, and others. Therefore, it is of great importance to systematically investigate the strategies to improve the mechanical properties of BC. Herein, this paper demonstrates the intrinsic factors affecting the mechanical properties of BC, along with the strategies to enhance the mechanical properties. Compared with the well-known adhesion reinforcement and chemical modification, six strategies to enhance the mechanical properties were discussed thoroughly in this paper. In addition, layer-by-layer self-assembly and orderly arrangement of fibrils are proposed in this paper to improve the mechanical properties of BC, which have not been described in detail in previous literature. [ABSTRACT FROM AUTHOR]

The effects of humidity on the electrical properties of thermal inkjet-printed copper tetrasulfonated phthalocyanine (CuTsPc) films onto paper substrates are reported. DC electrical measurements revealed that sample resistance decreases from 10 Ω in moderate vacuum to approximately 10 Ω at highly water-saturated atmosphere. This behavior is attributed to the creation of water pathways on the cellulose fibers that allow ionic species such as impurities, protons (H), and dissociated Na ions from the CuTsPc molecules, to flow. The contribution of the CuTsPc molecules and their dissociated Na ions on the sample resistance was elucidated analyzing the electrical response of bare and printed paper substrates. An increase of relative humidity levels (RH) from 10 % to 40-45 % revealed an increase of current of four orders of magnitude for printed samples, whereas less than one order of magnitude was registered for bare paper substrates. Electrical measurements as a function of temperature have shown that moisture can inhibit the semiconducting properties of CuTsPc. Thermal gravimetric studies revealed that approximately 11 % of mass accounting to the presence of water is released above 70 °C, the same temperature in which the sample recovers its dry-state semiconducting behavior. The semiconducting properties of CuTsPc can also be observed upon white light illumination, whereas the charge carrier extraction is governed by the RH level. These results point out the important role of humidity on the electrical properties of paper-based organic, electronic, and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cell (PEMFC) is a promising automotive power source that has been gradually applied due to its many advantages such as pollution-free and low-temperature start-up. The gas diffusion layer (GDL) is a key component for water and gas management in PEMFC. It can directly affect the performance of PEMFC. In this paper, we prepared a new type of GDL with hierarchical pores to improve the performance of PEMFC at high current density. The new GDL mainly includes a commercial carbon paper layer and two microporous layers on the same side of carbon paper. The microporous layer near carbon paper was modified with pore former, and another layer was produced without pore former. The pore size of the middle microporous layer was controlled by the content of pore former and times of sonication. From the results of the polarization curve, electrochemical impedance spectroscopy, water contact angle, conductivity, and pore size distribution, it was found that GDL with hierarchical pores shows obvious advancement than commercial GDL. The PEMFC performance was tested to compare the new and commercial GDL. The results show that the peak power of our GDL at 100% humidity reaches 1.24 W/cm2 and the limit current density is 3.500 A/cm2. The modification of the pore size of the microporous layer near the carbon paper side can improve the water management ability of the fuel cell. [ABSTRACT FROM AUTHOR]