The structures of carbonized products from cellulose are closely correlated with the raw material. In the present work, we proposed a self-reassembly strategy and successfully prepared a novel nano-scale cellulose material which exhibited a crumpled thin layer structure and high crystallinity (> 95%). The nano-cellulose undergoes partial graphitization-related transformation without any catalyst at the temperature lower than 300 degrees C, which was extremely lower than the graphite transition temperature for conventional cellulose (> 1800 degrees C). On this basis, we prepared a novel graphene oxide with high capacitance capability and ultra-long cycling stability. The present findings not only expand our understanding on the microstructure-property correlations of polymer materials but also are expected to achieve wider applications of nano-cellulose to energy-related areas or intelligent wearable devices.

Using NaOH/urea/water system as the solvent and anhydrous ethanol as the anti-solvent，a series of regenerated cellulose nanocrystal （RCNC） with controllable molecular weights and gradually decreasing yet stabilized sizes are prepared through a multi-step precipitation method. High-performance liquid chromatography and transmission electron microscopy results reveal that the sizes of the obtained RCNC gradually decreased as their molecular weights decreased （from 36 kDa to 9 kDa）. Pickering emulsion stability tests indicate that the prepared RCNC exhibits excellent emulsifying properties. Among them，RCNC-15 with an average molecular weight of 15 kDa exhibits the best emulsifying performance，with the smallest emulsion droplet size and the optimal emulsion stability at low concentrations. Using the RCNC with the best emulsifying properties as the carrier，zinc oxide nanoparticles are grown in-situ on it to conduct emulsion-assisted photo-degradation tests of Nile red. The degradation rate reaches 99.5% within 100 min，indicating that the obtained RCNC could be served as an efficient emulsion-assisted reaction carrier.

Using in-situ transmission electron microscopy (TEM), electron beam-induced cementite to ferrite transformation at the interphase boundary was observed in a pearlitic steel. The phase transformation is attributed to the irradiation-driven transport of interfacial carbon atoms into ferrite. Plastic deformation could reconstruct the interface into a structure with an analogous feature, suggesting the interfacial carbon depletion during the process.

This study investigates the influence of chloride ion concentrations on the initial corrosion behavior and product evolution of 3 % Ni weathering steel, with a focus on understanding the limitations of nickel's corrosion resistance in high-chloride environments. Accelerated wet-dry cyclic corrosion tests were performed, and the results were analyzed using XRD, XPS, SEM, TEM, and first-principles calculations. The findings reveal that 3 % Ni weathering steel exhibits limited corrosion resistance during the initial stages, with corrosion products predominantly composed of non-protective gamma-FeOOH and beta-FeOOH. Nickel, initially uniformly distributed, was observed to localize within beta-FeOOH regions but failed to form an effective protective layer. Computational results demonstrate that chloride ions significantly inhibit the transformation of gamma-FeOOH to alpha-FeOOH, while the persistence of beta-FeOOH is kinetically controlled. These mechanisms collectively weaken the corrosion resistance imparted by nickel. This study highlights the importance of initial corrosion behavior as a criterion for the rapid screening and design of weathering steels and provides valuable insights into improving their performance in marine environments.

In the past few decades, a development of organic magnets with room-temperature strong ferromagnetism is challenged by the difficulty of creating three-dimensional (3D) long-range magnetic orderings in organic materials at a temperature higher than room temperature. Here, we report room-temperature ferrimagnetism of a tetragonal organic–inorganic hybrid Fe14Se16(tepa)III (tepa = tetraethylenepentamine), where III represents a coordination of a tepa molecule with a Fe3+ ion for an organic complex. The layered hybrid in a nanoplate-like shape is formed by periodic incorporation of tetragonal β-Fe3Se4 inorganic layers and organic spacing layers consisting of tepa and Fe3+. Fe14Se16(tepa)III shows a saturation magnetization MS of 7.2 emu g−1 at 300 K and a record-high Néel temperature TN (>560 K) in the organic magnets reported experimentally. A Mössbauer spectrum confirms a 3D long-range magnetic ordering of Fe2+ [S = 2 (71.4%)] and Fe3+ ions [S = 5/2 (21.7%) and 1/2 (4.0%)] in β-Fe3Se4 layers and organic spacing layers of Fe14Se16(tepa)III,9. First-principles calculations explain that the 3D long-range antiferromagnetic interactions between interlayer and intralayer irons result in the strong ferrimagnetism of Fe14Se16(tepa)III. This study unveils the possibility of tuning magnetic couplings of interlayer and intralayer high-spin Fe3+ and Fe2+ for enhancing the ferrimagnetism of layered hybrids and, thus, for future room-temperature magnetic/spintronic applications.

The microstructures and corrosion behavior of 1.0wt% Gd-containing neutron-absorbing duplex stainless steel annealed at different temperatures were studied. Results reveal that the content of Gd-containing secondary phase increases with increasing the annealing temperatures to 1080 degrees C, and then decreases. In the sample annealed at 1080 degrees C, M-Gd (M=Fe, Cr, Ni) intermetallic with M3Gd as the core phase and M12Gd as the shell is the primary secondary phase. In the sample annealed at 1140 degrees C, M3Gd phase is dominant. The corrosion behavior of the two annealed steel samples were analyzed in NaCl, HCl and H3BO3 solutions. It is found that the sample annealed at 1140 degrees C has lower corrosion rate. M3Gd is more electrochemically active than M12Gd when the sample is immersed in NaCl and HCl solutions, but more noble in H3BO3 solution.

It is of great value to reuse dissolved carbohydrates from the spent liquor produced in the acid hydrolysis process of cellulose nanocrystals (CNCs). In the present study, the special flake-like nanocellulose crystals (FCNCs) were self-assembled from the dissolved cellulose chains or small-sized cellulose fragments via a “bottom-up” approach. Despite the low yield ( 0.44

It is still an enormous challenge to regulate microstructure of pure carbonaceous electromagnetic (EM) wave absorbents in order to gain superior wideband microwave absorption (MA) with environmentally adaptive ability. Herein, the novel pure cellulose-derived graphite carbon materials (CGC) with abundant defects were fabricated via the self-assembly strategy combined with simple carbonization for the first time. The EM and MA performance of as-prepared CGC with different carbonization temperatures were studied in detail. The minimum reflection loss of CGC was up to –46.2 dB (over 99.99% MA) at only 1.42 mm, and the maximum effective absorption bandwidth (EABmax, RL < –10 dB) was as wide as 6.32 GHz. The greatly improved MA of pure carbon materials outperformed those of many previously reported carbon-based composite absorbents with tedious preparation process. The excellent MA property was attributed to the optimal synergy of good impedance matching and satisfactory EM attenuation capability. Besides, the CGC still retains a strong and broadband MA ability in the simulated real harsh environmental conditions (acid rain/alkaline solution, salt spray and strong UV exposure). Hence, the CGC is believed to be a very promising candidate as high-efficiency EM wave absorbents with wide frequency and excellent environmental adaptability for practical application.

Developing strong electromagnetic (EM) wave absorbing materials to solve the issue of EM radiation emanating from electronic devices in low-frequency range remains currently a great challenge. The majority of current solutions in low-frequency range are based on magnetic absorbent. However, this approach is constrained by the poor impedance matching, high production cost and limited absorption bandwidth. Herein, the novel reproducible cellulose-derived flawed graphite carbon material (represented as CFGC) was prepared by chemical and following simple carbonization method. Besides, the unique defect structure and the mechanism underlying microwave absorption (MA) are elaborated in detail. By fine-tuning the content of CFGC, the MA property is optimized. The minimum reflection loss (RLmin) of 50 wt% filling for CFGC is -42.08 dB at 4.08 GHz, showing an excellent MA property within the low-frequency range of C bands. Thus, the novel CFGC in this study provides a new and convenient way to solve low-frequency EM pollution.

It is a major challenge to obtain broadband microwave absorption (MA) properties using low dielectric or magnetic nanoparticle-decorated carbon composites due to the limited single conductive loss or polarization loss of the carbon materials used as substrates. Novel pure cellulose-derived graphite carbon (CGC) materials can be used as an exceptional substrate option due to their special defective graphitic carbon structure, which provides both conduction and polarization loss. Herein, CGC@ZnO composites were first synthesized by atomic layer deposition (ALD) for use as microwave absorbents. Thanks to the multiple interfaces composed of graphitic carbon, defective carbon, and polar ZnO molecules, the CGC@ZnO composites exhibited superior MA properties. Specifically, the CZ-3 achieved a minimum reflection loss (RLmin) of -50.5 dB (over 99.999% MA) at 6.16 GHz in 2.98 mm. Amazingly, the maximum effective absorption bandwidth (RL < 10 dB, EABmax) could reach up to 6.48 GHz at only 1.59 mm. The ultra-broadband absorption property is mainly attributed to its strong electromagnetic attenuation capability and excellent impedance matching, making it one of the most promising materials for MA applications.

The corrosion resistance of stainless steels exposed to humid environment is closely related to the surface oxide film. To date, the formation process and its correlation with the alloy defects are still unclear. The present study, using in-situ atomic-scale TEM characterization, reveals the growth process of oxide film on a fresh steel surface. The oxide formation involves the oxygen adsorption, the inward diffusion into alloy lattice, and the outward expansion of stable oxide film. The metal-oxide solid transformation is found to be promoted by the lattice strain of the alloy. The atomic structures of the oxides are imaged and analyzed.

Organic magnetic semiconductors have aroused much attention for spintronic applications. However, it remains challenging to achieve organic semiconductors with strong room-temperature ferromagnetism. Here, we report a two-dimensional (2D) tetragonal organic-inorganic ferrimagnetic (FIM) semiconductor of Fe14Se16(peha)0.7 (peha = pentaethylenehexamine) with excellent thermal stability and a Curie temperature (TC) higher than 519 K. Magnetic and M & ouml;ssbauer measurements reveal a long-range magnetic ordering in single crystalline Fe14Se16(peha)0.7 nanosheets. The saturation magnetization and coercivity are 5.9 emu g-1 and 0.42 kOe at 5 K, which slightly reduces to 4.6 emu g-1 and similar to 0 Oe at 300 K. A direct optical bandgap of 2.22 eV is obtained by tuning electronic structure of beta-Fe3Se4 host layers through spacer layers consisting of Fe3+ and peha. Electrical and Seebeck coefficient data indicate that the n-type semiconductor follows the thermally-activated conduction mechanism (ln rho proportional to T-1) in a range of 130-300 K with an activation energy ( Ea ) of 62.69 meV. Thermal conductivity is 2.5 W m-1 K-1 at 300 K, while the Wiedemann-Franz law is strongly violated according to electrical-thermal transport data due to weak incorporation of organic spacer layers and host layers. This study sets the stage for exploiting new room-temperature organic magnetic semiconductor systems for spintronic materials. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The poor adhesion, which is related to the mechanical properties of the substrate and film, leads to the film peeling off from the substrate and failure. In this study, TiN films with various structure were prepared on Ti6Al4V titanium alloy (TC4), 316L stainless steel (316L), 4Cr5MoSiV1 hot work die steel (H13), and W6Mo5Cr4V2 high-speed steel (W6) by adjusting the discharge currents using a hot-wire plasma-enhanced magnetron sputtering rig. The morphologies of the single-layer TiN films varied from loose to dense and ductile to brittle, and the nanohardness and elastic modulus increased as the hot-wire discharge current increased. The morphologies, nanohardnesses, and elastic moduli of the multilayer TiN films gradually approached those of the dense TiN single-layer films as the thicknesses of the top dense layers increased. The results, both by numerical simulation and experimental tests, revealed that the interfacial tensile stress and surface strain of a TiN/substrate system increased as the elastic modulus differences between TiN and its substrate increased, resulting in a serious TiN film elastic and plastic deformation asynchrony and poor film–substrate adhesion. The loose layer between the top dense TiN layer and its substrate acts as a buffer because the elastic modulus of the loose layer is in the middle, higher than that of the substrate but lower than that of the top dense layer. For TiN/TC4 or 316L with large differences in elastic moduli, loose/dense thickness ratios of 1:2 or 1:4 for the multilayer TiN films were sufficient to improve their adhesion. For TiN/H13 or W6, with small elastic modulus differences, a ratio of 1:4 was sufficiently large and may not be necessary.

Borides have been found to play a significant role in determining the mechanical properties of cast TiAl alloys. In order to investigate the influence of cooling rate on the morphology and structure of borides, SEM and HRTEM techniques were utilized to analyze borides in Ti-43Al-4 Nb-1Mo-0.5B (at%) cast plates with varying thicknesses. A higher cooling rate was observed to result in the formation of elongated, curvy borides with high aspect ratios, increased planar faults, and complex structures consisting of a combination of B2 phase and various boride phases. Conversely, a slower cooling rate yielded shorter bar-shaped borides with fewer planar faults. This variation in boride morphology can be attributed to the differing thicknesses of the solute-rich layer, where the eutectic reaction occurs, at the solidification front during fast and slow cooling processes. The Bf-TiB with a habit plane of (010) was identified as the dominant phase at all cooling rates. Borides in the [100] and [001] directions demonstrated a faster growth rate compared to those in the [010] direction. Additionally, HRTEM results indicated the presence of TiB2 while Ti3B4 was absent. This can be explained by the limited phase region of Ti3B4 in both the binary Ti-B and ternary Ti-Al-B phase diagrams, which is the smallest among all phases. These findings enhance the understanding of how cooling rate influences the morphology and structure of borides in TiAl alloys, thus providing insights for optimizing alloy design and manufacturing processes.

It is of great value to reuse of the dissolved carbohydrates from the spent liquor produced in the acid hydrolysis process of cellulose nanocrystals (CNCs). In the present study, a special flake-like nanocellulose crystals (FCNCs) were self-assembled from the dissolved cellulose chains with low molecular weight via a "bottom-up" approach. The average diameters of FCNCs were 712 nm, with thickness in the range of 3 ~ 3.5 nm. They exhibited superior thermal stability relative to CNCs. XRD characterization revealed that the FCNCs with the cellulose type II structure possessed the hydrophobic (110) plane as the exposed surface which endowed the material with relatively hydrophobic property. Confirmed by the contact angle tests, the water contact angle value of FCNCs film was as high as 72.0°, almost twofold of that of CNCs film.

Nano 3C-SiC@multilayer graphene oxide (NS@MGO) heterostructure was in situ prepared by carbothermal reduction of pyrolyzed precursor composed of highly dispersed cured phenolic resin and silicon dioxide derived from tetraethyl orthosilicate. The heterojunction interface, number of layers of MGO, and defect content in graphene are the three most important factors for promoting photocatalytic activity. Direct contact between 3C-SiC nanograins and MGO layers facilitates the photogenerated electrons to migrate across the heterojunction interface and avoid the formation of SiO2 nanolayers on the surface of SiC nanograins. The number of MGO layers is supposed to be less than ten instead of over-thick MGO. The concentrations of oxygenated components, considered the defect contents, decrease with the increase of sintering temperature for NS@MGO 0.175-T-150, and relative carbon content in the multilayer graphene increases. According to the heterostructures, properties, and photocatalytic reaction performance of the NS@MGO materials, the highest photocatalytic kinetic rate constant of 0.00891/min for NS@MGO 0.175-1500-150 shows that the significant enhancement in photocatalytic degradation activity under visible light (>420 nm) irradiation is ascribed to the advantageous synergistic effects between the nano 3C-SiC particles and the direct contact multilayer graphene oxide with appropriate layers and sufficient oxygen content of 3.51% (atomic fraction) in MGO.

Enhanced interaction between metal precursors and silanol nests was demonstrated on a silanol-rich dealuminated beta zeolite by strong electrostatic adsorption, leading to the formation of highly dispersed Ni nanoparticles for effective catalysis.

Laves phase is generally prejudicial to the performance of ferritic stainless steels, so understanding the under-lying formation mechanism should be technologically useful. Here we demonstrate a new precipitation behavior of Laves phase in Fe-30Cr-2Mo super ferritic stainless steel by using transmission electron microscopy. It is revealed that the MC carbides firstly precipitate adhere to the M2SC carbosulphides with an orientation rela-tionship (OR) of (0001)M2SC//(111)MC and [1120]M2SC//[011]MC. Subsequently, the interfaces between MC carbides and ferrite matrix provide preferential nucleation sites for Laves phases, which hold OR with MC as follows: (111)MC//(0003)Laves and [011]MC//[1120]Laves. Notably, the transformation from MC to Laves phases is an in-situ process based on the dissolution of MC carbide, which supplies the niobium element for nucleation and growth of Laves phase. This work enriches the recognition of the precipitation mechanism of Laves phase, and should therefore facilitate the design of high-performance ferritic stainless steels.

Stabilisation of metal species using hydroxyl-rich dealuminated zeolites is a promising method for catalysis. However, insights into the interactions between the hydroxyl groups in zeolite and noble metals and their effects on catalysis are not yet fully understood. Herein, comparative studies were conducted using Pt catalysts supported on hydroxyl-rich dealuminated Beta (deAl-Beta) and the pristine proton-form Beta (H-Beta) for catalytic oxidation of toluene. The findings suggest that during impregnation the Pt precursor (i. e., Pt(NH3)(4)(NO3)(2)) interacted with different sites on deAl-Beta and H-Beta, leading to the formation of supported Pt nanoparticles with different physicochemical properties. In detail, for H-Beta, the Pt precursor interacted with Al-OH and isolated external Si-OH sites, yielding Pt NPs with a higher Pt-0 proportion of similar to 71 % compared to similar to 57 % Pt-0 on deAl-Beta. Comparatively, abundant hydroxyl groups on deAl-Beta such as silanol nest and isolated internal Si-OH stabilised highly active Pt-O species. The resulting Pt/deAl-Beta exhibited improved activity and anti-coking ability than Pt/H-Beta in catalytic toluene oxidation. For example, the temperature for 50 % toluene conversion was 193 degrees C for Pt/deAl-Beta vs. 232 degrees C for Pt/H-Beta, and the coke deposition was 1.7 % vs. 6.7 % (after the 24-h longevity test), respectively. According to the toluene-temperature programmed desorption (toluene-TPD), H-1 nuclear magnetic resonance (H-1 NMR) relaxation and in situ diffuse reflection Fourier transform spectroscopy (in situ DRIFTS) characterisation, the enhanced performance of Pt/deAl-Beta could be ascribed to (i) the active Pt-O sites stabilised by hydroxyl groups, which interact with toluene easily for conversion, and (ii) the acid-free feature of the deAl-Beta support, which avoids the formation of coke precursors (such as benzoate species) on the catalyst surface. Findings of the work can serve as the design guidelines for making effective supported metal catalysts using zeolitic carriers.

以MnCl2为原料,聚乙烯醇(PVA)为稳定剂,利用PVA介导沉淀法制备Mn3O4纳米粒子(PVA/Mn3O4),进一步将冻干的PVA/Mn3O4复合物炭化制备了超小尺寸的Mn3O4-C催化剂.使用XRD、XPS、TEM、BET表征制备材料的结构和形貌,发现PVA能够有效减小Mn3O4在制备过程中的聚集和长大.无PVA介导沉淀法制备的Mn3O4-P平均粒径为(38.8±9.3)nm.加入PVA后,制备过程中PVA分子链间的Mn3O4纳米粒子平均粒径为(3.2±0.8)nm,经过Ar保护炭化处理后,平均粒径为(4.5±1.2)nm的Mn3O4纳米粒子被均匀固定在碳基底上.制备的Mn3O4-C催化剂具有高效的类芬顿催化降解亚甲基蓝(MB)的能力,在MB质量浓度为40 mg/L的40 mL溶液中,催化剂质量浓度为75 mg/L,H2O2投加量为4 mL,反应时间为40 min,反应温度为80℃的条件下,MB的降解率为94.4％.催化剂经过3次循环使用后,MB的降解率保持在91.1％,且碳基底上的Mn3O4纳米粒子结构和形貌与使用前相似.