Kinds Of Composites Research Articles

Evaluating predictive scheme for thermomechanical properties of Si-diamond composites.

A novel, parameter-independent multiscale correlational constitutive model has been devised to predict thermomechanical properties of Si-diamond-SiC and Si-diamond composites, including the effective elastic modulus, effective bulk modulus, effective shear modulus, effective Poisson's ratio, average coefficients of thermal expansion as well as thermal conductivity. Based on this model, the effective thermomechanical response of two kinds of composites was simulated, and the underlying mechanisms of thermomechanical coupling between constituents were also critically evaluated. The findings were shown that the effective elastic properties of composites, including effective elastic modulus, effective bulk modulus, effective shear modulus, increased with diamond and SiC, and that the introduction of dispersed diamond with highly thermal conductivity and lowly thermal expansion significantly enhanced thermophysical properties of Si-diamond-SiC composites. The thermomechanical coupling of these composites was influenced by the effective elastic properties of composites and the disparity in the intrinsic properties of constituents.

Adsorption and desorption of phenanthrene and 1-hydroxyphenanthrene by goethite-coated polyvinyl chloride

Microplastics loaded with phenanthrene and derivatives are widely detected in aquatic environments, and the coating of natural minerals or organic macromolecules may change the environmental behavior of microplastics. In this study, three kinds of composites with different coverage were prepared by coating goethite on the surface of polyvinyl chloride microplastics to investigate the adsorption and desorption behavior of phenanthrene (PHE) and 1-hydroxyphenanthrene (1-OHPHE), and the effect of mucin on desorption was investigated. The results showed that goethite promoted the adsorption of PHE and 1-OHPHE by increasing the specific surface area of the composites. With the increase of the cover degree, the adsorption of PHE decreased because of the decrease in hydrophobicity; while the adsorption of 1-OHPHE initially increased and then decreased with the contributions of hydrophobic interaction and hydrogen bond. The adsorption of 1-OHPHE could be influenced by the pH and ionic strength primarily through electrostatic interactions and Ca2+ bridging. The goethite significantly increased the desorption hysteresis for two chemicals due to the complicated pore structures and increased adsorption affinity. Mucin promoted the desorption of PHE through competitive adsorption, and inhibit the desorption of 1-OHPHE through hydrophobic interaction, hydrogen bonding and Ca2+ bridging. This study elucidated the effects of natural minerals on the adsorption and desorption behavior of organic pollutants on microplastics, briefly discussed the effects of organic macromolecules on the desorption behavior of pollutants with different properties, and emphasized the different environmental behaviors of pollutants.

The dissolution of planetesimals in electrostatic fields

ABSTRACT Planetesimals or smaller bodies in protoplanetary discs are often considered to form as pebble piles in current planet formation models. They are supposed to be large but loose, weakly bound clusters of more robust dust aggregates. This makes them easy prey for destructive processes. In microgravity experiments, we apply strong electric fields on clusters of slightly conductive dust aggregates. We find that this generates enough tensile stress on the fragile clusters to sequentially rip off the aggregates from the cluster. These experiments imply that electric fields in protoplanetary discs can dissolve pebble pile planetesimals. This process might induce a bias for the local planetesimal reservoir in regions with strong fields. Planetesimals prevail with certain kinds of compositions where they are either good isolators or compacted bodies. The less lucky ones generate pebble clouds that might be observable as signposts of electrostatic activity in protoplanetary discs.

Clay minerals modified nickel boride for electrochemical supercapacitor electrode application

Nickel boride has attracted great interest in the field of energy storage due to its superior electrochemical performance, However, particles agglomeration and poor electability have limited its wider application. Clay minerals with high specific surface area and excellent wettability can reduce the agglomeration of particles. We synthesized eight kinds of composites Ni3B@montmorillonite (Ni3B@Mt), Ni3B@chlorite (Ni3B@Chl), Ni3B@vermiculite (Ni3B@Ver), Ni3B@kaolinite (Ni3B@Kaol), Ni3B@palygorskite (Ni3B@Pal), Ni3B@halloysite (Ni3B@Hal), Ni3B@sepiolite (Ni3B@Sep), and Ni3B@talc (Ni3B@Tal) materials with different morphologies and structures by simple liquid phase reduction method. We explored the influence of a series of clay minerals on the electrochemical performance of Ni3B. The results show that the specific capacitance of the Ni3B@clay minerals composites has been improved in different degrees. In addition, the Ni3B@Mt. shows the best specific capacitance of 1406 F g−1 at a current density of 0.5 A g−1, and still maintains a high specific capacitance of 944 F g−1 at a current density of 5 A g−1. The assembled asymmetric supercapacitor Ni3B@Mt.//AC using an activated carbon (AC) and the Ni3B@Mt. showed excellent electrochemical performance with achieving the maximum energy density of 92.60 W h kg−1 at the power density of 350 W kg−1, which suggests the practical application of clay minerals in the electrochemical energy storage field.

Augmentation of scarce data—A new approach for deep-learning modeling of composites

High-fidelity full-field micro-mechanical modeling of the non-linear path-dependent materials demands a substantial computational effort. Recent trends in the field incorporates data-driven Artificial Neural Networks (ANNs) as surrogate models. However, ANNs are inherently data-hungry, functioning as a bottleneck for the development of high-fidelity data-driven models. This study introduces a novel approach for data augmentation, expanding an original dataset without additional computational simulations. A Recurrent Neural Network (RNN) was trained and validated on high-fidelity micro-mechanical simulations of elasto-plastic short fiber reinforced composites. The obtained results showed a considerable improvement of the network predictions trained on expanded datasets using the proposed data augmentation approach. The proposed method for augmentation of scarce data may be used not only for other kind of composites, but also for other materials and at different length scales, and hence, opening avenues for innovative data-driven models in materials science and computational mechanics.

Information content of note transitions in the music of J. S. Bach

Music has a complex structure that expresses emotion and conveys information. Humans process that information through imperfect cognitive instruments that produce a gestalt, smeared version of reality. How can we quantify the information contained in a piece of music? Further, what is the information inferred by a human, and how does that relate to (and differ from) the true structure of a piece? To tackle these questions quantitatively, we present a framework to study the information conveyed in a musical piece by constructing and analyzing networks formed by notes (nodes) and their transitions (edges). Using this framework, we analyze music composed by J. S. Bach through the lens of network science, information theory, and statistical physics. Regarded as one of the greatest composers in the Western music tradition, Bach's work is highly mathematically structured and spans a wide range of compositional forms, such as fugues and choral pieces. Conceptualizing each composition as a network of note transitions, we quantify the information contained in each piece and find that different kinds of compositions can be grouped together according to their information content and network structure. Moreover, using a model for how humans infer networks of information, we find that the music networks communicate large amounts of information while maintaining small deviations of the inferred network from the true network, suggesting that they are structured for efficient communication of information. We probe the network structures that enable this rapid and efficient communication of information—namely, high heterogeneity and strong clustering. Taken together, our findings shed light on the information and network properties of Bach's compositions. More generally, our simple framework serves as a stepping stone for exploring further musical complexities, creativity, and questions therein. Published by the American Physical Society 2024

Рождение категории фантастического в русской эстетической мысли

The article attempts to identify the time when the category “fantastic” appeared in the aesthetic thought of the Pushkin era. Common and fixed in the poetics of this time was another, close in meaning, term “chudesnoe” (“miraculous”). It denoted the “supernatural” (a concept that has become crucial in literary fantastic) but did not fundamentally differ from similar phenomena, such as rare, unexpected, and extraordinary. According to the National Corpus of the Russian Language, the word “fantastic” finds frequent use only after 1830, which chronologically coincides with the period of active perception of foreign romantic prose in Russia, in particular the genre of the fantastic story. In most cases, the new lexeme appears in fiction, keeping “etymological” meaning (related to fantasy, dream, imagination). Many original statements and translations, however, reflect another trend: the “fantastic” in them describes a particular kind of composition or type of narrative, as well as the features of poetics inherent in these works. As such, the word acquires a wide range of meanings and evaluative characteristics, some of which reveal similarities with the semantic content of the concept of “fantastic literature” in contemporary studies. The publication in which a conceptual interpretation of the “fantastic mode of writing” was first proposed in Russian was the translation of Walter Scott’s article “On the Supernatural in Fictitious Composition, and particularly in the works of E.T.W. Hoffmann” (in Russian translation: “O chudesnom v romane” (“About the wonderful in the novel”)) (1829).

Low-firing of CaAl2B2O7 ceramics with Li2O–B2O3–SiO2 and LiF additions

Lithium borosilicate (LBS) and lithium fluoride (LiF) are verified to be effective sintering aids for CaAl2B2O7 microwave dielectric ceramic to reduce the sintering temperature and lower the activation energies. Benefiting from the liquid phase sintering, low-firing, low permittivity and low-loss CaAl2B2O7 microwave dielectric composite has been successfully obtained. Typically, CaAl2B2O7 assembled with 1 wt % LBS composite possesses desirable properties of εr = 5.91, Q × f = 39,443 GHz, τf = −23.51 ppm/°C (@16.53 GHz). For composite ceramics with 0.5 wt % LiF, the optimal microwave dielectric properties are εr = 6.08, Q × f = 37,295 GHz, τf = −22.39 ppm/°C (@15.78 GHz). The two kinds of composite are densified at 875 °C, with co-existed CaB2O4 and liquid phase. The mechanism underlying the low temperature sintering is revealed by well-matched wettability and lower activation energy of composite ceramics with additions.

Experimental Tests of Conduction/Convection Heat Transfer in Very High Porosity Foams with Lattice Structures, Immersed in Different Fluids

This experimental work presents the results of measurements of thermal conductivity λ and convection heat transfer coefficient h on regular structure PLA and aluminium foams with low density ratio (~0.15), carried out with a TCP (thermal conductivity probe), built by the authors’ laboratory. Measurements were performed with two fluids, water and air: pure fluids, and samples with the PLA and aluminium foams immersed in both fluids have been tested. Four temperatures (10, 20, 30, 40 °C) and various temperature differences during the tests ΔT (between 0.35 and 9 °C) were applied. Also, tests in water mixed with 0.5% of a gel (agar agar) have been run in order to increase the water viscosity and to avoid convection starting. For these tests, at the end of the heating, the temperature of the probe reaches steady-state values, when all the thermal power supplied by the probe is transferred to the cooled cell wall; thermal conductivity was also evaluated through the guarded hot ring (GHR) method. A difference was found between the results of λ in steady-state and transient regimes, likely due to the difference of the sample volume interested by heating during the tests. Also, the effect of the temperature difference ΔT on the behaviour of the pure fluid and foams was outlined. The mutual effect of thermal conductivity and free convection heat transfer results in being extremely important to describe the behaviour of such kinds of composites when they are used to increase or to reduce the heat transfer, as heat conductors or insulators. Very few works are present in the literature about this subject, above all, ones regarding low-density regular structures.

Investigation of the Mechanical Behavior of Acacia-Raffia Natural Fiber Composite.

Nowadays, industries place a strong emphasis on low-cost, biodegradable materials with long lifespans. As a result, businesses are concentrating on creating composite materials utilizing the world's plentiful supply of natural fibers. In this study, acacia and raffia fibers are combined with epoxy resin and a hand layup method to create a biodegradable composite laminate. This article investigates the effect of fiber orientation on the mechanical and morphological evaluation of composite materials that have been manufactured. Three different kinds of composites were fabricated in this work: Composite 1, which contained acacia fiber; Composite 2, which was built of acacia and raffia fiber; and Composite 3, which was made of raffia fiber. While Composite 2 is a hybrid composite in this instance, Composites 1 and 3 are monofiber composites. In accordance with the ASTM standards, testing was performed to investigate the different mechanical behaviors, including tensile, flexural, double shear, delamination, hardness, and impact. The results demonstrate that Composite 1 has strong tensile strength, flexural strength, double shear, and hardness tests with a 45° fiber orientation. The 90° fiber orientation of Composite 1 performs well in the inter delamination test. The result demonstrates that composite 1 of type 0 absorbs greater energy. Additionally, Scanning electron microscopy was used to conduct morphological examinations in order to investigate the internal structural failure of the composites. It was found that the composite laminate has fiber cracks, pullouts, and voids, which were reduced with the right curing times and stress.

Biomimetic construction of 3D needle‐punched CF/PEEK composites based on ladybug forewing structure for directional reinforcement

Abstract3D needle‐punched CF/PEEK composites are a kind of composites with promising applications in multiple fields, such as implant materials, but their mechanical properties in the Z‐axis and interlaminar are still weak at present. In this study, a bio‐inspired reinforcement structure based on ladybug forewing was developed to achieve directed reinforcement of 3D needle‐punched CF/PEEK composites. Carbon fiber yarns were stitched into the 3D needle‐punched CF/PEEK preforms according to the set structure, and the bio‐inspired CF/PEEK composites were obtained after hot pressing. The interlaminar and in‐plane mechanical properties of the composites were investigated at different stitch lengths. The results showed that the addition of the bio‐inspired structure greatly improved the interlaminar shear strength of the composites, reaching 111.30 MPa, an enhancement of 95.06%. The in‐plane mechanical properties, including tensile, flexural, and compression, were also significantly improved to different degrees. The “structure‐effect” relationship in the bio‐inspired CF/PEEK composites was investigated, and the effectiveness of such a bio‐inspired reinforcement structure was demonstrated. This new reinforcement strategy provides a new idea for the improvement of the mechanical properties of multi‐stage carbon fiber‐reinforced thermoplastic resin matrix composites.Highlights The in‐plane and interlaminar mechanical properties of composites were simultaneously improved. Up to 95.06% improvement in interlaminar shear strength. A novel bionic strategy of directional reinforcement was developed. The “structure‐effect” relationship in the composites was investigated.

Robust lamellar Fe2O3@SnO2 heterostructure for long cycling and high-rate lithium storage

Transition metal oxides (TMOs) have attracted great attention for lithium-ion batteries (LIBs) owing to their high theoretical capacity. Unfortunately, the painful volume expansion and inferior electrical conductivity of TMOs lead to nonreversing structural deterioration, disordered particle agglomeration and sluggish transfer efficiency, which results in low rate performance and poor cycling stability. This work reports a kind of lamellar Fe2O3 @SnO2 heterostructure composite for LIBs by the means of uniform epitaxial growth of the SnO2 nanorods on the lamellar Fe2O3. Due to the “synergistic effect” advantage of the unique heterostructure and two kinds of composition, the lamellar Fe2O3 @SnO2 heterostructure delivers a prominent and impressive capacity (1572.7 mA h∙g−1 at 4 A∙g−1), good rate performance (993.7 mA h∙g−1 at 5 A∙g−1) and stable long-cycle durability (848.4 mA h∙g−1 after 4000 cycles at 4 A∙g−1). The finite element mechanical simulation demonstrates that the stress is concentrated at the gap of SnO2 nanorods by epitaxial growth from the lamellar Fe2O3, the junction of SnO2 nanorods and the lamellar Fe2O3 is safeguarded. Hence, the lamellar Fe2O3 @SnO2 heterostructure has good rate performance in addition to being stable over a long cycling process. Therefore, the present work provides an outstanding method to improve the energy storage performance of metal oxide composites and other types of nanocomposites.

Study on antibacterial activity and repair of peripheral nervous system injury by Zno nanocomposites

In this paper, three samples of ZnO/PPy, ZnO/CNTs and ZnO/PPy/CNTs nano- composites were studied in the aspects of antimicrobial properties, cell imaging and tumor targeting. Firstly, Escherichia coli strains were selected and controlled test method was used. Colony data showed that the inhibition rate of ZnO/PPy was 73.06%, the inhibition rate of ZnO /CNTs was 99.44%, and the inhibition rate of ZnO/PPy/CNTs composite was 99.99%. The results showed that the three kinds of composites had certain antibacterial effect. At the same time, in order to optimize the application of nano-sized zinc oxide (ZnOs), ZnOs nanocomposite microspheres were prepared by emulsification and dispersion method with polypyrrole and carbon nanotubes as microballoon walls, and the animal model of peripheral nervous system (PNS) injury was established. ZnOs nanocomposite microspheres and control samples were implanted into the injured peripheral nervous system (sciatic nerve was used as the site). The experimental results show that ZnOs nanocomposite microspheres can repair peripheral nervous system injury in animals.

Effect of strength and toughness of ceramic particles on impact abrasive wear resistance of iron matrix composites

The wear resistance of ceramic particle reinforced metal matrix composites is closely related to the properties of ceramic particles. In this study, three kinds of ceramic particle (with 30 % volume fraction) reinforced iron matrix composites (Al2O3/Fe45, ZTA(Zirconia toughened alumina ceramic particles)/Fe45 and ZrO2/Fe45) were prepared by powder metallurgy method. The mechanical properties, impact abrasive wear resistance and impact abrasive wear mechanism of the composites were studied, and the phase transformation of ceramic particles in the composites was analyzed. The results show that the elastic modulus and hardness of ZTA/Fe45 composite are between Al2O3/Fe45 and ZrO2/Fe45, which are 248.5 GPa and 13.3 GPa, respectively. The ZTA/Fe45 composites exhibit a better impact wear resistance than the other two composites. The impact abrasive wear resistance of the three kinds of composites is positively correlated with the product value of fracture toughness and hardness (H·KIC) of ceramic particles. The wear mechanism of the Fe45 matrix of the composite is micro-furrow and plastic deformation. The brittle fracture and spalling of Al2O3 ceramic particles occur after impact abrasive wear, forming spalling pits and accelerating the wear of Al2O3/Fe45 composites. ZrO2 ceramic particles lead to easy removal from the Fe45 matrix due to lower hardness after impact abrasive wear. ZTA ceramic particles protruded from the surface of the Fe45 matrix after impact abrasive wear. On the surface of ZTA particle, the irregular protuberant steps morphology are formed by SiO2 abrasive impact and tangential wear. The ZTA and ZrO2 ceramic particles in the worn surfaces of the composites undergo t-ZrO2 to m-ZrO2 phase transformation during the impact wear, and the t→m phase transformation content is related to the impact energy. The amount of phase transition increases with the increase of impact energy, When the impact energy is higher than 2J, the amount of phase transition tends to be stable. Under the same impact energy, the amount of t→m phase transition in ZrO2 particles is much lower than that in ZTA. The t→m phase transformation increases the toughness of ZTA particle，improving the impact abrasive wear resistance of ZTA/Fe45 composite.

EXPERIMENTAL INVESTIGATION OF HYBRID COMPOSITES USING BIOWASTES AND CALOTROPIS GIGANTEA: AN ECO-FRIENDLY APPROACH

<p>The wastes are in many forms consist of organic materials like human, medical, food, plastics, construction waste etc. many researchers are focused on the waste management to gives more importance to the environment. The bio degradable waste was used in this research with naturals fibers. The need for hybrid composites has increased in a variety of industrial applications. A unique and useful substance is created when two or more distinct components join in this kind of composite. Because of its exceptional characteristics, research is being done on the integration of particles bio waste and fiber into polymers. The like a strong weight-to-strength ratio, immunity to rust and temperature changes, and several custom qualities. This research focuses on the property description of Calotropis Gigantea and Bio waste ashes in form of epoxy matrix and in concrete as retrofitting composite. Calotropis Gigantea and Bio waste ashes are in composite form. field emission scanning electron microscope (FESEM) The characterisation is used to make sure that the polymer's structural shape and particle dispersion are correct. The mechanical, dynamic mechanical, thermal wear and concrete strength qualities are assessed. When particles are added, the qualities improve. By raising the weight of particle at certain percentage to the matrix and concrete mixture is for to increase the mechanical properties like tension, elongation, impact. To analyze the tribological behaviour, wear analysis is carried out. The results revealed that, the laminates reinforced with Calotropis Gigantea and Bio waste ashes show maximum strength. This is correlated with the increased interaction between the fiber-matrix, waste ash and homogeneous dispersion particle and also having greater strength compare to conventional concrete. The FESEM micrographs for tensile fracture surface also provided structural morphology. The findings will provide a vivid understanding for the use of composites in various structural retrofitting applications.</p>

Mechanical and thermal insulation properties of carbon fibre-reinforced carbon aerogel composites

ABSTRACT Carbon fibre-reinforced carbon aerogel composites (C/CAs) were prepared by using polyacrylonitrile (PAN) and phenolic (PH) carbon precursor fibres as reinforcements, respectively, then impregnated with resorcinol-formaldehyde sol, aging, solvent exchanging, CO2 supercritical drying and carbonization at 1000°C. The physical properties, structural morphology and mechanical and thermal insulation behaviour of the two kinds of composites were further compared. Pore structure analysis shows that the PH-based C/CAs have a larger specific surface area (438.92 m2·g−1) and richer mesoporous volume than the PAN-based C/CAs. Mechanical behaviour of the C/CAs has been changed, but the stronger enhancement effects belong to PAN-based C/CAs (compressive strength in xy and z-directions are 1.63±0.10 MPa and 1.22±0.19 MPa, bending strength is 3.62±0.50 MPa). However, the PH-based C/CA composites have relatively low thermal conductivities, ranging from 0.027 to 0.164 W·m−1·K−1 between 25 and 1800°C.

Characterization of (B4C+Ti) Hybrid Reinforced Mg and AZ91D Composites

Ceramic hybrid particulate reinforced magnesium matrix composites have attracted much attention in recent years, owing to their light weight, high specific strength and stiffness, excellent wear and damping properties, and have very wide popularization and application prospects in the automotive and aerospace fields. A simple and novel technique, in situ reactive infiltration technique, was utilized to prepare (B4C+Ti) hybrid reinforced Mg and AZ91D composites. The microstructure, produced phases, wear, compression and bending performance were characterized and analyzed in depth. The results showed that extending the holding time for preparing the composites and magnesium alloy as the matrix were both beneficial for the generation of interpenetrating networks within the composites, which means more sufficient and complete in situ reactions between B4C and Ti particles. More sufficient and complete reactions facilitate stronger interfacial bonding, leading to an improvement of the wear, compression and bending performance of the composites. The wear mechanisms for both kinds of composites were abrasive and delamination wear. (B4C+Ti)/AZ91D composites exhibit better compression performance and this can be attributed to the microstructure of the composites and work-hardening and softening during compression.

Numerical investigations on the hybrid effect and deformation mechanism of TiB2p and TiBw reinforced Cu composites prepared by in-situ mixing casting

In this paper, a novel numerical modeling method for multiphase and multiscale Cu matrix composites (CMCs) is constructed from material characteristics, complex structure reconstruction, interface behavior characterization, and comprehensive mechanical properties prediction. On this basis, two 3D finite element models of (TiB2p + TiBw)/Cu composites and TiB2p/Cu composites are established respectively according to the actual microstructure of CMCs. Brittle fractures of TiB2p and TiBw, ductile fracture of Cu matrix, and interface behavior are taken into account in the model to predict the cracking evolution process of CMCs. The consistency with the experimental stress-strain curve verifies the reliability of the models. The deformation behavior and fracture mechanism of (TiB2p + TiBw)/Cu composites were studied. By analyzing the stress and strain distributions of reinforcements, interface and the evolution of cracks of matrix in (TiB2p + TiBw)/Cu composites, the model reveals hybrid effects of particle and whisker on the mechanical behavior in composites. The stress concentration factors are used to quantify the bearing capacity of particle and whisker in hybrid composites. The interface damage rate and the damage accumulation of matrix of the two kinds of composites are also discussed. A relationship between the macroscopic mechanical behavior and microstructure of (TiB2p + TiBw) reinforced CMCs is investigated. This work can provide useful guidance for the optimal design and industrial application of CMCs.

Multi-physical modelling, design optimization and manufacturing of a composite dielectric solar absorber

The work presented involves the multiphysical modelling, simulation and design optimization of a key component of a Solar Selective Coatings (SSC). The investigated SSC absorber consists of a near homogeneous distribution of nanoparticles of Titanium Nitride (TiN) in a matrix of Aluminium Nitride (AlN), to form a composite dielectric. With the aim of achieving high absorbance in the visible region of the spectrum and minimum reflectance in the infrared region of the spectrum, our work highlights the numerical design, the synthesis and optical characterization of a composite dielectric of approximately 500 nm thickness. A bottom-up approach for the preparation of a stack with alternate layers, consisting of a distribution of TiN nanoparticles with a layer of AlN on top, was adopted. The TiN nanoparticles, laid on a substrate (Silicon/Glass) by wet chemical method, are coated with conformal layer of AlN, via Plasma-enhanced Atomic Layer Deposition (PE-ALD). The control of the morphology at the nanoscale is fundamental in improving the optical performance of the material. For this reason, two composites were prepared. One starting with TiN dispersions made with dry TiN powder and deionized water, and the other with ready-made TiN dispersions. In both composites, the particles were 20–30 nm in diameter. In both the cases, fewer clusters of about 0.5–1 μm of TiN particles were present however, enough steps were taken to minimize these clusters into smaller particles. Parameters, such as the size of TiN nanoparticles, the thickness of AlN thin film, were revealed by the numerical simulations, performed using Wave-Optics module in COMSOL Multiphysics. The work showcased clearly compares the two kinds of composites, using scanning electron microscope, X-ray photoelectron spectroscopy and electrical conductivity measurement. In addition, the optical performance of the two prepared composites is used as a means of validating the computational model.

Flexible electrospun fluorescent anisotropic conductive Janus-typed nanoribbon membrane

Flexible multiple-functional conductive anisotropic membrane made of one-dimensional directional nanomaterial has the potential applicative prospects in advanced electronic skin and strain sensor. Nevertheless, it is hard to prepare aligned polymeric composites with poly-functional high conductive anisotropy and excellent interface properties, so it has been a vital topic to fabricate and investigate such kind of composites. In this work, the fluorescent anisotropic-conduction Janus-typed nanoribbon array membrane (named as FAJNAM for short) with [Eu(TTA)3bipy/polymethylmethacrylate (PMMA)]//[carbon black (CB)/PMMA] Janus-typed nanoribbon as construction unit is prepared by di-axial parallel electrospinning with a di-axial parallel spinneret. Since CB will seriously affect the fluorescence intensity of the Eu(TTA)3bipy complex, through using Janus-typed nanoribbon as construction unit, Eu complex and CB can be confined in their own regions, realizing efficacious separation of fluorescent and electrical substances to significantly reduce the adverse effects between the two functions so as to obtain excellent red fluorescence and electrical conduction. The percolation zone of CB in Janus-typed nanoribbons membrane is determined. By adjusting the content of CB, the transition from insulation to conductivity of the FAJNAM can be realized. The highest anisotropic conduction ratio reaches ca. 108 when the CB content is 10 %. For the first time, the crucial of critical diffusion concentration of two-phase spinning solutions in the parallel electrospinning process is advanced and studied in depth. Furthermore, the relationship between the critical diffusion concentration and the conductive aeolotropism degree has been explored. The concept of critical diffusion concentration is also applicable to other di-axial parallel electrospinning to prepare multi-functional materials, which will be of great significance to optimize electrospinning conditions. This research provides new technical support for the preparation of highly flexible, conductive anisotropy composite materials.