Formation Of Multilayer Structure Research Articles

Multi-layered structure and physicochemical properties of reconstituted meat-based products from minced fish by physical extrusion: Impact of extrusion strength

Multi-layered structure of reconstituted meat-based products from minced fish was formed by physical extrusion, followed by an investigation into the impact of extrusion strength on structural and physicochemical properties before and after frying. Under an appropriate pressure (3–9 kPa), the air within minced fish underwent enrichment and rearrangement to form a stratified phase, promoting the formation of multi-layered structure during frying. Conversely, the lower pressure (≤1.5 kPa) was insufficient for phase separation and directional rearrangement, while the higher pressure (≥15 kPa) would cause the stratified phase to flow out of food system. Moreover, by directly increasing water mobility and meat compactness, physical extrusion indirectly caused more water loss and stronger ionic bonds during frying, which was positively correlated with multi-layered structure. However, an excessive pressure caused an increase in random coil and hydrophobic interactions during frying, which was negatively correlated with multi-layered structure. In conclusion, appropriate physical extrusion strength promoted the formation of multi-layered structure.

Investigation of the influence of Al layer and total film thicknesses on structural and related magnetic properties in sputtered Ni/Al multilayer thin films

The effects of parameters of Al layer thickness and total film thickness on the structural and related magnetic properties of Ni/Al multilayer films were investigated. The films were deposited by a dual sputtering. The Ni content decreased gradually while the Al content increased as the Al layer thickness increased. It was also observed that the total film thickness had little effect on the film content. All films have a face-centred cubic structure. And, the surface morphology of Ni/Al films is more uniform and homogeneous than the surface of Ni film. For magnetic analysis, the properties were strongly changed with the parameters. The saturation magnetisation, Ms of Ni film was obtained as 572 emu/cm3 while the Ms of the Ni/Al films decreased from 441 to 298 emu/cm3 with increasing Al content in the films caused by the Al layer thickness. And, the increase of total film thickness resulted in a decrease of Ms value. While the coercivity, Hc value of the Ni film was 90 Oe, Hc of Ni/Al films was decreased to ~ 39 Oe with the formation of multilayer structure. Ni/Al multilayers were obtained magnetically softer than the Ni film. The Ms and Hc values were significantly affected by the variation of the film content and crystal structure caused by the changes in deposition parameters. Therefore, this is a fundamental step for Ni/Al multilayers to improve the properties of these films for their potential applications in microelectronic devices.

Formation of multilayer structure in metallic glass nanospheres

Formation of multilayer structure in metallic glass nanospheres

Multifunctional poly(vinylidene fluoride–co‐hexafluoropropylene) ‐ zinc stannate nanocomposite for high energy density capacitors and piezo‐phototronic switching

AbstractElectroactive multifunctional nanocomposite films of poly(vinylidene fluoride – co ‐ hexafluoropropylene) (P(VDF‐HFP)) and different zinc stannate (ZnSnO3) filler concentrations were processed by hot pressing to achieve multilayer structure formation. A notable increase in the dielectric constant (K ≈ 30 at 1 kHz) was achieved in the three‐layered hot‐pressed composite film. The resultant relaxation time, that is, the time required to reach the remnant polarization (Pr) from saturation polarization (Ps) of hot‐pressed films reduced to 1/20th time to that of its single‐layer film. Furthermore, ferroelectric loop data of hot‐pressed structure shows the lower value of remnant polarization (0.20 μC/cm2) as compared to nanocomposite film (0.28 μC/cm2) under similar measurement conditions, which further leads to an increase in energy density (2900 mJ/cm3 at 250 MV/m vs 500 mJ/cm3 at 150 MV/m). The study shows the dependency of energy storage and remnant polarization on the relaxation time of dielectric that can be further explored to enhance the energy density of dielectric capacitors. Thereafter, the multifunctional nature of nanocomposite film is shown by coupling semiconducting, light and piezoelectric effects in piezo‐phototronic switching under tensile and compressive strain in dark and light conditions.

Multi-layer structure formation of relativistic electron beams in plasmas

A two-dimensional electromagnetic particle-in-cell simulation model is proposed to study the density evolution and collective stopping of electron beams in background plasmas. We show here the formation of the multi-layer structure of the relativistic electron beam in the plasma due to the different betatron frequency from the beam front to the beam tail. Meanwhile, the nonuniformity of the longitudinal wakefield is the essential reason for the multi-layer structure formation in beam phase space. The influences of beam parameters (beam radius and transverse density profile) on the formation of the multi-layer structure and collective stopping in background plasmas are also considered.

Study of recrystallization process of multilayer metal materials

The aspects for the formation of multilayer structure in steel multilayer materials with the number of layers exceeding 1000, using multilayer composition 30KhGS + AISI 430 as the example are considered. The reasons for the lack of the layered structure of the samples are figured out based on the results got with X-ray spectrum and microdiffraction analysis methods. Model of recrystallization in multilayer materials is proposed based on the hypothesis of the interlayer boundary as source of nucleation of new grains during dynamic recrystallization.

High temperature oxidation behavior of MoSi2–Al2O3 composite coating on TZM alloy

A novel MoSi2–Al2O3 composite coating was prepared on Mo-based TZM alloy by slurry sintering method. The oxidation behavior of the coating was evaluated at 1600 °C in static air. Microstructure and phase composition of the as-prepared and oxidized coatings were characterized, and the antioxidant mechanism of the coating at high temperature was discussed. A three-layer structure was observed in the as-prepared coating, consisting of a ∼2 μm thick Mo5Si3 diffusion layer, a ∼65 μm thick MoSi2 inner layer and a ∼36 μm thick outer layer of mixture of MoSi2 and Al2O3. After oxidation at 1600 °C for 5 h, all MoSi2 phases were completely converted to intermediate silicide Mo5Si3 by solid-state diffusion, and the formed Mo5Si3 phase would be transformed into Mo3Si phase with further extending the oxidation time. Furthermore, a dense oxide layer of SiO2-mullite was formed on the specimen surface, which can effectively protect the material to further oxidation. The MoSi2–Al2O3 coating could protect the substrate effectively at 1600 °C for 20 h without failure. The enhanced oxidation resistance of MoSi2–Al2O3 coating is due to the formation of multi-layer structure containing a SiO2-mullite composite oxide outer layer with high thermal stability and low oxygen permeability.

Unraveling the multilayer structure formation mechanism of copper coating for the metallization of poly para-phenylene terephthalamide fibers

The Cu-clad PPTA fibers (Cu@PPTA), which combined conductive coating with high-performance fibers, have been successfully prepared through a simple and controllable chemical copper deposition process. Chemical phase analysis indicated that carboxyl group was successfully obtained by breaking amide bond via ultrasonic etching (UE), and Pd element after sensitization and activation was adsorbed on the surface of PPTA fibers, and the catalytic palladium accounted for 50 at%. Moreover, it was also confirmed that the state of metal coating was pure metal. Microstructure characterization demonstrated that the nanoscale cracks were achieved after UE treatment and the copper nanoparticles were nearly spherical but irregular in shape. Additionally, the growth of copper crystal was nonlinear, and the formation of copper film might be controlled by capillary force. The possible formation mechanism of copper film on the surface of PPTA fibers was proposed, including nucleation stage, planar growth stage and multiplanar growth stage.

Characterization and property of magnetic ferrite ceramics with interesting multilayer structure prepared by solid-state reaction

Polyhedral MnFe2O4 with multilayer structure was successfully synthesized, and the possible originating mechanism of multilayer structure was firstly determined in current study. The phase formation, morphology evolution and interface reaction of the solid-state reaction of MnO2 and Fe2O3 mixture under air and reduction atmospheres were comparatively investigated, and the microwave absorption property of polyhedral MnFe2O4 with multilayer structure were discussed via the XRD, SEM, XPS, TEM, AFM and vector network analyzer measurements. Experiment results showed that multilayer MnFe2O4 can be synthesized both in the air at 1200–1300 °C and in 4 vol%CO at 1000–1100 °C. The reduction atmosphere was favorable to the formation of multilayer structure of MnFe2O4 due to the occurrence of multilayer MnO as the intermedium. In addition, morphology evolution demonstrated that the particle size of MnO2 after reduction was decreased remarkably which was also beneficial to the formation of MnFe2O4. However, air atmosphere is unfavorable to the generation of MnFe2O4 due to the recrystallization growth of Fe2O3 to lump impeding the element diffusion. Resultantly, the required temperature for the synthesis of MnFe2O4 in air was much higher than that in 4 vol% CO. One possible mechanism for the polyhedral MnFe2O4 with multilayer structure was based on the combination of the greater growth speed of (111) plane in the cubic MnFe2O4 crystal and terrace-ledge-kink (TLK) growth model. Moreover, multilayer MnFe2O4 prepared by the solid-state reaction presented good microwave absorbing property compared with that of the ferrites synthesized via the representative wet chemistry and combined methods.

Formation of multilayer structure and evolution of shape recovery characteristics in proton irradiated TiNi alloy thin films

TiNi thin films have attracted wide attentions as actuator materials in the micro-electro-mechanical systems (MEMs) for aerospace craft. However, multiple irradiation, such as the proton, was generally considered as an essential expired factor for the materials used in the aerospace. The present paper focused on the microstructure, martensitic transformation and shape recovery property of TiNi thin films after being irradiated by proton. A single layer structure B19′ phase to a dual-phase (B2 and B19′) with multilayer structure after proton irradiation have been revealed through a combination technique of grazing incidence (GI) XRD and TEM. As-formed irradiated films with amorphous layer and B2 austenite phase displayed a two-step martensitic transformation behavior, which occurred in the irradiated and the unirradiated layer. In contrast, the unirradiated counterparts just exhibited a single-step martensitic transformation. In addition, some defects could be seen after the TiNi films being irradiated. Such defects could induce a stress field that produces the R phase in the B2 phase. Furthermore, the synergistic effect of preferential sputtering effect and inverse Kirkendall effect induced the GP zones in the irradiated layer after 120 keV proton irradiation. The existence of amorphous phase and precipitation significantly deteriorated the shape recovery property.

Improvement in corrosion resistance of ternary Zn-Fe-Mo plating by additional Mo-oxide coating

Despite the excellent corrosion resistance and the widespread application of Zn-Ni plating in industrial fields, the toxicity of Ni to the human body has caused the demand for alternative plating that does not contain harmful elements. In this respect, ternary Zn-Fe-Mo plating, which includes a third element Mo in binary Zn-Fe plating, has been considered as a promising alternative for Zn-Ni plating. In this study, the corrosion resistance of ternary Zn-Fe-Mo plating was evaluated and compared with conventional Zn and Zn-Fe plating by impedance measurements and cyclic corrosion tests (CCT). Furthermore, formation of a multi-layer structure via additional Mo-oxide coating over the ternary Zn-Fe-Mo plating was attempted to increase the corrosion resistance. Experimental results show that ternary Zn-Fe-Mo plating has higher impedance but lower corrosion resistance for CCT and that the Mo-oxide coating significantly enhances the corrosion resistance of the ternary Zn-Fe-Mo plating selectively by a factor of approximately 10. The role of the formation of multi-layer structure in improving the corrosion resistance of the ternary Zn-Fe-Mo plating is discussed through the structure change of the plating and the generated corrosion products.

Study of All Solution Processed Exciplex Organic Light-Emitting Diode

Organic light-emitting diodes (OLEDs) are widely used in full-color display panels, fluorescent tubes and solid-state lighting devices. In recent years, due to the material utilization yield of the vacuum deposition method is very low and maintaining a high vacuum further increases the fabrication cost and complexity, solution processing method has become a research hotspot. However, the development of solution-processed OLEDs has a great challenge in multilayer structure formation and nearly all prior reports on solution-processed OLEDs were utilizing a vacuum deposited electron-transport layer (ETL). Therefore, it is of great significance to further research on all solution-processed OLEDs whose ETL were spin-coated. In this paper, spin-coated ETL based OLED with high current efficiency that comparable with vacuum deposited ETL based OLED were successfully achieved.

Structural and magnetic tunability of Co/Cu multilayer nanowires induced by electrolyte acidity and spacer layer thickness

Co/Cu multilayer nanowires (MNWs) were ac pulsed electrodeposited into the 50 nm diameter nanopores of anodic aluminum oxide (AAO) templates in 2.5, 3.8 and 5.25 pH values using the single bath technique. In each acidity, thickness of the Co magnetic layers (tCo) was kept constant (∼45 nm) and that of the non-magnetic Cu layers (tCu) was changed (3, 15, 32, 65, 160 and 260 nm) by adjustment of pulse numbers. Structural and magnetic properties of the samples were studied by X-ray diffraction (XRD) patterns, transmission electron microscope (TEM), field emission scanning electron microscope (FESEM), hysteresis loops and first order reversal curve (FORC) diagrams. TEM images confirm the formation of multilayer structure and uniformity in thickness of the layers. XRD patterns show strong effect of the acidity and Cu-layer thickness on crystallographic characteristics. The acidity along with Cu-layer thickness caused the c-axis direction to change from parallel to perpendicular to the wires axis. A strong relation between crystalline features as preferred orientation and magnetic properties of the samples was also observed by hysteresis loops and FORC diagrams. As shown, both the acidity and tCu affect magnetic response of the magnetic system. FORC diagrams also showed that magnetostatic interactions between the magnetic layers significantly decrease with the increase in tCu, regardless of the electrolyte acidity. The coercivity distribution was also seen to vary through both crystalline structure and magnetostatic interactions.

Effect of electron beam processing on structure of electroexplosion coating of ZnO-Ag system

The structure, phase composition of the composite electroexplosion coating of ZnO- Ag system subjected to the irradiation by the high intense electron beam have been studied for the first time. The combined processing including the electroexplosion spraying of the coating of ZnO-Ag system and its subsequent electron beam processing results in the formation of multilayer structure of the coating. The electron beam melts and homogenizes the surface layer of the composite electroexplosion coating of ZnO-Ag system to the depth of 35-40 μm. The effect of the electron beam leads to the formation of the nanocrystalline phases of Ag, ZnO, Cu, CuZn, Ag5Zn8, Cu2O, Ag2O, Cu0.67Zn0.33, AgZn. The dependences of changes in crystal lattice parameters and coherent scattering regions of the phases being formed depending on the processing regime by high intense electron beam have been found.

Mathematical modelling of formation process for multi-layer 3D structure produced by additive method using arc heat sources

The results of modelling of temperature fields, kinetics of deposition of layers of dissimilar metals and nature of structural transformations in formation of multi-layer structure of 17G1S and 30KhGS steels are presented. Computer modelling was performed using COMSOL Multiphysics software package. The work takes into account effect of temperature on thermal and physical parameters of steels. To increase productivity of additive process the work has studied simultaneous effect of 3 arcs on process of deposit formation, kinetics of structural transformations and diffusion processes of alloying elements redistribution. The calculations show that preheating of the substrate by arc in the beginning of the process before application of deposited material is necessary in order to decrease a stress level between additive deposit and substrate to 50 MPa. It is shown that the time of passing between neighbor arc heat sources shall be kept in 5- 30 s range. It is determined that low power of arc (1 kW) mainly provokes formation of ferrite-bainite structure in the deposit, portion of bainite in which makes 71 %, ferrite 28% and martensite ~ 1%. Application of larger power arc (5 kW) forms in the deposit bainite-martensite structure, portion of bainite in which makes ~ 50%, portion of martensite rises up to 40% and that of ferrite to 10%. Increase of arc power results in rise of maximum temperature of liquid pool to 1750-1850 °C, growth of cooling rate to 15 – 25 °C/s , and, as a consequence, increase of martensite portion in the structure of deposited layers.

Self-organized Formation of Multilayer Structure in a High Nitrogen Stainless Steel during Solution Treatment

ABSTRACTCompared with traditional stainless steels, high nitrogen stainless steels (HNSS), have been widely used due to their high strength, toughness along with excellent corrosion resistance and low cost, formed by partial replacement of Ni (austenite-forming element) by N. The evolution of the microstructure of a Cr19Mn19Mo2N0.7 stainless steel is investigated after solution treatment at 1010, 1060, 1200 or 1250°C for 30min. A complex multilayer structure has been found under a negative pressure vacuum. A white ferritic layer at the surface is formed, and a subsurface layer with full austenitic structure and a bulk microstructure comprising of austenite and ferrite are detected. With increasing solution temperature, the surface layer thickness increases. The formation of the multilayer structure is attributed to an outward diffusion, a diffusive retardation and an abnormal accumulation of nitrogen during solution treatment.

Synthesis of multilayered carbon fiber arrays and their growth mechanism

Multilayered carbon fiber arrays (MLCFAs) were synthesized by thermal chemical vapor deposition (CVD) without growth substrate, in which plate-like basic copper nitrate was used as catalyst precursor, acetylene and hydrogen as carbon source and heat treatment gas, respectively. The formation of multilayered structure of the product has a close relation to the special thermal decomposition characterization of basic copper nitrate. The growth schematic of MLCFAs was established to elaborate their growth mechanism.

Decreased Skin Barrier Lipid Acylceramide and Differentiation-Dependent Gene Expression in Ichthyosis Gene Nipal4-Knockout Mice

NIPAL4 is one of the causative genes for autosomal recessive congenital ichthyosis. However, the role of NIPAL4 in skin barrier formation and the molecular mechanism of ichthyosis pathology caused by NIPAL4 mutations, have not yet been determined. Here, we found that Nipal4-knockout (KO) mice exhibited neonatal lethality due to skin barrier defects. Histological analyses showed several morphological abnormalities in the Nipal4-KO epidermis, including impairment of lipid multilayer structure formation, hyperkeratosis, immature keratohyalin granules, and developed heterochromatin structures. The levels of the skin barrier lipid acylceramide were decreased in Nipal4-KO mice. Expression of genes involved in skin barrier formation normally increases during keratinocyte differentiation, in which chromatin remodeling is involved. However, the induction of Krt1, Lor, Flg, Elovl1, and Dgat2 was impaired in Nipal4-KO mice. NIPAL4 is a putative Mg2+ transporter, and Mg2+ concentration in differentiated keratinocytes of Nipal4-KO mice was indeed lower than that of wild-type mice. Our results suggest that low Mg2+ concentration causes aberration in the proper chromatin remodeling process, which in turn leads to failure of differentiation-dependent gene induction in keratinocytes. Our findings provide insights into Mg2+-dependent regulation of gene expression and skin barrier formation during keratinocyte differentiation.

The Smart Blending for Multilayer Structure of PLA/EVOH

The concept of smart blender to form a multilayer structure of PLA/EVOH has been developed. Unlike conventional mixing, smart blending provides a formation of multilayer structure by dictating the motion of stir rod to agitate melts. The PLA and EVOH are supplied separately by a single-screw extruder. An experimental rig is assembled at the end of a co-extruder, and melt from an extruder entered an experimental rig via a cylindrical port. The molten EVOH is recursively stretched and folded in an experimental rig of PLA major phase to give an alternating layer structure. The rod is rotated by variable speed motor that is independently controllable. The rod rotational speed and volumetric flow rates of EVOH and PLA are of our interest. Careful design of stir rod in smart blending is necessary for effective performance. The computational model provided the visualization of flow profile inside an experimental rig. The simulation determined the geometry of the stir rod required to achieve the spiral flow developed of the melt. The experimental results suggest that the injected streams of EVOH are stretched and folded to multiple and distributed layers ranging thickness from 10 to 200 um. The characteristic folding of EVOH melt depends on the volumetric flow rate of the screw extruder and rod rotational speed. However, the coalescence of EVOH layers is observed for high rod rotational speed.

Effects of annealing on Al–Si coating synthesised by mechanical alloying

ABSTRACTAn Al–Si composite coating was synthesised on Ti–6Al–4 V alloy substrate by means of mechanical alloying. The as-synthesised coating had a composite structure. The effects of annealing treatment on the microstructure, the mechanical properties and the oxidation resistance of coating were investigated. The increase in annealing temperature was conductive to the formation of multilayered structure of the coating. The formation processes of the layers at different annealing temperatures were discussed. The coating annealed at 800°C had intermetallic layers, which improved the microhardness and wear resistance of the coating. The microhardness of the coating annealed at 800°C reached more than three times of the substrate microhardness. In addition, the coating annealed at 800°C had a thick inner protecting layer, which could retard the inward diffusion of oxygen during oxidation. The annealing of the coating at 800°C could improve the mechanical properties and oxidation resistance of the coating.