Addition Of Carbon Nanofibers Research Articles

Advancing Peripheral Nerve Regeneration: 3D Bioprinting of GelMA-Based Cell-Laden Electroactive Bioinks for Nerve Conduits.

Peripheral nerve injuries often result in substantial impairment of the neurostimulatory organs. While the autograft is still largely used as the "gold standard" clinical treatment option, nerve guidance conduits (NGCs) are currently considered a promising approach for promoting peripheral nerve regeneration. While several attempts have been made to construct NGCs using various biomaterial combinations, a comprehensive exploration of the process science associated with three-dimensional (3D) extrusion printing of NGCs with clinically relevant sizes (length: 20 mm; diameter: 2-8 mm), while focusing on tunable buildability using electroactive biomaterial inks, remains unexplored. In addressing this gap, we present here the results of the viscoelastic properties of a range of a multifunctional gelatin methacrylate (GelMA)/poly(ethylene glycol) diacrylate (PEGDA)/carbon nanofiber (CNF)/gellan gum (GG) hydrogel bioink formulations and printability assessment using experiments and quantitative models. Our results clearly established the positive impact of the gellan gum on the enhancement of the rheological properties. Interestingly, the strategic incorporation of PEGDA as a secondary cross-linker led to a remarkable enhancement in the strength and modulus by 3 and 8-fold, respectively. Moreover, conductive CNF addition resulted in a 4-fold improvement in measured electrical conductivity. The use of four-component electroactive biomaterial ink allowed us to obtain high neural cell viability in 3D bioprinted constructs. While the conventionally cast scaffolds can support the differentiation of neuro-2a cells, the most important result has been the excellent cell viability of neural cells in 3D encapsulated structures. Taken together, our findings demonstrate the potential of 3D bioprinting and multimodal biophysical cues in developing functional yet critical-sized nerve conduits for peripheral nerve tissue regeneration.

Mechanical, Crystallization, Rheological, and Supercritical CO2 Foaming Properties of Polybutylene Succinate Nanocomposites: Impact of Carbon Nanofiber Content.

As a substitute for conventional polymers for the preparation of biodegradable microcellular polymeric foams, polybutylene succinate (PBS) presents one of the most promising alternatives. However, the low melt strength of PBS makes it difficult to produce high-performance microcellular foams. This study aimed to improve the melt strength of PBS and explore the mechanical, thermal, crystalline, rheological, and supercritical CO2 foaming properties of PBS nanocomposites by using carbon nanofibers (CNFs). This study found that nanocomposites containing 7 wt% CNF exhibited the highest tensile strength, Young's modulus, and bending strength. Moreover, the CNF nanofillers were well dispersed in the PBS matrix without significant agglomeration, even at high filler concentrations. Furthermore, the nanocomposites demonstrated improved melting temperature and crystallinity compared with pure PBS. The rheological analysis showed that the addition of CNFs significantly increased PBS viscosity at low frequencies due to the interaction between the PBS molecular chains and CNFs and the entanglement of CNFs, resulting in a more complete physical network formation when the CNF content reached above 3 wt%. During the supercritical CO2 foaming process, the addition of CNFs resulted in increased cell density, smaller cells, and thicker cell walls, with good laps formed between the fibers on the cell walls of nanocomposite foams. Moreover, the electrical conductivity and electromagnetic interference (EMI) shielding properties of the foamed material were studied, and a nanocomposite foam containing 7 wt% CNF showed good electrical conductivity (4.5 × 10-3 S/m) and specific EMI shielding effectiveness (EMI SE) (34.7 dB/g·cm-1). Additionally, the nanocomposite foam with 7 wt% CNF also exhibited good compression properties (21.7 MPa). Overall, this work has successfully developed a high-performance, multifunctional PBS-based nanocomposite foam, making it suitable for applications in various fields.

Free-Standing 3D Printing of Epoxy-Vinyl Ether Structures Using Radical-Induced Cationic Frontal Polymerization.

The application of frontal polymerization to additive manufacturing has advantages in energy consumption and speed of printing. Additionally, with frontal polymerization, it is possible to print free-standing structures that require no supports. A resin was developed using a mixture of epoxies and vinyl ether with an iodonium salt and peroxide initiating system that frontally polymerizes through radical-induced cationic frontal polymerization. The formulation, which was optimized for reactivity, physical properties, and rheology, allowed the printing of free-standing structures. Increasing ratios of vinyl ether and reactive cycloaliphatic epoxide were found to increase the front velocity. Addition of carbon nanofibers increased the front velocity more than the addition of milled carbon fibers. The resin filled with carbon nanofibers and fumed silica exhibited shear-thinning behavior and was suitable for extrusion-based printing at a weight fraction of 4 wt %. A desktop 3D printer was modified to control resin extrusion and deposition with a digital syringe dispenser. Flexural properties of molded and 3D-printed specimens showed that specimens printed in the transverse direction exhibited the lowest strength, likely due to the presence of voids, adhesion issues between filaments, and preferential carbon nanofiber alignment along the filaments. Finally, free-standing printing of single, angled filaments and helical geometries was successfully demonstrated by coordinating ultraviolet-based reaction initiation, low air pressure for resin extrusion, and printing speed to match front velocity.

Effect of Carbon Nanofibers on the Strain Rate and Interlaminar Shear Strength of Carbon/Epoxy Composites.

The static bending properties, different strain rates and interlaminar shear strength (ILSS) of carbon-fiber-reinforced polymers (CFRP) with two epoxy resins nano-enhanced with carbon nanofibers (CNFs) are studied. The effect on ILSS behavior from aggressive environments, such as hydrochloric acid (HCl), sodium hydroxide (NaOH), water and temperature, are also analyzed. The laminates with Sicomin resin and 0.75 wt.% CNFs and with Ebalta resin with 0.5 wt.% CNFs show significant improvements in terms of bending stress and bending stiffness, up to 10%. The values of ILLS increase for higher values of strain rate, and in both resins, the nano-enhanced laminates with CNFs show better results to strain-rate sensitivity. A linear relationship between the logarithm of the strain rate was determined to predict the bending stress, bending stiffness, bending strain and ILSS for all laminates. The aggressive solutions significantly affect the ILSS, and their effects are strongly dependent on the concentration. Nevertheless, the alkaline solution promotes higher decreases in ILSS and the addition of CNFs is not beneficial. Regardless of the immersion in water or exposure to high temperatures a decrease in ILSS is observed, but, in this case, CNF content reduces the degradation of the laminates.

Effect of Carbon Nanofibers on the Viscoelastic Response of Epoxy Resins.

Two epoxy resins with different viscosities were enhanced up to 1 wt.%, applying a simple method with carbon nanofibers (CNFs). These were characterized in terms of static bending stress, stress relaxation, and creep tests. In bending, the contents of 0.5 wt.% and 0.75 wt.% of CNFs on Ebalta and Sicomin epoxies, respectively, promote higher relative bending stress (above 11.5% for both) and elastic modulus (13.1% for Sicomin and 16.2% for Ebalta). This highest bending stress and modulus occurs for the lower viscosity resin (Ebalta) due to its interfacial strength and dispersibility of the fillers. Creep behaviour and stress relaxation for three stress levels (20, 50, and 80 MPa) show the benefits obtained with the addition of CNFs, which act as a network that contributes to the immobility of the polymer chains. A long-term experiment of up to 100 h was successfully applied to fit the Kohlrausch-Williams-Watts (KWW) and Findley models to stress relaxation and creep behaviour with very good accuracy.

Crystallization Behavior and Sensing Properties of Bio‐Based Conductive Composite Materials

Poly(3‐hydroxyoctanoate) (PHO), a biocompatible polymer with a skin‐like feel produced by bacterial fermentation, is compounded with carbon nanofibers (CNFs) or carbon black (CB), respectively, to form flexible, 3D printable, bio‐based conductive composites. Conductivities up to 10 and 3 S m−1 can be achieved for CNF and CB, respectively, without negatively affecting the composites’ processability. Both filler materials act as nucleating agents for PHO crystallization, significantly accelerating this process which is extremely slow for the filler‐free polymer. Mechanical performance, for example, elastic modulus, is also improved by the addition of CNF or CB. Both types of filler form composites that show a distinct response to mechanical deformation: bending, twisting, and stretching (up to 10% elongation) result in a marked decrease in their electrical resistance (up to 30%). This phenomenon has been exploited to fabricate a 3D‐printed strain sensor that can detect flection and extension via a change in resistance. The results demonstrate the potential of this sustainable biopolymer and its composites for applications in the biomedical space.

Boost in the Electromagnetic Shielding Effectiveness of Polystyrene–Polyaniline Composites by Addition of Carbon Nanofibers

Boost in the Electromagnetic Shielding Effectiveness of Polystyrene–Polyaniline Composites by Addition of Carbon Nanofibers

Improved damage sensing with random/aligned carbon nanofiber in bulk epoxy and adhesive joints

AbstractIn situ health monitoring of polymeric materials and adhesive joints can be done by adding conductive carbon nanofillers that enable inherent piezoresistive sensing capability in nonconductive polymers. In this study, carbon nanofiber (CNF) was added to epoxy in bulk and adhesive form to investigate their potential applications as strain and crack detection sensors, respectively. Tensile specimens of CNF/epoxy nanocomposites with different filler concentrations were tested to study their strain sensing capability. The nanocomposites were further used as adhesive for sensing crack propagation in adhesive joints. CNFs alignment was carried out inside the adhesive by AC electric field to study the alignment effect on crack detection capability and fracture toughness of joints. Tensile specimens showed excellent strain sensing capability at CNF concentrations of 0.4, 0.8, and 1.2 wt%. However, the gauge factor was found to be highest at 0.4 wt% and decreasing further with increasing CNF content. The CNF addition was found to enhance the crack detection capability as well as the fracture toughness in adhesive joints. Further improvements in the crack detection capability and fracture toughness were observed in the case of aligned nanocomposite joints. However, the effect of alignment was observed to be more profound at lower CNF content.

Effect of Carbon Nanofibers on Physical, Adhesion and Rheological Properties of Liquid Epoxidized Natural Rubber Modified Asphalt

This study aimed to evaluate the effects of carbon nanofibers (CNFs) on the performance of liquid epoxidized natural rubber (LENR)-modified asphalt. The physical, adhesion and rheological properties were determined by several tests such as penetration, elastic recovery, ring and ball softening point, Brookfield rotational viscometer, AFM and dynamic shear rheometer. LENR was used at concentrations of 3, 6, and 9%, while CNFs were used at contents of 0.3, 0.4, and 0.5% by weight of asphalt. Conventional test results showed that the increases in LENR and LENR/CNFs composite contents in binder leads to an increase in the hardness and consistency and a reduction in the temperature susceptibility of base asphalt. Adhesion results revealed that the addition of CNFs significantly increases the adhesion and bonding properties of base and rubberized binders. Rheological properties analysis exhibited that LENR improved the viscoelastic properties and permanent deformation resistance of asphalt at different temperatures and frequencies. On the other hand, it was found that the addition of CNFs significantly improves the stiffness, elasticity, and hardness of LENR-modified binders. The 6% LENR and 0.4% CNFs were found to be the optimum to enhance the physical, adhesion, and rheological properties of asphalt in this study. Thus, it can be stated that the addition of CNFs is promising to improve the performance of rubberized binders for high temperature applications.

Carbon nanofibers (CNFs) dispersed in ultra-high performance concrete (UHPC): Mechanical property, workability and permeability investigation

This paper presents experimental data on the effect of carbon nano-fiber (CNF) dispersion on mechanical behavior, workability, and permeability of ultra-high-performance concrete containing CNF (UHPC-CNF). The addition of CNFs in concrete has been shown to provide improved performance. However, an inhomogeneous distribution of CNFs in the cement matrix can result in no impact or decreased mechanical performance. Due to the van der Waal's forces and hydrophobic surface properties of the CNFs, good dispersion in mix fluids and cement paste is challenging. Experimental studies of UHPC-CNF with different dispersion methods are provided. Further mixing with optimized UHPC paste allowed for the investigation of the optimal dosage of CNFs, impact on porosity, compressive strength, flexural strength, hydration rate, and slump. Scanning electron microscopy (SEM) analysis visually revealed the effect of dispersion. The results indicate that shear mixing and subsequent ultrasonic dispersion with chemical surfactants can provide a well-dispersion liquid admixture of CNFs resulting in high mechanical performance of UHPC-CNFs composites. The water permeability and chloride resistance of optimized UHPC-CNFs composites were further evaluated with the wicking test and ponding test to reveal improved performance for these properties as well.

Effects of the addition of carbon nanofibers on mechanical properties of woven glass/epoxy composites with different weave patterns

The harness and the weave style are among the most important properties of woven fabrics. Most of the previous studies utilized woven fabrics with specific harnesses to explore the effects of nanoparticles on woven composites. Therefore, an experimental study was conducted to examine the impact of three weave patterns, namely plain, 5-harness satin, and 8-harness satin, on the mechanical properties of woven composites under tensile and shear loads. Subsequently, the effect of applying carbon nanofibers (CNFs) to epoxy resin reinforced with woven glass fibers with various harnesses was studied. The experimental results were evaluated statistically, indicating that using CNFs differently affects composite properties with various fabric harnesses. The addition of 0.5 wt.% CNFs to woven composites with varied harnesses enhanced the tensile strength by 19.2%–22.9% and the tensile fracture strain by 12.9%–13.8%, respectively. However, the elastic tensile modulus of woven composites was not increased. A further increase in the CNFs weight fraction from 0.5 wt.% did not improve the tensile properties. The addition of 0.5 wt.%, 1.0 wt.% and 1.5 wt.% CNFs increased the shear strength up to 30.6% and the shear modulus up to 18.7%, respectively. The results showed that the addition of CNFs more significantly affected the shear than the tensile properties. It was also revealed that employing a proper weight fraction of CNFs and a proper fabric harness significantly improves the mechanical properties of woven composites. Finally, an empirical model was developed to predict the strength and elastic modulus of woven composites with different harnesses and CNF weight fractions.

Identification of the electrical connection in the catalyst layer of the polymer electrolyte membrane water electrolyzer

Mechanical deterioration of the catalyst layer (CL) in contact with the porous transport layer (PTL) can disconnect it from the electrical network and deactivate it during proton exchange membrane water electrolysis (PEMWE). This study presents a method for visual identification of the electrically connected region in the CL using in situ electrochemical reduction of iridium oxide to iridium, coupled with energy dispersive X-ray spectroscopy (EDS) mapping and environmental scanning electron microscopy (E-SEM) analyses. Because the iridium oxides in the catalyst layer can be electrochemically reduced to iridium only when they are in both ionic and electronic connection, the reduced portion corresponds to electrically connected region. Our results revealed that the region under the rib not in contact with porous transport layer (PTL) (non-PTL-contact region) is the most prone to electric disconnection because of the cracks formed by PTL compression. Finer CL fragmentation at lower catalyst loadings aggravates such disconnection. Cell polarization of a low catalyst-loaded CL is greatly reduced when the electrical connection at the non-PTL-contact region under the rib is improved with the addition of carbon nano-fibers to the CL. These results emphasize the importance of the electrical connection in the non-PTL-contact region for achieving high-performance low-catalyst-loaded PEMWE.

Wear and microstructural properties of Ni-B4C/CNF composites

The aim of this study is to investigate the microstructure and wear properties of nickel (Ni) matrix boron carbide (B4C) and carbon nanofiber (CNF)-reinforced composite materials. Microstructure and phase composition of the composites manufactured by powder metallurgy (PM) method were determined by SEM-EDS and XRD analysis. While hardness values of the composites were determined by Vickers hardness measurement method, their wear properties were determined by using pin-on-disc method. SEM images showed that B4C was homogeneously distributed, but CNF accumulated in some areas, even though it was slight. Addition of B4C and CNF to the matrix significantly increased it. The increase was quite high in B4C addition, and hardness was slightly lower in the addition of CNF. According to the results of the wear test carried out under dry conditions, the reinforcement to the Ni matrix reduced the wear rate and friction coefficient.

Effect of CNFs on the mechanical properties and microstructure of early strength seawater sea-sand engineered cementitious composites

Carbon nanofibres (CNFs) are a promising material for improving the mechanical properties of cementitious composites. Thus, it is necessary to disperse CNFs for use in materials. In this study, three types of surfactants used in distilled water and seawater were investigated. To obtain the optimal dispersion conditions, the effects of different types and concentrations of surfactants and ultrasonic treatment times on the dispersion of CNFs were investigated quantitatively. The CNF suspensions were studied via visual examination, Transmission electron microscopy (TEM), and Ultraviolet–Visible (UV–Vis) spectroscopy. The compressive strength, tensile strength, and porosity were examined to evaluate the mechanical properties of CNF-modified early strength seawater sea-sand engineered cementitious composites (SS-ECCs). Moreover, field-emission electron Scanning microscopy (SEM) was used to study their microstructures. After dispersion with surfactants and ultrasonication, individual fibres were found in the suspension. Seawater adversely affected the stability of the suspensions. Well-dispersed CNFs improved the mechanical properties of the cementitious composites, with an increase in compressive and tensile strengths of 21–24% and 16–20%, respectively. The tensile strain capacity increased by approximately twofold. The porosity was reduced and the pores structure was refined. Microscopic examination proved that CNFs were also well dispersed in cement matrix. The results showed that the addition of CNFs could significantly improve the mechanical properties of cement-based composites.

Additive manufacturing of polyamide nanocomposites for electrostatic charge dissipation applications

Polyamide 6 (PA 6) nanocomposites are viable engineered nanocomposite materials with potential application in electrostatic discharge dissipation applications. Creating an electrically conductive path to dissipate electrostatic charges in such materials can be a viable solution to electrostatic discharge (ESD) concerns. The addition of nanofillers can also enhance mechanical properties of the parent polyamide 6, a structural thermoplastic ideal for 3D printing via fused deposition modelling (FDM). While improving the ESD capability, it is imperative to sustain the structural integrity of the nanocomposites. Hence, this study evaluated the mechanical, thermal, and electrical properties of 3D printed PA6 nanocomposites for electrostatic discharge applications. 3 and 5 wt% of carbon nanofibers (CNF) was compounded with PA6 using co-rotating twin screw extruder to produce 1.75 mm diameter monofilaments for fused deposition modelling (FDM). The test samples were printed using commercial-off-the-shelf (COTS) 3D printer, Lulzbot TAZ 6 FDM printer. Mechanical, electrical, and thermal characterization was carried out according to their respective ASTM standard. The tensile and flexural properties were enhanced by 3 wt% addition of CNF, but no significant improvement was observed at 5 wt%. The CNF nanocomposites exhibited good thermal stability and crystallization phenomenon at both loading levels. The volume resistivity of the of the PA6 matrix was reduced to order of 1011 and 1012 by 3 wt% and 5 wt% CNF addition respectively, which seems promising for manufacturing static discharge products.

Hygrothermal aging behavior and aging mechanism of carbon nanofibers/epoxy composites

In this study, carbon nanofibers (CNFs)/epoxy composites incorporating different contents of CNFs were fabricated and immersed in distilled water for 180 days. Water absorption test, tensile tests, scanning electron microscopy (SEM) observation, dynamic mechanical analysis (DMA), and Fourier transform infrared (FTIR) spectroscopy were performed to evaluate the effect of CNFs content on hygrothermal aging behavior of CNFs/epoxy composites, and to reveal the hygrothermal aging mechanism of such composites. Test results showed that the addition of CNFs into pure epoxy resin could obviously improve its hygrothermal aging behavior. The CNFs/epoxy composites had better resistance to water absorption than pure epoxy because CNFs improved the water barrier properties of the composites. The improvements of glass transition temperature and the storage modulus of the composites before and after aging were attributed to the fact that the addition of CNFs limited the loosening of molecular chains and increased the second cross-link density of epoxy resin. FTIR spectroscopy showed that the number of –OH functional groups of CNFs/epoxy composites was decreased, which revealed that CNFs inhibited the hydrolysis of epoxy resin and water absorption. This study demonstrates that adding appropriate amount of CNFs into epoxy resin has potential to improve the long-term durability of epoxy-based composites in hygrothermal environment.

The silicon–carbon nanofibers-carbonized yeast powder composites with excellent electrochemical properties as lithium-ion anode materials

Silicon–carbon nanofibers-carbonized yeast powder composite (SCNFs/CYP) was fabricated using the electrostatic spinning and hydrothermal processes. Experimental results show that the carbon nanofibers can restrain the volume expansion of silicon in the electrochemical process and the microporous structure of carbonized yeast powder can increase the specific surface area and promote the penetration of electrolyte. The compound was cyclically tested at charge–discharge rate of [Formula: see text]C, and the first charge/discharge capacity was 1725 and 1732 mAh/g. Although it is lower than the capacity of single structure silicon–carbon nanofibers (SCNFs), with the increase of the number of cycles, the capacity of charging and discharging has been greatly improved, and it can be maintained at 1656 mAh/g after 180 cycles. The [Formula: see text] after 1 cycle, 10 cycles and 100 cycles were 486, 286.5 and 231 [Formula: see text], from which we can see that the SCNFs–CYP has lower overall impedance values as the cycle increases. This indicated that the addition of carbon nanofibers and carbonized yeast powder inhibited the volume expansion and increased the specific surface area, providing more electrical contact sites.

Mechanical and electrical properties of three‐dimensional printed polylactic acid–graphene–carbon nanofiber composites

AbstractThe addition of carbon nanofibers (CNFs) and graphene to thermoplastic polymers has the potential to increase the mechanical and electrical properties. The aim of the current study is to investigate the effect of CNF and graphene on the properties of three‐dimensional (3D) printed polylactic acid (PLA) samples. The samples are printed using the PLA–graphene–CNF composite filament via fused deposition modeling. As a first objective, composite filament and pure PLA filament characteristics were compared using tensile, scanning electron microscopy and thermogravimetric analysis (TGA) data. Compared with pure PLA filaments, composite filaments revealed an almost 28% reduction in tensile strength due to interfacial defects (poor bonding between PLA and graphene and CNF). Furthermore, 3D printed composite sample properties are compared with 3D printed pure PLA sample using tensile and electrical conductivity data. The 3D printed composite samples also showed less tensile strength (25 MPa) compared with pure PLA 3D samples (37–47 MPa) due to the presence of microvoids. These voids also caused reduction in tensile strength and electrical conductivity of 3D printed composites when compared with the filament properties. The effect of layer orientation was also studied by printing samples at [0°/90°] and [45°/−45°] orientations and found that samples with [45°/−45°] orientation revealed higher elongation (>100%) and lower electrical conductivity. It is observed that the presence of graphene and lack of bonding between PLA and CNF resulted in the improper fusion of the printed layers, which led to a decrease in tensile strength and electrical conductivity but an increase in toughness.

Enhanced effect of carbon nanofibers on heating efficiency of conductive cementitious composites under ohmic heating curing

Ohmic heating (OH) curing method has been proved to cure conductive fibers enhanced cementitious composites by electric-heating conversion under ultralow temperature, and this curing effect depends greatly on the heating efficiency. This paper presents a novel idea of utilizing carbon nanofibers (CNFs) to regulate and control the heating efficiency of carbon fibers (CFs) enhanced cementitious composites. The heating efficiency including peak curing temperature and temperature-increase rate of CF/CNFs reinforced cementitious composite (CF/CNF-CCC) with 0–0.3 vol% CNFs addition are traced. Results show that the increasing addition of CNFs shows a significantly increased enhancement effect to the heating efficiency during OH curing, in which the peak curing temperature and temperature-increase rate are increased from 44.8 °C to 0.139 °C/min to 73.2 °C and 0.39 °C/min as the content of CNFs is increased from 0 to 0.3 vol%. The microstructural heating mechanism based on CNFs distribution type in CF/CNF-CCC samples is clarified, two CNFs “bridge effects” are considered to effectively construct microscopic conductive network of CNFs among macroscopic conductive network of CFs. COMSOL Multiphysics simulation is conducted to further verify the improving effect of CNFs on the heating efficiency and to quantificationally guide the material composition design of CF/CNF-CCC for achieving the controllability of heating efficiency.

Carbon nanofibers addition on transport and superconducting properties of bulk YBa2Cu3O7\u2212\u03b4 material prepared via co-precipitation

The effects of carbon nanofibers addition on transport and superconducting properties of YBa2Cu3O7−δ (Y-123) superconductor were studied. Y-123 was prepared using co-precipitation method for good quality bulk of high temperature superconducting material. Carbon nanofibers with 0.2–0.8 wt% were added into Y-123 superconductors. The samples were characterized using electrical resistance measurement for critical temperature (Tc) and critical current density (Jc), powder X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray analysis. Most of the samples indicated a dominant Y-123 phase of an orthorhombic structure with a minor phase of BaCO3 and Y-124. Onset critical temperature was found to decrease from 90.5 to 80 K with increasing of carbon nanofibers concentration. The Jc for pure sample is 11 A/cm2 at 30 K while the Jc of sample with 0.4 wt% carbon nanofibers is 830 A/cm2 at 30 K. Introduction of carbon nanofibers enhanced Jc significantly. However, further addition of carbon nanofibers in Y-123 superconductor caused degradation in Jc.