Effect of Carbon Nanotube Dispersion on Glass Transition in Cross-Linked Epoxy–Carbon Nanotube Nanocomposites: Role of Interfacial Interactions

Bio-based epoxy resin/carbon nanotube coatings applied on cotton fabrics for smart wearable systems

Electroactive coatings for smart wearable textiles based on a furan bio-epoxy monomer (BOMF) crosslinked with isophorone diamine (IPD) and additivated with carbon nanotubes (CNTs) are reported herein. The effect of BOMF/IPD molar ratio on the curing reaction, as well as on the properties of the crosslinked resins was first assessed, and it was found that 1.5:1 BOMF/IPD molar ratio provided higher heat of reaction, glass transition temperature, and mechanical performance. The resin was then modified with CNT to prepare electrically conductive nanocomposite films, which exhibited conductivity values increased by eight orders of magnitude upon addition of 5 phr of CNTs. The epoxy/CNT nanocomposites were finally applied as coatings onto a cotton fabric to develop electrically conductive, hydrophobic and breathable textiles. Notably, the integration of CNTs imparted efficient and reversible electrothermal behavior to the cotton fabric, showcasing its potential application in smart and comfortable wearable electronic devices.

Investigations of the performance of 3D printed micro wind turbine composed of PLA material

Wind energy conversion systems (WECS) have gained increasing attention in recent years as promising renewable energy sources. Despite their potential, a clear research gap exists: the majority of WECS underperform in low wind speed conditions, limiting their applicability in many regions. To address this problem, this study proposes a novel approach by developing a 100 W micro wind turbine using Polylactic Acid (PLA) to generate efficient power in low wind speed conditions. The proposed wind turbine design employs Blade Element Momentum Theory (BEMT), which is commonly used for modeling wind turbine performance. Geometric design, mechanical analysis, and aerodynamic analysis are the fundamental considerations for designing any machine. In this work, the CREO 3.0 three-dimensional modeling software is used to create the geometric design of the proposed work. The airfoil SD7080 is selected due to its superior aerodynamic performance, and mechanical properties such as Young's modulus, density, and Poisson's ratio are attained to evaluate the wind blade's performance. Additionally, ANSYS 15.0 is used to conduct a detailed analysis of the proposed wind turbine, evaluating properties such as equivalent stress, deformation, and equivalent strain. Both simulation (ANSYS 15.0) and experimental setups are used to investigate the proposed wind turbine's performance, and the corresponding results are presented and discussed in this manuscript. The results indicate a significant performance improvement of the proposed wind blade when compared to conventional and ABS wind blades, demonstrating its potential as a more efficient solution for WECS. This proposed wind turbine design overcomes the problems like underprformance in low wind speed conditions and the wind turbine efficiency in all regions.

CNT-Reinforced Self-Healable Epoxy Dynamic Networks Based on Disulfide Bond Exchange

The design and utilization of polymers with healing capability have drawn increasing attention owing to their enhanced chain mobility and opportunity to heal minor cracks in composites. Rehealable thermoset polymers promise reduction in the maintenance cost and thus prolonged lifetime, reshaping, and recyclability. Introducing reversible covalent bonds is the mainstay strategy to achieve such plasticity in crosslinked polymers. Herein, we report a dynamic epoxy, which includes associative covalent adaptive networks (CANs) based on disulfide exchange bonds. Epoxy resin is chosen to study rehealing, as it is one of the most critical thermosetting polymers for various industries from aerospace to soft robotics. This study enlightens us about not only the consequences of CANs in the epoxy but also various factors such as soft segments and carbon nanotubes (CNTs). Epoxy dynamic networks are investigated in an attempt to explore the synergistic effect of the soft-segmented resins and CNTs on the healing and reshaping characteristics of epoxy networks along with varying stiffness. This research discusses epoxy dynamic networks in three main aspects: crosslink density, CAN density, and CNTs. Introducing soft segments into the epoxy network enhances the healing efficiency due to the increased chain mobility. A higher CAN density accelerates network rearrangement, improving the healing efficiency. It should also be noted that even with a low weight fraction of nanotubes, CNT-reinforced samples restored their initial strength more than neat samples after healing. The tensile strength of dynamic networks is at least 50 MPa, which is significant for their utility in primary or secondary structural components.

Semi-Continuous Heterophase Polymerization to Synthesize Poly(methacrylic acid)-Based Nanocomposites for Drug Delivery

The design of nanocomposites with the potential for drug delivery is a topic of great interest. In this work, the synthesis of nanocomposites of poly(methacrylic acid) (PMAA) grafted onto carbon nanotubes (CNTs) functionalized with poly(amidoamine) (PAMAM) dendrimer by semicontinuous heterophase polymerization SHP, at three different methacrylic acid (MAA) dosing rates, is reported. SHP is a polymerization technique poorly used to prepare nanocomposites containing CNTs and has the potential to produce more ordered alkyl methacrylic polymer chains, which could favor the obtaining of a homogenous nanocomposite. For the nanocomposites synthesized, a lowest addition rate monomer-starved condition was reached. Analysis by X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA) demonstrate that functionalized CNTs are grafted onto the PMAA matrix. The ability of prepared nanocomposites to deliver hydrocortisone was evaluated by ultraviolet-visible spectroscopy (UV-Vis). The hydrocortisone release profiles of pure PMAA and of their nanocomposites prepared at the lowest monomer fed rate were fitted with Higuchi and Korsmeyer–Peppas models, successfully. Functionalized CNTs have a crucial role to induce an effective release of hydrocortisone from the prepared nanocomposites.

Coarse-grained molecular simulation of the effects of carbon nanotube dispersion on the mechanics of semicrystalline polymer nanocomposites

With the incorporation of carbon nanotubes (CNTs), CNT/polypropylene (PP) nanocomposites are found to possess enhanced mechanical properties, but the reinforcing effect is reduced at large added CNT weight percentages due to CNT aggregation. Optimizing the properties of a nanocomposite requires a fundamental understanding of the effects of CNT dispersion on the nanocomposite. In this work, coarse-grained molecular models of CNT/PP nanocomposites are constructed, which consist of randomly dispersed or aggregated CNT bundles. Our simulation results reveal that with randomly dispersed CNT bundles, the nanocomposite shows properties that continuously improve with increasing CNT contents due to the effective CNT/PP interface and the reinforcing effect of CNTs. By comparison, the nanocomposite with aggregated CNT clusters exhibits a decline in yield strength at CNT contents over 3 wt%, which results from a reduced CNT load-carrying capacity due to the formation of structural voids in the interfacial region. This study achieves anin situobservation of the structural void evolution of loaded nanocomposites, provides valuable insights into the effects of CNT dispersion on the mechanics of CNT/PP nanocomposites, and paves the way for optimizing the design of nanocomposites with superior mechanical properties by designing the CNT dispersion in the structure.

Mechanical and Water Uptake Properties of Epoxy Nanocomposites with Surfactant-Modified Functionalized Multiwalled Carbon Nanotubes

The superior mechanical properties of multi-walled carbon nanotubes (MWCNTs) play a significant role in the improvement of the mechanical and thermal stability of an epoxy matrix. However, the agglomeration of carbon nanotubes (CNTs) in the epoxy is a common challenge and should be resolved to achieve the desired enhancement effect. The present paper investigated the thermal, mechanical, and water uptake properties of epoxy nanocomposites with surfactant-modified MWCNTs. The nanocomposites were prepared through the incorporation of different weight concentrations of MWCNTs into the epoxy matrix. Comparative analysis of neat epoxy and epoxy/CNT nanocomposites were conducted through thermal, mechanical, microscopic, and water uptake tests to reveal the improvement mechanism. The homogenous distribution of the CNTs in the epoxy was achieved by wrapping the surfactant onto the CNTs. The addition of surfactant-modified CNTs into the epoxy caused an obvious increase in the mechanical and thermal properties. This improvement mechanism could be attributed to the uniform dispersion of the CNTs in the epoxy matrix reducing the free volume between the polymer chains and restricting the chain segmental mobility, leading to strong interfacial bonding and an efficient load transfer capability between the CNTs and the epoxy matrix. However, the mechanical and thermal properties of the epoxy/CNT nanocomposite decreased owing to the agglomeration effect when the concentration of the CNTs exceeded the optimal percentage of 1.5%. Additionally, the CNTs could impart a reduction in the wettability of the surface of the epoxy/CNT nanocomposite, leading to the increase in the contact angle and a reduction in the water uptake, which was significant to improve the durability of the epoxy. Moreover, the higher weight concentration (2%) of the CNTs showed a greater water uptake owing to agglomeration, which may cause the formation of plenty of microcracks and microvoids in the nanocomposite.

Glass transition behaviour of thin polymer films coated on the 3D networks of porous CNT sponges

The glass transition behaviors of thin polymer films on the sidewalls of carbon nanotubes (CNTs) in CNT sponges (CNTSs) were studied. Due to the extremely large surface area of CNTS, the glass transition temperatures (Tg) of thin polystyrene (PS) and poly(methyl methacrylate) (PMMA) films were measured using a routine experimental method, differential scanning calorimetry (DSC). We thus provide a direct Tg comparison between the thin film and the bulk sample using the same DSC technique. For thin polymer films on the CNT sidewalls, free surface and polymer-substrate interfacial interactions co-exist. It is well-known that polymer chains at the liquid-like free surface tend to have a relatively high mobility, but the mobility in the interfacial layer near the substrate depends strongly on the polymer-substrate interaction strength. Accordingly, we tuned the polymer-substrate interaction strength by introducing an amphiphilic sodiumdodecylsulfate (SDS) molecule layer on the CNT sidewalls. The value and sign of Tg deviation were influenced by the competition between the free surface effect and the interfacial interactions. Strong polymer-substrate interactions led to a decrease in the mobility of polymer chains near the substrate and weak polymer-substrate interactions have little influence on the mobility of polymer chains near the substrate. When the polymer-substrate interactions are strong, both the free surface effect and the polymer-substrate interaction are key factors influencing the glass transition temperature. For thin polymer films having weak interactions with substrates, the free surface effect dominates the glass transition behavior and Tgs shows a large reduction. We also observed a double Tg behavior in the thin PS film and found the thickness of the PS film on the substrate was a deciding factor for controlling the spatial variation of Tg.

Analysis of Three-Phase Structure of Epoxy Resin/CNT/Graphene by Molecular Simulation

In this study, the three-phase structure consisting of epoxy resin, carbon nanotubes (CNTs), and graphene, which is assumed to be the surface of carbon fiber, was simulated using molecular dynamics. Models in which the CNT number and initial position of CNT are varied were prepared in this study. Relaxation calculation for each three-phase model was implemented, and the movement of molecules was investigated. When CNTs are located between the graphene and epoxy at initial, how the epoxy approaches to graphene was discussed. Besides, interaction energies between CNT/graphene, CNT/epoxy, and graphene/epoxy were evaluated after relaxations. The value of the interaction energy between two individual molecules (epoxy resin and graphene, CNTs and graphene, epoxy resin and CNTs) among three-phase structure were obtained, respectively, and those mechanisms were discussed in this study.

MARTINI-based simulation method for step-growth polymerization and its analysis by size exclusion characterization: a case study of cross-linked polyurethane

Simulation studies of step-growth polymerization, e.g., polymerization of polyurethane systems, hold great promise due to having complete control over the reaction conditions and being able to perform an in-depth analysis of network structures. In this work, we developed a (completely automated) simulation method based on a coarse-grained (CG) methodology, i.e., the MARTINI model, to study the cross-linking reaction of a diol, a tri-isocyanate molecule and one-hydroxyl functional molecule to form a polyurethane network without and with dangling chains. This method is capable of simulating the cross-linking reactions not only up to very high conversions, but also under rather complicated reaction conditions, i.e., a non-stoichiometric ratio of the reactants, solvent evaporation and multi-step addition of the reactants. We introduced a novel network analysis, similar to size-exclusion chromatography based on graph theory, to study the growth of the network during the polymerization process. By combining the reaction simulations with these analysis methods, a set of correlations between the reaction conditions, reaction mechanisms and final network structure and properties is revealed. For instance, a two-step addition of materials for the reaction, i.e., first the dangling chain to the tri-isocyanate and then the diol, leads to the highest integrated network structure. We observed that different reaction conditions lead to different glass transition temperatures (T_g) of the network due to the distinct differences in the final network structures obtained. For example, by addition of dangling chains to the network, the T_g decreases as compared to the network without dangling chains, as also is commonly observed experimentally.

Positive effect of functional side groups on the structure and properties of benzoxazine networks and nanocomposites

Calculated glass transition temperature of the MDP-a resin obtained through tetra-functional and penta-functional polymerization paths.

Effect of carbon nanotube (CNT) functionalization in Epoxy-CNT composites

The effect of carbon nanotube (CNT) functionalization in altering the properties of Epoxy-CNT composites is presented. The presence of functional groups effectively influenced the colloidal behavior of CNTs in the precursor epoxy resin and the hardener triethylenetetramine (TETA), which affected the synthesis process and eventually the interfacial interactions between the polymer matrix and the CNTs. The physical, thermal and electrical properties of the composites exhibited strong dependence on the nature of functionalization. At a 0.5 wt% CNTs loading, the enhancement in tensile strength was found to be 7.2, 11.2, 11.4 and 14.2 percent for raw CNTs, carboxylated CNTs, octadecyl amide functionalized CNTs and hydroxylated CNTs, respectively. Glass transition temperatures (T_g) also varied with the functionalization and composite prepared using hydroxylated CNTs showed the maximum enhancement of 34%.

Acid Free Oxidation and Simple Dispersion Method of MWCNT for High-Performance CFRP

Carbon nanotubes (CNT) provide an outstanding property spectrum which can be used to improve a wide range of materials. However, the transfer of properties from the nanoscale to a macroscopic material is a limiting factor. Different approaches of functionalizing the surface of a CNT can improve the interaction with the surrounding matrix but is connected to difficult and expensive treatments, which are usually inconvenient for industrial applications. Here, a simple and eco-friendly method is presented for the oxidation of CNT, where hydrogen peroxide (H₂O₂) is the only chemical needed and no toxic emissions are released. Also, the extensive step of the incorporation of CNT to an epoxy matrix is simplified to an ultrasonic dispersion in the liquid hardener component. The effectiveness is proven by mechanical tests of produced CNT/CFRP and compared to a conventional processing route. The combination of those simple and cost efficient strategies can be utilized to produce multiscale composites with improved mechanical performance in an ecological and economical way.

Do Carbon Nanotubes Improve the Thermomechanical Properties of Benzoxazine Thermosets?

Fillers are widely used to improve the thermomechanical response of polymer matrices, yet often in an unpredictable manner because the relationships between the mechanical properties of the composite material and the primary (chemical) structure of its molecular components have remained elusive so far. Here, we report on a combined theoretical and experimental study of the structural and thermomechanical properties of carbon nanotube (CNT)-reinforced polybenzoxazine resins, as prepared from two monomers that only differ by the presence of two ethyl side groups. Remarkably, while addition of CNT is found to have no impact on the glass-transition temperature ( T_g) of the ethyl-decorated resin, the corresponding ethyl-free composite features a surge by ∼47 °C (50 °C) in T_g, from molecular dynamics simulations (dynamic mechanical analysis measurements), as compared to the neat resin. Through a detailed theoretical analysis, we propose a microscopic picture for the differences in the thermomechanical properties of the resins, which sheds light on the relative importance of network topology, cross-link and hydrogen-bond density, chain mobility, and free volume.

Modeling the free-radical polymerization of hexanediol diacrylate (HDDA): a molecular dynamics and graph theory approach

In the printing, coating and ink industries, photocurable systems are becoming increasingly popular and multi-functional acrylates are one of the most commonly used monomers due to their high reactivity (fast curing). In this paper, we use molecular dynamics and graph theory tools to investigate the thermo-mechanical properties and topology of hexanediol diacrylate (HDDA) polymer networks. The gel point was determined as the point where a giant component was formed. For the conditions of our simulations, we found the gel point to be around 0.18 bond conversion. A detailed analysis of the network topology showed, unexpectedly, that the flexibility of the HDDA molecules plays an important role in increasing the conversion of double bonds, while delaying the gel point. This is due to a back-biting type of reaction mechanism that promotes the formation of small cycles. The glass transition temperature for several degrees of curing was obtained from the change in the thermal expansion coefficient. For a bond conversion close to experimental values we obtained a glass transition temperature around 400 K. For the same bond conversion we estimate a Young's modulus of 3 GPa. Both of these values are in good agreement with experiments.

Impact of ultrasonic assisted triangular lattice like arranged dispersion of nanoparticles on physical and mechanical properties of epoxy-TiO2 nanocomposites

Emerging ex-situ technique, ultrasonic dual mixing (UDM) offers unique and hitherto unapproachable opportunities to alter the physical and mechanical properties of polymer nanocomposites. In this study, triangular lattice-like arranged dispersion of TiO₂ nanoparticles (average size ∼ 48 nm) in the epoxy polymer has been attained via concurrent use of a probe ultra-sonicator and 4 blades pitched impeller which collectively named as UDM technique. The UDM processing of neat epoxy reveals the generation of triangular lattice-like arranged nanocavities with nanoscale inter-cavity spacing. The UDM processing of epoxy-TiO₂ nanocomposites reveals two unique features such as partial and complete entrapping of the nanoparticles by the nanocavities leading the arranged dispersion of particles in the epoxy matrix. Pristine TiO₂ nanoparticles were dispersed in the epoxy polymer at loading fractions of up to 20% by weight. The results display that the arranged dispersion of nanoparticles is very effective at enhancing the glass transition temperature (T_g) and tensile properties of the epoxy at loading fractions of 10 wt%. We quantify a direct relationship among three important parameters such as nanoparticle content, cluster size, and inter-particle spacing. Our results offer a novel understanding of these parameters on the T_g and tensile properties of the epoxy nanocomposites. The tensile fracture surfaces revealed several toughening mechanisms such as particle pull-out, plastic void growth, crack deflection, crack bridging and plastic deformation. We show that a strong nanoparticle-matrix interface led to the enhanced mechanical properties due to leading toughening mechanisms such as crack deflection, plastic deformation and particle pull-out. We showed that the UDM has an inordinate prospective to alter the dispersion state of nanoparticles in viscous polymer matrices.

Facile fabrication of epoxy-TiO2 nanocomposites: A critical analysis of TiO2 impact on mechanical properties and toughening mechanisms

Optimized ultrasonic assisted dispersion of un-functionalized titanium dioxide (TiO₂) nanoparticles (0.5-20wt%) into epoxy resin is reported. The investigation shows that there is a direct relation among nanoparticles content, inter-particle spacing and cluster size of the particles on the glass transition temperature (T_g) and tensile properties of the prepared nanocomposites. A significant improvement in tensile strength and modulus with minimal detrimental effect on the toughness was observed for the prepared composites, where compared to pristine epoxy resins, about 26% and 18% improvement in tensile strength and strain-to-break %, respectively, was observed for 10wt% particles loading, whereas a maximum improvement of about 54% for tensile toughness was observed for 5wt% particles loaded resins. The investigations found that a strong particle-matrix interface results in the enhancement of the mechanical properties due to leading toughening mechanisms such as crack deflection, particle pull out and plastic deformation.

Materials for Wind Turbine Blades: An Overview

A short overview of composite materials for wind turbine applications is presented here. Requirements toward the wind turbine materials, loads, as well as available materials are reviewed. Apart from the traditional composites for wind turbine blades (glass fibers/epoxy matrix composites), natural composites, hybrid and nanoengineered composites are discussed. Manufacturing technologies for wind turbine composites, as well their testing and modelling approaches are reviewed.

Molecular Mechanics of the Moisture Effect on Epoxy/Carbon Nanotube Nanocomposites

The strong structural integrity of polymer nanocomposite is influenced in the moist environment; but the fundamental mechanism is unclear, including the basis for the interactions between the absorbed water molecules and the structure, which prevents us from predicting the durability of its applications across multiple scales. In this research, a molecular dynamics model of the epoxy/single-walled carbon nanotube (SWCNT) nanocomposite is constructed to explore the mechanism of the moisture effect, and an analysis of the molecular interactions is provided by focusing on the hydrogen bond (H-bond) network inside the nanocomposite structure. The simulations show that at low moisture concentration, the water molecules affect the molecular interactions by favorably forming the water-nanocomposite H-bonds and the small cluster, while at high concentration the water molecules predominantly form the water-water H-bonds and the large cluster. The water molecules in the epoxy matrix and the epoxy-SWCNT interface disrupt the molecular interactions and deteriorate the mechanical properties. Through identifying the link between the water molecules and the nanocomposite structure and properties, it is shown that the free volume in the nanocomposite is crucial for its structural integrity, which facilitates the moisture accumulation and the distinct material deteriorations. This study provides insights into the moisture-affected structure and properties of the nanocomposite from the nanoscale perspective, which contributes to the understanding of the nanocomposite long-term performance under the moisture effect.

Effect of Interfacial Bonding on Interphase Properties in SiO2/Epoxy Nanocomposite: A Molecular Dynamics Simulation Study

Atomistic molecular dynamics simulations have been performed to explore the effect of interfacial bonding on the interphase properties of a nanocomposite system that consists of a silica nanoparticle and the highly cross-linked epoxy matrix. For the structural properties, results show that interfacial covalent bonding can broaden the interphase region by increasing the radial effect range of fluctuated mass density and oriented chains, as well as strengthen the interphase region by improving the thermal stability of interfacial van der Waals excluded volume and reducing the proportion of cis conformers of epoxy segments. The improved thermal stability of the interphase region in the covalently bonded model results in an increase of ∼21 K in the glass transition temperature (Tg) compared to that of the pure epoxy. It is also found that interfacial covalent bonding mainly restricts the volume thermal expansion of the model at temperatures near or larger than Tg. Furthermore, investigations from mean-square displacement and fraction of immobile atoms point out that interfacial covalent and noncovalent bonding induces lower and higher mobility of interphase atoms than that of the pure epoxy, respectively. The obtained critical interfacial bonding ratio when the interphase and matrix atoms have the same mobility is 5.8%. These results demonstrate that the glass transitions of the interphase and matrix will be asynchronous when the interfacial bonding ratio is not 5.8%. Specifically, the interphase region will trigger the glass transition of the matrix when the ratio is larger than 5.8%, whereas it restrains the glass transition of the matrix when the ratio is smaller than 5.8%.

Understanding n-Octane Behavior near Graphene with Scaled Solvent-Solute Attractions

We employ molecular dynamics simulations of n-octane near a layered graphene surface to study the related phenomena of solvation, density fluctuations, wettability, and structure and dynamics of n-octane molecules in the inhomogeneous interfacial environment. That solvation in bulk n-octane displays a lengthscale-dependent crossover similar to that of hydrophobic solvation in water is known. Here we show that, near an extended graphene interface having attractive interactions with n-octane, lengthscale-dependent solvation is similar to that in the bulk and displays a small to large crossover. However, as the n-octane-graphene interactions are reduced to make the surface increasingly solvophobic, the crossover behavior is modulated and essentially absent near the most solvophobic surfaces, similar to that in water near hydrophobic interfaces. We show that the macroscopic measure of wettability, namely, the contact angle, characterizes n-octane-graphene coupling over a limited range of attractions. In contrast, molecular measures such as the free energy of cavity formation or the local compressibility in the interfacial region provide an effective measure of this coupling over a broader range of attractions. Finally, as n-octane-graphene attractions are increased, the n-octane liquid displays a wetting transition and corresponding change from sigmoidal to layered density profile. Analysis of the local structure shows that n-octane molecules prefer approximately linear conformations and surface-parallel orientations near the graphene surface, and their translational dynamics slow down with increasing n-octane-graphene attractions. Our study highlights molecular scale behavior of n-octane molecules that is relevant to understanding nanoparticle-solvent coupling in composite materials with enhanced mechanical or thermal properties.

A carbon nanotube–epoxy interface improved damping below the glass transition temperature

Composites made from fibers and epoxy display a low viscous drag and are rarely used as mechanical dampers at room temperature.

Dynamic mechanical properties of multiwall carbon nanotube reinforced ABS composites and their correlation with entanglement density, adhesion, reinforcement and C factor

Herein, the dynamic mechanical properties of MWCNTs reinforced ABS composites have been studied using a DMA and the results have been correlated with entanglement density, adhesion, reinforcement and C Factor.

Depression in glass transition temperature of multiwalled carbon nanotubes reinforced polycarbonate composites: effect of functionalization

Acid functionalized MWCNTs/PC composites showed significant improvement in storage modulus upto 57% in glassy and 400% in rubbery region over pure polycarbonate.

Effect of carbon nanotube functionalization on mechanical and thermal properties of cross-linked epoxy-carbon nanotube nanocomposites: role of strengthening the interfacial interactions

We have used amido-amine functionalized carbon nanotubes (CNTs) that form covalent bonds with cross-linked epoxy matrices to elucidate the role of the matrix-filler interphase in the enhancement of mechanical and thermal properties in these nanocomposites. For the base case of nanocomposites of cross-linked epoxy and pristine single-walled CNTs, our previous work (Khare, K. S.; Khare, R. J. Phys. Chem. B 2013, 117, 7444-7454) has shown that weak matrix-filler interactions cause the interphase region in the nanocomposite to be more compressible. Furthermore, because of the weak matrix-filler interactions, the nanocomposite containing dispersed pristine CNTs has a glass transition temperature (Tg) that is ∼66 K lower than the neat polymer. In this work, we demonstrate that in spite of the presence of stiff CNTs in the nanocomposite, the Young's modulus of the nanocomposite containing dispersed pristine CNTs is virtually unchanged compared to the neat cross-linked epoxy. This observation suggests that the compressibility of the matrix-filler interphase interferes with the ability of the CNTs to reinforce the matrix. Furthermore, when the compressibility of the interphase is reduced by the use of amido-amine functionalized CNTs, the mechanical reinforcement due to the filler is more effective, resulting in a ∼50% increase in the Young's modulus compared to the neat cross-linked epoxy. Correspondingly, the functionalization of the CNTs also led to a recovery in the Tg making it effectively the same as the neat polymer and also resulted in a ∼12% increase in the thermal conductivity of the nanocomposite containing functionalized CNTs compared to that containing pristine CNTs. These results demonstrate that the functionalization of the CNTs facilitates the transfer of both mechanical load and thermal energy across the matrix-filler interface.