Dispersion Of Multi-walled Carbon Nanotubes Research Articles

Mechanical Properties of novel hardened cement paste reinforced with Multi-Walled Carbon Nano-Tubes (MWCNTs) and Glass Fibers Nano material

To improve the mechanical and durability properties of ordinary Portland cement (OPC) mortar and paste, the incorporation of multi walled Carbon nanotubes (MWCNTs) and their dispersion procedures, functionalization, and ultra sonication have been intensively implemented. Most of the studies showed significant enhancements in the mechanical properties of OPC mortar or paste; however, others showed impairments. The recent studies regarding the implementation of MWCNTs and Glass Fibres on the mechanical properties of OPC paste and mortar were reviewed and these properties include compressive, tensile, flexural strengths, and elastic modulus. A statistical study was conducted to evaluate the mechanical properties of concrete by dispersion of MWCNT’s and Glass Fibres in the cement paste. In these composites, the percentage of MWCNTs was fixed at 0.75% by weight of cement, while the percentage of Glass Fibers was fixed at 0.25% by weight of cement. The samples were cured in tap water for 28 days at 25 + 2?C.Composite specimens were tested for compression and flexure in order to evaluate their mechanical properties such as compressive strength, flexural strength, toughness and ductility and compared with the results of plain cement control beams. The maximum deflection was found to be 0.5mm with a maximum load of 500N. The flexural strength was observed to be 1250.50 N/mm2 as per ASTM D 790 which is 20% more than the flexural strength obtained with Plain Cement+MWCNT’s and 60 to 70% more than that obtained with Plain Cement + Glass Fibres. The flexural modulus as per deflection criteria is 535.94 N/mm2 which is 10 to 20% more than that obtained of Plain Cement+MWCNT’s and Plain Cement+ Glass Fibres. The compressive strength of Plain Cement+0.75% MWCNT’s+0.25% Glass fibres was found to be 65 N/mm2 which is greater than Plain cement and Plain cement+MWCNT’s. Surface morphology by Scanning Electron microscopy of the specimens infers the clustering of glass fibres and demonstr

Low-Cost and Highly Sensitive Pressure Sensor with Mold-Printed Multi-Walled Carbon Nanotubes Dispersed in Polydimethylsiloxane.

Flexible pressure sensors with piezoresistive polymer composites can be integrated into elastomers to measure pressure changes in sealings, preemptively indicating a replacement is needed before any damage or leakage occurs. Integrating small percentages of high aspect ratio multi-walled carbon nanotubes (MWCNTs) into polymers does not significantly change its mechanical properties but highly affects its electrical properties. This research shows a pressure sensor based on homogeneous dispersed MWCNTs in polydimethylsiloxane with a high sensitivity region (0.13% kPa, 0–200 kPa) and sensitive up to 500 kPa. A new 3D-printed mold is developed to directly deposit the conductive polymer on the electrode structures, enabling sensor thicknesses as small as 100 μm.

Enhanced heavy metals removal by a novel carbon nanotubes buckypaper membrane containing a mixture of two biopolymers: Chitosan and i-carrageenan

Although existing membrane filtration technologies offer practical solutions for the removal of heavy metal ions from wastewater, there remains a great need for the realization of a membrane simultaneously possessing excellent selectivity, high permeability, and antifouling capability. Towards this end, novel buckypaper (BP) membranes were fabricated from multi-walled carbon nanotubes (MWCNTs) via vacuum filtration technique and the capability of two biopolymers (i.e. chitosan and carrageenan) to facilitate the formation of aqueous dispersions of MWCNTs was investigated alone and in combination of each other. For the first time, this study shows that the combination of BP membrane and both biopolymers (MWCNTs/chitosan-carrageenan) performs remarkably in terms of mechanical properties and high rejection of heavy metals. At an applied pressure of one bar, the removal of copper and lead reached 94% and 91%, respectively. The MWCNTs/chitosan-carrageenan membrane was also found to be mechanically robust, with a tensile strength and Young’s modulus of 30.69 ± 2.6 MPa and 3.78 ± 0.03 GPa, respectively. However, the MWCNTs/chitosan membrane showed superior water permeate flux, reaching up to 180 L/h.m2. The morphological properties and surface area (193 ± 3 to 285 ± 5 m2/g) of the three membrane types were also characterized using scanning electron microscopy and Brunauer, Emmett, and Teller analysis.

Novel collagen/GO-MWNT hybrid fibers with improved strength and toughness by dry-jet wet spinning

ABSTRACT Considering the poor mechanical properties of regenerated collagen materials, the possibility of creating stronger and tougher collagen composite materials attracts particular research interests. In this study, we report that GO (Graphene oxide)-multiwalled carbon nanotube (MWNT) nanomaterials were constructed by using GO dispersed MWNT, and the strength and toughness of collagen fibers were significantly improved by introducing GO-MWNT nanomaterials into the collagen matrix during dry-jet wet spinning that exhibits the advantage of positive stretching to the extruded fiber before coagulation. We found that the combination of GO and MWNT can enhance the dispersion of both in the collagen matrix. Due to their strong interactions, they can not only spontaneously form the GO-MWNT network but also mutually induce collagen molecules to self-assemble and form aligned fibrils microstructure in dry-jet wet spinning process and resulting hybrid fibers. The interconnected networks of orderly aligned GO and MWNT can greatly enhance the interfacial interactions by forming hydrogen bonds with collagen molecules, resulting in the synergistic enhancement of the tensile strength, toughness and thermal stability of collagen hybrid fibers. This study provided asimple and environmentally friendly pathway to generate collagen-based fiber materials with improved performances and could be suitable for amyriad of biomedical applications.

Carbon nanotubes interaction with amorphous and semi‐crystalline domains of polypropylene in melt‐mixed composites: Influence of multiwall carbon nanotubes agglomerate and their modifications

AbstractPolypropylene (PP) and multi‐walled carbon nanotubes (MWCNTs) composites were prepared by melt‐mixing with two types of MWCNTs of varying agglomerate size. Agglomerate dominated dispersion was observed in the PP matrix, wherein N‐MWCNTs exhibit a finer dispersion as compared to D‐MWCNTs. Further, MWCNTs were encapsulated by Li‐salt of 6‐amino caproic acid in various proportions along with PP‐g‐maleic anhydride in order to achieve finer MWCNTs dispersion. Thermogravimetric analysis exhibited an increase in onset of degradation temperature and higher residual weight (%) at 500 °C of PP with increased MWCNTs concentration, which suggests the formation of a thicker “interphase.” Glass transition temperature of the PP phase was increased monotonically as a function of unmodified MWCNTs concentration, which suggests a strong interfacial interaction between PP and MWCNTs. An extensive analysis was carried out with modified MWCNTs based PP composites. Moreover, MWCNTs act as a strong hetero‐nucleating agent manifesting in smaller spherulite size of PP, wherein bulk crystallization temperature is increased to ~130 °C of the PP phase at 5 wt% MWCNTs content. The influence of unmodified and modified MWCNTs on the interaction between the PP chains and MWCNTs in the amorphous phase as well as in the crystalline domains are analyzed in PP/MWCNTs composites.

Carbon-nanotube-supported POXA1b laccase and its hydrophobin chimera for oxygen reduction and picomolar phenol biosensing

The immobilization of POXA1b laccase and its hydrophobin-fused chimera was performed at pristine Multiwalled Carbon Nanotube (MWCNT) and MWCNT-modified electrodes by electrografting of a 2-diazoniumanthraquinone salt. The influence of the hydrophobin domain and the MWCNT functionalization with anthraquinone groups towards immobilization of laccase was compared by direct electrochemistry under O2 and electrochemical biosensing of phenols. The hydrophobin domain affords the stable dispersion of MWCNT in water/ethanol, while being detrimental to the direct electron transfer between POXA1b and the electrode. On the contrary, the stronger hydrophobic interactions between anthraquinone and laccase affords direct electrochemistry of POXA1b and enabled the design of a highly sensitive phenol biosensor, reaching a limit-of-detection (LOD) of 2 pM and sensitivity of 23,600 mA L mmol−1 cm−2 for catechol, and a LOD of 15 nM and sensitivity of 0.053 mA L mmol−1 cm−2 for dopamine.

Multifunctional Leather Surface Design by Using Carbon Nanotube-Based Composites.

This paper deals with original research in smart leather surface design for the development of multifunctional properties by using multi-walled carbon nanotube (MWCNT)-based nanocomposites. The conductive properties were demonstrated for both sheepskin and bovine leather surfaces for 0.5% MWCNTs in finishing nanocompositions with prospects for new material design intended for flexible electronics or multifunctional leathers. The photocatalytic properties of bovine leather surface treated with 0.5% MWCNTs were shown against an olive oil stain after visible light exposure and were attributed to reactive oxygen species generation and supported by contact angle measurements in dynamic conditions. The volatile organic compounds’ decomposition and antibacterial tests confirmed the self-cleaning experimental conclusions. Ultraviolet protection factor had excellent values for leather surfaces treated with multi-walled carbon nanotube and the fastness resistance tests showed improved performance compared to control samples. Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray photoelectron spectroscopy (XPS), and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy analysis confirmed the influence of different leather surfaces on MWCNT dispersion with an effect on nanoparticle reactivity and efficiency in self-cleaning properties. Multifunctional leather surfaces were designed and demonstrated through MWCNT-based nanocomposite use under conventional finishing conditions.

Effect of using multiwall carbon nanotube reinforced epoxy adhesive in enhancing glass fiber reinforced polymer composite through cocure manufacturing technique

AbstractThe high‐performance epoxy‐based cocure manufacturing technique has been used to join composite structures such as wings, frames, and ribs in aerospace applications. The present study aims to examine the influence of multiwall carbon nanotubes (MWCNTs) addition on mechanical and free vibrational behavior of glass fiber reinforced polymer composites fabricated through cocure manufacture technique. The experimental results revealed that the addition of 1 wt.% of MWCNTs enriched the tensile and flexural properties of cocured composites by 27.8% (344 Mpa) and 26.16% (379.12 Mpa), respectively. Shear analysis depicted that 0.25 wt.% MWCNT reinforcement significantly enhanced the shear strength of cocured lap joints by 63.8% (16.79 MPa). The scanning electron microscopy and atomic force microscopy indicated that homogenous dispersion of MWCNTs enriched the interfacial bonding, deviated the crack path, and formed uneven surfaces. A comparison between the failure mode of neat and modified adhesive demonstrated the effective presence of MWCNTs in changing the adhesive failure mode of cocured composite to cohesive. Thus, it enhanced the failure strength of cocured composites. The experimental free vibrational analysis affirmed that addition of 1 wt.% MWCNTs enhanced the fundamental natural frequency whereas, lower wt.% MWCNT addition increased the cocured composites' inherent damping due to higher‐level formation of agglomeration area in the composite. Thus, it increased the stress level and minimized the bonding between fiber and matrix.

A New Method for Dispersing Pristine Carbon Nanotubes Using Regularly Arranged S-Layer Proteins.

Homogeneous and stable dispersions of functionalized carbon nanotubes (CNTs) in aqueous solutions are imperative for a wide range of applications, especially in life and medical sciences. Various covalent and non-covalent approaches were published to separate the bundles into individual tubes. In this context, this work demonstrates the non-covalent modification and dispersion of pristine multi-walled carbon nanotubes (MWNTs) using two S-layer proteins, namely, SbpA from Lysinibacillus sphaericus CCM2177 and SbsB from Geobacillus stearothermophilus PV72/p2. Both the S-layer proteins coated the MWNTs completely. Furthermore, it was shown that SbpA can form caps at the ends of MWNTs. Reassembly experiments involving a mixture of both S-layer proteins in the same solution showed that the MWNTs were primarily coated with SbsB, whereas SbpA formed self-assembled layers. The dispersibility of the pristine nanotubes coated with SbpA was determined by zeta potential measurements (−24.4 +/− 0.6 mV, pH = 7). Finally, the SbpA-coated MWNTs were silicified with tetramethoxysilane (TMOS) using a mild biogenic approach. As expected, the thickness of the silica layer could be controlled by the reaction time and was 6.3 +/− 1.25 nm after 5 min and 25.0 +/− 5.9 nm after 15 min. Since S-layer proteins have already demonstrated their capability to bind (bio)molecules in dense packing or to act as catalytic sites in biomineralization processes, the successful coating of pristine MWNTs has great potential in the development of new materials, such as biosensor architectures.

Deep-Ultraviolet Transparent Conductive MWCNT/SiO2 Composite Thin Film Fabricated by UV Irradiation at Ambient Temperature onto Spin-Coated Molecular Precursor Film.

Deep-ultraviolet (DUV) light-transparent conductive composite thin films, consisting of dispersed multiwalled carbon nanotubes (MWCNTs) and SiO2 matrix composites, were fabricated on a quartz glass substrate. Transparent and well-adhered amorphous thin films, with a thickness of 220 nm, were obtained by weak ultraviolet (UV) irradiation (4 mW cm−2 at 254 nm) for more than 6 h at 20−40 °C onto the precursor films, which were obtained by spin coating with a mixed solution of MWCNT in water and Si(IV) complex in ethanol. The electrical resistivity of MWCNT/SiO2 composite thin film is 0.7 Ω·cm, and transmittance in the wavelength region from DUV to visible light is higher than 80%. The MWCNT/SiO2 composite thin film showed scratch resistance at pencil hardness of 8H. Importantly, the resistivity of the MWCNT/SiO2 composite thin film was maintained at the original level even after heat treatment at 500 °C for 1 h. It was observed that the heat treatment of the composite thin film improved durability against both aqueous solutions involving a strong acid (HCl) and a strong base (NaOH).

Effect of MWCNT content on the mechanical and piezoelectric properties of PVDF nanofibers

In this study, the mechanical properties and morphology of aligned and random polyvinylidene fluoride (PVDF) fibers as well as the morphology and mechanical, piezoelectric, and thermal properties of PVDF fibers with different multi-walled carbon nanotubes (MWCNT) contents were analyzed. Although electrospun piezoelectric PVDF-based nanofibers have been extensively studied for application in wearable devices, they do not have sufficient flexibility and strength for practical application. Therefore, in this study, the effects of various experimental parameters, such as MWCNT content and fiber orientation, on the mechanical and piezoelectric properties of PVDF nanofibers were investigated in depth. Scanning electron microscopy analysis revealed that the average diameter of the PVDF nanofibers decreased with an increase in degree of orientation, while transmission electron microscopy analysis revealed the uniform dispersion of MWCNTs in the PVDF nanofibers. The PVDF nanofibers containing 0.008 wt% MWCNTs exhibited an excellent tensile strength. Furthermore, Fourier transform infrared spectroscopy analysis revealed that the β-phase fraction increased with increasing MWCNT content. The thermal stability of the nanofibers increased with an increase in β-phase fraction, as evidenced by the increase in melting and initial decomposition temperatures and decrease in weight loss determined by differential scanning calorimetry and thermogravimetric analysis.

Effect of multi-wall carbon nanotubes on the flexural performance of cement based composites

In this work, multi-wall carbon nanotubes (MWCNT) are added (0–0.5 wt%) into a cement matrix to improve the flexural performance of the resulting nanocomposites. Under static testing, the compressive and flexural strengths were found to increase with MWCNT content with an optimum content of 0.2% and 0.1%, respectively, before decreasing because of dispersion problems (agglomeration). But it was observed that increasing the mixing time and adding silica fume improved the MWCNT dispersion. Under fatigue testing, similar trends were obtained with respect to MWCNT content as the maximum fatigue life was observed at 0.2%. A comparison between nano-silica and MWCNT reinforced concrete is also made showing that MWCNT provides better improvement at lower content. The MWCNT reinforced cement-based composite results were well fitted using linear regressions. Finally, a morphological analysis via scanning electron microscopy (SEM) was performed to explain the results based on the micro-mechanical mechanism of MWCNT reinforced composites.

Preparation and Characterization of High-Performance Natural Rubber Latex Composites with Sodium Methylene Bis-naphthalene Sulfonate Modified Multiwalled Carbon Nanotubes

Multiwalled carbon nanotube (MWCNT) are widely used as reinforcing fillers for rubber materials due to their excellent mechanical, thermal and electrical properties. However, the MWCNT dispersion in the rubber matrix is normally poor owing to their high aspect ratio and agglomeration characteristics. In this paper we describe our research on natural rubber latex (NRL) composites filled with noncovalent modified multiwalled carbon nanotube (MWCNT), prepared by sodium methylene bis-naphthalene sulfonate (NNO) as an anionic surfactant. The high-performance NRL/NNO/MWCNT composites were prepared by a liquid latex blending method. Transmission electron microscopy (TEM) showed the dispersion of MWCNT modified by NNO in water was significantly improved. The original MWCNT dispersion state in the water was not sufficient, with a range of small to big agglomerates. On the other hand, the entangled bundles of NNO/MWCNT were reduced in size or eliminated. The NNO's interface interaction with the MWCNT was further studied by Raman spectroscopy and thermogravimetric analysis (TGA) which indicated the NNO was capable of modifying the surface of the MWCNT. In addition, the effects of the modified MWCNT on the mechanical and dynamic mechanical properties of rubber composites were also characterized. NNO was absorbed on the surfaces of the MWCNT through noncovalent action, which enabled the MWCNT to more evenly disperse in the rubber matrix, forming a good filler structure in the NRL and improving their composites mechanical properties. We note our approach is an easy and eco-friendly method to enhance the NRL composites.

Multiwall carbon nanotubes (MWCNTs) dispersion & mechanical effects in OPC mortar & paste: A review

The incorporation of multiwalled Carbon nanotubes (MWCNTs) and their dispersion procedures such as the use of surfactant agents, functionalization, and ultrasonication have been intensively implemented to improve the mechanical and durability properties of ordinary Portland cement (OPC) mortar and paste. Many studies stated significant enhancements in the mechanical properties of OPC mortar or paste; however, others showed impairments. The review observed the preparation techniques for dispersion and mixing MWCNTs with dry materials such as cement and sand. The recent studies regarding the implementation of MWCNTs on the mechanical properties of OPC paste and mortar were reviewed. These properties include compressive, tensile, flexural strengths, and elastic modulus. A statistical approach was conducted to observe the effects of the MWCNTs' amendment on the mechanical properties of Portland cement paste and mortar. The results showed that there is no consistent preparation technique for the dispersion of MWCNT. The ultrasonication, used in most studies either alone or as a surfactant combination, was the most effective technique for dispersion when the sonication duration was between 20 and 45 min. The statistical mechanical property observations revealed that the majority of compressive strength enhancements were below 40% (approximately 91% of the data) regardless of the MWCNTs %. The improvement in strength below 40% was 74% of the data for tensile/flexural strength of mortar. For cement paste, 50% of the enhancements were equal to or below a 40% increase. However, some studies showed impairments in the mechanical properties of OPC composites when MWCNTs were incorporated. Most reduction in compressive strength was below 40% compared to mortar and cement with 0% MWCNTs.

Well‐dispersed poly(ether‐ether‐ketone)/multi‐walled carbon nanotube nanocomposites prepared via a simple solution mixing approach

AbstractIncorporation of reinforcing nanoparticles, like multi‐walled carbon nanotubes (MWCNTs), in a polymer matrix is an effective way to enhance mechanical properties and expand structural applications of engineering polymers such as poly(ether‐ether‐ketone) (PEEK). Good dispersion of MWCNTs is critical for achieving optimal properties. In this work, a simple solution mixing approach was utilized to prepare PEEK nanocomposites reinforced with MWCNTs. By direct mixing of PEEK/dichloroacetic acid solution and MWCNT/N‐methyl‐2‐pyrrolidone solution, PEEK nanocomposites with individually dispersed MWCNTs were prepared. A PEEK wrapping of MWCNT mechanism is proposed to explain why this simple solution mixing approach resulted in such a good dispersion. Thermal stability of PEEK is not affected but crystallization is impeded due to the confinement effect of well‐dispersed MWCNTs. Young's modulus is increased by ca 20% while coefficient of thermal expansion above the glass transition temperature is decreased by ca 30% with only 1.5 wt% MWCNT loading in PEEK, which is critical for a variety of high‐temperature applications. © 2021 Society of Industrial Chemistry.

Electromagnetic interference shielding performance of carbon nanostructure reinforced, 3D printed polymer composites

We report the electrical, mechanical and electromagnetic interference (EMI) shielding performance of polypropylene random copolymer (PPR)/multi-wall carbon nanotube (MWCNT) nanocomposites enabled via customized fused filament fabrication process. The electro-conductive PPR/MWCNT filament feedstocks were fabricated via shear-induced melt-blending process that allows 3D printing of nanoengineered composites even at higher MWCNT loading (up to 8 wt%). The uniform dispersion of MWCNTs in PPR matrix confirmed via Raman spectroscopy and scanning electron microscopy facilitates better mechanical, electrical and EMI shielding performance. The results furthermore show enhanced shielding properties and higher attenuation for the nanocomposites printed in 90° direction (~ − 37 dB for 8 wt% MWCNT loading). Effective interfacial adhesion between the beads with lesser extent of voids (confirmed via micro-computed tomography) endorsed low transmission loss in nanocomposites printed in 90° direction compared to samples printed in 0° direction. Surface architected structure (frustum shape) reveals higher specific shielding effectiveness (maximum ~ − 40 dBg−1cm3, + 38%) over the plain structure. The realization of excellent shielding effectiveness (~ 99.9% attenuation) of additive manufacturing-enabled PPR/MWCNT nanocomposites demonstrates their potential for lightweight and strong EMI shields.Graphical

Fabrication of MWCNTs reinforced iron metal matrix composite by powder metallurgy: Effects of wet and dry milling

The present paper reports the effects of wet and dry milling on the phase transformation, microstructure evolution and mechanical properties during fabrication of iron based composite reinforced with 21 vol% MWCNTs (multi-walled carbon nanotubes) by using high energy planetary milling followed by pressureless conventional sintering. A powder mixture containing Fe-21 vol% MWCNTs is milled in both wet (toluene) and dry (argon atmosphere) condition for 12 h in a dual drive planetary mill. The change in particle size, morphology, evolution of phases and also dispersion of MWCNTs into iron matrix during wet and dry milling are highlighted. It has been observed that wet milled powders are fine (average size d50 = 10 µm) and exhibit narrow size distribution whereas dry milled powders (average size d50 = 90 µm) show wide range binomial distribution. The maximum hardness of 450 VHN and compressive strength of 525 MPa are achieved for the wet milled composite powders sintered at 1300 °C for 2 h.

Development of Conductive Gelatine-Methacrylate Inks for Two-Photon Polymerisation.

Conductive hydrogel-based materials are attracting considerable interest for bioelectronic applications due to their ability to act as more compatible soft interfaces between biological and electrical systems. Despite significant advances that are being achieved in the manufacture of hydrogels, precise control over the topographies and architectures remains challenging. In this work, we present for the first time a strategy to manufacture structures with resolutions in the micro-/nanoscale based on hydrogels with enhanced electrical properties. Gelatine methacrylate (GelMa)-based inks were formulated for two-photon polymerisation (2PP). The electrical properties of this material were improved, compared to pristine GelMa, by dispersion of multi-walled carbon nanotubes (MWCNTs) acting as conductive nanofillers, which was confirmed by electrochemical impedance spectroscopy and cyclic voltammetry. This material was also confirmed to support human induced pluripotent stem cell-derived cardiomyocyte (hPSC-CMs) viability and growth. Ultra-thin film structures of 10 µm thickness and scaffolds were manufactured by 2PP, demonstrating the potential of this method in areas spanning tissue engineering and bioelectronics. Though further developments in the instrumentation are required to manufacture more complex structures, this work presents an innovative approach to the manufacture of conductive hydrogels in extremely low resolution.

Damage Detection of Carbon Nanotube Cementitious Composites Using Thermal and Electrical Resistance Properties

This study aimed to detect damage based on thermal and electrical resistance properties by fabricating composites in which multi-walled carbon nanotubes (MWCNTs) and cement-based materials are mixed. The experimental parameters used were the cement-based material type, MWCNT concentration, curing period, and presence of damage. The experimental results showed that damage in cement paste can be detected using the heat property at every MWCNT concentration, and damage in mortar can be detected at MWCNT concentrations of ≤0.25 wt%. However, damage to concrete is difficult to detect using the heat property. Damage to cement paste, mortar, and concrete can be detected at every concentration using the electrical resistance property. Furthermore, field emission scanning electron microscopy (FE-SEM) results revealed uniformly dispersed MWCNTs inside the composites without agglomeration or the formation of carbon nanotube (CNT) networks.

Surface modification of YS-20 with polydopamine for improving the tribological properties of polyimide composites

Recently, great effort has been devoted to prepare various reinforce fillers to improve polymer performances, but ignoring the importance of raw polymer powders which are indispensable parts of hot-pressed polymer composites. Herein, we engineer raw polyimide (PI) powders with the assistance of polydopamine (PDA) in aqueous solutions. After the modification, polymer powders change from hydrophobic to hydrophilic, which makes it is possible to further modification of polymer powders in liquid phase. During the curing process of modified polymer powders, the partial dehydration of the catechol groups and crosslinking of PDA via C-O-C bonds are confirmed. Based on the features of PDA, a non-destructive mixing method is utilized to realize homogeneous dispersion of multi-walled carbon nanotubes (MWCNTs) in polymer matrix. In comparison with ball milling method, this way can preserve the integrated innate structure of MWCNTs effectively. Besides, by taking full advantage of the reducing and metal-coordination capability of PDA, Cu2+ is successfully loaded onto the surfaces of polymer powders. The related characterizations demonstrate that Cu2+in situ converts to metallic copper rather than copper oxide during the hot pressing process. The tribological properties of corresponding polymer composites are also studied. These results indicate that modifying polymer powders with PDA is multi-profit and presents practical application prospect.