Carbon Matrix Composites Research Articles

Enhanced Heterogeneous Peroxymonosulfate Activation by MOF-Derived Magnetic Carbonaceous Nanocomposite for Phenol Degradation.

Degradation efficiency and catalyst stability are crucial issues in the control of organic compounds in wastewater by advanced oxidation processes (AOPs). However, it is difficult for catalysts used in AOPs to have both high catalytic activity and high stability. Combined with the excellent activity of cobalt/copper oxides and the good stability of carbon, highly dispersed cobalt-oxide and copper-oxide nanoparticles embedded in carbon-matrix composites (Co-Cu@C) were prepared for the catalytic activation of peroxymonosulfate (PMS). The catalysts exhibited a stable structure and excellent performance for complete phenol degradation (20 mg L-1) within 5 min in the Cu-Co@C-5/PMS system, as well as low metal-ion-leaching rates and great reusability. Moreover, a quenching test and an EPR analysis revealed that ·OH, O2·-, and 1O2 were generated in the Co-Cu@C/PMS system for phenol degradation. The possible mechanism for the radical and non-radical pathways in the activation of the PMS by the Co-Cu@C was proposed. The present study provides a new strategy with which to construct heterostructures for environmentally friendly and efficient PMS-activation catalysts.

Preparation, structure and photocatalytic degradation property of a copper-based complex and its derivative material

In order to design a new type of photocatalyst for dye degradation, a novel Cu-based coordination polymer (CP) was prepared by hydrothermal method with a novel bis-pyridine-bis-amide ligand and an aromatic dicarboxylic acid, namely [Cu(3-bbpa)(1,3-BDC)(H2O)]n (Cu-CP, where 3-bbpa ​= ​N1,N4-di(pyridin-3-yl)fumaramide and 1,3-H2BDC ​= ​1,3-benzenedicarboxylic acid). The Cu-CP shown a two-dimensional (2D) layered structure with 10.39 ​Å ​× ​16.31 ​Å cavities, containing one-dimensional (1D) meso-helical [Cu(3-bbpa)]n chain and 1D zigzag [Cu(1,3-BDC)]n chain. The influence of bis-pyridine-bis-amide ligands on the structure of Cu-1,3-BDC-based CPs was discussed. Furthermore, by using the pyrolysis process, the Cu-CP was employed as a catalyst precursor to manufacture a carbon matrix composites (Cu/CuO@C) and was thoroughly described. The results show that both carbon matrix composites have photocatalytic degradability of dyes,the photocatalytic degradation rates of Cu-CP for methylene blue (MB), rhodamine B (RhB), gentian violet (GV), methyl orange (MO) and Congo red (CR) were 35.64%, 82.09%, 87.94%, 70.26%, and 66.71%, respectively. After the characterization of the Cu/CuO@C materials by XPS and solid ultraviolet, it can be seen that they contain metal and its oxide active sites, and the narrow bandgap promotes the rapid transport of photogenerated carriers and increases the photocatalytic degradation rate of five dyes. Therefore, the photocatalytic degradation rate of MB increased to 61.32%, 98.11% for RhB, 93.22% for GV, 72.12% for MO, and 88.36% for CR. According to the quenching studies and electron spin resonance (ESR) spectra characterization, the main species involved in the photocatalytic reaction were the radicals •OH. Cu/CuO@C composites derived from Cu-CP as precursors have been shown to be an efficient photocatalyst material compared to other photocatalysts.

Facile fabrication of Co-MOF/GNs derivatives as electromagnetic wave absorber with thin thickness for X and Ku bands

The application of carbon matrix and magnetic composites as electromagnetic wave absorbing materials has attracted extensive attention. The Co-MOF/Graphite nanoflakes (GNs) derived microwave absorbing material supported by MOF structure was acquired via hydrothermal method and subsequent calcination treatment. The best reflection loss value of the sample obtained by pyrolysis at 600 °C is −43.62 dB at 15.84 GHz, simultaneously, the thickness is only 1.6 mm, and the effective absorption bandwidth (EAB) can reach 5.2 GHz (12.8–18 GHz). The Co-MOF/GNs derivatives possess a thinner absorbent thickness and a rather wide EAB value (mainly distributed in the X and Ku bands). Its absorbing bandwidth and thickness of absorbing agent are far superior to most MOF-derived absorbing materials. Its excellent electromagnetic wave absorption performance is chiefly attributed to multi-component dipole polarization, interface polarization from multiple interfaces, and multiple reflection and scattering effects of sandwich micro-structure with high porosity on electromagnetic waves. This paper provides a certain reference value for the design of lightweight and efficient radar absorbers suitable for X and KU bands, which can be applied to radar absorbing materials, multi-band and various applications.

Facile Fabrication of NiFe Double Hydroxide on Carbon Matrix Composites as an Efficient Oxygen Electrocatalyst for Rechargeable Zn‐air Batteries

AbstractAir cathodes with highly effective oxygen reduction and oxygen evolution reaction performance are crucial for commercial applications in rechargeable Zn‐air batteries (RZABs). Commercial catalysts are expensive and scarce, which restricts their practical applications. Therefore, the design of high‐cost‐performance and electrochemical activities bifunctional non‐precious metal catalysts is urgent. The bifunctional catalyst (BZIF‐C@LDH) combining NiFe‐LDH and ZIF‐8&ZIF‐67 derivative (BZIF‐C) was readily prepared with a co‐precipitation approach. As expected, the obtained BZIF‐C@LDH exhibits outstanding bifunctional performance (ΔE=0.761 V) for oxygen reduction and oxygen evolution reaction. Furthermore, compared to commercial Pt/C‐RuO2 in RZABs, BZIF‐C@LDH displays a superior energy density (1033 Wh kg−1), which is close to the theoretical energy density (1086 Wh kg−1). This work provides a straightforward and inexpensive strategy for the synthesis of excellent and practicable bifunctional catalysts for RZABs.

Fabrication of novel multilayer core-shell structured nanofibers network reinforced carbon matrix composites for bone tissue engineering

To further optimize the structure of bone tissue engineering composites, silicon nitride nanowires-pyrolytic carbon-hydroxyapatite-carbon matrix (Si3N4nws@PyCnls-HA-C) composites with multilayer core–shell structures are synthesized by chemical vapor deposition (CVD), pulsed electrodeposition (PED), and chemical vapor infiltration (CVI) methods. The microstructure, in-vitro bioactivity, and in-vivo histocompatibility of Si3N4nws@PyCnls-HA-C (SPHC) composites are evaluated. In-vitro, the SPHC exhibited a cell proliferation rate of 157.7% and demonstrated outstanding protein adsorption. In-vivo, the SPHC demonstrated excellent histocompatibility. Therefore, the SPHC composites can serve as an alternative suitable biomaterial for bone tissue engineering.

In situ tensile damage characterization of C/C composites through X-ray computed tomography and digital volume correlation

Carbon fiber reinforced carbon matrix (C/C) composites have been used in aerospace applications due to their excellent performance. Exploring their failure mechanisms is a subject of extensive research. Nowadays, to obtain information about changes in the failure processes, a technology known as in situ X-ray computed tomography is used. In this paper, tensile loads were applied to 3D fine-woven punctured and needle-punched C/C composites perpendicular to the punctured and needle-punched directions. In situ X-ray computed tomography was employed to observe damage development, and digital volume correlation was used to assess the laboratory X-ray computed tomographs to measure local strains. Assimilation of pores is observed in C/C composites, with cracks evolving from original micro-pores. While fine-woven punctured C/C composites present an elegant linear failure, needle-punched C/C composites present a traditional non-linear failure. This difference is due to the different structures of the preforms. Furthermore, the C/C composites are weak at the sites where they are punctured or needle-punched.

Recent research progress of carbon-based and their composites for electromagnetic waves absorption

With the rapid development of electromagnetic (EM) technology and the wide application of mobile electromagnetic equipment, electromagnetic radiation pollution is increasingly aggravated, electromagnetic pollution has become another pollution source after air, water, and noise pollution, so electromagnetic protection for civil and military is of great significance. As the functional medium of electromagnetic energy sustainable transformation, microwave absorption (MA) materials are widely used in electromagnetic pollution prevention and control. Carbon-based materials have the advantages of low density, light weight, good electrical conductivity, good physical and chemical stability, etc., which can be combined with magnetic loss type, dielectric loss type, and multi-component to improve the absorbing performance. According to the dimensions, carbon-based materials can be divided into zero-dimensional (carbon spheres), one-dimensional (carbon nanotubes), two-dimensional (graphene), and three-dimensional (porous carbon) carbon materials. This paper briefly introduces the mechanism of microwave absorption and its performance evaluation index. Then, the research status of carbon materials with different dimensions is introduced. Then the application and research progress of carbon matrix composites in electromagnetic waves (EMW) absorption are reviewed. Finally, the future development prospect of carbon-based absorbing materials has been prospected.

Oxidation and ablation behaviours of a SiCnw@SiC–Si coating fabricated for carbon-fibre-reinforced carbon-matrix composites via thermal evaporation and gaseous silicon infiltration

A SiC-nanowire-modified SiC–Si (SiCnw@SiC–Si) coating was prepared for carbon-fibre-reinforced carbon-matrix (C/C) composites using a two-step method based on thermal evaporation and gaseous silicon infiltration, and the effects of SiC nanowires on the oxidation and ablation behaviours of the coated samples were studied. Oxidation tests conducted at 1500 °C revealed that the weight loss of the SiC–Si-coated C/C composite was 15.85% after 6 h, whereas the SiCnw@SiC–Si-coated C/C composite experienced a significantly lower weight loss of 1.27% after 50 h. Ablation tests suggested that the mass and linear ablation rates of the SiCnw@SiC–Si-coated C/C composite were 0.05 mg/s and 0.09 μm/s, respectively; they were reduced by 78.26 and 92.74%, respectively, compared with those of the SiC–Si-coated C/C composite. Careful characterisation suggested that the network structure of the SiC nanowires in the SiC–Si phase can suppress crack propagation and firmly attach to the coating surface to enhance the interfacial adhesion between the coating and substrate, leading to improved anti-oxidation and anti-ablation properties. The SiCnw@SiC–Si coating could offer a technological foundation for preventing the oxidation and ablation of C/C composites in aerospace engineering.

Hole surface morphology and tool wear mechanisms during cutting 3D carbon/carbon composites using diamond core drill

Carbon fiber reinforced carbon matrix (carbon/carbon) composites are a new class of ceramic engineering materials and applied in aerospace structures due to high strength in non-oxidizing atmospheres at extremely high temperatures, while it is a typical difficult-to-machine material due to its anisotropy and heterogeneity. Defects such as burrs, tears and fiber pullout are likely to be produced on machined surface when inappropriate machining parameters are employed. The material removal mechanisms during mechanical cutting of carbon/carbon composites are still not fully understood. In this work, the three-dimensional braided carbon/carbon composite was employed, hole surface morphology and tool wear mechanisms during drilling with a bronze sintered diamond core tool were studied. Result showed that fiber tearing and burrs were mainly observed at hole entrance and exit under low level of feed speed down to 20 mm/min. When the feed speed increased to 40 mm/min and 60 mm/min, severe tearing, uncut fibers, and delamination appeared at hole exit. Fiber orientation showed significant influence on material removal mechanisms as well as fiber shearing/bending fracture, fiber pullout and matrix fragmentation. The ground, pullout and fracture of abrasive particles were the main tool wear mechanisms, cutting chips were attached and blocked inside the core drill probably due to high cutting temperature in dry condition, as the temperature increased to ∼260 °C under the feed speed of 60 mm/min.

Study of Carbon Matrix Composite as Wear-Resistant Plate Material on Improving Wear Resistance and Mixing Effect in Mixing Process.

Silica and carbon black are the most important reinforcing systems in rubber formula. In the process of continuous optimization of the formula, silica gradually replaces carbon black by its characteristics. In view of the wear problem of the components of the mixer chamber caused by the increase in the proportion of silica in the formula, this research applied carbon matrix composite (CMC) materials to wear-resistant plate materials, and compared them with common wear-resistant (CWR) plate materials to explore the impact of replacing CWR plate with CMC on improving wear resistance and mixing effect. The results showed that compared with the CWR plate, CMC wear-resistant plate showed characteristics of a high friction coefficient and low wear rate (reduced by about 23%) in the mixing process of silica compound. However, the friction behavior of carbon black compound and carbon matrix composite wear-resistant plate showed an opposite trend, where the friction coefficient and wear rate increased simultaneously, especially the wear rate that increased by about 35%. The main reasons for the experimental results were related to the characteristics, elemental composition and surface morphology of carbon matrix composite, silica and carbon black. The experimental results also indicated that the carbon matrix composite wear-resistant plate is more suitable for a silica mixing process, and the increasing friction coefficient with decreasing wear rate of wear-resistant plate can further improve the importance of effective friction in mixing and prolonging the service life of wear-resistant plate.

Si3N4 nanowires@pyrolytic carbon nanolayers coupled with hydroxyapatite nanosheets as reinforcement for carbon matrix composites with boosting mechanical and friction properties

Extensive attention has been drawn to the development of carbon-matrix composites for application in the aerospace and military industry, where a combination of high mechanical strength and excellent frictional properties are required. Herein, carbon-matrix composites reinforced by Si3N4 nanowires@pyrolytic carbon nanolayers (Si3N4nws@PyCnls) coupled with hydroxyapatite nanosheets is reported. The Si3N4nws@PyCnls (SP) with coaxial structure could increase the surface roughness of Si3N4nws and promote the stress transfer to the carbon matrix, whereas the porous hydroxyapatite nanosheets favor the infiltration of the carbon matrix and promote the interfacial bonding between the SP and carbon matrix. The carbon matrix composites reinforced by SP coupled with hydroxyapatite nanosheets (Si3N4nws@PyCnls-HA-C) exhibit excellent mechanical strength. Compare with the conventional Si3N4nws reinforced carbon composites, Si3N4nws@PyCnls-HA-C (SPHC) have 162% and 249% improvement in flexural strength and elastic modulus, respectively. Moreover, the friction coefficient and wear rate decreased by 53% and 23%, respectively. This study provides a co-reinforcement strategy generated by SP coupled with hydroxyapatite nanosheets for effective improvement of mechanical and frictional properties of carbon matrix composites that are used for aerospace and military industry applications.

Microstructure-Based Thermochemical Ablation Model of Carbon/Carbon-Fiber Composites.

The microstructure of carbon fiber–reinforced carbon-matrix composites (carbon/carbon composites) has important effects on its ablation performance. However, the traditional macro-ablation methods have underestimated the ablation recession rate and ignored the influence of microstructure. To simulate the ablation of large-sized structures while accounting for the influence of microstructure, it is necessary to modify these methods. In this work, a thermochemical ablation model for carbon/carbon composites is proposed based on the evolution behavior of their microstructure. The ablation recession rate and surface temperature predicted by this model are in good agreement with the experimental results. Through numerical analysis, we found that the ablation recession rate of the material without carbon fibers is much greater than that of the material containing carbon fibers. The ablation recession rate is influenced by the fiber orientation due to the change in thermal conductivity. The anti-ablation efficiency of carbon/carbon composites can be improved by increasing their fiber radius, radiation coefficient, specific heat capacity, interphase density, and thermal conductivity coefficient. The thermochemical ablation model provides a guide for the design of better anti-ablation carbon/carbon composites.

Rough porous N-doped graphene fibers modified with Fe-based Prussian blue analog derivative for wide-band electromagnetic wave absorption

With the rapid development of wireless communication technology, human living environments are being polluted by a large number of electromagnetic waves (EWs), and EWs absorption materials play an important role in exploring green living spaces. Carbon matrix composites derived from metalorganic frameworks (MOFs) are a new kind of EWs absorbing material with great application prospect. However, obtaining efficient absorbent with low filling rates and wide absorption bands remains a challenge. Here, we designed one-dimensional rough, and porous N-doped graphene fibers (N-GFs) that were assembled from two-dimensional graphene sheets with surfaces modified using a Fe-based Prussian blue analog (PBA) derivative. The rough porous structure optimized impedance matching characteristics of the absorber by introducing air gaps while the PBA particles improved N-GF electromagnetic parameters of N-GFs, increasing EWs absorption. The results showed optimal EWs absorption in the synthesized Fe-based PBA/N-GFs after annealing at 600 °C. At a filling rate of 10 wt%, the EWs absorption bandwidth could reach 8.19 GHz when the matching thickness was 2.1 mm; this covers most of the X radar frequency band and the entire Ku radar frequency band. The Fe-based PBA/N-GFs have a special microstructure and excellent EWs absorption properties, which provide inspiration for further exploration of graphene-based absorbing materials.

ZrC, HfC, and ZrC/ZrxSiy coatings prepared via molten salt Solid–Liquid two-phase diffusion method and ablation properties

ZrC, HfC, and ZrC/ZrxSiy composite ceramic coatings were prepared on the surface of carbon-matrix composites via molten salt solid–liquid two-phase diffusion to improve the ablation resistance of the C/C composites. The preparation of the coating composition could be controlled by using different powders. The effects of temperature and holding time on the microstructures of ZrC coatings and their variation laws were studied. Results showed that the ZrC coating density increased with temperature and holding time. At a holding time of 16 h, the growth of the ZrC coating was slow. The volatilization of SiO2 caused loose ZrO2 to splash. Moreover, the Si content was found to affect the ablation performance of the ZrC/ZrxSiy composite ceramic coatings, and the ablation mechanism was studied. The ZrC, HfC, and ZrC/ZrxSiy composite ceramic coatings exhibited good ablation properties. The ablation rates of the ZrC and HfC coatings were 0.805 and 0.715 mg/s, respectively, after oxyacetylene flame ablation at 3000 °C for 60 s.

Preparation of porous CoNi/N-doped carbon microspheres based on magnetoelectric coupling strategy: A new choice against electromagnetic pollution

Magnetoelectric coupling is a key strategy to obtain high-performance microwave absorption materials. Especially for carbon matrix composites, the absorbing capacity can be optimized via the tuning of the graphitization degree and the content ratio of the magnetic and dielectric components. Based on this theory, a simple strategy, consisting of the solvothermal method and annealing in an inert atmosphere, is adopted in this study to combine CoNi magnetic alloys with graphitized carbon into micron-scale composite spherical particles. Additionally, special attention is paid to the correlation among the graphitization degree of carbon matrix, component proportion, and dielectric response ability, so as to achieve a flexible micromorphology design and a tunable microwave absorption performance. When the pyrolysis temperature is offset to the best of 700 ℃, a broadband absorption of 6.61 GHz (reflection loss < − 10 dB) is achieved at an ultrathin matching thickness of 1.9 mm. Adjusting the carbon content can further optimize the impedance matching and realize a high-intensity absorption with a reflection loss of − 72.7 dB. Our work proposes a useful strategy to realize the effective combination of the magnetic and dielectric loss mechanisms and boost the microwave absorption capacity toward achieving the desired broadband and a high-efficiency absorption performance.

Recent Progress in 1D Nanostructures Reinforced Carbon/Carbon Composites

AbstractCarbon fiber reinforced carbon matrix (carbon/carbon, C/C) composites have become the promising candidates for high‐temperature thermal structure materials in aerospace fields, owning to a series of excellent structural merits. However, for aculeate or thin‐walled C/C composites, due to the fact that continuous carbon fibers are cut off during the machining process and the amount of residual carbon fibers is limited, carbon matrix cannot be effectively strengthened just by using carbon fibers, resulting in a sharp decline in mechanical performance. Furthermore, the rapid development of aerospace vehicles requires that C/C composites not only have excellent mechanical properties but also possess multifunctional properties. To effectively solve these problems and meet the increasing demands, various 1D nanostructures as nanoreinforcements have been introduced into C/C composites, achieving the great improvement in mechanical and functional properties. In this review, the state‐of‐the‐art research activities regarding different 1D nanoreinforcements applied in C/C composites are systematically summarized. Finally, this review is concluded and the future research prospects are proposed. This review provides the “1D nanoreinforcements” strategy to further improve the properties of C/C composites, which could be widely used for reference by researchers in the fields of different fiber/matrix composites.

Tailoring carbon-matrix composites interfaces using reduced graphene oxide for high strength

The interfacial interaction between the carbonized matrix and binder directly correlates with the performance of the carbon-matrix composites. The involvement of the reduced graphene oxide (rGO) in composites is considered an effective strategy to enhance the performance of composites via improving the interface property. Herein, the rGO was converted in-situ from the graphene oxide (GO) on the interface between the matrix and the carbonized binder during the sintering process. Compared with the pristine composites, the compressive strength (203.90 MPa ±2.85 MPa) and flexural strength (40.53 ± 1.42 MPa) of carbon-matrix composites doping 0.2 wt% of GO can be increased by 112.1% and 71.2%, respectively. It is attributed to the fact that rGO forms an ideal interface bond with the carbonized matrix and binder, which effectively promotes the deflection of the crack propagation path. Meanwhile, molecular dynamics simulations unlocked an automatic protective reinforcement mechanism of the rGO-enhanced composites. A low-cost yet effective scheme for improving composites interfaces is proposed here, which lays a theoretical foundation for developing the high-strength carbon-matrix composites.

Exploration of the oxidation and ablation resistance of ultra-high-temperature ceramic coatings using machine learning

Carbon fiber-reinforced carbon matrix composites (C/C) will be easily oxidized in high temperatures, which will have a great negative effect on their performance. Preparing ultra-high-temperature ceramic (UHTC) coatings is a well-established method to improve the oxidation and ablation resistance of C/C. However, it is time-consuming and costly to obtain these coatings through the traditional experimental method. Motivated by the outstanding performance of machine learning (ML) algorithms in many fields, this study adopts ML algorithms based on historical experimental datasets to build a model. This model will predict the oxidation and ablation resistance, represented by mass ablation rate. For this purpose, variables that affect the mass ablation rate and are easily accessible were used as input features. That includes the chemical composition and essential physics/chemistry properties of coatings and experimental parameters. Seven different ML algorithms were used to establish the model; namely, ridge regression (Ridge), lasso regression (Lasso), kernel ridge regression (KRR), support vector regression (SVR), random forest regression (RFR), AdaBoost regression (ABR), and bagging regression (Bagging). The results show that RFR has the optimal generalization performance with a mean absolute error (MAE) of 0.55, mean-squared error (MSE) of 0.71 and coefficient of determination (R2) of 0.87 on the testing set. SHapley Additive exPlanations (SHAP) analysis of the RFR model explained how these input features affect the mass ablation rate and further provided the critical features for performance prediction. The model established in this study can predict coating performance accurately and accelerate the development of UHTC-coated C/C composites from a data-driven perspective.

Fabrication of LiOH-metal organic framework derived hierarchical porous host carbon matrix composites for seasonal thermochemical energy storage

Fabrication of LiOH-metal organic framework derived hierarchical porous host carbon matrix composites for seasonal thermochemical energy storage

Fe-doped MOF-derived N-rich porous carbon nanoframe for H2 S cataluminescence sensing.

Metal-doped porous carbon matrix composites are considered as outstanding H2 S cataluminescence sensing materials for their good sulfur tolerance and high cataluminescence activity. In this work, an Fe-doped MOF-derived N-rich porous carbon nanoframe was successfully fabricated using the pyrolysis of Fe-doped ZIF-8 in an Ar atmosphere at a temperature of 900°C, and used for H2 S cataluminescence sensing. Along with zinc volatilization, the obtained porous carbon nanoframe not only had high specific surface area and abundant voids, but also had well dispersed Fe species doped in the skeleton. Compared with Fe2 O3 /ZnO composites derived from the same precursor but different pyrolysis terms, this as-prepared Fe-doped N-rich porous carbon presented a three times increase in the cataluminescence intensity towards H2 S, attributed to the porous carbon skeleton that is indispensable for dispersing catalytic active sites and providing more absorptive surface and voids. Comparably, this proposed sensor demonstrated high sensitivity and good selectivity, with the detection range of 1.57-19.58 μg·ml-1 and detection limit of 0.13 μg·ml-1 towards H2 S. This work may provide a new pathway for preparing catalysts for cataluminescence sensing with better metal distribution, higher specific surface area, and richer pores than ever before.