Increasing Multi-walled Carbon Nanotubes Content Research Articles

Investigating the contribution of carbon nanotubes and diesel-biodiesel blends to emission and combustion characteristics of diesel engine

The ultimate purpose of the current research work is to trigger the effect of 50, 100 and 150 ppm multi-walled carbon nanotubes (MWCNTs) in addition to diesel-biodiesel blended fuels with a focus on the emission and combustion characteristics of diesel engine. A single-cylinder diesel engine, with 1800 rpm engine speed and 100% engine load, was used to run the experiments on all fuel blends. The results indicated a significant reduction of the carbon dioxide (CO2) formation as a result of increase in MWCNTs, particularly for B20 and B30 samples. Also, the results emphasized a significant reduction of nitrogen oxides (NOx) formation as fa as B20 and B40 blends were concerned. However, regarding the B10 blends, an increasing trend of NOx emissions were reported when there was an increase in MWCNTs content. Furthermore, increased in-cylinder pressure for the baseline diesel was not found to be influenced by 10% biodiesel addition and 50 ppm MWCNTs. In-cylinder pressure for B10C50 was found to follow the same behaviour as D100 baseline diesel. In addition, the highest in-cylinder pressure of 73.47 bar was attributed to the B10C150 sample, representing a value 4.64% higher than the conventional D100. It was also observed that at low MWCNTs content (50 ppm), the effect on the in-cylinder temperature was the highest. When there was maximum in-cylinder pressure, the 15°CA was determined to be the peak in-cylinder temperature for all samples. All in all, it was confirmed that the combustion characteristics and emission reductions were improved as a result of MWCNTs addition to the biodiesel-diesel blends.

Synthesis and cyclic voltammetry of CrFe2O4/(MWCNTs)x nanohybrids

The chemical co-precipitation route was opted for the synthesis of chromium ferrite (CrFe2O4) nanoparticles and the pristine multi-walled carbon nanotubes (MWCNTs) were used for the preparation of desired CrFe2O4/(MWCNTs)x; x = 0, 5, 10, 15, and 20 wt% nanohybrids using the ultra-sonication method. Toluene was used for the first time as dispersive medium for the preparation of these nanohybrids. The crystalline structure, morphology, vibrational modes, and electrochemical performance of these nanohybrids were characterized by using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry. The structural properties of pristine MWCNTs, CrFe2O4 nanoparticles, and CrFe2O4/(MWCNTs)x nanohybrids are evaluated by XRD and Raman spectroscopy. The SEM images presented the attachment of CrFe2O4 nanoparticles on the surface of MWCNTs. The specific capacitance was decreased with increasing number of cycles, while it was observed to be increased with increasing MWCNTs content. From EIS, the decrease in charge transfer resistance was observed with the increased loadings of MWCNTs, which showed the enhanced electrochemical behavior of these nanohybrids. Therefore, the significant improvement in electrochemical properties showed that these nanohybrids can be promising candidates for energy storage devices like lithium-ion (Li-ion) batteries.

Experimental investigation on heat transfer behavior of the novel ternary eutectic PCM embedded with MWCNT for thermal energy storage systems

In this paper, the variation of thermophysical properties such as the thermal conductivity, thermal energy storage capacity, viscosity, and phase change temperature of the novel ternary eutectic phase change material (PCM) with respect to multi-walled carbon nanotubes (MWCNTs) concentration are investigated. The novel ternary eutectic PCM was formed by the permutation of oleic acid, isopropyl palmitate, butyl stearate in a eutectic mole fraction of 0.44–0.33–0.23. The heat transfer analysis of the materials encapsulated in spherical ball was experimentally investigated. The results concluded that the ternary eutectic PCM with 0.10 mass percentage of MWCNT enhances the heat transfer rate by 34.45% with respect to the pure PCM. Furthermore, the thermal conductivity of the MWCNT dispersed ternary eutectic PCM shows an increasing trend and reaches the maximum enhancement of 67.28% for 0.10 mass percentage of MWCNT concentration. The crystallinity decrement of the composite PCM was increased linearly from 0.19 to 3.2% for the increasing MWCNT concentration along with the convergence of melting and solidification enthalpy at the maximum dispersion of MWCNT concentration. New correlations governing the variation of thermal conductivity, viscosity and thermal expandability of the ternary eutectic PCM with respect to MWCNT concentrations have also been developed and presented in this study. The novel ternary eutectic PCM with 0.10 mass percentage of MWCNT with good thermal reliability after 500 thermal cycles and compatibility with the spherical encapsulated high-density polyethylene ball could be an eminent candidate for low-temperature cold storage applications.

Effect of small amount of multi-walled carbon nanotubes on crystallization and thermal-mechanical properties of overflow microinjection molded isotactic polypropylene

Herein, the solution-melt blended multi-walled carbon nanotubes (MWCNTs)/isotactic polypropylene composites are molded by an overflow microinjection molding. All parts exhibit the highly oriented structures, and the number of oriented shish-kebab structures progressively increase with increasing MWCNTs content. More importantly, small amount of MWCNTs (i.e., 0.1 wt%) can significantly improves crystallization rate and crystallinity of all composite parts, nevertheless, the formation of β-crystal is remarkably suppressed. Moreover, compared with the pure part, tensile modulus, toughness and thermostability of composite parts are mildly enhanced. This work provides a facile method to fabricate high-performance composite parts via overflow microinjection molding, which would lay a foundation for optimizing the macroscopic performances of polymer-based composites.

Effect of Surface Modification on Multi-Walled Carbon Nanotubes and their Reinforced Nylon Composites

In this study, a series of nanocomposites were prepared by melt-blending method using Nylon (Nylon12, PA12) and multi-walled carbon nanotubes (MWCNTs) with various contents such as 0.0 wt.%, 0.5 wt.%, 1.0 wt.%, 3.0 wt.%. In order to improve the dispersion of MWCNTs in composites, the MWCNTs were first acid treated by the HNO3 solution to functionalize the carboxylic groups on the surface. Subsequently, this acid treated MWCNTs were reacted with Polyetheramine (Jeffamine® M2070) and Polyethylenimine under mild conditions, respectively, to obtain the chemically modified MWCNTs (M-M2070 and M-PEI). The amide groups formed on these chemically modified MWCNTs will enhance the compatibility of MWCNTs and Nylon. The effects of different modification methods on the thermal properties, mechanical properties and electrical resistance of these Nylon12/MWCNTs composites were investigated. The results showed that M-M2070 and M-PEI dispersed in Nylon12 homogeneously, and can improve the mechanical and thermal properties of the composite materials effectively. The DMA analysis revealed that the storage moduli of nanocomposites were increased with increasing MWCNTs content. Among all, the nanocomposites containing 3wt% of M-M2070 and M-PEI were shown increased storage moduli 48.2% and 29.8%, respectively. TGA analysis showed that pyrolysis temperature of neat Nylon12 was 412.7 °C, and was increased about 43 °C by addition of M-M2070 and 36.7 °C by addition of M-PEI. Moreover, the surface resistance of neat Nylon12 was 1.68×1014 ohm/sq, and was decreased to 1.33×105 and 4.34×106 ohm/sq by addition of 3wt% M-M2070 and M-PEI, respectively. The resistance values of these nanocomposites have achieved the level of static dissipation, and can prevent the harm of static electricity.

Influence of Carbon Nanotube Concentration on the Interconnection Properties of Solderable Isotropic and Anisotropic Conductive Adhesive

In this paper, two types of multi-walled carbon nanotube (MWCNT)-filled solderable electrically conductive adhesive (SECA) systems were formulated, a solderable isotropic conductive adhesive (SICA) containing 40 vol% of low melting point alloy (LMPA), and a solderable anisotropic conductive adhesive (SACA) with 20 vol% of LMPA, with different MWCNT contents (0, 0.03, 0.5 and 2 wt%). A quad flat package (QFP) interconnection test was conducted for each SECA system to investigate the influence of the MWCNT concentration on the interconnection properties of the SICA and SACA systems. The results indicated that the interconnection properties (i.e., electrical and mechanical properties) of each SECA were enhanced at low MWCNT concentration, due to the reinforcing effects of the MWCNT. However, the interconnection properties of each SECA joint deteriorated with increasing MWCNT concentration over 0.5 wt% because of defects in the conduction path, such as entrapped MWCNT-filled polymer (SICA), or reduction of the conduction path area (SACA) due to increased polymer viscosity and diminished molten LMPA mobility. Key words: Anisotropic conductive adhesive, Defect, Interconnection properties, Isotropic conductive adhesive, Low melting point alloy, Multi-walled carbon nanotube

Preparation of MWCNT/PDMS Conductive Micro-Patterned Nanocomposites

Conductive multi-walled carbon nanotube (MWCNT)/polydimethylsiloxane (PDMS) nanocomposites were prepared via solution method and their conductive micro-patterns were made using the doctor blade technique. The prepared patterns were characterized via scanning electron microscopy (SEM), cyclic voltam-metry, and four-point probe conductivity meter. SEM images of the cross-sections of micro-patterns revealed that by increasing MWCNT concentration from 5 to 10%, while the dense and smooth bulk structure converted to a brittle one, their conductivities raised from 0.07 up to 0.33 S/cm. These micro-patterns preserved their conductivities under high bending cycles except for high MWCNT loading which loses almost half of its conductivity. The cyclic voltammetry analyses showed that MWCNT/ PDMS conductive micro-patterns had supercapacitor properties. The specific capacitance of the composite containing 10 wt% of MWCNT was 0.35 F/g These nanocomposites can be used in cochlear implants due to their high conductivities. Their low working voltages ensure the safety of the neural tissues.

Synthesis, optical, thermal, electric properties and impedance spectroscopy studies on P(VC-MMA) of optimized thickness and reinforced with MWCNTs

The synthesis of polymeric blends and nanocomposites with improved physical properties has attracted increasing attention worldwide, for its practical and technological applications. The present study aims to tune the physical properties of thermoplastic polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) blends by adjusting the film thickness and loading with multiwall carbon nanotubes (MWCNTs). To this end, P(VC/MMA) films of thickness in the range 36.4–204 µm and P(VC/MMA)/MWCNTs films were prepared using solution casting. A scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to investigate the films morphology and cross-sectional area and the vibrational properties, respectively. UV–vis measurements demonstrated that the transmittance spectra and absorption index were significantly affected by the film thickness and fillers content ratio. Moreover, both the direct and indirect optical bandgap increased with increasing thickness and decreased with increasing MWCNTs content inside P(VC/MMA) films. Further, thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) showed that the films exhibit thermal stability in the temperature range of 179–230 °C, and the melting temperature and degree of crystallinity increased with increasing thickness and decreased after doping with MWCNTs. The influences of film thickness and MWCNTs on the refractive index, dielectric constant, dielectric modulus, ac conductivity, impedance, and Nyquist plots have been discussed, along with the induced capacitance nature of the samples. Consequently, it was ascertained that the observed improvement in the optical properties and ac conductivity make these blends and nanocomposites suitable for optical devices and dielectric applications.

Effect of MWCNT on the Structure and Property of Nanofibrous Bundles by Blown Bubble Spinning.

Many spinning patents and technologies have been explored to produce diverse types of nanomaterials for different applications. As a novel method, the blown bubble-spinning is a one-step process for fabrication of nanofibrous bundles. In this study, polyamide6/66(PA6/66) nanofibrous bundles filled with different concentrations of multi-walled carbon nanotubes (MWCNTs) were prepared by the blown bubble-spinning. The dispersion of MWCNT in nanofibers under different treatments was investigated and a detailed characterization focusing on the influence of the presence of MWCNT on the morphology, thermal property and electrical property was carried out. The results showed that MWCNTs treated by Tween60 and ultrasonication were embedded in the PA6/66 nanofibers with uniform dispersion. In addition, it was observed that thermal stability and electrical conductivity of nanofibrous bundles increased with an increase in MWCNT content. The PA6/66/MWCNT nanofibrous bundles fabricated by the blown bubble spinning have the great potential applications in sensors and supercapacitors.

Flexible Electrode Based on MWCNT Embedded in a Cross-Linked Acrylamide/Alginate Blend: Conductivity vs. Stretching

A polyacrylamide-alginate hydrogel electrolyte, blended with Multi-Walled Carbon Nanotubes (MWCNT) as an electronically conductive fraction, allows for the creation of a flexible, durable, and resilient electrode. The MWCNT content is correlated with mechanical characteristics such as stretch modulus, tensile resistance, and electrical conductivity. The mechanical analysis demonstrates tensile strength that is comparable to similar hydrogels reported in the literature, with increasing strength for MWCNT-embedded hydrogels. The impedance spectroscopy reveals that the total resistance of electrodes decreases with increasing MWCNT content upon elongation and that bending and twisting do not obstruct their conductivity. The MWCNT-inserted hydrogels show mixed ionic and electronic conductivities, both within a range of 1–4 × 10−2 S cm−1 in a steady state. In addition, the thermal stability of these materials increases with incrementing MWCNT content. This observation agrees with long-term charge-discharge cycling that shows enhanced electrochemical durability of the MWCNT-hydrogel hybrid when compared to pure hydrogel electrolyte. The hydrogel-carbon films demonstrate an increased interfacial double-layer current at a high MWCNT content (giving an area-specific capacitance of ~30 mF cm−2 at 2.79 wt.% of MWCNT), which makes them promising candidates as printable and flexible electrodes for lightweight energy storage applications. The maximum content of MWCNT within the polymer electrolyte was estimated at 2.79 wt.%, giving a very elastic polymer electrode with good electrical characteristics.

An experimental investigation on natural convection of non-covalently functionalized MWCNTs nanofluids: Effects of aspect ratio and inclination angle

Abstract An experimental analysis was conducted to study natural convection heat transfer of water-based nanofluids. Two enclosures with the length × width × height(cm) dimensions of 10 × 10 × 10 and 20 × 10 × 10 and the inclination slopes of 0, 45 and 90° were considered. One of the walls was cooled and the opposite wall was heated. Multi-walled carbon nanotube (MWCNT)/water nanofluids were used as the heat transfer fluid while the MWCNTs were non-covalently functionalized by gum Arabic (GA). The MWCNT-GA/water nanofluids were prepared using 0.005, 0.05 and 0.1 wt% nanoparticles. According to the results, adding MWCNTs to water reduced free convection heat transfer in both enclosures. The effect of increasing MWCNT concentration on Nusselt number was found to be greater than the impact of changing Rayleigh number. Furthermore, free convection heat transfer increased with reducing inclination angle from 90° to 0° at high Rayleigh numbers. It was noticed that changing inclination angle has no considerable influence on Nusselt number at lower Rayleigh numbers. Moreover, free convection heat transfer increased about 8.77% with increasing the aspect ratio from 1 to 2. The highest reduction of Nusselt number was attributed to a system with the aspect ratio, concentration and inclination angle of 1, 0.1 wt% and 90°, respectively.

Electrical, mechanical, and optical changes in MWCNT-doped PMMA composite films

In this study, we report the preparation of poly (methyl methacrylate)/multi-walled carbon nanotube (MWCNT) composite thin films by simple and efficient solution mixing and ultrasonic method and the electrical, optical, and mechanical characterizations. Scattered light intensity ( I sc), tensile modulus ( E), and surface conductivity ( σ) of these composites have increased with the addition of MWCNT into the composite. The observed behavior in electrical, optical, and mechanical properties of the poly (methyl methacrylate)/MWCNT composites was interpreted by site and classical percolation theory. The optical mechanical and electrical percolation thresholds of poly (methyl methacrylate)/MWCNT composites were determined as φ op = 3 wt%, φ m = 0 wt%, and φσ = 5 wt%, respectively. The optical ( t op), mechanical ( t m), and electrical ( t σ) critical exponents were calculated as 2.23, 0.43, and 0.11, respectively. Both the tensile modulus and tensile strength of poly (methyl methacrylate)/MWCNT composites were increased with increasing MWCNT content until it reaches to 10 wt%. However, above φ = 10 wt%, the mechanical properties of the composites were decreased due to the aggregation of MWCNTs, while the toughness does not show a significant change until φ = 10 wt% MWCNT content, whereas it was decreased above this value.

Comprehensive study of effects of filler length on mechanical, electrical, and thermal properties of multi-walled carbon nanotube/polyamide 6 composites

In spite of active studies on multi-walled carbon nanotube (MWCNT)-incorporated polymer, MWCNTs of different thickness and lengths have been employed. Here, the effects of MWCNT morphology, specifically its length, on the mechanical, thermal, and electrical properties of MWCNT/polymer composites were examined in comparison with theoretical modeling. Field-emission scanning electron microscopy and micro-computed tomography observations revealed that short MWCNTs were dispersed more uniformly than long MWCNTs in a polyamide 6 (PA6) polymer. Correlation of this result with the tensile performance revealed that at low MWCNT concentrations the long-MWCNT/PA6 composite showed superior tensile properties since the effect of length was dominant. However, at high MWCNT concentrations, the short-MWCNT/PA6 showed superior tensile properties to the long-MWCNT/PA6 due to the better dispersion of the former. The thermal conductivity gradually improved with increasing MWCNT concentration, showing larger improvement for the long-MWCNT/PA6, while the electrical conductivity reached percolation threshold at 1 wt% for both MWCNTs.

Improvement of ablation resistance of epoxy composites reinforced with low concentrations of multi walled carbon nanotubes

Ablative materials are used as a thermal protection system for objects exposed to extreme friction and ultrahigh temperature. The ablation resistance of epoxy resin reinforced with multi-walled carbon nanotubes (MWCNTs) at low concentration was investigated. The ablation resistance improved with increasing MWCNT content. The linear ablation rate of 0.5 wt% MWCNT was 30.7% less than that of neat epoxy. On the ablated surface, curved cylinder structures with superior strength to the surrounding matrix were formed around MWCNTs which acted as nucleation sites. X-ray diffraction and Raman spectroscopy revealed the formation of near-graphite structures around MWCNTs in the non-graphitizable epoxy matrix. In conclusion, MWCNTs at low concentration could facilitate the formation of near-graphitic structures in quite large region of epoxy matrix, so dramatically enhanced ablation resistance.

TAILORING THE ELECTRICAL AND OPTICAL PROPERTIES OF CARBON NANOTUBE REINFORCED TRANSPARENT TiO2 COMPOSITES BY VARYING NANOTUBE CONCENTRATIONS

In the present work, multi-walled carbon nanotube (MWCNT)-doped TiO2 nanocomposite films were synthesized by sol–gel method. The influence of nanotube concentration on the structural, electrical and optical properties of the films was investigated. The beneficial effects of the addition of carbon nanotubes into a TiO2 film and titania-coated MWCNTs have much in common. On the other hand, this work contributes to the previous studies in terms of the optical and electrical properties of MWCNT. For this reason, MWCNT/rare brookite-phased TiO2 matrix as simple sol–gel deposited composite films were investigated in our study. The XRD studies showed that the composite film has a brookite crystal structure at the annealing temperature of 450∘C. According to the surface morphology investigations, SEM image of nanocomposite film shows that composite film has a granular and rod-like structure. The absorbance measurements of the films were carried out by the UV–Vis spectrophotometer to investigate transparency and to calculate the bandgap energy of composite films. The surface resistivity of the MWCNT-doped TiO2 composites decreased from [Formula: see text] to [Formula: see text] ohm/sq with increase in MWCNT content.

Effect of pristine MWCNTs on the fatigue life of GFRP laminates-an experimental and statistical evaluation

This research investigation explores the dispersion effectiveness of Pc (percolation threshold), 0.5, 1.0, 1.5 and 2.0 vol fraction of MWCNTs (Multiwalled Carbon Nanotubes) in epoxy using UV–Vis (Ultraviolet Visible Region) spectroscopy, their effect on the rheological properties of the solvent and mechanical properties of the fabricated NCs (nanocomposites). Addition of higher amount of MWCNTs increased the absorptivity of the solution in UV–Vis region depicting higher number of untangled and individual MWCNTs in the solution. However, post ultrasonication reagglomeration of these nanoparticles was found to be inevitable and its rate depended upon the amount of nanotubes in the epoxy. Addition of MWCNTs increased the viscosity of the polymer but they were found to be unable to diminish its shear thinning behaviour. Once proper dispersion of the nanotubes in the epoxy was confirmed by UV–Vis spectroscopy, their NCs with (three-phased) and without (two-phased) glass fibers were prepared. Tensile tests asserted that an increase in MWCNT content in the matrix increase toughness of the prepared nanocomposites. Individual CNTs contributed to the ultimate strength of the laminates and their aggregates enhanced the strain to failure. Addition of MWCNTs in GFRP (glass fiber reinforced polymer) laminates not only increased their cycles to failure but also imparted large coefficient of variation in their fatigue life. Reliability analysis and survival probability of the concerned laminates were included for their design considerations.

Electromagnetic properties and mechanisms of multiwalled carbon nanotubes modified cementitious composites

Abstract The effects of different types and contents of multiwalled carbon nanotubes (MWCNTs) on the electromagnetic wave absorption and shielding properties of cementitious composites as well as their mechanisms were investigated in this paper. Experimental results show that the electromagnetic properties of cementitious composites are improved with the increase of MWCNTs content and size. Besides, MWCNTs is more effective in enhancing the electromagnetic wave absorption performance of cementitious composites. The cementitious composite containing 0.8% of carboxylated MWCNTs with larger tube diameter achieves the best electromagnetic wave absorption property with a minimum reflectivity of −36 dB, which is 4.3 times that of cementitious composites without MWCNTs. The incorporation of 0.8% untreated MWCNTs with larger tube diameter and tube length endows cementitious composites a maximum electromagnetic wave shielding effectiveness of 3.3 dB, which is 27% higher than that of control samples. The electromagnetic wave absorption properties of cementitious composites with MWCNTs are dominated by dielectric loss rather than magnetic loss, and the electromagnetic wave shielding properties are dominated by reflection.

Fascinating thermo-mechanical features of layered hydroxides/MWCNTs nanocomposites

Multiwalled carbon nanotubes (MWCNTs) has been synthesized using chemical vapor deposition (CVD) method. Al – Layered Hydroxide (Al–LH) and MWCNTs nanocomposites; (1-x) Al–LH + (x) MWCNTs, 0.0 ≤ x ≤ 1; have been synthesized using citrate nitrate assisted hydrothermal technique. The crystal structure and the functional groups of the prepared samples were examined using X-ray diffraction (XRD) and Infrared spectroscopy (FTIR) respectively. The layered structure seemed under the high-resolution transmission electron microscopy (HRTEM), and the morphology was observed using field emission scanning electron microscopy (FESEM). Moreover, the synthesized nanocomposites were further characterized using Zeta potential, size analysis and Brunauer– Emmett–Teller (BET) surface area which showed their different characteristics as the MWCNTs content is changed. Thermal gravimetric analysis assured the thermal stability of the nanocomposites over the temperature from room up to 480 °C depending on the MWCNTs content. The obtained results revealed the improvement of all mechanical properties with the increase of MWCNTs content.

Enhanced mechanical properties of PDMS/PMMA composite membrane using MWCNTs and its application in phenol separation from saline wastewater

ABSTRACTThis work describes the enhanced mechanical properties of composite polydimethylsiloxane/poly(methyl methacrylate) (PDMS/PMMA)/multi‐walled carbon nanotubes (MWCNTs) nanofiber membrane and its application in the phenol separation from saline wastewater. MWNCTs with varied content were immobilized in the membrane matrix using electric field of electrospinning. The neat PDMS/PMMA and composite PDMS/PMMA/MWCNTs membranes were characterized by scanning electron microscopy, universal testing machine, contact angle measurement, 3D automatic optical profiler, and pore size analyzer. Results indicated that tensile strength of composite PDMS/PMMA/MWNCTs membrane was drastically increased six times with a water contact angle (WCA) of 163.3° due to increased roughness parameters compared to neat membrane. However, porosity and fiber diameter of PDMS/PMMA/MWCTs membrane decreased with the increase of MWCNTs content. Moreover, phenol extraction efficiency of PDMS/PMMA/MWNCTs membrane was found to be 34.5% higher than neat one with similar salt rejection efficiency of 99.97%. The stability of MWCNTs in the membrane matrix was confirmed by the cross‐sectional morphology, which indicated the robust and novel design of membrane. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47123.

Isothermal and non-isothermal crystallization kinetics of composites of poly(propylene) and MWCNTs

The isothermal and non-isothermal crystallization behaviour of composites of a poly(propylene) (PP) and multi-walled carbon nanotubes (MWCNTs) were investigated using Differential Scanning Calorimetry (DSC). An Avrami analysis was used to study the isothermal crystallization kinetics of unfilled PP and composites of PP with MWCNT loadings up to 2 (w/w). The value of the Avrami exponent (n) was greater than 2 for all samples, confirming the primary stage of crystal growth is a three-dimensional phenomenon. The activation energy (ΔE), determined using an Arrhenius type expression, for the isothermal crystallization of PP increased from 87 kJ for unfilled PP to 228 kJ on incorporation of 2 (w/w) MWCNTs to PP. An attempt was made to model the non-isothermal crystallization kinetics of composites of PP and MWCNTs using a range of mathematical models, including the Jeziorny extended Avrami equation, Ozawa equation, Caze and Chuah average Avrami exponents, and a combined Avrami/Ozawa approach. The Jeziorny extended Avrami approach confirmed that the non-isothermal crystallization of MWCNT filled PP is clearly a two-stage process. Fitting of the Ozawa model was shown to be not valid and both the Caze and Chuah average Avrami approaches were ineffective as neither took in to account the effects of secondary crystallization. Only the combined Avrami/Ozawa method successfully modelled the two-stage crystallization of composites of PP and MWCNTs. The activation energy (ΔE) for the non-isothermal crystallization of PP on addition of MWCNTs increased with increasing MWCNT content, up to as high as 726 kJ.