Multifunctional Composites Research Articles

In situ pretreatment of wood samples with deep eutectic solvents for enhanced lignin removal and enzymatic Saccharification efficiency optimization

Deep eutectic solvents (DESs) are commonly utilized as an effective pretreatment method for biomass materials, particularly for enhancing the value of lignocellulosic biomass. However, to the best of our knowledge, the utilization of DESs for in situ pretreatment of wood samples has been seldom reported. In this study, the ability of five DESs systems to in-situ pretreatment of balsa wood samples was investigated. Among of them, the Choline Chloride-Ethylene Glycol-P-Toluenesulfonic Acid (ChCl-EG-PTSA) system showing an excellent lignin removal rate (the lignin removal of 87.34 % and cellulose retention of 86.32 %), which is significantly better than the delignification effect of the traditional acid chlorite method (lignin removal of 72,13 % and cellulose retention of 64.57 %). In addition, in the subsequent enzymatic saccharification experiments, after the wood samples were pretreated in situ by the ChCl-EG-PTSA system, the enzymatic saccharification yield of cellulose reached 75.46 %, and the enzymatic saccharification yield of xylose reached 92 %. At the same time, this study also used SEM, FTIR, XPS, TGA and other testing technologies to conduct detailed analysis and characterization of the pretreated samples. This comprehensive analysis unequivocally demonstrated the viability of the ChCl-EG-PTSA system as an environmentally sustainable and efficient approach for pretreating forest biomass. Significantly, this in-situ wood pretreatment strategy significantly lays a robust research groundwork for the development of multifunctional wood fiber composites in subsequent stages.

Multifunctional polyimide/boron nitride nanosheet/Ti3C2Tx MXene composite film with three-dimensional conductive network for integrated thermal conductive, electromagnetic interference shielding, and Joule heating performances

With the demand for further miniaturization and higher frequency operation of electronic devices, polymer films with high thermal conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) are urgently required. Herein, polyimide (PI)/boron nitride nanosheets (BNNS) aerogels with oriented porous structure are fabricated by unidirectional-freezing and freeze-drying methods. Subsequently, hierarchical PI/BNNS/Ti3C2Tx composite films with consecutively electrically and thermally conductive networks are successfully prepared via a unidirectional PI/BNNS aerogels-assisted immersion and hot-pressing strategy. Owing to the three-dimensional conductive dual networks of BNNS and Ti3C2Tx, the composite film exhibits excellent thermal conductivity with the maximum in-plane value of 4.73 W/(m·K), increased by 456 % compared to pure PI film. Moreover, the conductive network of Ti3C2Tx is conducive to the excellent EMI shielding performance, endowing the PI/BNNS/Ti3C2Tx composite film with an outstanding EMI SE value of 49.2 dB at 8.2 GHz with a low MXene content of 6 wt% and thickness of 300 μm. Furthermore, the composite film shows the superior Joule heating performance with fast thermal response and sufficient reliability. Therefore, the resulting composite film exhibits excellent thermal conductive, EMI shielding and Joule heating performance, which enables the potential application of multifunctional composites for thermal management and EMI shielding.

Multifunctional Conductive Hydrogel Composites with Nickel Nanowires and Liquid Metal Conductive Highways.

The dramatic growth of smart wearable electronics has generated a demand for conductive hydrogels due to their tunability, stimulus responsiveness, and multimodal sensing capabilities. However, the substantial trade-off between mechanical and electrical properties hinders their multifunctionality. Here, we report a double-network hydrogel composite that features a conductive "highway" constructed using magnetic-field-aligned nickel nanowires and liquid metal. The liquid metal fills the gaps between the aligned nickel nanowires. Such interconnected structures can form efficient conductive paths at low filler content, resulting in high conductivity (1.11 × 104 S/m) and mechanical compliance (Young's modulus, 89 kPa; toughness, 721 kJ/m3). When used as a wearable sensor, the hydrogel displays a high sensitivity and fast response for wireless motion detection and human-machine interaction. Furthermore, by exploiting its outstanding conductivity and electrical heating capacity, the hydrogel integrates electromagnetic shielding and thermal management functionalities. Owing to these all-around properties, our design offers a broader platform for expanding hydrogel applications.

High modulus carbon fiber based composite structural supercapacitors towards reducing internal resistance and improving multifunctional performance

Carbon fibers (CFs) based composite structural supercapacitors (CSSs) are promising multifunctional energy storage composites which can simultaneously realize load bearing and electricity storage. The device power is still low due to the high internal resistance of CSS. Herein, the CFs, electrolytes, monofunctional devices and multifunctional composite devices were investigated to show the attribution of the internal resistances. Both the normally used T300 CF and high modulus M55J CF fabrics were utilized. The electric in-plane and through-the-thickness resistances of CF fabric electrodes were characterized, respectively. The internal resistance of the monofunctional supercapacitor devices which were assembled using liquid electrolyte were evaluated considering the effects of CF sizing. The bicontinuous structural electrolytes (BSEs) composed of epoxy (EP) and ionic liquid (IL) were prepared as the multifunctional matrix of the CSSs. The chemical structure, thermal stability and ionic conductivity of the BSEs were assessed. The activated carbon (AC) loaded CFs and BSEs were used to fabricate the CSSs. Both the tensile and charge/discharge properties of the M55J CF CSSs were higher than those of the T300 CF CSSs. This work could provide new insights into the resistance attribution of CSS and how to simultaneously improve both mechanical and electrochemical performances of CSSs.

Unraveling chemical and rheological mechanisms of self-healing with EMAA thermoplastics in fiber-reinforced epoxy composites

Interlaminar delamination is a prevalent and insidious damage mode limiting the mechanical integrity and lifetime of fiber-reinforced composites. Conventional resolution involves over-design, laborious inspection, and repair/replacement at cost to the economy and environment. Self-healing via in situ thermal remending of thermoplastic interlayers offers a promising solution. However, better understanding of the healing agent and related mechanisms is necessary to tailor healing performance. Here, we compare non-neutralized (copolymer) and metallic-ion neutralized (ionomer) poly(ethylene-co-methacrylic acid) (EMAA) thermoplastics for healing interlaminar fracture. We reveal (i) how EMAA chemistry affects the interfacial reactions driving healing and (ii) the influence of molten viscosity on repair efficiency. At fixed viscosity, higher methacrylic acid content, chain mobility, and lower neutralization positively influence healing, where lower melt viscosity at fixed temperature improves delamination recovery. Thus, this study deepens scientific understanding of key variables for healing interlaminar fracture with EMAA, providing new insight for the design of multifunctional composites.

Multifunctional 3D-printed composites based on biopolymeric matrices and tomato plant (Solanum lycopersicum) waste for contextual fertilizer release and Cu(II) ions removal

The production of tomatoes faces significant challenges, including the high amount of waste generated during the harvest stage and copper-contaminated soil due to pesticide use. To address these issues and to promote a more sustainable agriculture, innovative biodegradable green composites for contextual controlled soil fertilization and Cu removal were produced by 3D-printing technology. These composites were made by incorporating NPK fertilizer flour and tomato plant waste particles (SLP) into three different biodegradable polymeric matrices: polylactic acid (PLA); a commercial blend of biodegradable co-polyesters (Mater-Bi®, MB) and their blend (MB/PLA, 50:50). Rheological characterization suggested the potential processability of all of the composites by FDM. Morphological analysis of printed samples confirmed the good dispersion of both filler and fertilizer, which also acted as reinforcement for MB and MB/PLA composites. SLP and NPK moduli were evaluated by powder nanoindentation and, for almost composites, the theoretical Halpin-Tsai model satisfactorily fitted the actual tensile moduli. The decrease in NPK fertilizer release rate and the increase in Cu(II) removal efficiency were achieved using whole 3D-printed composites. By selecting the appropriate matrix and incorporating SLP particles, it was possible to tune the NPK release rate and achieve copper absorption efficiency. Notably, MB samples containing SLP particles displayed the fastest release and the highest Cu(II) removal efficiency.Graphical abstract

Innovative multifunctional fire retardance of poly(butylene adipate-co-butylene terephthalate)-based bio-composite formulation

Poly(butylene adipate-co-butylene terephthalate) (PBAT), a biodegradable aromatic-aliphatic copolyester, has been widely applied in various fields, but it shows the flammability, resulting in serious fire risk. The flame retardancy of some PBAT/polymer blend systems have been studied, but that of neat PBAT was seldom reported. In particular, the research and development of the bio-based green flame retardant agent is highly desired. In this work, fully bio-derived modified chitosan particles (C-CS), were synthesized and used to prepare a novel PBAT-based multifunctional flame-retardant composite. The PBAT/3%C-CS composite (PC3) exhibited an excellent anti-dripping and self-extinguishing performance and achieved the highest fire safety rating (V-0). Peak of heat release rate and total heat release reduced by 39.8 % and 14.9 %, respectively. The char residue yield of the PC3 increased by 211.6 % in the PC3, compared with that of neat PBAT. Both condensed- and gas-phase played dual roles on increasing the flame-retardant performance of the PC3. The PC3 showed a relatively compact and continuous char layer which acted as a physical barrier to suppress the heat exchange and O2 entry (into the matrix) in the combustion process. Meanwhile, the concentration of O2 and H·/HO· free radicals were diluted by a small portion of non-flammable gas products in the pyrolysis process. Also, the PC3 presented elevated crystallizability and anti-bacterial effect, and reduced UV-transmittance characteristic.

A bionic strong nanostructured soy protein-based adhesive enabled antistatic and self-extinguishing wood-based composites

Wood composites represent one kind of sustainable functional materials for interior decoration and packaging, but their tendency to generate static electricity poses discomfort and potential fire hazards. To address this huge challenge, we herein report a strong, conductive, nanostructured formaldehyde-free soy protein-based adhesive by mixing nanocellulose and tannic acid functionalized MXene, and soy protein, which is then used to create antistatic and fire-extinguishing wood composites. The resulted soy protein-based adhesive exhibited an exceptional bonding capability due to its bionic organic-inorganic hybridized crosslinking structure. With this soy protein-based adhesive, as-prepared wood composites achieved a static flexural strength of 14.08 MPa, meeting the demanding interior use requirement. Because of the presence of both MXene and quaternary ammonium salt in the adhesive, the resultant wood composite shows an electrical resistance of 3.123 × 109 Ω·cm, satisfying the antistatic requirements for wood-based composites, and a desired self-extinguishing ability. This work offers a promising strategy to create strong nanostructured bio-adhesive, which can be used for producing multifunctional wood composites as decoration and packaging materials.

Design synthesis of melamine amino tris-methylene phosphonate modified halloysite nanotubes for epoxy resin with simultaneously improved flame retardancy, dielectric properties and mechanical performance

The development of epoxy resin (EP) with simultaneous enhancements in flame retardancy, mechanical performance, and low dielectric properties represents a significant and complex challenge. In this study, halloysite nanotubes (HNTs) were modified with melamine amino tris-methylene phosphonate (MA) to produce MA-modified HNTs (HMA), which were then integrated into EP to form EP/HMA composites. The incorporation of 1 wt% HMA significantly enhanced the flame retardancy (limit oxygen index up to 29.7%, UL-94 V-0 rating), reduced peak heat release rate by 23.4%, decreased total heat release by 11.9%, reduced total smoke production by 18.4%, and improved mechanical properties (tensile strength by 17.0%, impact strength by 61.0%) compared to pure EP. Additionally, EP/HMA showed a low dielectric constant (3.16) and a dielectric loss (0.019) at 1 GHz. This research presents a versatile strategy for creating multifunctional EP composites with high potential for applications in microelectronics, electronic packaging, and other relevant fields.

A Quantum Chemical Study on the Bonding Mechanism, Electronic Structure, and Optical Properties of Cellulose and Polyaniline Nanohybrid

A Quantum Chemical Study on the Bonding Mechanism, Electronic Structure, and Optical Properties of Cellulose and Polyaniline Nanohybrid

Facile hydrothermal synthesis of a multifunctional copper zinc tin sulfide (CZTS) nanoparticle-coated sepiolite fiber composite: structural characterization and photocatalytic properties

This work presents a facile hydrothermal synthesis method for fabricating a multifunctional composite of copper zinc tin sulfide (CZTS) nanoparticles coated onto sepiolite fibers. Morphological analysis confirms the firm attachment of approximately 10 nm CZTS nanoparticles onto the sepiolite surface. Elemental analysis verifies the presence of constituent elements from both CZTS and sepiolite, with a slight deficiency in Cu and an abundance of Zn observed. The compositional formula of CZTS in the composite is estimated as Cu1.93Zn1.05Sn0.98S4.04. Notably, the material exhibits a narrow band gap of 1.5 eV, enabling effective utilization of the entire visible light spectrum, making it promising for photocatalytic applications. BET nitrogen adsorption/desorption measurements reveal a substantial surface area of approximately 85.720 m2 /g, confirming the composite’s versatility and applicability, particularly in photocatalysis and adsorption processes. Additionally, X-ray diffraction analysis indicates reflections consistent with the crystal structures of kasterite CZTS and sepiolite, further confirming the composite’s composition. The multifunctional CZTS/Sepiolite composite demonstrates exceptional potential for simultaneous photocatalytic degradation and adsorption of organic pollutants, presenting a promising avenue for sustainable water treatment applications.

Topologically optimized flexible tricolor-shape micro-fibre arrayed film and three-dimensional tube display concurrent magnetism, luminescence and conductive aeolotropy

From the perspective of topology design, innovative devise concepts and manufacturing technologies are of great significance for manufacturing high-performance multifunctional composites. Herein, a one-dimensional tricolor-shape micro-fibre was innovatively devised and constructed via a triaxial parallel electro-spinning. As a study case and application, the unique structured [CoFe2O4/polymethylmethacrylate (PMMA)]//[polyaniline (PANI)/PMMA]//[Eu(TTA)3phen/PMMA] magnetic-conductive-luminescent multi-functionalized tricolor-shape micro-fibre arrayed film (marked as MTMAF) were fabricated by orientational arrangement of the tricolor-shape micro-fibres. Meanwhile, magnetic-conductive-luminescent multi-functional quasi tricolor-shape micro-fibre arrayed film (marked as MQMAF) and magnetic-conductive-luminescent multi-functional tricolor-shape nano-strip arrayed film (marked as MTNAF) were also fabricated by alteration of the proportions of solvents. It is further found that MTMAF has better performances than those of MTNAF and MQMAF. The tricolor-shape micro-fibre achieves the partitioning of three separate functional partitions on the microscopic-level through the elaborate topology devise and an electrospinning technology. More importantly, since magnetic, conductive, and luminescent fillings are limited in their subareas, adverse interactions among them can be effectively avoided, resulting in superior poly-functional performances. Since the intense conductive aeolotropism and multifunctionality, MTMAF can be employed as a stable micro-circuit interconnection, offering a foundation for practical applications. Red luminescence can be used to supervise whether MTMAF properly works or not in darkness. Three-dimensional tubes are constructed via crimping the MTMAF in two various modes. The high integration of zero-dimensional nanoparticles, one-dimensional micro-construction blocks, two-dimensional films and three-dimensional tubes is achieved in one material. The construction of three-dimensional tubes achieves the transformation of materials from two-dimension to three-dimension. Furthermore, a universal technique to manufacture micro-fibre/nano-strip with three micro-subareas has been established for constructing multi-functional composites, other functional fillings also can be introduced into the tricolor-shape micro-fibre/nano-strip to achieve different multi-function.

Engineering a staggered type-II Bi2WO6/WO3 heterojunction with improved photocatalytic activity in wastewater treatment

In recent years, the removal organic pollutants from wastewater by advanced oxidation processes, especially photocatalysis, has become a meaningful approach due to its eco-friendliness and low cost. Herein, staggered type-II Bi2WO6/WO3 heterojunction photocatalysts were prepared by a facile hydrothermal route and investigated by modern physicochemical methods (X-ray diffraction, scanning electron microscopy, low-temperature nitrogen adsorption-desorption, and diffuse reflectance spectroscopy). The optimized BWOW-5 photocatalyst exhibited a H2O2-assisted photocatalytic methylene blue removal efficiency of 94.1% (k = 0.01414 min−1) within 180 min under optimal reaction conditions, which is much higher than that of unmodified Bi2WO6 and WO3 due to efficient separation of the photogenerated charge carriers. The trapping experiments demonstrated that photogenerated hydroxyl radicals and holes play a key role in the photodegradation reaction. Moreover, the optimized BWOW-5 heterojunction photocatalyst exhibited excellent activity in the H2O2-assisted degradation of other pollutants, namely phenol, isoniazid, levofloxacin, and dibenzothiophene with the removal rate of 63.1, 73.6, 95.0, and 72.4%, respectively. This investigation offers a design strategy for Bi2WO6-based multifunctional photocatalytic composites with improved activity for organic pollutant degradation.

A unified hybrid micromechanical model for predicting the thermal and electrical conductivity of graphene reinforced porous and saturated cement composites

Graphene fillers have gained widespread attention as functional reinforcements for cement composites due to their excellent physical properties. The prediction of the thermal and electrical properties of graphene reinforced cement composites (GRCCs) is of great importance for developing intelligent and multifunctional civil engineering materials and structures. In this current work, a unified hybrid micromechanical model combining effective medium theory (EMT) and Mori-Tanaka-Benveniste (MTB) is developed to simultaneously predict the thermal and electrical conductivity of the GRCCs with considering pores and saturation, in which mechanisms including phonon transport, electron tunnelling and Maxwell-Wagner-Sillars (MWS) polarization are incorporated. Graphene nanoplatelets (GNPs) reinforced cement composites (GNPRCCs) samples are prepared and tested to validate the developed unified model. The results show that the electrical conductivity of the GNPRCCs is more sensitive to saturation than the thermal conductivity. When the porosity n = 0.2 and the GNP concentration is 1 wt%, the relative thermal and electrical conductivity increases by 5 % and 193 %, respectively, when the saturation index increases from 0.6 to 1. Elongated pores are more favorable for the formation of ionic networks for electrical conductivity in the saturated GNPRCCs, while spherical pores are more beneficial for heat transport. Elongated graphene fillers are preferred for enhancing both the thermal and electrical conductivity of dry and saturated GNPRCCs. The work is envisaged to provide guidelines for developing multifunctional cement composites.

Biobased, recyclable, and multi-functional high-performance composites for electromagnetic interference shielding

High-performance fiber-reinforced thermoset composites (FRTCs) are highly demanded in modern society but are challenged because they depend on nonrenewable fossil-based feedstocks, are hard to recycle after service, and lack advanced functions. Here, we report a methodology to fabricate sustainable, recyclable, high-performance, and multifunctional FRTCs from renewable feedstocks such as vanillin, glycerol triglycidyl ether, 1,10-diaminodecane, and basalt fiber. We designed a mussel-inspired approach to prepare high conductive basalt fiber (CBF), and combined the CBF with a fully biobased covalent adaptable network (CAN) based on dynamic imine bonds to produce the composites i.e., CAN/CBF laminar composites through a solvent-free method. The CAN/CBF composites showed highly reinforced mechanical properties and multiple functionalities including electromagnetic interference shielding, shape memory, and self-adhesion characters through combination in the advantages and functions of both CAN and CBF. Furthermore, we demonstrated that the CAN matrix and the reinforced CBF can be recycled separately and can be further reformed to the CAN/CBF composites due to the dynamic nature of the CAN matrix. Our study thus provides an urgently applicable approach for advanced manufacturing toward the green and circular advanced composites economy.

Portable and Flexible Hydrogel Sensor for On-Site Atrazine Assay on Agricultural Products.

There is growing attention focused toward the problems of ecological sustainability and food safety raised from the abuse of herbicides, which underscores the need for the development of a portable and reliable sensor for simple, rapid, and user-friendly on-site analysis of herbicide residues. Herein, a novel multifunctional hydrogel composite is explored to serve as a portable and flexible sensor for the facile and efficient analysis of atrazine (ATZ) residues. The hydrogel electrode is fabricated by doping graphite-phase carbon nitride (g-C3N4) into the aramid nanofiber reinforced poly(vinyl alcohol) hydrogel via a simple solution-casting procedure. Benefiting from the excellent electroactivity and large specific surface area of the solid nanoscale component, the prepared hydrogel sensor is capable of simple, rapid, and sensitive detection of ATZ with a detection limit down to 0.002 ng/mL and per test time less than 1 min. After combination with a smartphone-controlled portable electrochemical analyzer, the flexible sensor exhibited satisfactory analytical performance for the ATZ assay. We further demonstrated the applications of the sensor in the evaluation of the ATZ residues in real water and soil samples as well as the user-friendly on-site point-of-need detection of ATZ residues on various agricultural products. We envision that this flexible and portable sensor will open a new avenue on the development of next-generation analytical tools for herbicide monitoring in the environment and agricultural products.

Bone osteon-like structures: A biomimetic approach towards multiscale fiber-reinforced composite structures

Natural materials show astonishing mechanical properties, despite their rather poor building blocks. This counterintuitive behavior can be traced back to their hierarchical organization that enhances the properties of the building blocks. A classic example is bone: lightweight, stiff, strong, yet tough. This property combination is attributed particularly to the microstructure, where osteons deflect and arrest cracks. In this work, we mimic the bone microstructure with fiber-reinforced composites: we perform a numerical parametric study, by varying the layup of the osteon-like structures (OLS) and interconnecting layers representing the interstitial bone lamellae, and we manufacture and test single OLS as proof of concept. Results show the key role of OLS and interconnecting layers in deflecting and arresting cracks, whereas the combination of diverse materials affects the elastic properties. Finally, the introduction of hollow OLS, not affecting fracture toughness, might be used to expand the material functionality, paving the way toward novel multifunctional composites.

High-performance Thermoplastic-based Magnetic Composites

Magnetic polymer-based composites combine the cost-effectiveness, low density, and manufacturing flexibility of conventional polymers with the unique characteristics of magnetic powders/fillers to form multi-functional magneto polymeric composites that offer superior properties to conventional materials. At higher temperatures, magnetic properties change significantly and the particles within the magnetic powders experience sporadic motion due to the heat which causes misalignment of the magnetic domains, leading to a decrease in magnetism. Due to these adverse temperature effects, high-performance polymers such as polyetheretherketone (PEEK), polyetherimide (PEI), high-performance polyamides (HPPA), or other high-temperature thermoplastics have been considered suitable matrix for the magnetic fillers, thereby creating a much wider usage for magneto polymeric composite in applications that requires higher temperature (typically above 175°C). Thus, this review discusses the fabrication processes-injection molding, fused filament fabrication; magnetic performance, and applications of high-performance thermoplastic-based magnetic composites that can be viable for stringent engineering devices such as sensors, actuators, motors, and generators.

Design of Multi-Functional Bio-Safe Dental Resin Composites with Mineralization and Anti-Biofilm Properties.

This study aims to develop multi-functional bio-safe dental resin composites with capabilities for mineralization, high in vitro biocompatibility, and anti-biofilm properties. To address this issue, experimental resin composites consisting of UDMA/TEGDMA-based dental resins and low quantities (1.9, 3.8, and 7.7 vol%) of 45S5 bioactive glass (BAG) particles were developed. To evaluate cellular responses of resin composites, MC3T3-E1 cells were (1) exposed to the original composites extracts, (2) cultured directly on the freshly cured resin composites, or (3) cultured on preconditioned composites that have been soaked in deionized water (DI water), a cell culture medium (MEM), or a simple HEPES-containing artificial remineralization promotion (SHARP) solution for 14 days. Cell adhesion, cell viability, and cell differentiation were, respectively, assessed. In addition, the anti-biofilm properties of BAG-loaded resin composites regarding bacterial viability, biofilm thickness, and biofilm morphology, were assessed for the first time. In vitro biological results demonstrated that cell metabolic activity and ALP expression were significantly diminished when subjected to composite extracts or direct contact with the resin composites containing BAG fillers. However, after the preconditioning treatments in MEM and SHARP solutions, the biomimetic calcium phosphate minerals on 7.7 vol% BAG-loaded composites revealed unimpaired or even better cellular processes, including cell adhesion, cell proliferation, and early cell differentiation. Furthermore, resin composites with 1.9, 3.8, and 7.7 vol% BAG could not only reduce cell viability in S. mutans biofilm on the composite surface but also reduce the biofilm thickness and bacterial aggregations. This phenomenon was more evident in BAG7.7 due to the high ionic osmotic pressure and alkaline microenvironment caused by BAG dissolution. This study concludes that multi-functional bio-safe resin composites with mineralization and anti-biofilm properties can be achieved by adding low quantities of BAG into the resin system, which offers promising abilities to mineralize as well as prevent caries without sacrificing biological activity.

Nanoscale brick and mortar strategy for mechanically strong multifunctional composites with extremely high filler-loading

To achieve the best physico-chemical properties of polymer composites, the concentration of fillers should be maximized in many cases. However, at extremely high concentrations of fillers, the discontinuity of the polymer matrix results in poor mechanical properties. To overcome this problem, we propose an efficient protocol to improve the mechanical strength significantly, even at an extremely high concentration of microscale fillers (graphite flakes, 95 wt%). Since the mechanical strength of the polymer composite strongly depends on both the homogeneous distribution of the polymer matrix around microscale fillers and the adhesion between them, we increased the mechanical strength of the composite by the preparation of a hybrid filler decorated with polymer nanoparticles. The decorated polymer nanoparticles eventually turned to the matrix during hot-pressing process like a mortar between bricks. Systematic studies on the mechanical strength as well as electrical and thermal conductivities of the composites revealed that both the precisely controlled size of the polymer nanoparticles and even distribution of them on the hybrid fillers were critical variables to enhance the material's properties above. The newly developed polymer composites with superior physical properties exhibited good electromagnetic interference shielding (EMI shielding effectiveness >80 dB in X-band, thickness ∼ 1.5 mm), making them suitable as electric heaters.