Lamellar Structure Research Articles

Microemulsion-Based Synthesis of Highly Efficient Ag-Doped Fibrous SiO2-TiO2 Photoanodes for Photoelectrochemical Water Splitting

Fibrous SiO2-TiO2 (FST) is one of the most promising materials for advancing photoelectrochemical water-splitting technology due to its cost-effectiveness and environmental friendliness. However, FST faces intrinsic limitations, including its low conductivity and wide bandgap. In this study, significant progress was made in modifying FST to overcome some of these limitations. This work involved synthesizing a new photoanode made of Ag-doped FST utilizing the microemulsion process. The Ag-doped FST was characterized using XRD, FTIR, UV–Vis, DRS, N2 adsorption–desorption, FESEM, TEM, and XPS. The results confirmed the formation of a continuous concentric lamellar structure with a large surface area. The addition of Ag species into the FST matrix caused interactions that reduced the bandgap. The Ag-doped FST photoanode exhibited an impressive photocurrent density of 13.98 mA/cm2 at 1.2 V (vs. RHE). This photocurrent density was notably higher than that of FST photoanodes, which was 11.65 mA/cm2 at 1.2 V (vs. RHE). Furthermore, the conduction band of Ag-doped FST is positioned closer to the reduction potential of hydrogen compared to that of FST, SiO2, and TiO2, facilitating rapid charge transfer and enabling the spontaneous generation of H2. The fabrication of Ag-doped FST provides valuable insights into the development of high-performance photoanodes for PEC water splitting.

Interface engineering design of compressible and hydrophobic cellulose nanofibril aerogel with porous lamellar structure as highly efficient oil adsorbent

Interface engineering design of compressible and hydrophobic cellulose nanofibril aerogel with porous lamellar structure as highly efficient oil adsorbent

Degradation Characteristics of PBAT Fully Biodegradable Mulch Film

Replacing traditional plastic mulch with fully biodegradable mulch is an important research direction to solve the problem of "white pollution," but whether it can truly realize biodegradation is still the focus of many scholars. In this study, field and indoor experiments were carried out in Pingluo County, Ningxia Hui Autonomous Region, using poly（butyleneadipate-co-terephthalate） （PBAT） fully biodegradable mulch film and ordinary polyethylene （PE） mulch film, with no mulch film （CK） as the control. Macroscopic characteristics such as the degree of apparent cracking of the mulch film, loss of the mulch film area, and the rate of weight loss were observed, and the results were combined with the results of scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR）, and thermogravimetry （TGR）. Combined with microscopic features such as SEM, FTIR, thermogravimetric analysis （TG）, and CO2 release, the degradation characteristics of PBAT in the irrigation area of Yinbei District were comprehensively investigated, and data support was provided for the promotion of PBAT on a large scale. The results showed that, macroscopically, the PBAT film had begun to rupture after 60d of covering, the loss rate of film area was 27.92%, and the mass loss rate reached 19.04% after 110d of PBAT treatment, which was much larger than those of PE film. Microscopically, the SEM, FTIR, and thermogravimetric analyses showed that there was no obvious change in PE film after 110d of embedding, while the surface structure of PBAT changed greatly, with a more obvious lamellar structure, altered ester base structure, and deteriorated thermal stability. The indoor simulation test showed that the mineralization rate of PBAT film was 18.30% after 90d of incubation, which was close to that of leaves, while PE film had almost no mineralization.

Low-cycle fatigue property and damage mechanisms of Ti-6Al-4V-0.55Fe alloy with lamellar microstructure

Low-cycle fatigue property and damage mechanisms of Ti-6Al-4V-0.55Fe alloy with lamellar microstructure

Enhanced mechanical properties of Nb-18.7Si alloy by addition of ceramic nano particles for microstructural control

The phase composition, microstructure and mechanical properties of arc-melted eutectic Nb-18.7Si (at.-%) alloys with different nano-ceramic particle addition (Al2O3, TiC, SiC, 5 mol.-%) were investigated. The results showed that ceramic Al2O3 and TiC nanoparticle are thermally and chemically stable and can be used to tailor phase composition and refine the microstructure, while SiC dissolves completely in the melt. Al2O3 and TiC nanoparticle were found mainly in two different areas: (1) at grain boundaries of eutectic structures and (2) on the phase boundaries of silicides inside the eutectics. The presence of the particles refined the microstructure down to nano-scale lamellae by functioning as heterogeneous nuclei for the silicide phase. Without nano particle addition, the Nb-18.7Si alloy was mainly composed of Nb solid solution (Nbss) and Nb3Si. The addition of 5 mol.-% Al2O3 promoted the decomposition of the Nb3Si phase and an ultrafine nano-scale lamellar eutectic structure (Nbss + α-Nb5Si3) formed. With the addition of 5 mol.-% TiC, primary Nb3Si and coarse Nbss were observed, as well as fine eutectic Nbss + γ-Nb5Si3 structures. The complete dissolution of SiC led to a hypereutectic alloy with primary Nb3Si and γ-Nb5Si3 phase, coarse Nbss and eutectic Nbss + γ-Nb5Si3 structures. The compressive strength was increased from 3068 MPa to 3446 MPa by adding 5 mol.-% Al2O3 due to the formation of the high strength α-Nb5Si3 phase, the ultrafine nano-scale lamellar structures of Nbss + α-Nb5Si3 and the strong interface of Nbss/α-Nb5Si3. However, the small grain size of the Nbss phase was not effective in inhibiting crack propagation. Crack bridging and branching seem to be important mechanisms at the Nbss phase to inhibit crack propagation. Therefore, the size and distribution of Nbss play a key role. The results indicate that a continuous Nbss phase with embedded silicide phase and coarse Nbss phases can inhibit crack propagation.

Deformation mechanism and microstructure evolution of newly developed Ti-42.5Al-4Nb-0.5Mo-0.1B-(C, W, Y) alloy

A novel Ti-42.5Al-0.5Mo-0.1B-0.2W-0.25C-0.05Y alloy with a nearly lamellar structure was explored to better understand the deformation behavior and microstructure evolution during hot compression test at a high strain rate of 10s-1. Cylindrical samples were compressed in the temperature range of 1373K to 1523K, with the true strain reaching 69%. The results show that the crystal structure and phase transformation have an influence on the deformation mechanisms. Regarding the Tα2→α transformation within the deformation temperature range of 1373K - 1473K, the nucleation and growth of dynamically recrystallized (DRXed) γ and α grains can alternate in dominating the hot deformation of the present alloy. When the deformation temperature is 1523K, the softening mechanism mainly is the dynamic recovery (DRV) of the α phase. Moreover, the deformation temperature also has a significant effect on phase fractions and the critical values of dynamic recrystallization. Specifically, as the temperature rises, the proportion of the α phase increases, the proportion of the γ phase decreases sharply, the content of the β phase remains stable, and the critical values of dynamic recrystallization decrease. Additionally, fine equiaxed α2 grains with an average size of 8 μm were obtained at 1523K and 10s-1, which provided a reference for obtaining a fine near-lamellar or full-lamellar microstructure in TiAl alloys.

Mechanisms of alignment of lamellar-forming block copolymer under shear flow.

The potential applications of block copolymer thin films, utilising their self-assembly capabilities, are enhanced when achieving long-range ordering. In this study we explain the experimental alignment of lamellae under shear flow findings [S. Pujari et al. Soft Matter, 2012, 8, 5258] and classify the alignment mechanisms based on shear rate and segregation, uncovering similarities to the systems subjected to electric fields, suggesting a common pathway of lamellae orientations. However, the presence of thin films surfaces introduces distinct features in the lamellae orientation under shear compared to electric fields. Notably, we observe the emergence of a three-dimensional rotation alongside the conventional two-dimensional rotation. Furthermore, a transient regime has been identified within the melting mechanism, which confirms the existence of the checkboard pattern proposed by Schneider et al. [Macromolecules, 2018, 51, 4642]. These findings significantly enhance our understanding of block copolymer alignments and shed light on the intricate interplay between external fields and the lamellar structure.

Hot press sintering of Y2O3-Al2O3 glasses: Impact of particle size on thermal behaviour, sintering ability and mechanical properties of sintered bodies.

The impact of grinding on particle size, thermal behaviour, and sintering ability of yttrium aluminate glass microspheres with eutectic composition (76.8mol % Al2O3 and 23.2mol % Y2O3) was studied. The work was conducted with the aim of determining the optimal particle size and grinding conditions of glassy powder used for hot-pressing of ceramic and glass-ceramic materials with desired mechanical properties. The flame synthesis was used for the preparation of glass microspheres (diameter∼40μm). Ball milling procedure under different conditions was applied to adjust of size of prepared microbodies. The milled powders were subsequently hot pressed. The prepared samples (raw, milled microspheres and hot-press sintered bodies were characterised by X-ray powder diffraction, and scanning electron microscopy. Thermal analysis and particle size analysis in combination with X-ray powder diffraction and high temperature X-ray diffraction was used for detailed inspection of thermal behaviour and phase changes in raw and milled systems in the temperature interval 25-1200°C. The samples after flame synthesis and after milling were found to be X-ray amorphous. The particle size measurements showed that the systems with a smaller average size D [0.9]∼25μm and a monomodal particle size distribution were prepared after 6h of milling. Thermal analysis in combination with X-ray and high temperature X-ray analysis indicated a difference in the crystallization mechanism of the yttrium aluminate garnet phase depending on the milling time. The bulk glass ceramic with fine lamellar eutectic microstructure and interesting mechanical properties (Vickers hardness HV=17.6±0.2GPa, indentation fracture toughness KIC=4.3±0.3MPa.m1/2) resulted from the sintering of microspheres milled for 6h under the "gentlest" conditions (milling speed - 200rpm, and milling balls size - 5mm in diameter).

Multiple synergistic strengthening mechanisms of ultrahigh-strength plastic medium-Mn steel with a lamellar heterogeneous structure

Multiple synergistic strengthening mechanisms of ultrahigh-strength plastic medium-Mn steel with a lamellar heterogeneous structure

A highly compressible and expandable cellulose sponge with arch-like lamellar structures for non-compressible hemorrhage

A highly compressible and expandable cellulose sponge with arch-like lamellar structures for non-compressible hemorrhage

Lamellar Double Hydroxides Intercaled with Humic Substances and Nitrate: Evaluation of Phosphate Removal in Water and Application in Agricultural Sectors

Phosphate species can affect aquatic ecosystems, as excess of this nutrient can cause eutrophication, generating environmental impacts. Lamellar double hydroxides have shown promise in removing phosphate at low concentrations (10-50 mg L-1). In this context, lamellar double hydroxides were synthesized interspersed with nitrates and humic substances, searching for a new product that favors phosphorus adsorption. X-ray diffraction showed the presence of characteristic peaks of lamellar double hydroxides and thermogravimetric analysis showed the decomposition behavior of lamellar structure. The adsorption capacity occurred quickly (< 30 min), being more efficient for lamellar double hydroxides with NO3. The maximum adsorption capacity showed results of 35.03 and 44.20 mg g-1 for lamellar double hydroxides with humic substances and lamellar double hydroxides with NO3, respectively. The complexation capacity showed that pH directly influences complexation, being greater for lamellar double hydroxides with humic substances at pH 6.5. Thus, nanostructured materials with humic substances are promising for use in contaminant remediation and adsorption can be a fast and efficient technique for use in soil and water.

Microstructure, mechanical properties and corrosion resistance of laser direct energy deposited AlMo0.25FeCoCrNi2.1 high-entropy alloy: adjusted by annealing heat treatment

ABSTRACT A novel AlMo0.25FeCoCrNi2.1 high-entropy alloy (HEA) was additively manufactured using laser direct energy deposition (LDED) process. The microstructure, mechanical properties and corrosion resistance of the prepared alloy were investigated and adjusted by annealing heat treatment. The results showed that inadequate melting and diffusion of Mo powders cause the nonuniform Mo concentration and finally result in the microstructure diversity in the banded layer. Fine lamellar eutectic structures composed of Mo-rich σ phase and body-centered cubic (BCC) phase form within Mo supersaturated FCC phases. The annealing heat treatment promotes the precipitation and coarsening of needle-like B2 phases within the incipient FCC phases and granular σ phases at phase boundaries between FCC and BCC/B2, synergistically improving the toughness of this alloy with slight deterioration of ultimate tensile strength. The corrosion resistance of the alloy is notably improved by a 2-hour annealing heat treatment. These results contribute to rapidly designing/manufacturing/adjusting novel HEAs by LDED process.

Ultrathin MWCNT/Ti3C2Tx Hybrid Films for Electromagnetic Interference Shielding.

The disordered assembly and low conductivity of carbon nanotubes are the main problems that limit the application of electromagnetic interference (EMI) shielding. In this work, an ordered lamellar assembly structure of multiwalled carbon nanotube/Ti3C2Tx (MWCNT/Ti3C2Tx) hybrid films was achieved by vacuum-assisted filtration through the hybridization of Ti3C2Tx nanosheets and carbon nanotubes, where carbon nanotubes were tightly sticking on the surface of Ti3C2Tx nanosheets via physical adsorption and hydrogen bonding. Compared with the pure carbon nanotubes films, the hybrid MWCNT/Ti3C2Tx films achieved a significant improvement in conductivity of 452.5 S/cm and EMI shielding effectiveness (SE) of 44.3 dB under 50 wt% Ti3C2Tx with a low thickness (8.6 μm) and orderly lamellar stacking structure, which finally resulted in high specific SE (SSE/t, SE divided by the density and thickness) of 55,603.1 dB∙cm2∙g-1.

Electrochemically-Formed Disordered Rock Salt ω-Li x V9Mo6O40 as a Fast-Charging Li-Ion Electrode Material.

Electrochemically-formed disordered rock salt compounds are an emerging class of Li-ion electrode materials for fast-charging energy storage. However, the specific factors that govern the formation process and the resulting charge storage performance are not well understood. Here, we characterize the transformation mechanism and charge storage properties of an electrochemically-formed disordered rock salt from V9Mo6O40 (VMO). The crystal structure of VMO has similar motifs to that of α-V2O5, a well-studied analogue, but VMO has less mechanical flexibility due to additional corner-sharing octahedra in its structure. As a result, VMO undergoes a single-step transformation pathway, which we characterize through operando X-ray diffraction, and forms an unusual highly distorted lamellar microstructure, as we show with high-resolution transmission electron microscopy. The resulting Li x VMO material shows fast charging and other electrochemical characteristics and performance typical of many nanomaterials, even though the material is composed of relatively large particles.

Effect of tempering temperature on the microstructure and mechanical properties of Q125 shale gas casing steel

Abstract This study investigates the effects of tempering temperature on the microstructure and mechanical properties of Q125 grade shale gas casing steel using experimental methods such as optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results show that during the tempering process at 500–560°C, the morphology of the quenched laths gradually disappeared and the microstructure gradually recovered. Carbides precipitate from lamellar structures and gradually transform into short rod-like and fine dispersed spherical shapes, mainly distributed along the prior austenite grain boundaries (PAGB) and lath boundaries, accompanied by a decrease in dislocation density. At a tempering temperature of 530°C, the steel exhibited optimum overall mechanical properties, with a tensile strength of 961 MPa, yield strength of 921 MPa, and impact energy of 138.9 J. Within the tempering range of 500–560°C, the macroscopic tensile fracture surfaces exhibited obvious necking and delamination, with a microscopic morphology characterized by dimples accompanied by secondary cracks and tearing ridges. Both the initiation and propagation zones of the impact fracture surfaces exhibited dimple features, indicating good ductility. Microcracks and micropores observed in the longitudinal section of the tensile fracture are distributed along the PAGB or lath boundaries, with carbides located at the interfaces, reducing the interfacial energy.

Ultrasound-Assisted Enzymatic Extraction of Polysaccharides from Tricholoma matsutake: Optimization, Structural Characterization, and Inhibition of α-Synuclein Aggregation.

This study optimized ultrasound-assisted enzymatic (UAE) extraction of TMP (Tricholoma matsutake polysaccharide) through response surface methodology. The optimal conditions included complex enzyme comprising 1.15% cellulase, 0.60% pectinase, and 0.95% dispase, with ultrasound for 24 min at 84.5 °C and enzyme hydrolysis at pH 5.0. This process yielded 19.74 ± 0.51% TMP, exceeding traditional hot water extraction by over four times. Fourier transform infrared spectroscopy (FT-IR) confirmed that UAE did not alter the structure of TMP. In vitro experiments indicated that TMP-UAE demonstrated enhanced antioxidant properties. Further purification through DEAE-52 and Sephadex G-100 chromatography resulted in a homogenous polysaccharide fraction (TMP). Characterization indicated that TMP has an average molecular weight of 2.79 × 104 Da, composed of fucose, galactose, glucose and mannose in a 2.00:9.44:86.29:2.28 molar ratio. FT-IR indicated the presence of C-O-C glycosidic bonds and pyranyl-type sugar rings. Scanning electron microscopy displayed loose lamellar structures with small pores. Finally, TMP exhibited therapeutic potential against C. elegans in Parkinson's disease, including reducing α-synuclein aggregation, protecting dopaminergic neurons, and prolonging lifespan. This study provides an efficient extraction method for TMP and an insight into its neuroprotective effect in PD C.elegans.

Didecyldimethylammonium chloride-induced lung fibrosis may be associated with phospholipidosis.

In the current study, we dosed Didecyldimethylammonium chloride (DDAC) in mice by pharyngeal aspiration for 28 days or 90 days (weekly) and tried to elucidate the relationship between lamellar body formation and the lesions. When exposed for 28 days (0, 5, 10, 50, and 100 μg/head), all the mice in the 50 and 100 μg/head groups died since Day 2 after the third dosing (Day 16 after the first dosing). Edema, necrosis of bronchiolar and alveolar epithelium, and fibrinous exudate were observed in the lungs of all the dead mice, and chronic inflammatory lesions were observed in the lung tissues of alive mice. When dosed with DDAC of 0, 1, 4, and 8 μg/head for 13 weeks, the total number of pulmonary cells and the pulmonary levels of pro- and anti-inflammatory cytokines significantly increased, and chronic inflammatory lesions were detected with the production of collagen, collagen fibers, and lamellar body-like structures. Swelling of the nuclear envelope and nucleoplasmic components and generation of lipid droplets were also notably observed in the lung tissues of DDAC (8 μg/head)-treated mice. Furthermore, transcriptomic analysis performed using human bronchial epithelial cells showed that DDAC affected the expression of DNA damage, ER stress, lipid metabolism, and transcription regulation-related genes at 6 h after treatment, as it did 24 h treatment and that early growth response factor 1 gene was added to a list of the most up-regulated genes. Meanwhile, cytokines that are associated with the pathology of chronic lung diseases (IL-11, IL-24, and TGF-β) were slightly increased in the lung of DDAC-treated mice, and only the pulmonary level of CCL-2, but not CXCL-1 and CCL-3, increased in both sexes of mice. More importantly, the GM-CSF level increased dose-dependently in the lungs of both sexes of mice exposed to DDAC. Considering that the wound-healing process can take several weeks to complete, we suggest that DDAC-induced pulmonary fibrosis may be attributable to disruption of the wound-healing process due to continuous exposure to DDAC. We also hypothesize that the formation of lamellar bodies may be attributable to lysosomal accumulation of phospholipids separated from the destroyed lung tissue membrane.

Orbital Septum Posterior to Medial Canthal Tendon Area.

To examine the anatomy of the orbital septum posterior to the medial canthal tendon area. We performed 3 anatomical dissections in the present study. The first one was a microscopic study in which exenterated specimens from 6 Japanese cadavers (age from 77 to 93 years at death) were cut inferno-horizontally, including the Müller muscle, medial rectus pulley, and lateral rectus pulley, and stained with Masson's trichrome. The second one was also a microscopic study in which the exenterated specimens from 5 Japanese cadavers (age from 73 to 87 years at death) were cut horizontally, 1 mm superior to the upper eyelid margin and 1 mm inferior to the lower eyelid margin, and stained with Masson's trichrome. The third one was a macroscopic study in which exenterated specimens from 5 Japanese cadavers (age from 73 to 91 years at death) were cut horizontally at the medial palpebral commissure. In the first study, all the specimens showed the orbital septa with close vicinity to the orbicularis oculi muscle in the medial area. The second and third studies both demonstrated the double lamellar structure of the medial canthal tendon area. The anterior one was the fibrous tissue corresponding to the white medial canthal tendon. The posterior one referred to the preseptal orbicularis oculi muscle. The orbital septum was located directly posterior to this muscular structure. The orbital septum posteriorly lined the preseptal orbicularis oculi muscle, the muscular part of the medial canthal tendon.

Structure and Morphogenetic Properties of Collagen Matrixes Obtained from Connective Tissue Sheaths of Paravertebral Tendons

The morphogenetic properties of a collagen gel prepared by acetic acid extraction from the tendon sheaths (peritenons) of the paravertebral tendons of Wistar rats were studied. The gel was used as a substrate during in vitro cultivation together with mesenchymal stromal cells for 14 days in the growth and osteogenic incubation media. It has been established that the collagen framework of the peritenon substrate is strengthened by increasing the connectivity of fibrillar nodes and is structured with the formation of lamellar and tangle formations. Sesamoid globules, penetrating into the substrate from the initial peritenon gel, during cultivation remain inert in the growth medium, but exhibit an increased ability to structure calcium phosphates in the osteogenic medium. The formation of cell-mediated structures occurs by directions of fibro-, tendo-, ligament- and osteogenic differentiation. The fibrogenic direction provides a structuring framework; the tenogenic direction – the formation of embryonic tendons according to the mechanism of lateral assembly of collagen subfibrils on cell surfaces and their autonomization in the form of tendon filament primordia; the ligamentogenic direction – structuring of collagen ribbons associated with tangles and elastic fibers; the osteogenic direction – the formation of lamellar, trabecular and nodular osteoid structures through intramembranous ossification, accompanied by activation of alkaline phosphatase and mineralization. The formation of enthesis predictors is the organization of commissures between mechanically different-phase components of osteoid structures and frame. A classification of taxonomic forms has been developed and a hypothesis has been proposed about the role of evolutionary tools in the structuring of the collagen framework in tissue cultures in vitro. The classification of taxonomic forms has been developed and a hypothesis has been proposed about the role of evolutionary tools in the structuring of the collagen framework in tissue cultures in vitro.

Influence of Discontinuous Precipitation on Microhardness and Wear Resistance in (FeCoNi)86Al7Ti7 High‐Entropy Alloy

In this study, the effects of discontinuous precipitation, a process known to enhance mechanical properties in alloys, on the microstructure and mechanical properties of the (FeCoNi)86Al7Ti7 high‐entropy alloy (HEA) are investigated. Varying the aging temperatures leads to the formation of lamellar structures consisting of face‐centered cubic (FCC) and body‐centered cubic phases, which significantly influence the mechanical properties of the alloy. The aging treatments reveal an inverse relationship between temperature and microhardness, with values decreasing from 890 to 700 HV as the temperature rises from 550 to 650 °C. Despite this reduction, the alloy retains a high hardness level, suitable for wear‐resistant applications. The best wear resistance is observed at 550 °C, with a wear rate as low as 8.45 ± 1.6 × 10−5 mm3 N−1 m−1. This is attributed to stacking faults and dislocations within the FCC lamellae, which enhance resistance to dislocation glide. In this study, the critical role of microstructural engineering in optimizing the properties of HEAs is highlighted, providing valuable insights for developing high‐performance materials for specific engineering applications.