Carbon Foam Materials Research Articles

Atomistic-to-continuum modeling of carbon foam: A new approach to finite element simulation

Carbon foam materials exhibit useful characteristics for unique and diverse applications. However, accurately modeling three-dimensional carbon foam remains a significant challenge. This paper introduces a novel technique for transitioning atomistic-scale models of porous carbon, obtained via molecular dynamics simulation, to continuum-scale carbon foam models suited for finite element simulations. We present our method using the fractal properties of porous media, specifically carbon foams. The resulting models demonstrate testable properties consistent with those derived from computed tomography (CT) scans and experimental data. Stress–strain curves obtained from finite element analysis (FEA) calculations of our models correlate well with experimental measurements from dogbone testing samples of carbon foam sourced from CONSOL Innovations LLC, WV, USA, as well as CT scan models derived from the carbon foams. Our approach presents a computationally efficient alternative and encourages innovation in modeling porous media, particularly in extracting physical properties from an ensemble of models.

Metal-Catalyzed Carbon Foams Synthesized from Glucose as Highly Efficient Electromagnetic Absorbers.

This paper introduces a novel method for preparing high-performance, metal-containing carbon foam wave-absorbing materials. The process involves foaming glucose through catalysis by transition metals followed by high-temperature pyrolysis. The resulting carbon foam materials exhibit a highly porous structure, which is essential for their wave-absorption properties. Notably, at a thickness of 2.0 mm, the glucose-derived carbon foam composite catalyzed by Fe and Co (GCF-CoFe) achieved a minimum reflection loss (RLmin) of -51.4 dB at 15.11 GHz, along with an effective absorption bandwidth (EAB) of 5.20 GHz, spanning from 12.80 GHz to 18.00 GHz. These impressive performance metrics indicate that this approach offers a promising pathway for developing low-density, efficient carbon foam materials for wave-absorption applications. This advancement has significant implications for fields requiring effective electromagnetic interference (EMI) shielding, stealth technology, and other related applications, potentially leading to more efficient and lightweight solutions.

Flame-retardant ammonium polyphosphate/MXene decorated carbon foam materials as polysulfide traps for fire-safe and stable lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low cost. However, the development of high-energy density Li-S batteries with high loading of flammable sulfur faces the challenges of electrochemical performance degradation owing to the shuttle effect and safety issues related to fire or explosion accidents. In this work, we report a three-dimensional (3D) conductive nitrogen-doped carbon foam supported electrostatic self-assembled MXene-ammonium polyphosphate (NCF-MXene-APP) layer as a heat-resistant, thermally-insulated, flame-retardant, and freestanding host for Li-S batteries with a facile and cost-effective synthesis method. Consequently, through the use of NCF-MXene-APP hosts that strongly anchor polysulfides, the Li-S batteries demonstrate outstanding electrochemical properties, including a high initial discharge capacity of 1191.6 mA h g−1, excellent rate capacity of 755.0 mA h g−1 at 1 C, and long-term cycling stability with an extremely low-capacity decay rate of 0.12% per cycle at 2 C. More importantly, these batteries can continue to operate reliably under high temperature or flame attack conditions. Thus, this study provides valuable insights into the design of safe high-performance Li-S batteries.

Simple, additive-free, extra pressure-free process to direct convert lignin into carbon foams

To achieve lignin valorization, we reported a simple method to direct covert lignin into carbon foam materials in this work. Unlike multiple steps required to fabricate traditional carbon foams from most of other precursors (often non-renewable), the approach herein required solely heating for carbon production. We found that the intrinsic features of lignin render the formation of lignin block meanwhile generate the porous structure under the invented heating course. Three key factors including glass transition temperature, crosslinking ability, and thermal stability of lignin were identified to determine the successful fabrication of lignin foam (i.e., precursor of carbon foam). Upon tuning the heating profile or fractionating the lignin, lignin foam with different morphologies and properties were obtained. After carbonization, the selected lignin-derived carbon foams possessed well porous structures with bulk densities of 0.52 or 0.62 g cm−3, superior integrity with strength properties of around 10 MPa, BET surface areas of 143.29 or 325.86 m2 g−1, and many other attractive properties. This work is expected to stimulate further seek of lignin valorization in carbon foam production.

Performance evaluation of coated carbon foam material in heat exchanger applications

The overall decrease in the size and the weight of electronic components has led to high power dissipation and the need for innovative cooling designs. The current work presents an experimental study that has been conducted to use several types of pristine and coated carbon foams as heat sink and heat exchanger in a thermoelectric cooler for cooling vest application. Various parameters were measured and calculated to investigate the performance of carbon foam. Such parameters are weight, effective thermal conductivity, mass flowrate, the outlet temperature for both heat sink, and heat exchanger in addition to their temperature difference. The results from this work were compared to a previous study conducted on aluminum fins. The results showed that the coating technique improved the thermal conductivity of the foam with low thermal conductivity more than the foam with high thermal conductivity. The performance of carbon foam was much better than aluminum in dissipating the heat, especially for the high thermal conductive carbon foam. The largest weight value of the foam was around 70% of aluminum fins, while its thermal conductivity was 300% more. The foam has the potential to improve heat transfer, thus reducing the size and the weight of equipment while simultaneously increasing its efficiency and capabilities.

Mechanical and Electromagnetic Shielding Properties of Carbon Foam

More importance is being attached to the harm caused by electromagnetic interference (EMI) problems. Plenty of research in this field has used carbon foam materials to solve EMI, and some excellent results are obtained, whereas the mechanical properties of carbon foam are poor, which limit applications in particular fields. The physical mechanism of electromagnetic shielding is unanswered and further study is needed. Herein, a kind of carbon foam material is obtained by the templating method; the effect of foam structure on the electromagnetic shielding properties of the carbon foam material is investigated through experiment and simulation. The electromagnetic shielding performance, mechanical properties, and thermal stability of carbon foam are also studied. The electromagnetic shielding performance of carbon foam material is 20 dB in the X‐band range with the thickness and density as 2 mm and , respectively. In addition, the compressive strength of the carbon foam is 0.55 MPa.

Improvement Measures for Components of Dielectric Elastomers for Heavy Duty Uses Such as Robots and Power Assist Devices

Dielectric Elastomers (DE) are currently being rapidly researched and developed all over the world as a technology that has begun to be incorporated at a practical level. As a product, game vibrators using DEs are already on the market in the United States and Europe. However, much of the market demand is dominated by more output-focused applications such as DE power suits, DE motors, DE muscles for robots, and larger DE power systems. Attempts have been made to improve elastomers and use new carbon foam materials such as single-walled carbon nano tubes (SWCNTs) and multi-walled carbon nano tubes (MWCNTs) as electrodes for DEs to meet these demands. This paper discusses these issues. Also, by reversing the movement of the DE, it is possible to generate electricity with high efficiency. By attaching the power generation system to the robot, which generates electricity from the movement of the robot, and charges the robot’s battery of the robot, it becomes possible to move the robot more efficiently. This is also discussed in this paper

Оптические свойства отечественного сетчатого стеклоуглерода и его основы

The paper presents the results of experimental studies and mathematical modeling of the optical properties of glassy carbon and domestic reticulated foam materials based on it. Since the optical properties of the surface are studied on dense samples, dense samples were previously created, identical in physical properties to glassy carbon - the basis of highly porous cellular carbon materials. From the experimentally measured the spectral hemispherical reflectivity of the surface of the samples under its normal illumination and by the Kramers-Kronig relations the spectra of optical constants of glassy carbon - the refractive indices and absorption, as well as a number of their derivative characteristics were determined. For them, simple approximating relations are given in the paper. The obtained spectral data was incorporated into the previously developed optical statistical simulation model of ultra-porous reticulated foam materials, which is based on a rigorous electromagnetic theory and allows you to take into account both the features of their microstructure and physical processes that occur in such systems at different spa-tial and temporal scales. The results of the calculation of local spectra, the scattering phase function, and radiation thermal conductivity are presented for the reticulated glassy carbon foam, which has wide prospects for use as a structural and heat-shielding material. Some additional features of the mathematical model are demonstrated also.

Preparation, thermal stability and deflection of a density gradient thermally-conductive carbon foam material derived from phenolic resin

A density (ρ) gradient thermally-conductive (λ) phenolic foam material was initially prepared and it was used as a precursor to prepare a carbon foam (CF) material (ρ-λ-CF). The precursor was carbonized at the temperature between 900 and 1100 °C under the protection of N2 gas and graphitized between 2100 and 2500 °C under the protection of Ar gas, respectively. The thermogravimetric analysis was carried out to investigate the influence of temperature on the thermal stability of the achieved ρ-λ-CF during carbonization and graphitization. The deflection of ρ-λ-CF reinforced with different types of carbon fibers by mass fractions of 0 wt%, 3 wt%, 6 wt%, and 9 wt% was investigated. The microstructure of the composites was observed and analyzed by scanning electron microscopy. The results show that the prepared ρ-λ-CF consisted of three parts: reticulated carbon, carbon microspheres, and voids. It had the graphite structure and exhibited a well structured obturator microsphere shape. The toughening mechanism of ρ-λ-CF reinforced with carbon fibers was preliminarily discussed.

Temperature-induced selective-defect nucleation in (Cu3−XCoX) Pt filled graphitic carbon foams by controlled Raman-laser irradiation

Introducing nanoscale level defects into graphene- and graphite-based materials has recently become a promising strategy for band gap manipulation. In this work we have focused our attention on the nucleation of boundary- and vacancy-defects in a novel type of graphitic carbon foam material filled with ferromagnetic (Cu3−XCoX) Pt. We have investigated such defect nucleation process by (1) temperature dependent Raman laser irradiation and (2) prolonged Raman laser irradiation at the fixed temperature of 400 °C. An unusual systematic increase in the D/D′ ratio with the increase of the temperature is reported, implying the presence of a transition from a boundary-defect configuration existing for the T-range of 25 °C–400 °C to a vacancy-defect configuration for the T-range of 450 °C–550 °C. Also, we show an anomalous decrease of the D and G band intensities with the increase of the temperature, attributable to a transformation of the multilayered carbon foam into a defect-rich monolayer-like carbon material at high temperature. This unusual effect was tuned/controlled also by varying the Raman-laser irradiation time for a chosen temperature, with an increase of D/D′ ratios from 3.55 to 7.36 after 1 min of irradiation. Such a variation in the Raman spectra characteristics implies also possible future band gap manipulation in analogy to the results recently reported in chlorinated graphene systems.

Encapsulation of FePt and FePt3 alloys inside carbon-foam materials

We demonstrate an advanced chemical vapour deposition (CVD) approach in which the addition of Pt-containing hydrocarbons to ferrocene allows the nucleation of a novel carbon-foam material completely filled with elemental Fe and Pt crystal-phases. These phases are then found to alloy into tetragonal FePt and cubic FePt3 in specific annealing conditions. A dependence of the FePt nucleation on the Ar/H2 flow rate is reported. In addition, high pressure (5 GPa) experiments are found to favor the formation of a single FePt3 encapsulated phase together with the nucleation of C–O rich carbon layers in the foam surface.

Enhanced cycle performance of hierarchical porous sphere MnCo2O4 for asymmetric supercapacitors

A binary transition metal oxides MnCo2O4 with hierarchical porous sphere structure (MnCo2O4 PSs) electrode material for supercapacitor was prepared by a moderate methanol solvothermal and calcination method. The MnCo2O4 PSs presents a large specific surface area (213.2 m2 g−1). Hierarchical porous sphere is beneficial for forming conductive networks and furnishing more electrochemically active sites. Amazingly, the MnCo2O4 PSs exhibits brilliant electrochemical properties that a relatively high specific capacitance of 1044 F g−1 and remarkable cycling stability (133.3% retention after 10000 cycles) are owned. A mimetic asymmetric supercapacitor (ASC) was constructed by the MnCo2O4 PSs and the starch-derived carbon foam material (SCF) as positive and negative electrode, respectively. The MnCo2O4 PSs//SCF ASC shows excellent specific energy (42.27 Wh kg−1) at the specific power of 400 W kg−1 under the optimal output potential difference of 1.6 V and long-term cycling stability. Herein, the MnCo2O4 PSs electrode material prepared in this work is a distinguished candidate material for supercapacitor.

Temperature driven magnetic transitions in FePd3 filled monolayer carbon foam and Fe3C/α-Fe filled carbon nanotubes

An unusual observation of magnetic transition and Pd/C rehybridization effects is reported in novel monolayer carbon foam materials filled with doubled FePd3 crystal lattices. We reveal the presence of not previously observed sharp Pd/C interfaces, as confirmed by X-ray photoelectron spectroscopy, which give rise to localized paramagnetic features in the ESR spectra for a g value of 2.05 at 130 K. Also, as revealed by vibrating sample magnetometry and electron spin resonance measurements, an increase in the magnetization values with the decrease of the temperature is found. This result is compatible with a structural rearrangement from a face centered cubic metastable paramagnetic FePd3 phase into a primitive ferromagnetic cubic Fe3Pd phase. Comparative studies performed in Fe3C/α-Fe filled thin walled carbon nanotubes also give further confirmations of these unusual types of transitions by revealing a bcc to fcc phase shift with the decrease of the temperature as confirmed by zero field cooled measurements of the magnetization and ESR. In addition, a temperature dependent variation in the intensity and position of the π-electron’s differential absorption feature is observed and implies the possible existence of antiferromagnetic correlations in the carbon-nanotubes structure.

Significantly enhanced vapor-liquid mass transfer in distillation process based on carbon foam ring random packing

Applications using foam material as distillation column internals have been demonstrated higher performance than classical mass transfer units, except for the operation range. In this paper, the novel Foam Ring Random Packing (FRRP) made of Carbon foam material has been developed to overcome this disadvantage. The hydraulic performance and the mass transfer efficiency of FRRP are measured as 300 mm i.d. diameter column. The experimental values of FRRP are compared with the values of traditional ring random packing. In general, the comparison results indicate that the hydrodynamics and mass transfer performances of FRRP has been intensified by the foam materials (best HETP 0.24 m and additional 20% operation range). In order to explain the cause of intensification, flow behavior experiments were also carried out on both FRRP and Raschig ring packing. Special emphases on the effects of orientations, liquid flow rate and feed point on wetting area were investigated. Compared with other traditional random packing, the results show that the FRRP has some advantages, such as better extensive wetting area (maintain no less than 80%) and more uniform wetting distribution (fluctuate within 20%). Finally, an analysis of wetting process on single FRRP was presented to help understand the flow pattern on the packing. All results indicate that FRRP has outstanding performance, which will be a potential candidate used in distillation process.

A short review on preparation and application of carbon foam

This paper reviews about the preparation and various application of carbon foam. Some of the major preparation methods were discussed. By these processes pore size, density, porosity specific area were been controlled. Carbon foam material prepared from various methodology act to be very active material and helps in various application such as electrode, thermal energy savers, adsorbent and other microwave activities.

An Experimental Study on Heterogeneous Porous Stacks in a Thermoacoustic Heat Pump

Growing evidence suggests that research must be done to develop energy efficient systems and clean energy conversion technologies to combat the limited sources of fossil fuel, its high price, and its adverse effects on environment. Thermoacoustic is a clean energy conversion technology that uses the conversion of sound to thermal energy and vice versa for the design of heat engines and refrigerators. However, the efficient conversion of sound to thermal energy demands research on altering fluid, operational, and geometric parameters. The present study is a contribution to improve the efficiency of thermoacoustic devices by introducing a novel stack design. This novel stack consists of alternative conducting and insulating materials or heterogeneous materials. The author examined the performance of eight different types of heterogeneous stacks (combination 1–8) that are only a fraction of the displacement amplitude long and consisted of alternating aluminum (AL) and Corning Celcor or reticulated vitreous carbon (RVC) foam materials. From the thermal field measurements, the author found that combination eight performs better (12% more temperature difference at the stack ends) than all the other combinations. One interesting feature obtained from these experiments is that combination 7 produces the minimum temperature at the cold end (17% less than other combinations). The thermal performance of the heterogeneous stack is compared to that of the traditional homogeneous stack. Based on the study, the newly proposed stack design provides better cooling performance than a traditionally designed stack.

An experimental investigation of using carbon foam–PCM–MWCNTs composite materials for thermal management of electronic devices under pulsed power modes

The present article reports on a detailed experimental investigation of using carbon foam–PCM–MWCNTs composite materials for thermal management (TM) of electronic devices subjected to pulsed power. The TM module was fabricated by infiltrating paraffin wax (RT65) as a phase change material (PCM) and multi walled carbon nanotubes (MWCNTs) as a thermal conductivity enhancer in a carbon foam as a base structure. Two carbon foam materials of low and high values of thermal conductivities, CF20 and KL1-250 (3.1 and 40 W/m K), were tested as a base structure for the TM modules. Tests were conducted at different power intensities and power cycling/loading modes. Results showed that for all power varying modes and all carbon foams, the infiltration of RT65 into carbon foam reduces the temperature of TM module and results in damping the temperature spikes height. Infiltration of MWCNTS into RT65 further improves the effectiveness of TM module. Temperature damping was more pronounced in stand-alone pulsed power cycles as compared to pulsed power spikes modes. The effectiveness of inclusion of RT65 and RT65/MWCNTs in damping the temperature spikes height is remarkable in TM modules based on KL1-250 as compared to CF-20.

Thermal shock resistivity of hybrid carbon foam materials: Experiments and model predictions

This work presents computational solutions and experimental results on the most important parameters influencing thermal shock. The focus lies on the thermal shock parameters of hybrid carbon foams reinforced with yttria-stabilized zirconia (YSZ) and silicon carbide (SiC) coatings as well as MgO matrix composites under thermal and mechanical load. The computational approach is related to the quantification of failure stresses as a function of structural foam parameters (e.g. cell size, strut diameter, and strut length) using a microstructurally based finite element analysis. Similar to the early stages of thermomechanical modeling of refractories, the MgO–C hybrid foam is modeled by linear elasticity. The maximal occurring tensile stresses are used as a failure criterion. For the first time, numerical results of this simplified computational approach are correlated to the experimentally motivated extended Hasselman’s equations. Based on the numerical simulation of the Hasselman relation it is shown, that crack initiation under thermal shock loading could be simulated with this simplified only linear elastic approach, outlined in this work. Along with the computational investigation of the influence of microstructural parameters on the thermal shock resistivity, the experimental results, e.g. the parameters of final crack length and the final crack densities, make it possible to draw conclusions about the microstructural foam parameters that are the most suitable to achieve advanced thermal shock characteristics of next generation hybrid carbon foam refractories.

Thermal management of electronic devices using carbon foam and PCM/nano-composite

A detailed experimental study of a hybrid composite system for thermal management (TM) of electronics devices was performed. Three different TM modules made of pure carbon foam (CF), a composite of CF and Paraffin wax (RT65) as a phase change material (PCM), and a composite of CF, RT65 and multi wall carbon nanotubes (MWCNTs) as a thermal conductivity enhancer were developed and tested. Two types of carbon foam materials of different thermal conductivities, namely CF-20 of low thermal conductivity (3.1 W/m K) and KL1-250 of medium thermal conductivity (40 W/m K) were used in the three Modules. Tests conducted at different power densities showed a reasonable delay in reaching the heater steady state temperatures using TM module made of CF + RT65 as compared to pure CF. Heat transfer enhancement due to entrapped MWCNTs in the CF micro cells have a significant effect on the thermal response of the TM modules. The delay and decrease of heater surface temperature increase with the inclusion of MWCNTs in the TM module made of CF + RT65/MWCNTs. TM modules with enhanced thermal conductivity of carbon foam KL1-250 was shown to have good capability to control a high power loads as compared to CF-20. The effectiveness of inclusion of MWCNTs was remarkable in TM modules based on CF-20 as compared to KL1-250.

One-step synthesis of biomass-derived porous carbon foam for high performance supercapacitors

We report a facile, cost-effective and one-step carbonization and activation of cattail biomass to prepare porous carbon foam. Due to its high specific surface area (1951m2g−1) and cross-linked foam structure, carbon foam material demonstrates is a promising electrode material for supercapacitor with high specific capacitance of 336Fg−1, good rate performance and cycle stability.