Grafted Carbon Nanotubes Research Articles

Research Progress on the Impact Resistance of Basalt Fiber-Reinforced Polymer Composites

Abstract Basalt fibers exhibit excellent properties and have diverse applications. This paper thoroughly investigates the impact resistance of polymer matrix composites reinforced by basalt fibers and analyzes the failure mechanisms during impact, including micro-deformation, delamination, and fiber fracture. Basalt fiber-reinforced resin matrix composites consist of a reinforcement phase, a matrix phase, and an interface phase. To strengthen the material’s resistance to impacts, various approaches have been explored, including optimizing the matrix resin (e.g., selecting vinyl resin and toughening treatments), optimizing the reinforcement phase (e.g., fiber hybridization, morphology optimization, and interlayer hybridization), and improving the interface phase (e.g., coupling agent modification and carbon nanotube grafting). These optimization measures can significantly enhance the impact resistance of basalt fiber-reinforced polymer materials under low-velocity impact loads. Under high-velocity impact loads, increasing the number of laminate layers or employing three-dimensional weaving techniques can significantly improve the material’s impact resistance. These research findings aim to provide a theoretical foundation and practical references for the application of basalt fiber-reinforced polymer materials within the domain of impact resistance.

Functional Interfaces: Chemical Grafting of Starch onto Multiwalled Carbon Nanotubes for Biomedical Applications

This study provides a detailed investigation into the chemical grafting of multiwalled carbon nanotubes (MWNTs) with starch at various concentrations and reaction temperatures. Utilizing Raman spectroscopy and Fourier-transform infrared spectroscopy (FTIR), we identified structural defects in the MWNTs and characterized the functional groups introduced by the grafting process. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) deepened our understanding of the interactions between starch and MWNTs, and quantified the polysaccharide content. Transmission electron microscopy (TEM) unveiled nanostructures arising from the interplay between MWNTs and starch molecules. Our findings highlight the potential of starch-grafted MWNTs for applications in nanotechnology and nanomedicine, positioning them as a promising material for targeted drug delivery and tissue engineering, aligning with Nano LIFE’s multidisciplinary goals in life sciences, nanosciences and nanomedicine.

Preparation of boron nitride grafted carbon nanotubes for enhancing the tribological performance of poly (ether ether ketone) composite

The impendency demands for the excellent wear resistance materials are blossoming as the increasing possibilities of complex application environments. Poly (ether ether ketone) (PEEK) is regarded as a promising candidate for its outstanding mechanical properties and remarkable thermal stability. Herein, a feasible strategy is proposed to obtain hydroxylated boron nitride (BNO) grafted carbon nanotubes (CNTs). Then, introduce the as- prepared reinforcements into the matrix to fabricate the BNO-CNT/PEEK composites. The incorporation of BNO-CNT significantly increases the nano- hardness and elastic modulus of composites. The interfacial interactions between components promote the synergistic enhancement effects, ultimately increasing the thermal conductivity and tribological performance of composites. The coefficient of friction and wear rate remarkably decline with the introduction of 3 wt% BNO-CNT. Thus, this facile approach demonstrates its potential for improving tribological properties in PEEK composites.

Surface Grafting of Magnetic Carbon Nanotubes and Their Vertical Alignment in PVDF Asymmetric Ultrafiltration Membranes for Fast Nanochannel Construction

The application of carbon nanotubes (CNTs) in water treatment membranes can increase the permeability and selectivity of the membranes. However, traditional CNTs are usually affected by van der Waals forces, which makes them prone to agglomerate in polymer membranes, and their non-directional arrangement in the membranes limits their transport efficiency as water channels in the membranes. In this paper, a reversible addition-fragmentation chain transfer (RAFT) polymerization method was used to synthesize propargyl methacrylate - random copolymerization - poly (ethylene glycol) methacrylate - block - polymethyl methacrylate [P(PgMA-r-PEGMA) -b-PMMA]. The P(PgMA-r-PEGMA)-b-PMMA grafting rate was 60.4% on the surface of magnetic sulfhydryl functionalized carbon nanotubes (mCNTs-SH) by click-reaction grafting. Poly (vinylidene fluoride) (PVDF)/CNTs composite ultrafiltration membranes were prepared using vapor-induced phase separation (VIPS) combined with magnetic field arraying. When the mCNTs-g-P(PgMA-r-PEGMA)-b-PMMA were vertically aligned in the PVDF membrane through a magnetic field, the effective construction of the vertical nanochannels was realized, and an increased purified water flux from 25.6 LMH to 35.8 LMH, with the composite ultrafiltration membranes was obtained. In addition, the membranes also showed excellent hydrophilicity, mechanical properties, and polyethylene glycol 1200 (PEG1200) rejection. The water contact angle was reduced from 105° to 79°, the rejection of PEG1200 was increased from 44% to 91% of the 0.5 g/L PEG aqueous solutions, and excellent mechanical properties (tensile strengthes up to 9.3 MPa) were achieved. By designing the interface structure of the CNTs and studying the orientation of the CNTs in PVDF membranes, this work provides a new research idea for the field of water treatment ultrafiltration membranes.

Improving interfacial and mechanical properties of epoxy resin composites by chemical grafting modification of poly‐ether‐ether‐ketone microparticles with carbon nanotubes

AbstractThe research on epoxy resin toughening is of great significance for its application in aerospace, automotive industries, marine vessels, and other fields. Poly‐ether‐ether‐ketone (PEEK) and carbon nanotubes (CNTs) are ideal candidates for epoxy reinforcement in thermoplastic materials and nanomaterials, respectively. In this study, CNTs were first chemically grafted onto PEEK microparticles using an amidation reaction. These modified hybrid materials were then utilized as fillers in epoxy composites to enhance their strength and toughness. The changes in sample structure, composition, thermal properties, and wettability during the chemical grafting process between CNTs and PEEK were systematically studied. In comparison to pure PEEK, the surface energy of CNTs‐PEEK hybrid materials increased by 11.58% due to CNTs grafting, resulting in improved wettability and enhanced interface bonding between PEEK and the epoxy matrix. Concurrently, the CNTs‐PEEK/epoxy composites exhibited significant enhancements, with the highest tensile strength, tensile elongation at break, flexural strength, and flexural modulus increased by 31.00%, 30.84%, 121.43%, and 23.22%, respectively. The positive reinforcement effect of modified CNTs‐PEEK fillers in epoxy composites and the exploration of CNTs grafting onto PEEK extend the potential applications of epoxy composites.Highlights CNTs were bonded to PEEK via an amidation reaction by the chemical grafting method. CNTs‐PEEK have an 11.58% increase in surface energy compared to pure PEEK. CNTs‐PEEK/epoxy composites showed improved mechanical properties. The enhancement mechanisms of CNTs‐PEEK/epoxy composites were analyzed.

The effect of CNT grafting on the mechanical properties of the UHMWPE fiber/HDPE composite

In order to improve the mechanical properties of the ultra‐high molecular weight polyethylene (UHMWPE) fiber‐reinforced high‐density polyethylene (HDPE) composite, carbon nanotube (CNT) was grafted on the UHMWPE fiber. The UHMWPE fiber/HDPE composite was prepared by injection molding process, and the effects of CNT contents on the mechanical properties of composite materials were studied. The results show that the mass fraction of CNT will significantly affect the mechanical properties of the composite. When the CNT content is 4 wt%, the tensile strength, tensile modulus, flexural strength, flexural modulus, and impact strength of the UHMWPE fiber/treated CNT/HDPE composite increased compared to the UHMWPE fiber/CNT/HDPE composite and UHMWPE fiber/HDPE composite. When the CNT content is 4 wt%, the above‐mentioned performance is the best. Pull‐out and fracture, bridging effect, and crack deflection effect are the main mechanisms of CNTs in UHMWPE fiber/HDPE composites. This study provides new insights into the interface design of UHMWPE fiber/HDPE composites and paves the way for their further development.

Carbon nanotubes grafting aminated epoxy resin with improved elasticity and surface adhesion for enhanced thermal management performance

It is a great challenge to develop thermal interface materials that enable fast heat transfer between the surface of microelectronic materials and heat sinks. In this paper, multi-walled carbon nanotube/epoxy composites (EP-NH2-x) were synthesized by amidation reaction using aminated epoxy resin as matrix and carboxylated multi-walled carbon nanotubes. EP-NH2-x can reduce the interfacial thermal resistance and the promotion of phonon conduction through the chemical bonding connection between the resin and the carbon nanotubes, which will in turn improve the thermal conductivity of the composites. The thermal conductivity of EP-NH2-10 reaches 0.531 W·m−1·K−1 at a and has good variable temperature cycling stability, internal elasticity and surface adhesion. This work highlights the potential application of carbon materials to improve the thermal conductivity of epoxy resins.

Study of Mechanical and Surface Properties of Multi-Walled Carbon Nanotube Grafted Flax Fiber and Its Composites

ABSTRACT The modification method of grafting multi-walled carbon nanotubes (MWCNT, abbreviated as CNT in this paper) on the surface of flax fibers was investigated, i.e. CNT were grafted onto the surface of flax fibers by silane coupling agent under the action of ultrasonic waves to form covalent bonding. The tensile strength of CNT grafted flax fiber is 22% higher than that of untreated flax fiber monofilament. The tensile strength of FFRP composites after CNT grafting treatment increased by 14.2%; however, the tensile modulus of single fiber and composites did not show a significant increase, the interfacial shear strength of the fiber-resin is 38.3% higher than that of untreated filament. The improvement of the contact angle after grafting was investigated by observing the surface morphology, and the surface of flax filament was characterized by scanning electron microscopy and atomic force microscopy. Also the elemental changes of the flax single fiber surface before and after the treatment were analyzed using X-ray photoelectron spectroscopy. The results showed that the tensile strength of flax single fibers, its composites, and interfacial shear strength of fiber-matrix was improved after CNT grafting treatment but the increase of modulus was not obvious.

Carbon-nanotube-grafted glass-fiber-reinforced composites: Synthesis and mechanical properties

Glass fibers (GFs) are commonly used as reinforcements for advanced polymer composites. To improve the interfacial shear properties and mechanical properties of GF-reinforced composites (GFRPs), carbon nanotubes (CNTs) are directly grafted onto GFs using chemical vapor deposition (CVD). However, this process requires high temperatures, which causes thermal degradation of GFs, deteriorating their mechanical properties. In this study, a low-temperature CNT-grafting process was investigated using a bimetallic catalyst introduced onto a GF fiber surface via precursor solutions. The mechanical properties of the CNT-grafted GFs fabricated at different CVD temperatures were evaluated; they consistently showed low tensile strengths at temperatures above 400 °C. Subsequently, various CNT-grafted GFRPs were manufactured, and their mechanical properties were characterized. Interestingly, the flexural strengths of the composites increased with maintained tensile strength, despite a deterioration of the CNT-grafted GF reinforcements due to the CVD process. This could be attributed to the improved interfacial shear strength (IFSS) of the CNT-grafted GFs at the fiber level, and the enhanced compressive strength and interlaminar shear strength (ILSS) of CNT-grafted GFRPs at the composite level. Considering the properties of GF through CVD processes, particularly in relation to temperature, and factors such as IFSS, ILSS, tensile, compressive and flexural properties of composite materials, grafting CNTs on GF via a CVD system demonstrated its highest optimality at 450 °C.

Fabrication of molecularly imprinted carbon nanotubes integrating ionic liquids for efficient detection of perfluoroalkyl carboxylic acid in environmental water

It is extremely significant while challenging to accurately detect low-levels of perfluoroalkyl carboxylic acid compounds (PFCAs) in environmental water. Herein, adopting perfluorotetradecanoic acid as the dummy template, selective molecularly imprinted composites (CNTs@ILs@MIPs) grafted carbon nanotubes integrating hydrophilic ionic liquids were successfully prepared via surface imprinting and dummy-template imprinting techniques. The obtained CNTs@ILs@MIPs were applied as selective extraction adsorbent for specifically extract PFCAs in environmental water coupled with gas chromatography-mass spectrometry quantification. Detailed studies were conducted on the main preparation parameters and extraction conditions. The CNTs@ILs@MIPs displayed excellent adsorptivity, and the established method exhibited low LODs (0.60–1.64 ng L−1), wide linearity with R2 above 0.9994, and satisfactory adsorption recoveries (80.5–112.5%) for seven PFCAs. This proposed method provides a new applicable approach for the detection of targeted pollutants in environmental water by utilizing the high affinity and recognition ability of molecularly imprinted carbon nanotube functional materials modified with ionic liquids.

Constructing ‘bayberry shape’ structure on HGMs surface using CNTs to enhance the mechanical properties of HGMs/epoxy composites

The lightweight composites, composed of epoxy resin (EP) and hollow glass microspheres (HGMs), have been widely applied in marine buoyancy materials, insulation for marine pipelines, and aerospace. However, achieving lower density often requires a significant addition of HGMs, leading to a compromise in mechanical properties. To address this problem, this paper proposes a method to enhance the mechanical properties of HGMs/EP composites without altering the HGMs content. Here, the ‘bayberry shape’ structure of HGMs was achieved by chemically grafting carbon nanotubes (CNTs) onto their surface through an esterification reaction. Subsequently, a lightweight CNTs-HGMs/EP composite with improved strength was fabricated using these ‘bayberry’ HGMs as fillers and EP as the matrix. The effect of different grafted-CNTs content on HGMs' surface on the mechanical properties of CNTs-HGMs/EP composites, along with the enhancement mechanism, were systematically analyzed. The tensile strength, flexural strength and compressive strength of CNTs-HGMs/EP composites demonstrated remarkable increases of 39.14%, 21.78% and 17.87%, respectively, compared to pure HGMs/EP composites. Our results demonstrate that surface modification of HGMs could significantly improved the mechanical properties of HGMs/EP composites without affecting their density. Moreover, this method was characterized by its simplicity in operation and batch preparation, which holds great significance for the efficient production of lightweight composites.

Spaced-Confined Janus Engineering Enables Controlled Ion Transport Channels and Accelerated Kinetics for Secondary Ion Batteries.

The large grain boundary resistance between different components of the anode electrode easily leads to the low ion transport efficiency and poor electrochemical performance of lithium-/sodium-ion batteries (LIBs/SIBs). To address the issue, a Janus heterointerface with a Mott-Schottky structure is proposed to optimize the interface atomic structure, weaken interatomic resistance, and improve ion transport kinetics. Herein, Janus Co/Co2P@carbon-nanotubes@core-shell (Janus Co/Co2P@CNT-CS) refined urchin-like architecture derived from metal-organic frameworks is reported via a coating-phosphating process, where the Janus Co/Co2P heterointerface nanoparticles are confined in carbon nanotubes and a core-shell polyhedron. Such a Janus Co/Co2P heterointerface shows the strong built-in electric field, facilitating the controllable ion transport channels and the high ion transport efficiency. The Janus Co/Co2P@CNT-CS refined urchin-like architecture composed of a core-shell structure and the grafting carbon nanotubes enhances the structure stability and electronic conductivity. Benefiting from the spaced-confined Janus heterointerface engineering and synergistic effects between the core-shell structure and the grafting carbon nanotubes, the Janus Co/Co2P@CNT-CS refined urchin-like architecture demonstrates the fast ion transport rate and excellent pseudocapacitance performance for LIBs/SIBs. In this case, the Janus Co/Co2P@CNT-CS refined urchin-like architecture shows high specific capacities of 709 mA h g-1 (200 cycles) and 203 mA h g-1 (300 cycles) at a current density of 500 mA g-1 for LIBs/SIBs, respectively.

Facile fabrication of bismuth vanadate grafted carbon nanotubes composite for enhanced oxygen evolution reaction

The increasing demand of maintainable energy boosts researchers to develop reliable electrocatalysts for enhanced water splitting mechanisms. All thesynthesized materials, including CNTs, BiVO4, and BiVO4/CNTs, were characterized utilizing a variety of methodologies to assist the structural, configurational, morphological, and topographical investigations. This work aims to create unique BiVO4/CNTs nanocomposite, which may have higher electrocatalytic activity then previous materials (81 mV dec−1 tafel slope and overpotential of 237 mV at 10 mAcm−2). The composite exhibits notable qualities, including extended stability lasting up to 100 h, a substantial electrochemically active surface area (ECSA) of 586.5 cm2, minimal charge transfer resistance (Rct) of 1.3 Ω, a low onset potential, a reasonably reduced overpotential, and a relatively modest Tafel slope. The synergistic interaction between CNTs and BiVO4 is responsible for electrocatalyst's exceptional catalytic efficiency and unique stability for 100-hour retaining both morphological and structural features, showcasing structural integrity of BiVO4/CNTs nano-composite. The objective of this research is to split water into its componentmolecules using a nano-composite made, and may also useful for future applications.

Preparation of CNTs/SCF reinforcement using multiple continuous surface treatments to achieve synergistic improvement of epoxy resin-based composites interfacial properties: Towards industrial production of carbon fiber surface treatment

The silane/maleimide co-modified waterborne polyurethane (WPU-M-S) sizing agent and furan-functionalized carbon nanotubes (CNTs-FA) were prepared through chemical modification method. The continuous grafting of carbon nanotubes (CNTs) was realized on the carbon fiber surface by multiple continuous surface treatments, including electrochemical anodizing (EAO), sizing, and chemical grafting of CNTs. The stable physical and chemical connection between carbon fiber, sizing agent, and resin was constructed through the preparation of CNTs/SCF reinforcement. The results of different surface treatment processes such as ultrasound and CNTs grafting process were contrastively studied in terms of surface morphology, microstructure, and mechanical properties. It is reflected that carbon fiber grafted with CNTs-FA (CNTs/SCF) that were prepared by ultrasound assisted chemical grafting provide optimal wettability and interfacial performance. The interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of CNTs/SCF reinforced epoxy resin composites are 115.37 % and 93.91 % higher than those of the untreated carbon fiber (UCF), respectively. The synergistic improvement mechanism of reinforcement on carbon fiber reinforced epoxy resin composites interfacial properties was proposed. This research provides a multiple continuous surface treatment technology that matches the industrial production of carbon fiber to prepare CNTs/SCF reinforcement.

Transparent Oil-Water Separating Hydrophobic Sponge Prepared from a Pickering High Internal Phase Emulsion Stabilized by Octadecyltrichlorosilane Grafting Carbon Nanotubes.

Increasingly, oil spills and industrial discharges are wreaking havoc on the water environment; in order to efficiently separate oil and water from sewage containing oil or organic solvents, a novel porous polymer (P(EHA-co-BA)) was prepared by Pickering high internal phase emulsion (HIPE) template method. To obtain polyHIPE with better oil/water separation capacities, octadecyltrichlorosilane (OTS)-modified carbon nanotubes (CNTs) and surfactants were used as costabilizers for HIPE, which improved the stability of HIPE as well as the mechanical properties and the separation efficiency of polyHIPE. In the presence of 1 wt % OTS-CNT adding in the oil phase, 1%OTS-CNT polyHIPE has high porosity (92.21%), favorable hydrophobicity (a water contact angle of 128°), and excellent mechanical properties. As a result, 1%OTS-CNT polyHIPE has high absorption of oils and oily solvents, e.g., dichloromethane up to 36 g/g, and maintains an absorption efficiency of >97% after 20 reapplications. In the formulation of polyHIPE, cinnamaldehyde (CA) has been added to provide superior antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). It appears that the novel polyHIPE proposed in this work is a reusable antibacterial porous polymer with promising applications for oil-water separation.

A facile strategy to prepare boron nitride grafted carbon nanotubes coating for CF/ PEEK composites interfacial enhancement

Due to the inertness of carbon fiber (CF) and poly (ether ether ketone) (PEEK), the relatively weak interface is a constantly issue that hinders the application of CF/PEEK composites. Herein, a facile approach is proposed to graft carbon nanotubes (CNTs) onto hydroxylated boron nitride (BNO). The obtained BNO-CNT, along with polyetherimide (PEI) is used to prepare the sizing agents, coating the CF surface. The introduction of BNO-CNT/PEI sizing agents provides abundant functional-groups, generating hydrogen bonds and π-π interaction at interface. Moreover, the surface roughness and mechanical interlocking are improved due to the existence of sizing agents. These synergistic effects contribute to an enhanced interfacial and mechanical properties. This feasible and effective method exhibits its great potential for fabricating high-performance CF/PEEK composites.

Preparation of the urchin-like structured Ti3C2@CNTs for high-performance lithium storage and microwave absorbers

Two-dimensional (2D) MXene-based materials are gained significant attention as a prospective anode in lithium-ion batteries (LIBs) due to their superior metallic conductivity, high volumetric capacitance, and thermal stability. However, the unsatisfactory electrochemical performance of MXene-based anodes essentially restricts their practical use attributed to the prevalent interlayer stacking. The urchin-like Ti3C2 @CNTs involve grafting carbon nanotubes (CNTs) onto the 3D hollow MXene via catalytic growth could promise to overcome this obstacle. As conductive bridges, the CNTs further expedite the exchange of charges at the interface, resulting in improved electrochemical kinetics of the composite, which exhibits a high specific capacity of 286.2 mA h g−1 at 1 A g−1 after 2000 cycles. Beneficial from the well-designed architecture, outstanding microwave absorption was achieved with the optimal reflection loss of −48.1 dB covering the C band. This study proposed a practical strategy for fabricating the Ti3C2 @CNTs composite in high-performance lithium-ion batteries and microwave absorbers.

Observation of High Magnetic Bistability in Lanthanide (Ln = Gd, Tb and Dy)-Grafted Carbon Nanotube Hybrid Molecular System.

There is an immense research interest in molecular hybrid materials posing novel magnetic properties for usage in spintronic devices and quantum technological applications. Although grafting magnetic molecules onto carbon nanotubes (CNTs) is nontrivial, there is a need to explore their single molecule magnetic (SMM) properties post-grafting to a greater degree. Here, we report a one-step chemical approach for lanthanide-EDTA (Ln = GdIII, 1; TbIII, 2 and DyIII, 3) chelate synthesis and their effective grafting onto MWCNT surfaces with high magnetic bistability retention. The magnetic anisotropy of an Ln-CNT hybrid molecular system by replacing the central ions in the hybrid complex was studied and it was found that system 1 exhibited a magnetization reversal from positive to negative values at 70 K with quasi-anti-ferromagnetic ordering, 2 showed diamagnetism to quasi-ferromagnetism and 3 displayed anti-ferromagnetic ordering as the temperature was lowered at an applied field of 200 Oe. A further analysis of magnetization (M) vs. field (H) revealed 1 displaying superparamagnetic behavior, and 2 and 3 displaying smooth hysteresis loops with zero-field slow magnetic relaxation. The present work highlights the importance of the selection of lanthanide ions in designing SMM-CNT hybrid molecular systems with multi-functionalities for building spin valves, molecular transistors, switches, etc.

Telecom Band Single-Photon Source Using a Grafted Carbon Nanotube Coupled to a Fiber Fabry–Perot Cavity in the Purcell Regime

Telecom Band Single-Photon Source Using a Grafted Carbon Nanotube Coupled to a Fiber Fabry–Perot Cavity in the Purcell Regime

Interfacial Enhancement by CNTs Grafting towards High-Performance Mechanical Properties of Carbon Fiber-Reinforced Epoxy Composites.

The problem of interfacial interaction between carbon fiber (CF) and the matrix is the key to the failure of CF-reinforced plastic (CFRP). A general strategy to enhance interfacial connections is to create covalent bonds between the components, but this usually reduces the toughness of the composite material, which in turn limits the range of applications of the composite. In this study, carbon nanotubes (CNTs) were grafted onto the CF surface using the molecular layer bridging effect of the dual coupling agent to prepare multi-scale reinforcements, which significantly improved the roughness and chemical activity of the CF surface. By introducing a transition layer structure between the carbon fibers and the epoxy resin matrix to moderate the large modulus and scale differences between them, the interfacial interaction was improved while enhancing the strength and toughness of CFRP. We used amine-cured bisphenol A-based epoxy resin (E44) as the matrix resin and prepared the composites by the hand-paste method and performed tensile tests on the prepared composites, which showed that, compared with the original CF-reinforced composites, the modified composites showed an increase in tensile strength, Young's modulus and elongation at break by 40.5%, 66.3% and 41.9%, respectively.