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Results for “Multifunctional nanocomposites”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Direct ink writing of shear exfoliated two-dimensional nanomaterial- elastomeric multifunctional nanocomposite

Direct ink writing (DIW) of polymer nanocomposites with high loadings of two-dimensional (2D) nanofillers (graphene and hexagonal boron nitride (hBN)) is challenging because of potential clogging, use of hazardous solvents, and agglomeration. Here, in this work, a shear exfoliation and sieving method to prepare DIW ink with high loading of nanofillers produced from low-cost bulk layered materials such as graphite and bulk hBN powder for successful DIW printing without the use of any solvents, binders, or plasticizers. The single-step exfoliation technique resulted in a composite with substantial layer reduction along the c-axis, as confirmed by SEM, TEM, XRD, and Raman analysis. Incorporating exfoliated graphene (40 wt%) increased viscosity by ∼6 orders of magnitude due to enhanced particle–matrix interactions, leading to pronounced yield stress behavior and a yield stress of approximately 1598 Pa, which enabled excellent shape retention during extrusion. Using the DIW technique, porous structures such as desalination membranes, self-sensing bone scaffolds, thermal management coating, and serpentine strain sensors were fabricated. When tested in a direct contact membrane distillation setup, the fabricated membrane demonstrated a promising permeate flux of 21.85 Lm −2 h −1 and a salt rejection of 74.3 %. The fabricated serpentine sensor exhibited stable signal variations under cyclic tensile loading, with a working range of 0–200 % strain and a maximum gauge factor of 43,735. A cell culture test using the printed bone scaffold demonstrated promising cell attachment and proliferation. The DIW printed hBN nanocomposite exhibited reversible shape change under heat, demonstrating potential 4D printing capability and efficient thermal management when exposed to high heat or flame.

Desalination↗
NASA NTRS2026

Application of Energy-efficient Electromagnetic Melt-Processing for the Upcycling of Recycled Polyphenylene Sulfide into Multifunctional Segregated Nanocomposites

Polyphenylene sulfide (PPS) is widely used in structural and functional composites because of its thermal stability, chemical resistance, and mechanical strength. As circular manufacturing becomes increasingly important, extending the service life of recycled PPS (rPPS) is essential. However, conventional high-temperature reprocessing accelerates thermo-oxidative degradation, reducing recycled composite performance. This study proposes a rapid and potentially energy-saving upcycling strategy for rPPS using electromagnetic (EM) melt-processing to form segregated carbon nanotube (CNT) networks and produce EM-responsive nanocomposites. The aim was to determine whether CNT-assisted EM heating could reduce polymer degradation while improving multifunctional properties at ultralow filler loadings. rPPS micropellets were coated with CNTs by ball milling to create conductive shells, then compacted into green bodies (GBs) and selectively melted by rapid EM irradiation. Structural, electrical, mechanical, rheological, and electromagnetic interference (EMI) shielding properties were evaluated. Electrical percolation occurred at an ultralow CNT loading of 0.08 wt%, with conductivity reaching (1.24 ± 0.74) × 10 -5 S⋅m -1 at 0.1 wt%. At this concentration, tensile strength and modulus increased by 72% and 99%, respectively. At ~ 0.7 mm thickness, X-band EMI shielding effectiveness reached 6 dB for GBs and 3 dB after EM processing. This shows that EM melt-processing upcycles rPPS into high-performance multifunctional nanocomposites with minimum thermal degradation.

recycled↗
NASA NTRS2015

Multifunctional Electroactive Nanocomposites Based on Piezoelectric Boron Nitride Nanotubes

Space exploration missions require sensors and devices capable of stable operation in harsh environments such as those that include high thermal fluctuation, atomic oxygen, and high-energy ionizing radiation. However, conventional or state-of-the-art electroactive materials like lead zirconate titanate, poly(vinylidene fluoride), and carbon nanotube (CNT)-doped polyimides have limitations on use in those extreme applications. Theoretical studies have shown that boron nitride nanotubes (BNNTs) have strength-to-weight ratios comparable to those of CNTs, excellent high-temperature stability (to 800 C in air), large electroactive characteristics, and excellent neutron radiation shielding capability. In this study, we demonstrated the experimental electroactive characteristics of BNNTs in novel multifunctional electroactive nanocomposites. Upon application of an external electric field, the 2 wt % BNNT/polyimide composite was found to exhibit electroactive strain composed of a superposition of linear piezoelectric and nonlinear electrostrictive components. When the BNNTs were aligned by stretching the 2 wt % BNNT/polyimide composite, electroactive characteristics increased by about 460% compared to the nonstretched sample. An all-nanotube actuator consisting of a BNNT buckypaper layer between two single-walled carbon nanotube buck-paper electrode layers was found to have much larger electroactive properties. The additional neutron radiation shielding properties and ultraviolet/visible/near-infrared optical properties of the BNNT composites make them excellent candidates for use in the extreme environments of space missions. utilizing the unique characteristics of BNNTs.

Kang, Jin Ho↗
DOE OSTI2020

ReaxFF Simulations of Laser-Induced Graphene (LIG) Formation for Multifunctional Polymer Nanocomposites

Irradiation of polymer films by a CO 2 infrared laser under ambient conditions converts the polymer into porous graphene or laser-induced graphene (LIG). In this work, we simulate the formation of LIG from five different commercially available polymers using reactive molecular dynamics. We determined that the molecular structure of the parent polymer has a significant effect on the final graphitic structure. CO is liberated during the initial part of the LIG formation process when the polymer is converted into an amorphous structure, while H 2 is evolved steadily as the amorphous structure is converted to an ordered graphitic structure. The LIG structure has out-of-plane undulations and bends due to a significant number of 5- and 7-member carbon rings present throughout the structure. We find that the simulated molecular structure compares well with recent experimental observations from the literature. We also demonstrate that the yield of LIG is higher in inert conditions, compared to environments with oxygen. Polybenzimidazole-derived LIG has the highest surface area and yield among the five polymers examined. These findings provide knowledge of LIG formation mechanisms that can be leveraged for bulk LIG applications such as sensors, electrocatalysts, microfluidics, and targeted heating for welding polymers.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Tea ( Camellia sinensis ) Extract-Mediated Green Synthesis of Co 3 O 4 and Co 3 O 4 @Graphene Nanocomposites for Multifunctional Applications in Pollutant Degradation, Sensing, and Energy Storage

A novel solution-mixing method was proposed to synthesize Co 3 O 4 /graphene nanocomposites (Co 3 O 4 @Gr) using a green tea leaf (Camellia sinensis) extract as the reducing agent. XRD analysis shows that the as-prepared Co 3 O 4 @Gr exhibits a cubic spinel crystal structure. From morphological analysis, the obtained Co 3 O 4 NS forms spherical clusters that are uniformly distributed on the graphene surface. FT-IR and Raman analyses confirmed the strong molecular and vibrational interactions between the Co 3 O 4 NS and Gr. The suppressed PL intensity peak of the Co 3 O 4 @Gr NCs indicated significant inhibition in the recombination of charge carriers between the hybrid orbitals within the composites. As a result, the catalytic efficiency of Co 3 O 4 @Gr NCs increased to 80% compared to pristine Co 3 O 4 , which exhibited only 45% efficiency against methylene blue (MB) dye. Moreover, the as-prepared NCs exhibited a detection limit of 0.01−224 μM, demonstrating a superior low-DPA detection with high sensitivity. The Co 3 O 4 @Gr/GCE exhibits admirable selectivity for various pesticides, fungicides, and metal ions, with outstanding reproducibility and stability. From electrochemical investigations, the highest specific capacitance values of the as-synthesized Co 3 O 4 @Gr were 349 F/g at a scan rate of 5 mV/s and 158 F/g at a current density of 1 A/g.

Capacitors↗
DOE OSTI2025

Polylactic acid (PLA)-based multifunctional and biodegradable nanocomposites and their applications

Polylactic acid (PLA)-based nanocomposites are emerging as multifunctional, biodegradable materials, offering sustainable alternatives to petroleum-based plastics. This review examines recent advancements in PLA nanocomposites, focusing on enhanced mechanical strength, thermal stability, and biodegradability achieved through nanofillers like metallic particles, carbon-based materials, and ceramics. Techniques such as in situ polymerization, melt mixing, and electrospinning enable application-specific improvements. PLA's limitations, including brittleness and low barrier properties, are addressed to support diverse applications: in packaging (e.g., extended shelf life), biomedicine (e.g., degradable implants), and electronics (e.g., flexible devices). Despite challenges with filler dispersion and thermal resistance, continued innovations expand PLA's potential across multiple industries, contributing to a sustainable, circular economy.

Biodegradable polymers↗
DOE OSTI2020

Room-Temperature Ferroelectric LiNb 6 Ba 5 Ti 4 O 30 Spinel Phase in a Nanocomposite Thin Film Form for Nonlinear Photonics

Tetragonal tungsten bronze (TTB) materials are one of the most promising classes of materials for ferroelectric and nonlinear optical devices, owing to their very unique noncentrosymmetric crystal structure. In this work, a new TTB phase of LiNb 6 Ba 5 Ti 4 O 30 (LNBTO) has been discovered and studied. A small amount of a secondary phase, LiTiO 2 (LTO), has been incorporated as nanopillars that are vertically embedded in the LNBTO matrix. The new multifunctional nanocomposite thin film presents exotic highly anisotropic microstructure and properties, e.g., strong ferroelectricity, high optical transparency, anisotropic dielectric function, and strong optical nonlinearity evidenced by the second harmonic generation results. An optical waveguide structure based on the stacks of α-Si on SiO 2 /LNBTO–LTO has been fabricated, exhibiting low optical dispersion with an optimized evanescent field staying in the LNBTO–LTO active layer. Lastly, this work highlights the combination of new TTB material designs and vertically aligned nanocomposite structures for further enhanced anisotropic and nonlinear properties.

36 MATERIALS SCIENCE↗
NASA NTRS2008

Multifunctional Nanotube Polymer Nanocomposites for Aerospace Applications: Adhesion between SWCNT and Polymer Matrix

Multifunctional structural materials can enable a novel design space for advanced aerospace structures. A promising route to multifunctionality is the use of nanotubes possessing the desired combination of properties to enhance the characteristics of structural polymers. Recent nanotube-polymer nanocomposite studies have revealed that these materials have the potential to provide structural integrity as well as sensing and/or actuation capabilities. Judicious selection or modification of the polymer matrix to promote donor acceptor and/or dispersion interactions can improve adhesion at the interface between the nanotubes and the polymer matrix significantly. The effect of nanotube incorporation on the modulus and toughness of the polymer matrix will be presented. Very small loadings of single wall nanotubes in a polyimide matrix yield an effective sensor material that responds to strain, stress, pressure, and temperature. These materials also exhibit significant actuation in response to applied electric fields. The objective of this work is to demonstrate that physical properties of multifunctional material systems can be tailored for specific applications by controlling nanotube treatment (different types of nanotubes), concentration, and degree of alignment.

Park, Cheol↗
DOE OSTI2023

Synthesis of a novel multifunctional organic–inorganic nanocomposite for metal ions and organic dye removals

In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h -1 ) was double that of Ze/AC (0.01 h -1 ). The reaction rate of Ze/L/AC (4.8 h -1 ) was also extraordinarily higher than that of Ze/AC (0.6 h -1 ) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R 2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R 2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol -1 ) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol -1 ).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Multifunctional Metal–Oxide Nanocomposite Thin Film with Plasmonic Au Nanopillars Embedded in Magnetic La 0.67 Sr 0.33 MnO 3 Matrix

Searching for multifunctional materials with tunable magnetic and optical properties has been a critical task toward the implementation of future integrated optical devices. Vertically aligned nanocomposite (VAN) thin films provide a unique platform for multifunctional material designs. In this work, a new metal–oxide VAN has been designed with plasmonic Au nanopillars embedded in a ferromagnetic La 0.67 Sr 0.33 MnO 3 (LSMO) matrix. Such Au–LSMO nanocomposite presents intriguing plasmon resonance in the visible range and magnetic anisotropy property, which are functionalized by the Au and LSMO phase, respectively. Furthermore, the vertically aligned nanostructure of metal and dielectric oxide results in the hyperbolic property for near-field electromagnetic wave manipulation. Such optical and magnetic response could be further tailored by tuning the composition of Au and LSMO phases.

36 MATERIALS SCIENCE↗
NASA NTRS2010

Highly Conductive Multifunctional Graphene Polycarbonate Nanocomposites

Graphene nanosheet bisphenol A polycarbonate nanocomposites (0.027 2.2 vol %) prepared by both emulsion mixing and solution blending methods, followed by compression molding at 287 C, exhibited dc electrical percolation threshold of approx.0.14 and approx.0.38 vol %, respectively. The conductivities of 2.2 vol % graphene nanocomposites were 0.512 and 0.226 S/cm for emulsion and solution mixing. The 1.1 and 2.2 vol % graphene nanocomposites exhibited frequency-independent behavior. Inherent conductivity, extremely high aspect ratio, and nanostructure directed assembly of the graphene using PC nanospheres are the main factors for excellent electrical properties of the nanocomposites. Dynamic tensile moduli of nanocomposites increased with increasing graphene in the nanocomposite. The glass transition temperatures were decreased with increasing graphene for the emulsion series. High-resolution electron microscopy (HR-TEM) and small-angle neutron scattering (SANS) showed isolated graphene with no connectivity path for insulating nanocomposites and connected nanoparticles for the conductive nanocomposites. A stacked disk model was used to obtain the average particle radius, average number of graphene layers per stack, and stack spacing by simulation of the experimental SANS data. Morphology studies indicated the presence of well-dispersed graphene and small graphene stacking with infusion of polycarbonate within the stacks.

Yoonessi, Mitra↗
NASA NTRS2007

Multifunctional, High-Temperature Nanocomposites

In experiments conducted as part of a continuing effort to incorporate multifunctionality into advanced composite materials, blends of multi-walled carbon nanotubes and a resin denoted gPETI-330 h (wherein gPETI h is an abbreviation for gphenylethynyl-terminated imide h) were prepared, characterized, and fabricated into moldings. PETI-330 was selected as the matrix resin in these experiments because of its low melt viscosity (<10 poise at a temperature of 280 C), excellent melt stability (lifetime >2 hours at 280 C), and high temperature performance (>1,000 hours at 288 C). The multi-walled carbon nanotubes (MWCNTs), obtained from the University of Kentucky, were selected because of their electrical and thermal conductivity and their small diameters. The purpose of these experiments was to determine the combination of thermal, electrical, and mechanical properties achievable while still maintaining melt processability. The PETI-330/MWCNT mixtures were prepared at concentrations ranging from 3 to 25 weight-percent of MWCNTs by dry mixing of the constituents in a ball mill using zirconia beads. The resulting powders were characterized for degree of mixing and thermal and rheological properties. The neat resin was found to have melt viscosity between 5 and 10 poise. At 280 C and a fixed strain rate, the viscosity was found to increase with time. At this temperature, the phenylethynyl groups do not readily react and so no significant curing of the resin occurred. For MWCNT-filled samples, melt viscosity was reasonably steady at 280 C and was greater in samples containing greater proportions of MWCNTs. The melt viscosity for 20 weightpercent of MWCNTs was found to be .28,000 poise, which is lower than the initial estimated allowable maximum value of 60,000 poise for injection molding. Hence, MWCNT loadings of as much as 20 percent were deemed to be suitable compositions for scale-up. High-resolution scanning electron microscopy (HRSEM) showed the MWCNTs to be well dispersed in the polymer matrices, while high-resolution transmission electron microscopy shows splits in the walls of the MWCNTs but no catastrophic breakage of tubes. To further assess processing characteristics prior to scale-up, samples containing 10, 15, and 20 weight-percent of MWCNTs were processed through a laboratory melting extruder. HRSEM of the extruded fibers shows significant alignment of MWCNTs in the flow direction (see figure). For the samples containing 20 weight-percent of MWCNTs, difficulties were encountered during feeding, and the temperature of a rotor in the extruder rose to 245 C because of buildup of frictional heat; this indicates that materials of this type having MWCNT concentrations .20 weight- percent may not be melt-processable. On the basis of the results from the foregoing characterizations, samples containing 10, 15, and 20 weight-percent of MWCNTs were scaled up to masses of .300 g and used to make specimens having dimensions of 10.2 by 15.2 by 0.32 cm. These specimens were molded by (1) injecting the mixtures, at temperatures between 260 and 280 C, into a tool made of the low-thermal-expansion alloy InvarR and then (2) curing for 1 hour at 371 C. The tool was designed to impart shear during the injection process in an attempt to achieve some alignment of the MWCNTs in the flow direction.

Connell, John W.↗
NASA NTRS2003

Design and Characterization of Carbon Nanotube Nanocomposites

Revolutionary design concepts in future aerospace vehicles will depend on extraordinary material properties to permit significant reduction of mass and size of components, while imparting intelligence. Due to their combination of remarkable electrical and mechanical properties, carbon nanotubes (CNT) are expected to enable this paradigm shift in design concepts. However, significant challenges still exist in translating these CNT properties into the macrostructures required for future generations of aerospace vehicles. While an accepted route for making the leap from nanostructures to useful macrostructures has not been fully charted, this paper will give an overview of the approach taken by some researchers at NASA Langley Research Center to sort out issues involved in the development of CNT nanocomposites for multifunctional structures. Specifically, the dispersion of carbon nanotubes in polymer matrices, characterization of nanocomposites, the role of quantum computation in providing guidance for processing and the use of computational analysis in data interpretation will be covered. Significant improvements in mechanical and electrical properties of CNT nanocomposites with very low loadings of CNTs are described and lend credence to the potential for using CNTs in achieving technological leaps in composite development.

Siochi, Emilie J.↗
DOE OSTI2023

Development of multifunctional nylon 6,6-based nanocomposites with high electrical and thermal conductivities by scalable melt and dry blending methods for automotive applications

With the advent of intelligent automobile technology, the demand for multifunctional composites with higher electrical and thermal conductivities is increasing. We have herein reported for the first time the effect of polyolester on the dispersion of carbon nanotube (CNT) in the short-carbon fiber (CF)/nylon 6,6 (PA66) composite using a scalable melt-mixing and dry-blending method and its subsequent improvement in electrical and thermal conductivities. Masterbatches were prepared with a higher concentration of CNT (both untreated and polyolester-treated) followed by dry blended with reference composite (30 wt% CF and 10 wt% mineral fiber filled PA66) before making coupons via injection molding. A 500% and 63% improvements in electrical (3.14 S cm -1 ) and thermal conductivities (in-plane) (1.99 W m -1 K -1 ) conductivities were observed by adding 1.5 wt% treated CNT compared to the reference composite. The improvements were even higher than that of untreated CNT due to better dispersion. Furthermore, the electromagnetic shielding effectiveness reached 61 dB for 1.5 wt% treated CNT-filled composite (39% enhancement). In conclusion, these results are significant in imparting multiple functionalities to the automotive composite parts.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Pore-Confined Polymers Enhance the Thermal Conductivity of Polymer Nanocomposites

In this work, molecularly confined polymer fillers in nanopores were found to give superior mechanical properties of polymer nanocomposites. In this work, we study the thermal conductivity of such nanocomposites and unveil the effect of polymer confinement on thermal conductivity. Using the time-domain thermoreflectance method, we measure the cross-plane thermal conductivity of polymer nanocomposites that consist of polystyrene fillers confined within a nanoporous organosilicate matrix. Compared to unconfined bulk polystyrene fillers, we find that pore-confined polystyrene fillers enhance the thermal conductivity of the polymer nanocomposites. This enhancement is attributed to the better aligned and less entangled chains in the confined phase, where chain–chain phonon scatterings are reduced. Our work provides essential insights into the thermal conductivity of polymer nanocomposites for multifunctional thermal and mechanical applications.

36 MATERIALS SCIENCE↗