Preparation Of Composite Materials Research Articles

Chimeric protein-mediated dual mineral formation on biopolymer: Non-segregated and well-distributed deposition of CaCO3 and silica particles

Incorporation of biogenic or biocompatible synthetic polymers with inorganic mineral components have been suggested for the preparation of more bioactive materials. However, when two different inorganic minerals such as Ca- and Si-based minerals are introduced onto organic polymers, each mineral is deposited in a segregated form. Here, we presented a biomolecule-mediated preparation method for dual mineral-deposited polymer, in which two inorganic minerals were well-deposited on organic polymer with the aid of biological molecules. A chimeric bio-macromolecules, a fusion protein (CA-SFP) of carbonic anhydrase (CA) and silica-forming peptide (SFP), was designed and used. Surface-immobilized CA-SFP enabled the deposition of CaCO3 and silica nanoparticles on biopolymer without any segregated aggregation. SEM, EDS, FTIR, and swelling ratio analysis indicated that in the developed dual mineral-deposited polymer, each mineral was well-distributed across the polymer surfaces. Investigation by MTS assays, fluorescent imaging, and RT-qPCR revealed that the dual mineral-deposited polymer, when used as bone scaffolds, led to better cell proliferation and differentiation without any significant cytotoxicity compared to the counterparts. These results show that our mineral-deposition method mediated by biomolecules not only overcomes mineral-segregation involving multi-mineral formations, but also facilitates the preparation of highly-bioactive composite materials.

A microscale regulation strategy for strong, tough, and efficiently self-healing energetic adhesives

In general, robust mechanical properties require a stable strong physical or covalent network inside the polymer, limiting the mobility of molecular chains and the dynamics of physical crosslinks or reversible covalent bonds. Therefore, high healing efficiency at moderate temperature and robust mechanical properties are contradictory, which is difficult to optimize simultaneously. Therefore, this study introduced a new strategy. First, acyl semicarbazides motifs were utilized to endow energetic adhesives with strong and tough mechanical properties. Then, the asymmetric structure was introduced to regulate the hydrogen bonding array density and micro-scale trim the size of the hard domain, thereby improving the hydrogen bonding dynamics and the polymer-chains mobility. Finally, the synthesized energetic polymer adhesive (EPA) exhibited excellent comprehensive ability in terms of mechanical properties, self-healing efficiency, and energy level. Hereafter, the adhesive was further to be used with Al powder for the preparation of the EPA-based energetic composite materials (EPA/ECM), which could be mechanically comparable to commercial non-energetic adhesive-based ECMs. In addition, the high crack-healing efficiency of EPA/ECM indicated that the adhesive possessed strong application potential, which is expected to provide new ideas for improving the safety and service life of energetic composites.

Additive manufacturing low shrinkage Si-based composite ceramics with SiCO microsphere/polyvinyl silicon acetylene slurry

In this paper, SiCO microsphere/polyvinyl silicon acetylene slurry was prepared for the first time with low viscosity and good rheological behavior. The dispersion of microspheres in the precursor resin and the UV-light curing performance of the slurry were investigated. After pyrolysis at 1000 °C, the properties of the three-dimensional (3D) printed samples were characterized. The introduction of SiCO microspheres reduced the specimen shrinkage of the pure precursor photosensitive resin used for additive manufacturing and improved their mechanical properties. When the addition of SiCO powder increased from 0 wt% to 10 wt%, the linear shrinkage decreased from 33 % to 26 %, and the flexural strength increased from 43.9 MPa to 79.8 MPa. This study realizes the preparation of Si-based composite materials through low-cost LCD additive manufacturing technology. It confirms the great potential of low-cost light-curing additive manufacturing to fabricate complex functional composite ceramic materials.

Preparation and thermal properties of novel inorganic-organic eutectic composite material with high latent heat and thermal conductivity based on aluminum sulfate salt

Potassium aluminum sulfate dodecahydrate (Alum) and ammonium aluminum sulfate dodecahydrate (AAS) are two potential inorganic phase change materials with high transformation enthalpy. To make them more flexible to match temperature requirements of various fields, the melting temperature needs to be manipulated but less effect on latent heat. In this work, two novel eutectic mixtures of Alum-E and AAS-E were obtained by adding erythritol (E) with high latent heat into aluminum sulfate salts. The results denoted that the melting temperatures of the two eutectic mixtures were 72.46 °C and 73.20 °C when containing 35 wt% and 37 wt% erythritol, respectively. It was worth noting that they still possessed high latent heat of 243.4 J/g and 257.4 J/g. Considering the stability of NH4+ at high temperature, Alum-E was chosen to fabricate Alum-E/EG (expanded graphite) composite material with high thermal conductivity via melt-blending method. EG not only increased the thermal conductivity from 0.61 W/(m·K) to 10.95 W/(m·K) as an excellent enhanced heat transfer carrier, but also prevented leakage of Alum-E/EG composite material effectively as a porous adsorption carrier when contained 15 wt% EG. Moreover, the thermal stability tests indicated that Alum-E possessed favorable thermal stability after 250 heat-cooling cycles. Above all, the obtained composite energy storage material is a promising candidate for afterheat recovery and medium and low-temperature energy storage areas else.

Preparation of Composite Multi-Iron Material 0.2NiFe2O4/0.8BaTiO3 and Its Application in Sports Practice

Competitive sports has always been the front line of high-tech applications, from electronic timers to "shark skin" swimsuits, from "bird's nest" and "water cube" to blood lactic acid detectors; from electronic science to material science, from architecture to biology chemistry. To find more suitable sports equipment materials, we prepared the composite multiferroic material 0.2NiFe2O4/0.8BaTiO3 by solution casting, spin coating, and hot pressing, and used various instruments to understand its various properties. The study found that the two exothermic peaks of the material in the range of 110–220 °C are attributed to the large amount of adsorbed water and the degradation of hydroxyl compounds. The 20% weight loss associated with the strong exothermic peak at 300 °C is due to the degradation of inorganic salts and citric acid. What is more worth mentioning is that there is almost no weight loss when the temperature exceeds 340 °C, which proves that 80% of the total mass of organic species (such as: citric acid), inorganic nitrates, and other adsorbents (such as: water, ethanol, etc.) have been completely removed. In addition, the heat treatment process can change the crystallinity and physical and chemical properties of the material. In competition sports, 0.2NiFe2O4/0.8BaTiO3 material has the characteristics of good bounce and excellent balance. It can be applied to ski poles. Its good ductility and light weight make it very useful in bow, arrow and hull design space. In folk sports, 0.2NiFe2O4/0.8BaTiO3 composite sports equipment can be widely used in various sports and various types of sports equipment.

Recent Advances in Bio-Based Smart Active Packaging Materials.

The shortage of oil resources is currently a global problem. The use of renewable resources instead of non-renewable ones has become a hot topic of research in the eyes of scientists. In the food industry, there is a lot of interest in bio-based smart active packaging that meets the concept of sustainability and ensures safety. The packaging has antibacterial and antioxidant properties that extend the shelf life of food. Its ability to monitor the freshness of food in real time is also beneficial to consumers’ judgement of food safety. This paper summarises the main raw materials for the preparation of bio-based smart active packaging, including proteins, polysaccharides and composite materials. The current status of the preparation method of bio-based smart active packaging and its application in food preservation is summarised. The future development trend in the field of food packaging is foreseen, so as to provide a reference for the improvement of bio-based smart active packaging materials.

Polydimethylsiloxane-based stretchable conductive elastomer fiber by using oil bath-spinning for wearable devices

Flexible stretchable conductors are widely used in various wearable devices and flexible electronic components due to their unique engineering structure adaptability. Fiber has anisotropic stretchability due to its linear structure and it is used in the study of stretchable conductors. However, traditional fibers have low axial stretchability and poor adhesion to conductive particles, so they are not suitable for high-strain engineering structures. Here, a simple and fast preparation method with oil bath thermal curing and a blade coating method is proposed to obtain polydimethylsiloxane-based stretchable elastomer fibers. The fibers have excellent flexibility, stretchability (greater than 100%), elasticity (recovery rate greater than 96%), conductivity (176.5 S/m), and rapid electromechanical response. In particular, the fibers have good weaving ability for their stable performance under bending and twisting load, which is important to weave flexible high conductivity fabric. The effect of conductive particle types (carbon black, carboxylated multi-arm carbon nanotubes) on the fiber properties is also studied. The results show that the carbon nanotube/polydimethylsiloxane fiber has better stable performance under bending and twisting load due to a uniform and dense conductive layer formed. This work provides a research basis for the preparation of silicone rubber-like fibrous composite materials, and the prepared polydimethylsiloxane-based stretchable conductive elastomer fibers have broad application prospects in flexible wearable electronic devices.

Water sorption, thermal, and fire resistance properties of natural shell‐based epoxy composites

AbstractIn this study, walnut shell (WSh), hazelnut shell (HSh), and mussel shell (MSh) waste as inexpensive reinforcements were recycled for the preparation of epoxy composite materials. Subsequent used inexpensive fillers are chars (WShC and HShC), which are the pyrolysis solid products of the natural WSh and HSh wastes. Three types of epoxy resins: bisphenol‐A type (DGEBA), modified with polyurethane (MER with PU), and rubber modified (MER with rubber) epoxy resins were used as the matrix in MSh composites. Thermogravimetric analysis of the composites showed that the thermal strength of the epoxy matrix increased significantly with the MSh and chars. The best water sorption results were obtained with the MSh. The contact angle values of MSh composites prepared with DGEBA epoxy resin were quite high (111°–113.5°) and their water retention values ranged from 0.2% to 0.32%. The composites that were produced using 50 wt% chars and the same epoxy resin showed better flammability stability. The full extinction times were determined as 63 and 58 s for WShC and HShC composites, respectively.

Fe-C-based materials: synthesis modulation for the remediation of environmental pollutants-a review.

Presently, the rapid pace in the discovery of emerging aquatic pollutants is increasing the demand for the remediation and treatment of our natural resources. Regarding this, nanotechnology is being considered the potential solution for contaminated water remediation with techniques such as filtration, adsorption, catalysis, and desalination. For this purpose, zerovalent iron (ZVI) is being widely used in the remediation of environmental pollutants due to its large specific surface area and high reactivity. However, ZVI is easy to agglomerate and oxidize, limiting its application in the real environment. Therefore, the present study was designed to discuss the preparation and characterization methods of ZVI composite materials, factors affecting adsorption, the removal effect, and adsorption mechanism of different pollutants by Fe-C materials because the optimization and modification of nano-zero-valent iron is a hot research topic nowadays in this field. Moreover, this paper does also analyze the possibility of the practical application prospects of the team's technology for preparing iron-carbon materials. Thus, this information will be helpful for the development and application of Fe-C-based technologies for water and soil remediation and the prediction of the future research direction of Fe-C composite materials.

Novel Fluorescent Polyurethane Coating on Fabric with Acid‐Base Indicating Function in Solution

AbstractThe preparation of multifunctional composite materials with maximum fluorescence emission is an ideal choice to replace fluorescent dyes. We synthesized a series of novel fluorescence polyurethane (FPU) films. The effect of different contents, different solvents and different pH on the fluorescence intensity were investigated in detail. In accordance with increasing proportion of 2, 7‐Dichlorofluoresce (DCF) in the FPU, the emission peak exhibit a gradual bathochromic shift and the fluorescence intensity show a trend of increasing first and then decreasing. The strong fluorescence emission of the obtained fluorescent film is in the range of about 570 nm. The maximum fluorescence intensity is 842, and the reflectance of the film is 21 % with a bright yellow at this time. In addition, acid‐base response fluorescence emission performance are endowed the fluorescent polyurethane film in the solution state. Different luminous intensities are emit by the film solution samples in near neutral (540 nm, yellow‐green light) and alkali (580 nm, orange‐yellow light). The maximum displacement exceeds 40 nm. Compared near neutral (pH=7) to alkaline (pH=12) environmental, the fluorescence emission intensity is increased by 1800 % (from 90 increasing to 1680). By establishing the relationship between the concentration and the fluorescence emission intensity, the fluorescence intensity can be clearly known through the color difference, and the concentration of 0.25 % is selected for doping to achieve the balance between the emission intensity and the color of the fluorescent substance. We use hot‐pressing to finish the fluorescent polyurethane (FPU) film on the surface of the fabric at a lower temperature (Compared with high temperature and high pressure dyeing method). There is a potential application prospects for our fluorescent polyurethane films in chemical sensing, biological imaging, anti‐counterfeiting technology, and smart light‐emitting fabrics.

Alginate sponge assisted instantize liquid metal nanocomposite for photothermo-chemotherapy

Ga-based liquid metals nanoparticles (LMPs), which exhibit both fluidity and metallicity, together with unique physicochemical properties, are emerging as next-generation functional materials in broad biomedical applications. However, various negative effects accompanying with the storage and utilization of LMPs, including spontaneous coalescence, aggregation and oxidation, insufficient dissolution, as well as instability in aqueous solutions, severely hinder their further clinical translation. Here, we proposed a concept of instantize LMPs composite material based on a spongy structural scaffold encapsulating strategy, and synthesized in-situ cross-linked Ga-alginate microgels (ALGa microgels) loaded composite sponge (ALGa sponge) by a facile sonochemical method. Strikingly, it was found that the fast-dissolving spongy structural scaffolds could not only effectively overcome the instability of oxidizable LMPs for long-term preservation in an air environment at room temperature, but also ensure instant dissolution and colloidal stabilization for convenient and efficient utilization in aqueous solution. Simultaneously, the encapsulated ALGa microgels exhibited complementary advantages of in situ cross-linked microgel shells (enhancing water stability, improving biosafety, and drug loading/stimulus-responsive releasing capacity) and internal LMPs cores (radiopacity cellular internalization, and photothermal effect). Moreover, the in vitro and in vivo studies demonstrated that the developed ALGa sponge could enable synergistic phototherapy/chemotherapy under near-infrared laser irradiation, thereby effectively eliminating cancer cells and significantly inhibiting tumor growth. Overall, this pattern provides the possibility for the convenient preparation of multifunctional instantize LMPs composite material, which exhibits great potential to elevate the overall therapeutic performance of photothermal/chemotherapy.

Noble metal-free core-shell CdS/iron phthalocyanine Z-scheme photocatalyst for enhancing photocatalytic hydrogen evolution

Improving the separation efficiency of photogenerated carriers and broadening the light absorption range of the photocatalyst are two important factors for improving the performance of the photocatalyst. In this paper, a new and efficient Z-scheme CdS/iron phthalocyanine (CdS/FePc) core-shell nanostructure composite material is prepared by a simple solid-phase reaction method. There are two key points in the preparation of composite materials: one is that hydrogen bonding energy is closely connected with FePc, another is that FePc can be uniformly assembled on CdS nanoparticles. The photocatalytic hydrogen evolution (PHE) of the CdS/FePc nanocomposite (73.01 μmol/h) is 2.6 times higher than that of pure CdS (26.67 μmol/h). In addition, after 4 photocatalytic cycles, the PHE of the CdS/FePc composite is still 92.3% of the first cycle. There are three reasons for this situation: (1) The Z-scheme heterojunction is formed to improve the separation efficiency of photogenerated carriers; (2) FePc expands the visible light absorption range of CdS; (3) The large core-shell contact area is favorable for the separation of photo-induced carriers at the interfaces. This research is conducive to the further development of new photocatalytic materials with high efficiency, low cost and simple preparation.

On twin screw extrusion parametric optimisation using hybrid approach of ANOVA and TOPSIS for 3D printing applications

ABSTRACT In the last decade, several studies have been performed on the preparation of smart composite matrix materials by twin-screw extrusion (TSE) followed by its process parametric optimisation based on analysis of variance (ANOVA) for 3D printing applications. But, hitherto little has been reported on TSE process optimisation using a hybrid approach, that is, ANOVA in the first stage followed by a technique for order of preference by similarity to ideal solution (TOPSIS) in the second stage for multi-objective selection. In this study, an effort has been made to develop a feedstock filament of polylactic acid (PLA) based composite matrix (comprising polyvinyl chloride (PVC) – wood dust (WD), and Fe3O4 as reinforcement) with TSE. The result of the study suggests that the proposed hybrid model of analysis is more useful than the single approach (in which the user may first use the ANOVA technique for optimisation followed by TOPSIS for locating the best and worst parametric conditions). Finally, the correlation matrix has been prepared for the mechanical and magnetic properties of the PLA-PVC-WD- Fe3O4 composite matrix.

Fabrication of lightweight flexible thermoplastic polyurethane/multiwalled carbon nanotubes composite foams for adjustable frequency-selective electromagnetic interference shielding by supercritical carbon dioxide

In this study, the thermoplastic polyurethane (TPU)/multiwalled carbon nanotubes (MWCNTs) lightweight flexible foam with sandwich structure was achieved by supercritical carbon dioxide (scCO2) foaming. This work studied the relationship between foaming behavior and electromagnetic interference (EMI) shielding performance. The results showed that the formation of cell structure could not only achieve the purpose of lightweight, but also control the position of electromagnetic interference shielding efficiency (EMI SE) peak by adjusting foaming temperatures. The EMI SE peak could shift to high frequencies as the foaming temperature increases, and the adjustable frequency ranged from 9.76 GHz to 14.72 GHz. The maximum EMI SE of TPU/MWCNTs composite foams increased to 44.86 dB under 2.5 wt% filler content with a density of 0.61 g/cm3. This work provided a feasible idea for the preparation of lightweight and adjustable frequency-selective EMI shielding composite materials by supercritical fluid foaming.

Preparation and characterization of shape-stable bio-based composite phase change materials for thermal energy storage: coconut oil / activated carbon from cherry stones doped composites

ABSTRACT The new, bio-based, shape-stable, composite phase change materials (PCMs) were designed and characterized for thermal energy storage applications. Coconut oil (CO) as PCM was impregnated into activated carbon (AC)-doped porous polymer composite foam as a support material. Cherry stones (CHSs) were used as AC precursor and AC was obtained by carbonization under N2 atmosphere following the chemical activation with phosphoric acid (PA). The properties of CHSs and AC were determined by elemental analysis, Fourier Transfer Infrared (FTIR) Spectroscopy, Scanning Electron microscope (SEM), and Brunauer–Emmet–Teller (BET) surface area measurements. AC-doped unsaturated polyester resin (UPR)-based composite matrix was prepared by high internal phase emulsion (HIPE) templating approach. The obtained macroporous composite PCM frameworks were fully characterized in terms of chemical, morphological, and mechanical properties and used as support materials for shape stabilization of CO. The composite PCMs were produced successfully and exhibited leak-proof properties. It was found that 5.0 wt% AC-doped composite PCM with a melting enthalpy of 42.92 J · g−1 and a melting temperature of 24.02°C has the highest thermal energy storage capacity. The designed low-cost, bio-based, composite PCMs have application potential for developing smart textile materials with thermo-regulating property.

Preparation of Iron Carbon Composite Material by Extracting Iron from Bauxite Residue and Its Adsorption of Heavy Metal Cd(II).

An effective method of iron extraction from bauxite residue was explored, and iron was used to prepare iron carbon composite material, which have a good adsorption effect on the heavy metal cadmium. After acid washing, acid leaching, Fe(III) reduction and ferrous oxalate decomposition, FeSO4·H2O(RM) was successfully extracted from bauxite residue, and the iron loss was only 4.35%. FexOy-BC(RM) nanocomposite materials were prepared by loading FeSO4·H2O(RM) onto walnut shell biochar (BC) (a kind of agricultural and forestry waste) by an in situ reduction and oxidation method. The results showed that the adsorption effect of FexOy-BC(RM) on Cd(II) was better than that of commercial FexOy-BC. XPS, TEM, SEM characterization analysis showed that FexOy-BC(RM) immobilized Cd(II) by adsorption, complexation, etc.to achieve a highly efficient adsorption of heavy metal Cd(II) in wastewater.

An experimental study on the binary hydrated salt composite zeolite for improving thermochemical energy storage performance

Thermochemical energy storage is a promising approach in thermal energy storage because of its advantages in high heat storage density, low heat loss and long period stability. The hydrated salt is a commonly used material in low temperature heat storage. A thermochemical energy storage experiment is conducted based on the material of MgCl2 and CaCl2 binary hydrated salt composite zeolite. In the preparation of binary hydrated salt, it's found that the optimum concentration is 15 wt% and the better mass ratio of MgCl2 to CaCl2 is 1:1.5. The metal mesh net packed method is adopted for further improvement of thermal performance. The results of energy release process show that the binary hydrated salt composite zeolite can increase the temperature rise up to 45.8 °C at the air velocity of 0.18 m/s. It can achieve the highest energy storage density of 719 kJ/kg and thermal efficiency of 41.9% at the air velocity of 0.32 m/s. Also, the combination with metal mesh packed nets can further improve the temperature rise peak, energy storage density and the thermal efficiency to 52.7 °C, 918 kJ/kg and 46.1%, respectively. This study provides references for multicomponent composite material preparation and thermochemical reactor improvement.

Capturing Polysulfides with a Functional Anhydride Compound for Lithium–Sulfur Batteries

Lithium–sulfur batteries are the focus of the current development of high-energy storage devices. However, their practical application is hindered by the fast capacity decay caused by the “shuttle effect” of intermediate lithium polysulfides during cycling. In this study, we combine graphene (G) with the organic molecule 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) to form the G-PTCDA composite as the host material of sulfur cathodes. In particular, PTCDA with the conjugated benzene rings and the anhydride group is absorbed tightly on graphene through π–π stacking and thus enhances the polarity and conductivity of the G-PTCDA composite. Meanwhile, PTCDA can capture the otherwise dissolved intermediate polysulfides on the sulfur cathode by forming the Li–O bond with the oxygen atoms on the acid anhydride group in a collaborative manner. Thus, the “shuttle effect” can be effectively depressed, and the electrochemical performance is improved during discharge and charge cycling. We hope that the findings of this study can provide a deeper understanding of the design and preparation of the sulfur-based composite cathode material with functional organic molecules for lithium–sulfur batteries.

Preparation and Properties of Titanium Dioxide-Based Composite Photocatalytic Materials

Preparation and Properties of Titanium Dioxide-Based Composite Photocatalytic Materials

Synthesis of the Porous ZnO Nanosheets and TiO2/ZnO/FTO Composite Films by a Low-Temperature Hydrothermal Method and Their Applications in Photocatalysis and Electrochromism

In this paper, porous zinc oxide (ZnO) nanosheets were successfully prepared by a simple low-temperature hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer–Emmett–Teller (BET) tests showed that the synthesized product was ZnO with porous sheet structure. The diameter of porous nanosheets was about 100 nm and the thickness was about 8 nm. As a photocatalyst, the degradation efficiencies of porous ZnO nanosheets for methyl orange (MO), methylene blue (MB) and Rhodamine B (RhB) were 97.5%, 99% and 96.8%, respectively. In addition, the degradation efficiency of ZnO for mixed dyes (Mo, MB and RhB) was satisfactory, reaching 97.7%. The photocatalytic stability of MB was further tested and remained at 99% after 20 cycles. In the experiment, ZnO/FTO (fluorine-doped tin oxide) composites were prepared by using ZnO as the conductive layer. Titanium dioxide (TiO2) was deposited on the surface of ZnO/FTO by electrodeposition, so as to obtain a TiO2/ZnO/FTO composite. By studying the electrochromic properties of this composite, it was found that the TiO2/ZnO/FTO composite shows a large light modulation range (55% at 1000 nm) and excellent cycle stability (96.6% at 200 cycles). The main reason for the excellent electrochromic properties may be the synergistic effect between the porous structure and the polymetallic oxides. This study is helpful to improve the photocatalytic efficiency and cycling stability of metal oxides, improve the transmittance of thin films and provide a new strategy for the preparation of ZnO composite materials with excellent photocatalytic and electrochromic properties.