Excellent Heat Insulation Research Articles

Zr4+ and Al3+ coordinated cross-linked conductive collagen fibers/solvent-free polyurethane foam with ultra-low reflective electromagnetic shielding properties

In recent years, electromagnetic shielding materials with low reflectance have developed rapidly. However, high material cost, poor bonding fastness, weak mechanical properties and other problems seriously limit its effect in practical use. In this work, flexible conductive collagen fibers (CLF-Zr4+/Al3+-CNTs) were prepared using chromium tanned waste leather as ingredient, carbon nanotubes (CNTs) as conductive filler and transition metal ions as coordination crosslinking agents, and their molecular dynamics were investigated by quantum chemical simulation software. On this basis, a flexible conductive foam with the double layer and double core-clad structure containing carbon nanotubes was constructed using the solvent-free polyurethane (SFPU) chemical foaming technology, and their electromagnetic shielding properties and reflectance were studied. The experiment results showed that when the ratio of CLF-Zr4+/Al3+-CNTs to SFPU polyol is 1:9 and the impregnation times of CNTs are 2, the loading capacity of CNTs in conductive foam is 0.14 mg/cm3, the electrical conductivity is 57.8 S/m, and the thermal conductivity is 0.061 W/(m·K). Meanwhile, when the thickness is 3 cm, the electromagnetic shielding performance is 42.09 dB, and the reflection efficiency is 0.66 %, the lowest reflection efficiency reaches 0.16 % in the experiment. The mechanism of electromagnetic shielding in conductive foams with the double layer and double core-clad structure has been further explored. The experiment results proved that the flexible conductive foam has excellent mechanical properties, stability, heat insulation and flame retardant properties, and has excellent electromagnetic shielding and low reflection characteristics due to its abundant holes, functional group, interface and hierarchical structure.

Enhancing flame retardancy and heat insulation performances of polyamide 66 composite film by adding CNC/Al2O3 nanohybrids

Polyamide 66 (PA66) has garnered significant attention due to its exceptional properties; unfortunately, its flammability is challenging. Adding flame retardants (FRs) is a primary approach to enhance PA66 flame retardancy. This study developed a highly flame-retardant PA66 composite film by adding corn-like functional nanohybrids (CNC/Al2O3). Interestingly, CNC/Al2O3 nanohybrids not only formed hydrogen bond interactions with PA66 but also improved crystallization properties as heterogeneous nucleating agents, resulting in the excellent mechanical properties of PA66 composite film. Remarkably, the incorporation of 3 wt% CNC/Al2O3 nanohybrids into PA66 matrix contributed to increasing the LOI to 28.5 %. The pHRR, THR, and TSR were reduced obviously by 55.7 %, 15.3 %, and 65.2 %, respectively. The excellent flame retardancy of PA66 composite film was attributed to the forming of a compact carbon layer catalyzed by the CNC/Al2O3 nanohybrids. Besides, the homogeneous distribution of CNC/Al2O3 nanohybrids endowed the composite film with excellent heat insulation, and the heat insulation rate was up to 31.9 %. Thus, such PA66 composite films with excellent flame retardancy, heat insulation, and mechanical properties could meet the broader application requirements.

One-Step Spraying Strategy for Fabricating Bioinspired, Graphene-Based, and Multifunctional-Integrated Coatings on Structural Steel with Good Water Repellency, Fireproofing, Anticorrosion, and Durability.

Traditionally, many coatings were merely concentrated on settling the inherent fire protection problem of steel structures, while surface contamination and corrosion susceptibility should also be considered. Concurrently addressing these problems in fireproof efficiency and surface multifunctionality has become an issue of great significance in further expanding the application value in industrial and daily scenarios. Based on this condition, ecofriendly, graphene-based, and superhydrophobic coatings with multifunctional integration were constructed on steel via a one-step spraying method. The as-prepared coatings mainly consist of epoxy resin (EP), silicone resin (SR), a cyclodextrin-based flame retardant (MCDPM), expandable graphite (EG), and multilayered graphene (MG). The results demonstrate that the water contact angle (WCA) and water sliding angle (WSA) of as-prepared coatings can reach 156.8 ± 1.6 and 5.8 ± 0.7°, respectively, revealing good water repellency and self-cleaning properties. The coatings can also exhibit adequate adaptability for various substrates including wood, polyurethane foam, and cotton fabrics. Besides, good durability and robustness of coatings have been also verified via acid/alkali immersion, outdoor exposure, O2/plasma etching, and linear abrasion tests. Simultaneously, the coatings can exhibit excellent anticorrosion capacity for steel materials via a double barrier effect. Most importantly, the coatings have exhibited the lowest backside temperature (234.5 °C) during fire impact tests, suggesting excellent fireproof and heat insulation performance. This fact can be ascribed to the conjunct action between the physical/chemical charring process of flame retardants and the remarkable thermal stability of graphene. Consequently, this article can be expected to further promote the development and application of multifunctional-integrated coatings for steel structures in more fields.

Preparation of P/N/Si‐containing covalent organic framework‐based flame retardants and their application in epoxy resins

AbstractBalancing the enhancement of flame retardancy of epoxy resin while maintaining its mechanical capacities intact poses a significant challenge in the realm of flame‐retardant epoxy resins. To reach the above objectives, a COF‐based synergistic flame retardant with phosphorus, nitrogen, and silicon (PA‐COF@MT) was synthesized using phytic acid (PA), montmorillonite (MT), and covalent organic framework (COF). When PA‐COF@MT was added at 4 wt%, EP/PA‐COF@MT exhibited a reduction of 42.1% in peak heat release rate (PHRR), 45.84% in total heat release (THR), and 59.8% in total smoke production (TSP) compared with the pure EP. LOI increased by 30.5% and UL‐94 tested to V‐0 grade. flame‐retardant index (FRI) value of 3.03, achieving a “good” rating. Fire growth indices and mean effective combustion heat were increased while mechanical properties also improved. These findings suggest that the flame retarding mechanism of PA‐COF@MT is mainly through vapor phase and condensed phase actions. The combined effects of phosphorus, nitrogen, and silicon make the surface of carbon residue solid and dense, resulting in excellent heat insulation and smoke suppression effects. In simple terms, this study provides new insights into COF‐based flame retardants. Combining low‐cost and simple preparation methods, PA‐COF@MT has broad application prospects in flame‐retardant epoxy resin systems.

Lightweight and robust electrospun zirconia fiber reinforced carbon aerogel composites for efficient microwave absorption and heat insulation

Carbon aerogel (CA) is recognized as a promising microwave absorption (MA) material, but it remains greatly challenging to integrate the multiple functions of MA, mechanical strength, and heat insulation. In this work, a novel zirconia fiber reinforced CA (ZF/CA) composite is successfully fabricated via electrospinning technology coupled with a sol-gel impregnation process for the first time. The density (0.132–0.206 g/cm3) of the obtained ZF/CA composites can be regulated by simply varying the initial sol concentration, thus effectively tuning their performance. Notably, the ZF/CA composites display excellent MA properties, with a strong absorption of −80.30 dB at the thickness of merely 1.71 mm and the optimal effective absorption bandwidth reaches 5.16 GHz, which is a significant improvement compared to CA (−11.70 dB, 0.58 GHz). Simultaneously, the brittleness and cracking problems of CA are effectively addressed by the soft reinforcement strategy of electrospun zirconia fibers, and superior mechanical strength is obtained. Furthermore, the nanopore structure and hierarchical design endow the ZF/CA composites with low thermal conductivity (0.029–0.038 W m−1 K−1) and favorable heat insulation performance. Outstanding MA capacity and excellent heat insulation properties along with lightweight construction and high strength make ZF/CA composites a great candidate for efficient MA and heat insulation.

Dynamically frequency‐tunable and environmentally stable microwave absorbers

AbstractThe threat to information security from electromagnetic pollution has sparked widespread interest in the development of microwave absorption materials (MAMs). Although considerable progress has been made in high‐performance MAMs, little attention was paid to their absorption frequency regulation to respond to variable input frequencies and their stability and durability to cope with complex environments. Here, a highly compressible polyimide‐packaging carbon nanocoils/carbon foam (PI@CNCs/CF) fabricated by a facile vacuum impregnation method is reported to be used as a dynamically frequency‐tunable and environmentally stable microwave absorber. PI@CNCs/CF exhibits good structural stability and mechanical properties, which allows precise absorption frequency tuning by simply changing its compression ratio. For the first time, the tunable effective absorption bandwidth can cover the whole test frequency band (2−18 GHz) with the broadest effective absorption bandwidth of 10.8 GHz and the minimum reflection loss of −60.5 dB. Moreover, PI@CNCs/CF possesses excellent heat insulation, infrared stealth, self‐cleaning, flame retardant, and acid‐alkali corrosion resistance, which endows it high reliability even under various harsh environments and repeated compression testing. The frequency‐tunable mechanism is elucidated by combining experiment and simulation results, possibly guiding in designing dynamically frequency‐tunable MAMs with good environmental stability in the future.

Micro-helical Ni3Fe chain encapsulated in ultralight MXene/C aerogel to realize multi-functionality: Radar stealth, thermal insulation, fire resistance, and mechanical properties

Magnetic carbon aerogels with high porosity, ultralow density, and excellent impedance matching are considered to be a promising microwave absorption (MA) material. In this study, ethylene glycol polymerization is used to assemble Ni3Fe particles into a micro-helical chain, which is further wrapped by MXene and then encapsulated in poly-Schiff-base aerogels through the carbonyl–amine condensation reaction. Finally, ultralight TiO2/Ni3Fe/MXene/C (NFMC) aerogels are synthesized through calcination treatment. Benefiting from the electromagnetic synergistic effect of multi-dimensional and multi-component materials, the NFMC-7 aerogel exhibits excellent MA performance with a minimum reflection loss of −61.6 dB at 3.0-mm thickness and an effective absorption bandwidth of 8.16 GHz at 2.77-mm thickness under a low filler loading of 7.6 wt%. Commercial computer simulation technology is used to verify the strong magnetic and dielectric loss characteristics of Ni3Fe chains. At the same time, the NFMC-7 aerogel exhibits excellent radar stealth, heat insulation, compression resistance, and fire resistance performance, which verifies its practical applicability. Overall, this work establishes an effective strategy to fabricate multi-functional magnetic aerogels, which can serve as lightweight, thin, and strong microwave absorbers with broad absorption bandwidth.

Study on the thermal characteristics and heat-insulation ability of gel-stabilized foam used for preventing the spontaneous combustion of coal

Gel-stabilized foam serves a critical role in preventing spontaneous combustion of coal by impeding heat transfer from the coal-fire area to adjacent safe areas. To elucidate the thermal characteristics of gel-stabilized foam, the microstructure and heat-transfer characteristics were investigated. The results revealed that gel-stabilized foam was an accumulation system of many stable and closed bubbles, and there was a layer of gel structure on the bubble surface. This gel layer endows the bubbles with exceptional heat-insulation capability by effectively encapsulating air. To further analyze the relationship of heat-transfer characteristics and foam structure parameters, a theoretical thermal-conductivity model was established to revel the thermal characteristics of gel-stabilized foam. Moreover, the experimental tests were conducted to verify the accuracy of theoretical model, and found that the fitting errors were around 8 %, affirming the model's suitability for gel-stabilized foam. Notably, the theoretical model demonstrated that foam's thermal-conductivity was only monotonically related to foam expansion ratios in theory. In addition, the heat-insulation experiments indicated that the heat-transfer rate of foam depended not only on the thermal-conductivity but also on the foam's stability, both of which were affected by the expansion ratio. Hence, the effective heat-insulation time (EHT) was proposed to assess gel-stabilized foam's heat-insulation characteristics. The heat-insulation ability tests results showed that EHT values initially increased and then decreased with rising foam expansion ratios, primarily influenced by the volume of air encapsulated within the foam. Particularly noteworthy were the test results indicating that gel-stabilized foam with an expansion ratio of 10 times and a stacking thickness of at least 15 cm exhibited excellent heat-insulation capability against heat transfer from the spontaneous combustion zones. The research may provide a theoretical foundation and offer guidance for the prospective utilization of gel-stabilized foam in coal mines.

RbxCsyWO3 based superhydrophobic transparent thermal insulation film for energy saving

Superhydrophobic transparent insulation film has attracted more attentions in the field of energy-saving glass due to its excellent near-infrared (NIR) shielding property and good self-cleaning performance. In this study, Rb+, Cs+ co-doped tungsten bronze powders were synthesized through a solvothermal reaction, and the superhydrophobic transparent thermal insulation film was constructed on glass. Results show that the strategy of Rb+, Cs+ co-doping can improve the NIR shielding property by incorporating more alkali metal ions into the hexagonal channel and can increase the content of W5+. When n(Rb)/n(Cs)=2, the film exhibits the best NIR shielding performance, with a visible transmittance of 55.6% and an NIR shielding rate of 94.6%. The superhydrophobic tungsten bronze film was successfully prepared with a water contact angle of 163.3±4.1°. The film also exhibits good chemical stability and water impact resistance, with a visible light transmittance of 62.7%, and an NIR shielding rate of 92.9%. The maximum temperature difference in insulation between the uncoated glass and the glass coated with R2WO's PVA/PDMS/SiO2-2 film is 8.9℃ under the irradiation of a tungsten lamp. In conclusion, R2WO's PVA/PDMS/SiO2-2 film, which exhibits excellent heat insulation and good self-cleaning ability, holds great potential for application in the energy-saving glass industry.

High-Compressive, Elastic, and Wearable Cellulose Nanofiber-Based Carbon Aerogels for Efficient Electromagnetic Interference Shielding.

Developing excellent electromagnetic interference (EMI) shielding materials with robust EMI shielding efficiency (SE), high mechanical performance, and multifunctionality is imperative. Carbon materials are well recognized as promising alternatives for high-performance EMI shielding, but their high brittleness greatly hampers their applications. In this work, a cellulose nanofiber/reduced graphene oxide-glucose carbon aerogel (C-CNFs/rGO-glu) with high compression, elasticity, and excellent EMI shielding performance was fabricated by directional freeze-drying followed by carbonization. Specifically, the height and stress retention are 88% and 90.9%, respectively, after 100 cycles of compression release at a high strain of 70%. The electromagnetic shielding effectiveness of the aerogels reached 67.5 dB and presented an absorption-dominant shielding mechanism with a 97.5% absorption loss ratio. Further, the carbon aerogel could capture subtle electrical signals to monitor different human behaviors and showed excellent heat insulation and infrared stealth performance.

A method for fabricating polyvinylidene fluoride/poly methyl methacrylate/graphite nanoplates nanocomposites foams with high strength, large expansion ratio and outstanding heat insulation properties

Developing lightweight and high-performance polymer foams for heat insulation is of utmost significance for energy conservation, emission reduction, and improving energy efficiency. Introducing carbon fillers such as graphite nanoplates (GNPs) can effectively reduce heat radiation in foams and greatly enhance their mechanical and flame-retardant properties. However, there are technical challenges in achieving eco-friendly and scalable production of lightweight polymer/GNP nanocomposite foams, including poor dispersion of GNPs and lower foaming ratios. In this work, a method for fabricating lightweight nanocomposite foams through melt blending combined with a carbon dioxide molten-foaming process was proposed. By using this method, the ultralight, high-strength, and hydrophobic polyvinylidene fluoride (PVDF)/poly (methyl methacrylate) (PMMA)/GNP nanocomposite foams with excellent heat insulation and flame-retardant properties were successfully prepared. It was found that the addition of GNP improves the melt viscoelasticity and increases the initial crystallization temperature of PVDF. Furthermore, GNPs can also expand the foaming temperature window, refine the cell size, and induce open-cell structures in the foams. The nanocomposite foams fabricated using this method have a foaming temperature window of over 20 °C, a foaming ratio exceeding 40, and a density below 0.04 g/cm3. Thanks to the higher foaming ratio, well-developed open-cell structures, and the heat radiation attenuation effect of GNPs, the nanocomposite foam exhibits a remarkably low thermal conductivity of 30.14 mW⋅m−1⋅K−1. Additionally, the foams display favorable compressive mechanical properties, hydrophobicity, and flame retardancy.

A tri-modal tactile sensor based on porous ionic hydrogel for decoupled sensing of temperature and pressure

Developing simple device configurations to satisfy independent thermal and force sensing is critical for improving the recognition and manipulation capabilities of robotic hands on objects, but it remains a challenge. In this paper, through the composition adjustment of polyvinyl alcohol, KOH, nano-silica, glycerin, and the microporous structure design, the prepared ionic hydrogel sensor has promising comprehensive performance. It shows thermal sensitivity (−0.47 % °C−1, 0–20 °C; −0.24 % °C−1, 20–50 °C), pressure sensitivity (1 kPa−1, 0–300 kPa), pressure detection limit of 1 Pa, and mechanical durability (1000 compression fatigue cycles at 100 kPa). More importantly, the pressure-sensitive and thermal-sensitive properties hardly interfere with each other due to the ionic hydrogel network's synergy of excellent water retention, anti-freezing properties and heat insulation ability. The multifunctional tactile sensor is integrated into a robot hand to obtain force and thermal information of the measured object, and combined with machine learning algorithms to realize object recognition. The proposed sensing scheme has been applied to 6 kinds of fruit and vegetable classification tasks in a cold chain logistics scenario, showing a classification accuracy of 95 %.

Fabrication of thermal insulation sodium alginate/SiO2 composite aerogel with superior radiative cooling function for firefighting clothing

Purpose This study aims to evaluate the thermal performance of sodium alginate (SA) aerogel attached to nano SiO2 and its radiative cooling effect on firefighting clothing without environmental pollution. Design/methodology/approach SA/SiO2 aerogel with refractory heat insulation and enhanced radiative cooling performance was fabricated by freeze-drying method, which can be used in firefighting clothing. The microstructure, chemical composition, thermal stability, and thermal emissivity were analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analyzer and infrared emissivity measurement instrument. The radiative cooling effect of aerogel was studied using thermal infrared imager and thermocouple. Findings When the addition of SiO2 is 25% of SA, the prepared aerogel has excellent heat insulation and a high radiative cooling effect. Under a clear sky, the temperature of SA/SiO2 aerogel is 9.4°C lower than that of pure SA aerogel and 22.1°C lower than that of the simulated environment. In addition, aerogel has more exceptional heat insulation effect than other common fabrics in the heat insulation performance test. Research limitations/implications SA/SiO2 aerogel has passive radiative cooling function, which can efficaciously economize global energy, and it is paramount to environment-friendly cooling. Practical implications This method could pave the way for high-performance cooling materials designed for firefighting clothing to keep maintain the wearing comfort of firefighters. Originality/value SA/SiO2 aerogel used in firefighting clothing can release heat to the low-temperature outer space in the form of thermal radiation to achieve its own cooling purpose, without additional energy supply. Graphical abstract

Study the Al2O3 nano-fillers performances of metallic hollow microlattice material as a heat insulation on the high-temperature

Hollow microlattice material is a kind of excellent heat insulation material due to its special microstructural characteristics and ultra-low relative density. However, the possibility of oxidation at the temperature higher than 500℃ limits its application in the high-temperature insulation fields, such as rockets and aircraft engines. In order to overcome this obstacle, this study successfully prepared nano-Al2O3 reinforced metallic hollow microlattice materials with an equivalent density of 26.5 mg/cm3. Heat insulation tests and thermogravimetric (TG) experiments were also carried out to investigate the thermal performances of the Al2O3 reinforced metallic hollow microlattice materials, while the effect of the concentration of the Al2O3 was also investigated in accordance with the comparative tests. The results indicate that the Al2O3 plays a significant role in hindering the high-temperature oxidation of hollow microlattice material, especially with Al2O3 concentration in the range of 2 g/L to 4 g/L, and the heat insulation performance can be improved by 13.9%.

Application of Halogen-Free EPDM Flame Retardants

Flame retardant materials have been widely used in different fields because of their unique physical and chemical properties, such as aerospace and chemical products. However, although the traditional halogen-based flame retardant has shown excellent application performance in the actual application process, there are serious environmental pollution problems after its use. In order to solve the environmental problems caused by halogen flame retardants, different types of environmentally friendly flame retardant materials have been developed, such as ethylene propylene diene monomer (EPDM) flame retardant. As a new type of energy saving and environment friendly rubber, the EPDM has excellent heat resistance, aging resistance, corrosion resistance and insulation performance, and thus it has been widely used in all walks of life. To this end, EPDM has been used to develop different types of flame retardant materials. Herein, this research will mainly analyze the application performance of different types of EPDM flame retardants and their flame retardant mechanisms, where the research and application of EDPM flame retarder are mainly described from three aspects: intumescent flame retarder, phosphorous flame retarder and inorganic flame retarder

Sustainable bacterial cellulose-based composite aerogels with excellent flame retardant and heat insulation

Sustainable bacterial cellulose-based composite aerogels with excellent flame retardant and heat insulation

Damage Grading Evaluation of Thermal Barrier Coatings under CMAS Corrosion

Thermal barrier coatings (TBCs) material has excellent high-temperature resistance and heat insulation performance, which plays a vital role in improving the working efficiency and running life of the engine. During the flight, the engine will inhale dust particles in the air. These particles are mostly from siliceous debris, which are usually called calcium magnesium aluminum silicate (CMAS). At present, CMAS corrosion has become one of the important problems affecting the service life of thermal barrier coatings. In this study, conventional yttrium oxide stabilized zirconia (YSZ) coatings and ytterbium oxide and yttrium oxide co-stabilized zirconia (YbYSZ) coatings were prepared by atmospheric plasma spraying. The two coatings were examined under thermal cycling-CMAS coupling conditions and divided into six life stages. The failure modes, CMAS permeation behavior, crack characteristics and mechanical properties of the two coatings at different life stages were evaluated systematically. The experimental results show that the YbYSZ coating has a longer life than YSZ coating under the thermal cycling and CMAS coupling condition, which increases by about 83% compared with the conventional YSZ coating. In the whole life stage, the porosity of YbYSZ coating is always higher than that of YSZ coating. The phase transition is not the reason for the failure and spalling of the coatings. The crack length of the two coatings showed an increasing trend, but the crack length of the YSZ coating was higher than that of the YbYSZ coating, and the crack density of the two coatings showed a “saddle shape”, which was more obvious for the YSZ coating. The YbYSZ coating shows better mechanical properties under the thermal cycling-CMAS coupling condition with the evolution of life.

High‐temperature resistance and excellent electrical insulation in epoxy resin blends

AbstractThe packaging insulation material was a crucial component to guarantee the stable and safe operation of electronic devices. Epoxy resin, one of the most popular packaging materials, was widely used as an electronic packaging material because of its good corrosion resistance and electrical insulation, low price, and easy processing and molding. However, the unsatisfied heat resistance cannot meet the requirements of the rapid development of third‐generation power semiconductors, so it was meaningful to modify the epoxy resin with both excellent heat resistance and insulation. In this paper, tetrafunctional epoxy resin AG70 and phenolic epoxy resin F51 was blended in different proportions to combine their individual advantages, and the microstructure and electrical/thermal properties of epoxy resin blends had been systematically studied. The results showed that with the increase of blending ratio of AG70 with F51, both high glass transition temperature of 213.3°C and electric breakdown of 206.1 kV/mm were achieved when the blending ratio was 5:5, displaying excellent overall performances and exhibiting great application potential in electronic and microelectronic industries.

Multifunctional and magnetic MXene composite aerogels for electromagnetic interference shielding with low reflectivity

Lightweight and multifunctional compressible aerogels with low reflectivity are highly demanded to protect electronic devices from increasingly serious electromagnetic interference and radiation. Although simply incorporating magnetic particles can reduce the strong electromagnetic (EM) reflection caused by the high conductivity of MXene, high density, inhomogeneous dispersion and weak interfacial interactions may impede the potential applications. Here, we report the fabrication of three-dimensional magnetic MXene/Fe3O4@acidified-MWCNT (aMWCNT) composite aerogel by a directional freezing and subsequent freeze-drying process, and the shielding effectiveness of composite aerogel can be tuned from 32.5 to 51.6 dB in the X-band. At the same time, since the Fe3O4 nanoparticles are pre-decorated onto aMWCNTs, the heterogeneous interface polarization and magnetic loss are enhanced at low loadings. Therefore, the reflected power coefficient of the aerogel is as low as 0.31 with an ultra-light density of only 10 mg cm-3. Moreover, the good reversible compressibility, fatigue resistance, excellent heat insulation, and infrared stealth grant the aerogels great application prospects for anti-infrared detection and green shielding materials.

Multifunctional composite foam with high strength and sound‐absorbing based on step assembly strategy for high performance electromagnetic shielding

AbstractSoft polyurethane (PU) materials exhibit excellent structural stability, sound absorption and heat insulation, and they can be used to prepare multifunctional conductive composites with electromagnetic interference (EMI) shielding function. On the basis of a multistep assembly strategy, our study constructed composite foams with sound absorption and EMI shielding properties by designing different functional layers and expanded the application field of PU foam. First, carbon black particles are compounded with PU foam to improve the mechanical properties and conductivity of pure foam. Then, an aluminum layer and a knitted fabric layer were introduced to construct composite foam samples with a sandwich structure, endowing the materials with excellent EMI shielding performance. The resultant composite foam material exhibits effective EMI shielding performance and good sound absorption performance, which are 58.33 dB and >0.3, respectively. Moreover, the composite foam material demonstrates high bursting strength and compression resistance, suggesting that it can be used under different conditions. The employment of the multistep assembly strategy provides PU foam with a flexible range of applications, offering an innovative approach for preparing multifunctional conductive composite materials.