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Results for “polymer coatings”

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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

A capacitive technique for real-time monitoring polymer coating thickness on carbon filaments during prepregging process

A technique for gauging the coating thickness during prepreg processing of carbon fibers was developed. It is based on the concept of measuring the capacitance of a cylindrical condenser through which a bundle of prepregged fibers is passed axially. Empirical results indicate the capacitance of this condenser element is linearly related to the polymer coating thickness on the fibers in the bundle. The capacitive transducer was successfully used to measure the polymer thickness on several test fiber bundles under static conditions.

Eftekhari, Abe↗
DOE OSTI2025

Electrokinetically Enhanced Rare Earth Element Separation through Polymer Coated Capillary Arrays

I, Kyle McCarthy, will give an oral presentation on research findings from Energy and Homeland Security LDRD "A New, Green Approach to Rare Earth Element (REE) Purification Based on Electrokinetics." in talk titled "Electrokinetically Enhanced Rare Earth Element Separation through Polymer Coated Capillary Arrays." at the upcoming Sandia postdoc technical showcase. I will also attend other live presentations and conduct professional networking. This fits within Sandia's energy security mission.

McCarthy, Kyle Patrick [Sandia National Laboratori↗
DOE OSTI2025

Stabilizing lithium-metal electrodes with polymer coatings

Increasing the energy density of batteries can accelerate the deployment of electric vehicles, expand the utilization of renewable energy and, in turn, reduce greenhouse gas emissions. Different from commercially available lithium-ion batteries, high-energy-density lithium-metal batteries use metallic lithium instead of graphite as the negative electrode. Furthermore, the commercialization of lithium-metal batteries is hindered by the electrochemical instability of lithium metal. Polymer coatings have shown promise in addressing issues related to each step of heterogeneous lithium deposition. Here we summarize the current understanding of key design principles and highlight relevant coating compositions. Moreover, we discuss high-performing coating–electrolyte pairs and provide an outlook on interface design for novel electrolytes.

Batteries↗
NASA NTRS1989

Polymer Coatings Reduce Electro-osmosis

Poly(ethylene glycol) film controls electrostatic potential. Electro-osmosis in quartz or glass chambers reduced or reversed by coating inside surface of chambers with monomacromolecular layers of poly(ethylene glycol). Stable over long times. Electrostatic potential across surface of untreated glass or plastic chamber used in electro-phoresis is negative and attracts cations in aqueous electrolyte. Cations solvated, entrains flow of electrolyte migrating toward cathode. Electro-osmotic flow interferes with desired electrophoresis of particles suspended in electrolyte. Polymer coats nontoxic, transparent, and neutral, advantageous for use in electrophoresis.

Herren, Blair J.↗
NASA NTRS2008

Thermal Spray Formation of Polymer Coatings

This innovation forms a sprayable polymer film using powdered precursor materials and an in-process heating method. This device directly applies a powdered polymer onto a substrate to form an adherent, mechanically-sound, and thickness-regulated film. The process can be used to lay down both fully dense and porous, e.g., foam, coatings. This system is field-deployable and includes power distribution, heater controls, polymer constituent material bins, flow controls, material transportation functions, and a thermal spray apparatus. The only thing required for operation in the field is a power source. Because this method does not require solvents, it does not release the toxic, volatile organic compounds of previous methods. Also, the sprayed polymer material is not degraded because this method does not use hot combustion gas or hot plasma gas. This keeps the polymer from becoming rough, porous, or poorly bonded.

Coquill, Scott↗
DOE OSTI2022

Transport of polymer-coated metal–organic framework nanoparticles in porous media

Abstract Injecting fluids into deep underground geologic structures is a critical component to development of long-term strategies for managing greenhouse gas emissions and facilitating energy extraction operations. Recently, we reported that metal–organic frameworks are low-frequency, absorptive-acoustic metamaterial that may be injected into the subsurface to enhance geophysical monitoring tools used to track fluids and map complex structures. A key requirement for this nanotechnology deployment is transportability through porous geologic media without being retained by mineral-fluid interfaces. We used flow-through column studies to estimate transport and retention properties of five different polymer-coated MIL-101(Cr) nanoparticles (NP) in siliceous porous media. When negatively charged polystyrene sulfonate coated nanoparticles (NP-PSS-70K) were transported in 1 M NaCl, only about 8.4% of nanoparticles were retained in the column. Nanoparticles coated with polyethylenimine (NP-PD1) exhibited significant retention (> 50%), emphasizing the importance of complex nanoparticle-fluid-rock interactions for successful use of nanofluid technologies in the subsurface. Nanoparticle transport experiments revealed that nanoparticle surface characteristics play a critical role in nanoparticle colloidal stability and as well the transport.

58 GEOSCIENCES↗
DOE OSTI2023

Mechanical Actuation via Homeomorphic Transformations of Topological Solitons within Polymer Coatings

Abstract Topological solitons are currently under investigation for their exotic properties, especially in nonlinear physics, optics, and material sciences. However, challenges of robust generation and limited stability over time have hindered their practical uses. To address this issue, an approach is developed to form structured arrays of solitons in films of polymerizable liquid crystals. Their complex molecular architecture is preserved by in situ photopolymerization forming a stable liquid crystal network. Most excitingly, their properties are advanced to include responsiveness functions. When thermally actuated, these topological solitons mediate the reconfiguration of surface topographies. Complex shape changes occur depending on the intrinsic complex spatial distribution of the director, which may even lead to full shape inversion and topographical changes as high as ≈40% of the initial thickness. Conversely, the shape changes provide information on the initial director profile, which is consistent with the mathematical model. The soliton‐containing polymer coatings are applicable in multiple domains, ranging from tunable optics to haptics, and from shape‐coupled sensing systems to temperature‐coupled heat management.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Dendrite Suppression by a Polymer Coating: A Coarse‐Grained Molecular Study

Abstract A major hurdle to the successful deployment of high‐energy‐density lithium metal based batteries is dendrite growth during battery cycling, which raises safety and cycle life concerns. Coating the Li metal anode with a soft polymer layer has been previously shown to be effective in suppressing dendrite growth, leading to uniform lithium deposition even at high current densities. A 3D coarse‐grained molecular model to study the mechanism of dendrite suppression is presented. It is found that the most effective coatings delay or even prevent dendrites from penetrating the polymer layer during deposition. The optimal deposition can be achieved by jointly tuning the polymer stiffness and relaxation time. Higher polymer dielectric permittivity and coating thickness are also effective, but the deposition rate and, therefore, the charging current density is reduced. These findings provide the basis for rational design of soft polymer coatings for stable lithium deposition.

Kong, Xian↗
NASA NTRS2017

Insulation Materials Comprising Fibers Having a Partially Cured Polymer Coating Thereon, Articles Including Such Insulation Materials, and Methods of Forming Such Materials and Articles

Insulation materials have a coating of a partially cured polymer on a plurality of fibers, and the plurality of coated fibers in a cross-linked polymeric matrix. Insulation may be formed by applying a preceramic polymer to a plurality of fibers, heating the preceramic polymer to form a partially cured polymer over at least portions of the plurality of fibers, disposing the plurality of fibers in a polymeric material, and curing the polymeric material. A rocket motor may be formed by disposing a plurality of coated fibers in an insulation precursor, curing the insulation precursor to form an insulation material without sintering the partially cured polymer, and providing an energetic material over the polymeric material. An article includes an insulation material over at least one surface.

Morgan, Richard E.↗
DOE OSTI2026

Polymer coatings on zirconia microspheres via rotating flow fluid dynamics

Conventional tristructural isotropic (TRISO) coatings for nuclear fuels require multi-step and expensive formation processes; any breakage of the coatings may lead to fission species release. Polymer derived ceramic (PDC) coatings can be a suitable alternative to address these issues. In this study, allylhydridopolycarbosilane (SMP-10) coatings were created on yttria stabilized zirconia (YSZ) microspheres using a Rotating Flow Fluid Dynamics (RFFD) coating method. The effects of curing temperature, rotation speed, and coating cycle/time on the coating were analyzed. Surface functionalization of YSZ microspheres with NaOH resulted in good adhesion between the polymer precursor and the YSZ kernel particles. Spectroscopy analysis revealed complete curing of SMP-10 coated YSZ at 160 °C. Rotation speed and coating time significantly affect the coating characteristics. After 3 cycles at lower rotation speed (50 rpm) for 10 min each, the coating obtained was uniform and homogeneous. In comparison, the coating showed almost 10 times less eccentricity at a high rotation speed of 300 rpm. Compared with the coatings prepared at 300 rpm condition, the coatings have higher sphericity and lower eccentricity at 50 rpm. Overall, this study provides a novel and effective route for fabricating and curing SMP-10 precursor coatings on YSZ microspheres.

Ravi, Nivetha [University of Alabama, Birmingham]↗
NASA NTRS1978

Aqueous vinylidene fluoride polymer coating composition

A water-based coating composition which may be air dried to form durable, fire resistant coatings includes dispersed vinylidene fluoride polymer particles, emulsified liquid epoxy resin and a dissolved emulsifying agent for said epoxy resin which agent is also capable of rapidly curing the epoxy resin upon removal of the water from the composition.

Bartoszek, Edward J.↗
NASA NTRS2019

Mitigation of Silver Ion Loss from Solution by Polymer Coating of Metal Surfaces

Spacecraft potable water systems require a biocidal agent that effectively provides both immediate and residual disinfection over long periods of time. Ionic silver (Ag+) is a leading candidate for this application, but suffers from rapid concentration loss due interactions with the metal storage containers and tubing. In order to maintain biocidal efficacy in systems with long periods of dormancy and to reduce the required rate of Ag+ injection, it is necessary to develop alternative materials and coatings for certified metal alloys that significantly reduce the Ag+ loss. In this work, we investigate the performance of two unusual polymers, Teflon AF 2400 and parylene-AF4, as barrier coatings under immersion in 400 ppb Ag+. We show that 25 m-thick parylene-AF4 is a promising coating with Ag+ losses similar to PTFE. Key challenges with this material include maintenance of adhesion under long-term immersion and control of deposition during the internal coating of high-aspect ratio tubing. Solutions to these problems may including surface structuring of substrates for mechanical anchoring or an alternative parylene-C chemistry (with more stable adhesion), and dynamic spatio-temporal control of substrate temperature, respectively.

water↗
NASA NTRS2004

Assessment of Erosion Resistance of Coated Polymer Matrix Composites for Propulsion Applications

The erosion behavior of tungsten carbide-cobalt (WC-Co) coated and uncoated polymer matrix composites (PMCs) was examined with solid particle impingement using air jets. Erosion tests were conducted with Arizona road dust impinging at 20 degrees, 60 degrees, and 90 degrees angles at a velocity of 229 meters per second at both 294 and 366 K. Noncontact optical profilometry was used to measure the wear volume loss. Results indicate that the WC-Co coating enhanced erosion resistance and reduced erosion wear volume loss by a factor of nearly 2. This should contribute to longer wear lives, reduced related breakdowns, decreased maintenance costs, and increased product reliability.

Miyoshi, Kazuhisa↗
DOE OSTI2024

Multi-coat polymer photonic crystal films

Polymer composite photonic crystal materials are disclosed as coatings and topcoats which have high reflection (>30%) in a specific range of the electromagnetic spectrum, such as ultraviolet (<400 nm), visible (Vis, 400 nm-700 nm), or near-infrared radiation range (NIR, 700-2000 nm), and relatively low reflection (<20% reflection) in a second, different range of the electromagnetic spectrum. Surprisingly, it was found that through a formulation and additives approach, the optical properties of polymer composite photonic crystal films can be selectively modified from a variety of different coating methods, including spray deposition.

Pearson, Ryan Michael↗
NASA NTRS2020

Mitigation of Silver Ion Loss from Solution by Polymer Coating of Metal Surfaces, Part II

“Spacecraft potable water systems require a biocidal agent that effectively provides both immediate and residual disinfection over long periods of time. Ionic silver (Ag+) is a leading candidate for this application, but suffers from rapid concentration loss due to interactions with the metal storage containers and tubing. In order to maintain biocidal efficacy in systems with long periods of dormancy and to reduce the required rate of Ag+ injection, it is necessary to develop alternative materials and coatings for certified metal alloys that significantly reduce the Ag+loss.”1In this work, we continue our investigation of vapor-deposited parylene (AF4, and now C) polymers as conformal barrier coatings under long-term (ca. 1-year) immersion in ca. 400 ppb Ag+. The performanceof internal coatings in tubing/two-ferrule fitting systems is characterized. We report successful “aging” and high concentration Ag+pretreatment of parylene coatings for quantitative reduction of Ag+loss rates. In addition, we observe long-term blister-free adhesion of mechanically anchored parylene-AF4 on nano-structured Ti-6Al-4V alloy and chemically bonded parylene-C on 316L stainless steel. Finally, we report preliminary experiments with mechanical and chemical anchoring of laboratory-deposited parylene-C on 316L.

Silver↗
NASA NTRS1982

Polymer coating of glass microballoons levitated in a focused acoustic field

Inertial confinement fusion (ICF) glass microballoons (GMBs) levitated in a focusing radiator acoustic device can be coated with liquid materials by deploying the liquid into the levitation field with a stepped-horn atomizer. The GMB can be forced to the center of the coating liquid with a strong acoustically generated centering force. Water solutions of organic polymers, UV-curable liquid organic monomers, and paraffin waxes have been used to prepare solid coatings on the surface of GMBs using this technique.

Young, A. T.↗
NASA NTRS1994

Mechanical properties of crosslinked polymer coatings

The objectives of this experiment are to: fabricate and test thin films to explore relations between a polymer's structure and its mechanical properties; expose students to testing methods for hardness and impact energy that are simple to perform and which have results that are easy to comprehend; show importance of polymer properties in materials that students frequently encounter; illustrate a system which displays a tradeoff between strength and impact resistance, the combination of which would need to be optimized for a particular application; and to expose students to coatings technology and testing.

Csernica, Jeffrey↗