Carbon Nanohorns Research Articles

Xerogel synthesis from carbon materials and glue inspired by Japanese-solid-calligraphy ink

Abstract Japanese-solid-calligraphy ink is a xerogel made by mixing soot and glue followed by molding and drying. Herein, we prepare xerogels from glue and 1 or 2 carbon materials (fullerene C60, multiwalled and single-walled carbon nanotubes, nanodiamonds, graphite, graphene, and carbon nanohorns) and characterize their surface morphology, indentation hardness, surface resistivity, and other physical properties. Our ecofriendly and simple synthesis does not require special equipment and affords xerogels holding promise as electrode materials.

Facile constructing core-shell F–CIP@O/N-SWCNHs composites for high-performance microwave absorption and anti-corrosion

The development of electromagnetic wave-absorbing materials (EWAMs) with good environmental adaptability has emerged as a focal point of research in the realm of electromagnetic protection. Herein, a core-shell structure composite EWAMs, in which flake carbonyl iron powders and O, N co-doped single-walled carbon nanohorns are respectively a core and a shell (F–CIP@O/N-SWCNHs), has been prepared by a simple electrostatic adsorption method. The high-shape anisotropy of the F–CIP core exhibits strong specific saturation magnetization (160.47 emu/g) and excellent magnetic loss capacity. The tunable O/N-SWCNHs shell effectively enhances the dielectric properties and improves impedance matching, while the oxygen and nitrogen doping strengthens the dipole polarization. The surface protection provided by O/N-SWCNHs imparts favorable corrosion resistance and anti-oxidation properties to the F-CIP@O/N-SWCNHs. Moreover, F–CIP@O/N-SWCNHs exhibit excellent wave absorption performance. When the sample thickness is 1.53 mm, the minimum reflection loss reaches −74.8 dB. This study provides a feasible approach for the preparation of efficient EWAMs with strong environmental adaptability for the practical application of composite-absorbing materials.

Calcium-mediated zoledronate loading onto carbon nanohorns.

Previously, we showed that the anti-osteoclast effect of zoledronate (ZOL), a type of bisphosphonate, is enhanced when it is used as a nanocomposite comprising ZOL, an "oxidized single-walled carbon nanohorn (OxCNH) with a spherical shape" and calcium phosphate (CaP). This nanocomposite, termed OxCNH-CaP-ZOL, is a potential therapeutic agent for patients with bone fragility associated with metastatic bone cancer. Because OxCNH-CaP-ZOL contains by-products that comprise CaP-ZOL nanocomposites, the aim of this study was to prepare more sophisticated nanocomposites lacking such by-products; it was achieved by reducing the availability of calcium and phosphate ions during the preparation process. In this new nanocomposite, ZOL loading onto OxCNH was mediated by Ca, and therefore it is referred to as OxCNH-Ca-ZOL. Because the amount of ZOL in OxCNH-Ca-ZOL was about half that in OxCNH-CaP-ZOL and murine macrophages (RAW264.7 cells) took up less OxCNH-Ca-ZOL than OxCNH-CaP-ZOL, the amount of ZOL inside RAW264.7 cells exposed to OxCNH-Ca-ZOL was less than that inside cells exposed to OxCNH-CaP-ZOL. Despite this drawback, OxCNH-Ca-ZOL had suppressive effects similar to OxCNH-CaP-ZOL on the viability of RAW264.7 cells. The reason for these phenomena is not clear; however, it could be due to the differences in the ZOL release rate between OxCNH-Ca-ZOL and OxCNH-CaP-ZOL. In addition, receptor activator of nuclear factor kappa-B ligand (RANKL)-induced differentiation of RAW264.7 cells into osteoclasts was suppressed by co-administration of RANKL with OxCNH-Ca-ZOL as effectively as with OxCNH-CaP-ZOL, and indeed, their effects were greater than those of free ZOL.

Sensitive and selective fluorescence detection of acetamiprid using oxidized single-walled carbon nanohorns and cryonase-assisted signal amplification

To address the low accuracy of pesticide residue detection in traditional Chinese medicine, we developed a biosensor for acetamiprid detection. First, an oxidized single-walled carbon nanohorn capable of adsorbing and quenching fluorescence was prepared. Second, a novel fluorescence sensing system was constructed based on this nanomaterial. The detection performance of the sensor system was evaluated, which revealed that fluorescence quenching by the biosensor was primarily due to the adsorption of the aptamer by the nanomaterials. Optimal conditions were found to be a nanomaterial mass concentration of 800 ng/mL and an incubation time of 70 min, which resulted in the best fluorescence response. Under these optimal conditions, the system was used to detect acetamiprid residues in traditional Chinese medicine. The fluorescence intensity showed a strong linear relationship with acetamiprid concentration, with a correlation coefficient of 0.9985 and a detection limit of 6.33 ng/mL. In the sample test, the biosensor demonstrated high accuracy, with good average recovery rates and low relative standard deviation. The system showed excellent selectivity and detection performance, with no interference from other pesticides.

Electrochemical Sensor Based on Glassy Carbon Electrode Modified with Carbon Nanohorns (SWCNH) for Determination of Cr(VI) via Adsorptive Cathodic Stripping Voltammetry (AdCSV) in Tap Water

In this study, a new and simple glassy carbon electrode modified with carbon nanohorns (SWCNH/GCE) was used for the determination of Cr(VI) in aqueous matrices via adsorptive cathodic stripping voltammetry (AdCSV). The modified electrode was characterized via field emission scanning electron microscopy and cyclic voltammetry, which revealed a homogeneous distribution of spherical agglomerates of SWCNH on the electrode surface. The modification increased the electrochemically active area from 0.10 cm2 ± 0.01 (GCE) to 0.16 cm2 ± 0.01 (SWCNH/GCE). The optimized analytical conditions were as follows: a supporting electrolyte (0.15 mol L−1 HCl), an accumulation potential of 0.8 V versus Ag/AgCl, and an accumulation time of 240 s. Validation of the analytical methodology was performed, obtaining a linear range between 20 and 100 µg L−1, a limit of detection of 3.5 µg L−1, and a limit of quantification of 11.6 µg L−1 with good accuracy and precision. The method was applied to the analysis of spiked tap water samples, and the results were compared using a flame atomic absorption spectrophotometer (FAAS) with no significant statistical differences.

Effects of novel halogen-free flame-retardant binary additives on thermal stability, degradation kinetics and flame retardancy of cotton cellulose biomacromolecule

The principal component of cotton fibers is the cellulose biological macromolecule. However, its highly flammable nature has significantly constrained its utilization in fields where flame retardancy is essential. Herein, in this work, a highly effective binary composite flame retardant coating (APP/MEL-SWCNHs) with ammonium polyphosphate and modified single-walled carbon nanohorns (MEL-SWCNHs) was chemically attached to cotton fabric. With the add-on of 11.3 %, the treated cotton fabric (APP/MEL-SWCNHs)4 exhibited remarkable flame-retardant and self-extinguishing properties. Its LOI value increased to 23.7 ± 0.1 %, and the damage length was significantly reduced from 30.0 ± 0.1 % cm to 7.9 ± 0.1 % cm compared to the pristine cotton fabric. Despite partial carbonization, (APP/MEL-SWCNHs)4 preserved its original structure. Importantly, in the cone calorimeter test, both the pHRR and THR of (APP/MEL-SWCNHs)4 were drastically decreased by 71.8 % and 35.8 %, respectively. The APP/MEL-SWCNHs coating functioned as a flame retardant by inhibiting the emission of flammable volatiles, releasing non-flammable gases, and encouraging the formation of char layer during combustion. Significantly, thermal degradation kinetic analysis revealed that the third-order kinetic equation (O3) was found to have the strongest correlation with (APP/MEL-SWCNHs)4 in both air and N2 atmospheres. The higher activation energy (E) for (APP/MEL-SWCNHs)4 confirmed that incorporating MEL-SWCNHs improved the thermal stability of the char layer.

Engineered hybrid carbon nanohorns-lipid platforms for the delivery of cisplatin to the colorectal cancer

Carbon nanostructures are considered distinctive multi-functional drug delivery platforms for cancer therapy. However, their potential biocompatibility is still a significant challenge and rational design of these carriers is a prospect in the context of efficient cancer therapy. Herein, we report on the synthesis of two bio-inspired carbon nanohorns (CNH) platforms with tumor targeting capabilities for the delivery of cisplatin. Oxidized CNH wrapped with either polyethylene glycol (PEG) and fusogenic lipids (PEG/DSPG CNH-CP) or glutamic acid-cisplatin complex (CNH-GA-CP), revealed nanosized dahlia-like structure approved by dynamic light scattering (DLS) and transmission electron microscopy (TEM) analysis. Further structure features analysis by using RAMAN, FTIR spectroscopy and TGA indicated CNH surface modification. Excitingly, the superior nanofeatures of the CNH platforms was due to the reduced hydrophobic interactions, and thus closely linked to the surface modifications. Both platforms preserved cisplatin toxicity in vitro on C26 cells. The PEGylated nanoplatform demonstrated elongated circulation time compared to the free drug, and showed a site-specific delivery to the tumor site, while reducing the accumulation within kidney. Following 3 i.v. doses at 3 mg/kg of cisplatin, PEGylated CNH significantly delayed tumor growth and improved the life span of C26-bearing BALB/c mice. These notable results were further approved by the histopathological data, demonstrating reduced degeneration, necrosis and inflammation in both kidney and liver tissues following PEGylated nanoplatform administration. In conclusion, our findings suggest that the systemic toxicity of cisplatin including nephrotoxicity can be resolved by delivering this chemotherapeutic through a rationally-fabricated surface-modified carbon nanoplatform to improve the cancer therapy outcome.

Biomimetic Functional Nanocomplexes for Photothermal Cancer Chemoimmunotheranostics

This study presents a novel multimodal cancer theranostic platform developed using tumor cell‐coated biomimetic carbon nanohorn (CNH) complexes that encapsulate the anticancer drug paclitaxel (PTX). This platform combines photothermal therapy, chemotherapy, and immunotherapy to fight against malignant colorectal cancer. These engineered nanocomplexes are designed to deliver sufficient PTX molecules into a targeted solid tumor in a light‐controllable manner while inducing significant photothermal and antitumor immune responses. The outstanding photothermal conversion property of the CNHs under near‐infrared light enables effective cancer cell ablation and awakening of cytotoxic immune responses. Tumor cell membrane‐coated CNHs show improved water dispersibility, immune evasion, and targeting capabilities alongside enhanced immune activation against tumors. The efficacy of the biomimetic functional CNH nanocomplexes is demonstrated through excellent tumor‐targeting, controlled drug‐releasing behavior, and induction of cancer cell death, contributing to a robust antitumor response. This study provides a promising approach to cancer treatment by integrating multiple therapeutic modalities into a single platform, potentially enhancing treatment efficacy to combat intractable cancer.

Absorption, distribution, metabolism and excretion of carbon nanostructures

The interaction of any substance with the body is determined by several parameters, namely: its penetration, distribution, transformation and excretion, in other words, ADME properties. Naturally, this fully applies to such a class of compounds as carbon nanostructures (CN). They are mainly formed by sp2-hybridized carbon atoms (with the exception of nanodiamonds formed by sp3-hybridized atoms). However, their properties differ markedly from each other. This review is devoted to examining these differences. This review includes fullerenes, nanoionions, carbon nanotubes, carbon nanohorns, graphene and its derivatives, and nanodiamonds.

Designing of carbon nanohorn‐based heterostructure for improved mechanical properties, flame retardancy, and hydrophobicity of composite aerogels

AbstractDeveloping flame‐resistant thermal insulation aerogels with strong mechanical properties is crucial for addressing the fire hazards in high‐rise buildings. Carbon nanomaterials have garnered significant attention for enhancing the flame retardancy and mechanical properties of polymers due to their safety, nontoxicity, and low additions. In this work, the effect of single‐walled carbon nanohorns (SWCNHs) on the mechanical properties, thermal insulation properties, thermal stability, flame retardancy, and hydrophobicity of polyvinyl alcohol/KH560/phytic acid composite aerogel (PKASx) was investigated. By adjusting the concentration of SWCNHs, the mechanical properties of the aerogel were significantly improved, owing to robust interactions between SWCNHs and the matrix. However, a declining trend was observed in both the compressive modulus and specific modulus when the quantity of SWCNHs exceeded 0.3%. Simultaneously, the PKAS0.3 aerogel exhibited remarkable flame retardancy and self‐extinguishing characteristics. It possessed a high LOI value of 34.2 ± 0.2%, with a 25.2% reduction in pHRR and an 18.6% reduction in THR. Moreover, the analysis of TSP and SPR curves affirmed that the inclusion of SWCNHs effectively minimized the production of gaseous by‐products during combustion. In addition, the introduction of SWCNHs introduced a trade‐off in the roughness of the aerogel. The maximum contact angle occurred at the optimal concentration of SWCNHs.

Rheological Behavior of an Aqueous Suspension of Oxidized Carbon Nanohorn (CNHox).

Oxidized carbon nanohorn (CNHox) a carbon nanomaterial that has attracted attention due to its unique material properties. It is expected to be applied in various areas like cancer treatment, gene-expression technology, fluids with high thermal conductivity, lubricants, and so on. While the rheological measurements of suspensions provide information on the effective size and interactions of suspended particles, the rheological behaviors of aqueous suspensions of CNHox have never been systematically investigated. To clarify the rheological behaviors of aqueous suspensions of CNHox, their viscosity and dynamic viscoelasticity were measured with changing particle concentration and salt concentration. The viscosity of a CNHox suspension showed yield stress at low shear rates and showed shear-thinning behavior with increasing shear rates. The viscosity of 5 weight % CNHox suspensions was comparable to that of 60 weight % silica suspensions. This high viscosity at a low CNHox concentration is probably due to the porous structure and large effective volume of the CNHox particle. The estimated effective volume of CNHox calculated by the Krieger-Dougherty equation was 18.9 times larger than the actual volume calculated by the mass concentration and density. The dependence of rheological behavior of the CNHox suspension on salt concentration was weak compared to that of the colloidal silica suspension. This weak dependence on salt concentration may be due to the roughness of the particle surface, which would weaken the effect of electric double-layer interactions and/or van der Waals interactions between particles. These rheological behaviors of the aqueous suspension of CNHox shown in this research will be useful in efforts to improve the efficiency of its utilization for the various applications.

CoFe2O4@N‐CNH as Bifunctional Hybrid Catalysts for Rechargeable Zinc‐Air Batteries

AbstractImproving the efficiency of bifunctional electrocatalysts is a decisive challenge in the area of long‐lasting rechargeable zinc‐air batteries. Enhancing the catalysts' performance is crucial for advancing zinc‐air batteries. Transition‐metal oxides have emerged as promising non‐precious, noble‐metal‐free catalysts. Herein, a unique precursor directed approach is introduced for preparing a cobalt ferrite@nitrogen doped carbon nanohorns (CoFe2O4@N‐CNHs) nanohybrid catalyst in a single step annealing process involving stoichiometric amounts of single‐source cobalt and iron molecular precursors and carbon nanohorns (CNHs) under an argon/ammonia (Ar/NH3) atmosphere. This procedure enables a simultaneous CoFe2O4 ferrite synthesis and nitrogen functionalization of CNHs. The precious metal free nanohybrid CoFe2O4@N‐CNHs‐30% containing 30% of carbon presents an oxygen reduction reaction (ORR) half wave potential and onset potential comparable to the standard ORR catalyst 20% Pt/C. CoFe2O4@N‐CNHs‐30% also establishes superior oxygen evolution reaction (OER) performance with a low overpotential and a small Tafel slope than benchmark OER catalyst RuO2. Furthermore, the rechargeable zinc‐air battery with the CoFe2O4@N‐CNHs‐30% nanohybrid as air electrode demonstrates steadier and more durable charge–discharge cycles, and outstanding energy density relative to the state‐of‐the‐art 20% Pt/C‐RuO2 catalyst.

Poly(vinyl alcohol) Composite Aerogel toward Lightweight, Remarkable Flame Retardancy, and Thermal Insulation Properties by Incorporating Carbon Nanohorns and Phytic Acid

Poly(vinyl alcohol) Composite Aerogel toward Lightweight, Remarkable Flame Retardancy, and Thermal Insulation Properties by Incorporating Carbon Nanohorns and Phytic Acid

A novel electrochemical sensor for sensitive detection of carbendazim based on zeolitic-imidazolate-framework-67/carbon nanohorns nanocomposite

Herein, the zeolitic-imidazolate-framework-67/carbon nanohorns (ZIF-67/CNHs) nanocomposite was synthesized by an efficient method under mild conditions, which was applied for carbendazim (CBZ) detection. ZIF-67 with adsorption capacity of CBZ was employed as the support of proposed sensor. CNHs with excellent conductivity and large specific surface area (SSA) not only compensated the poor conductivity of ZIF-67 but also improved the SSA. The functional groups of ZIF-67 and CNHs could form hydrogen bonding, thereby reducing the aggregation of CNHs. The synergistic effect of CNHs and ZIF-67 significantly enhanced the conductivity and SSA of ZIF-67, reduced the aggregation of CNHs, and thus improved its catalytic ability towards CBZ. Based on superior characteristics of the ZIF-67/CNHs nanocomposite, the proposed sensor exhibited a low limit of detection (LOD) of 1 ng mL-1 with wide linear range of 3–3000 ng mL-1. Moreover, the proposed sensor demonstrated good selectivity, superior reproducibility, and satisfactory applicability in real samples analysis.

Effects of supercritical-CO2 treatment on the pore structure and H2 adsorptivity of single-walled carbon nanohorns

Effects of supercritical-CO2 treatment on the pore structure and H2 adsorptivity of single-walled carbon nanohorns

Carbon nanomaterials: Pioneering innovations in bioimaging and biosensing technologies

Carbon-based nanomaterials, including carbon nanotubes, graphene, carbon dots, carbon nano onions, and carbon nano horns, exhibit exceptional properties such as high electrical and thermal conductivity, mechanical strength, and biocompatibility. These characteristics make them attractive for various biomedical applications, particularly in bioimaging and biosensing. In bioimaging, carbon-based nanomaterials offer several advantages. Their unique properties enable precise imaging of biological events in cells, tissues, and organs, with minimal interference in living processes. By leveraging these properties, researchers can achieve high-resolution imaging for accurate diagnosis and therapy. Similarly, carbon-based nanomaterials are crucial in biosensing applications. They provide a platform for developing highly sensitive biosensors due to their distinctive electrical properties and surface characteristics. Functionalizing these nanomaterials with specific biomolecules or receptors allows for the detection and extraction of target molecules with exceptional precision and sensitivity, inspired by principles found in living systems. A review article focusing on the applications of carbon-based nanomaterials in bioimaging and biosensing would provide insights into their potential in advancing biotechnology. This article discusses a variety of carbon-based nanomaterials, including carbon nanotubes, graphene, carbon dots, carbon nano onions, and carbon nano horns, emphasizing their unique properties and applications in bioimaging and sensing. The review emphasizes the importance of detection accuracy and sensitivity in biomedical applications and investigates how carbon-based nanomaterials help to advance biotechnology. This exploration will allow researchers to explore and create novel diagnostic and therapeutic methods.

Heterostructured Ti3C2Tx/carbon nanohorn-based gas sensor for NH3 detection at room temperature

In this study, a two-dimensional Ti3C2Tx MXene compounded with carbon nanohorn (CNH) by an electrostatic self-assembly method was proposed and then fabricated as room temperature ammonia (NH3) gas sensors. The successful preparation of the Ti3C2Tx/CNH nanocomposite has been characterized in detail. The NH3 sensing performance based on Ti3C2Tx/CNH also has been tested at room temperature. The optimal Ti3C2Tx/CNH sensor has a response value of 21.6% to 100 ppm NH3 at room temperature, which is 10 times higher than that of the pure Ti3C2Tx sensor. Furthermore, this sensor is endowed with excellent selectivity, reliable long-term stability, and reproducibility. The enhanced sensing performance is associated with the interconnected structure and the synergistic effect of Ti3C2Tx and CNH. This work provides an effective way to prepare MXene-based sensitive materials for NH3 sensors, which shows excellent NH3 detection potential at room temperature.

Computational fluid dynamics simulations of the heat transfer properties of graphene-based nanolubricants and application to hydrodynamic lubrication

In this paper, we consider experimental data available for graphene-based nanolubricants to evaluate their convective heat transfer performance by means of computational fluid dynamics (CFD) simulations. Single-phase models with temperature-dependent properties are employed for this purpose. The base fluid is a polyalkylene glycol, and we show the effect of the addition of carbon nanohorns and graphene nanoplatelets (GNPs), in different volume fractions, on the convective heat transfer coefficient between two parallel plates. Then, an application to hydrodynamic lubrication is discussed. The extreme in-plane thermal conductivity of graphene allows a smaller temperature rise of the GNP-based nanolubricant, i.e., a more effective heat removal. To the best of our knowledge, this work represents the first application of single-phase nanofluid models to hydrodynamic lubrication.

Evaluating the effect of unidirectional loading on the piezoresistive characteristics of carbon nanoparticles

The piezoresistive effect of materials can be adopted for a plethora of sensing applications, including force sensors, structural health monitoring, motion detection in fabrics and wearable, etc. Although metals are the most widely adopted material for sensors due to their reliability and affordability, they are significantly affected by temperature. This work examines the piezoresistive performance of carbon nanoparticle (CNP) bulk powders and discusses their potential applications based on strain-induced changes in their resistance and displacement. The experimental results are correlated with the characteristics of the nanoparticles, namely, dimensionality and structure. This report comprehensively characterizes the piezoresistive behavior of carbon black (CB), onion-like carbon (OLC), carbon nanohorns (CNH), carbon nanotubes (CNT), dispersed carbon nanotubes (CNT-D), graphite flakes (GF), and graphene nanoplatelets (GNP). The characterization includes assessment of the ohmic range, load-dependent electrical resistance and displacement tracking, a modified gauge factor for bulk powders, and morphological evaluation of the CNP. Two-dimensional nanostructures exhibit promising results for low loads due to their constant compression-to-displacement relationship. Additionally, GF could also be used for high load applications. OLC’s compression-to-displacement relationship fluctuates, however, for high load it tends to stabilize. CNH could be applicable for both low and high loading conditions since its compression-to-displacement relationship fluctuates in the mid-load range. CB and CNT show the most promising results, as demonstrated by their linear load-resistance curves (logarithmic scale) and constant compression-to-displacement relationship. The dispersion process for CNT is unnecessary, as smaller agglomerates cause fluctuations in their compression-to-displacement relationship with negligible influence on its electrical performance.

Ternary Holey Carbon Nanohorn/Potassium Chloride/Polyvinylpyrrolidone Nanohybrid as Sensing Film for Resistive Humidity Sensor

The study presents findings on the relative humidity (R.H.) sensing capabilities of a resistive sensor. This sensor utilizes sensing layers composed of a ternary nanohybrid, consisting of holey carbon nanohorn (CNHox), potassium chloride (KCl), and polyvinylpyrrolidone (PVP), with mass ratios of 7/1/2, 6.5/1.5/2, and 6/2/2 (w/w/w). The sensing structure comprises a silicon substrate, a SiO2 layer, and interdigitated transducer (IDT) electrodes. The sensing film is deposited on the sensing structure via the drop-casting method. The sensing layers’ morphology and composition are investigated through Scanning Electron Microscopy (SEM) and RAMAN spectroscopy. The resistance of thin-film sensors based on ternary hybrids increased with exposure to a range of relative humidity (R.H.) levels, from 0% to 100%. The newly designed devices demonstrated a comparable response at room temperature to that of commercial capacitive R.H. sensors, boasting excellent linearity, swift response times, and heightened sensitivity. Notably, the studied sensors outperform others employing CNHox-based sensing layers in terms of sensitivity, as observed through manufacturing and testing processes. It elucidates the sensing mechanisms of each constituent within the ternary hybrid nanocomposites, delving into their chemical and physical properties, electronic characteristics, and affinity for water molecules. Various alternative sensing mechanisms are considered and discussed, including the reduction in holes within CNHox upon interaction with water molecules, proton conduction, and PVP swelling.