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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 OSTI2013

Modeling Methane Adsorption in Interpenetrating Porous Polymer Networks

Porous polymer networks (PPNs) are a class of porous materials of particular interest in a variety of energy-related applications because of their stability, high surface areas, and gas uptake capacities. Computationally derived structures for five recently synthesized PPN frameworks, PPN-2, -3, -4, -5, and -6, were generated for various topologies, optimized using semiempirical electronic structure methods, and evaluated using classical grand canonical Monte Carlo simulations. We show that a key factor in modeling the methane uptake performance of these materials is whether, and how, these material frameworks interpenetrate and demonstrate a computational approach for predicting the presence, degree, and nature of interpenetration in PPNs that enables the reproduction of experimental adsorption data.

Martin, RL↗
DOE OSTI2016

Porous polymer network materials

Functionalized Porous Polymer Networks (PPNs) exhibiting favourable characteristics such as high surface area′ and gas uptake properties are disclosed, including methods of making such networks. A method of preparing a porous polymer network, comprising: (a) a step of homo-coupling a monomer in the presence of 2,2′-bipyridyl, 1,5-cycloocta-1,5-diene, a mixed solvent of DMF/THF and a compound or mixture selected from the group consisting of bis(1,5-cydoocta-1,5-diene)nickel(0), Ni(PPH3) 4, and Zn/NiCI2/NaBr/PPH3 at a temperature in the range of 20 to 40° C. These stable PPNs may be useful in the context of carbon capture, gas storage and separation, and as supports for catalysts.

Zhou, Hong -Cai↗
DOE OSTI2015

Facile one-pot synthesis of porphyrin based porous polymer networks (PPNs) as biomimetic catalysts

Stable porphyrin based porous polymer networks, PPN-23 and PPN-24, have been synthesized through a facile one-pot approach by the aromatic substitution reactions of pyrrole and aldehydes. We report PPN-24(Fe) shows high catalytic efficiency as a biomimetic catalyst in the oxidation reaction of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) in the presence of H 2 O 2 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Aromatic porous polymer network membranes for organic solvent nanofiltration under extreme conditions

Aromatic porous polymer networks (PPNs) are promising candidate materials for organic solvent nanofiltration (OSN) membranes, in which molecular-sieving selectivity, high permeability, and chemical/structural stability can be integrated. In this work, aromatic PPN membranes p-PPN, m-PPN and tri-PPN are fabricated by in situ aldol triple condensation cross-linking. These membranes demonstrate high stability, permeability and sharp selectivity in OSN, thanks to the aromatic nature of the backbone, high surface area (up to 1235 m 2 g -1 ), and narrowly distributed pore sizes. They possess a high organic solvent permeability so that a good permeance is achieved despite a thickness of over 100 μm. The molecular weight cut-off and molecular weight retention onset of these membranes are ~600 g mol -1 and 350 g mol -1 , respectively, making it possible to efficiently separate molecules from a complex mixture composed of compounds with only marginally different molecular weights. As a result of the highly stable nature of the aromatic backbones, these PPN membranes show retained structural integrity and OSN performance in the presence of either a strong acid or strong base for over 50 h. The extraordinary stability integrated with excellent permeability and selectivity renders these PPN membranes promising candidates for challenging OSN applications under extreme conditions.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Evaluation of amine-incorporated porous polymer networks (aPPNs) as sorbents for post­combustion CO 2 capture

This is the final report for the TAMU project “Evaluation of amine-incorporated porous polymer networks (aPPNs) as sorbents for post­combustion CO 2 capture.” During this project, a team consisting of the Zhou group at Texas A&M University and framergy Inc. were tasked with developing a porous polymer network (PPN) based sorbent system for CO 2 capture applications. The three year project was divided up into 3 individual budget periods. During budget period 1 the team develop multiple novel PPN based sorbents and began initial CO 2 capture experiments. During the course of this research the team determined that two sorbents were the standout targets, PPN-150-DETA and PPN-151-DETA. During budget period 2 the team further developed these two materials, gathering data to determine their performance under both wet and dry conditions, determine their CO 2 adsorption capacities, heats of adsorption, regenerative energy demands, and mechanical attrition. In addition, budget period 2 saw the development of 50 g and 250 g batches of both sorbents, while still maintaining >0.10 g/g uptake capacity under wet gas conditions. Following budget period 2 testing, the team opted to continue on with PPN-151-DETA due to its superior CO 2 cycling capabilities, with a consistent uptake capacity observed over 30 cycles at the lab scale. During budget period 3 the team further developed the material at scale, producing a 1 kg batch of material. Following this, the team performed multiple long-term cycling tests in the presence and absence of SO 2 using a 100 mL column. During this testing the team observed that the material loses significant uptake capacity due to SO 2 , as well as shows some level of DETA loss, which resulted in instrument breakdown and a request for a no-cost extension. The team was able to finalize the experiment with a test using a 1.5 L column in the absence of SO 2 , with the final cycle uptakes being around 0.035 g/g due to the need to harshly activate the material to prevent DETA desorption.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2015

Porous polymer networks and ion-exchange media and metal-polymer composites made therefrom

Porous polymeric networks and composite materials comprising metal nanoparticles distributed in the polymeric networks are provided. Also provided are methods for using the polymeric networks and the composite materials in liquid- and vapor-phase waste remediation applications. The porous polymeric networks, are highly porous, three-dimensional structures characterized by high surface areas. The polymeric networks comprise polymers polymerized from aldehydes and phenolic molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Porous polymer networks and ion-exchange media and metal-polymer composites made therefrom

Porous polymeric networks and composite materials comprising metal nanoparticles distributed in the polymeric networks are provided. Also provided are methods for using the polymeric networks and the composite materials in liquid- and vapor-phase waste remediation applications. The porous polymeric networks, are highly porous, three-dimensional structures characterized by high surface areas. The polymeric networks comprise polymers polymerized from aldehydes and phenolic molecules.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Amine-incorporated porous polymer networks (PPNs) as sorbents for post-combustion CO2 capture

The Zhou group has long been interested in the development of CO2 capture sorbents, having investigated both metal-organic frameworks (MOFs) and porous polymer networks (PPNs). In this work, we have begun an investigation of a new generation of PPN based sorbents. These PPN sorbents are low cost alternatives to expensive MOF sorbents, while achieving the low heats of adsorption necessary for economic CO2 capture.

post-combustion carbon capture, porous polymer net↗
DOE OSTI2019

Improving Alkylamine Incorporation in Porous Polymer Networks through Dopant Incorporation

The industrial scale capture of CO 2 from flue gas streams is becoming an increasingly important environmental issue. However, many of the existing CO 2 capture systems either have regenerative energy demands that are too high or are cost prohibitive. A promising solution is the utilization of functionalized solid sorbents, such as porous polymer networks (PPNs). PPNs are attractive due to their inherent structural stability, flexibility, high surface areas, and ability to incorporate various functional groups within the chemical scaffold. Herein, a low cost, scalable alternative to common carbon capture systems using a series of robust mesoporous melamine-formaldehyde resins (mPMFs) loaded with active alkylamine sorbents is presented, which is dubbed as the PPN-150 family. The variants within this material class are differentiated based on the incorporation of functionalized dopants; small molecules added at low molar percent concentrations to impart additional functionality into the PPN in order to achieve low cost noncovalent tethering of alkylamines. The cyanuric acid doped PPN-151-DETA (DETA = diethylenetriamine) demonstrate unique features such as improved cycling capacity and heat of adsorption. To show its scalability, PPN-151-DETA is successfully synthesized at the 250 g scale without loss of the sorbent properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Functionalized Porous Polymer Networks as High-Performance PFAS Adsorbents

Toxic per- and polyfluoroalkyl substances (PFAS) are now found in nearly every water source on the planet. Exposure to these molecules can have negative health consequences, but the low concentration of PFAS relative to other solutes in water makes their removal challenging. Adsorbents offer a promising treatment route, but often exhibit low selectivities and removal capacities, as well as slow kinetics. The performance in these metrics can be improved by chemically optimizing PFAS binding sites and maximizing PFAS-adsorbent interactions. To explore how to achieve this, a porous polymer network solid (PPN-6, also known as PAF-1) was postsynthetically modified with various chemical moieties capable of leveraging unique combinations of electrostatic, hydrogen-bonding, hydrophobic, and fluorophilic interactions with PFAS molecules. Batch adsorption experiments and computational studies revealed that electrostatic and hydrogen-bonding interactions drive short-chain PFAS adsorption, while hydrophobic and fluorophilic interactions improve long-chain PFAS adsorption. In complex water matrices, a combination of electrostatic and fluorophilic interactions led to the greatest total PFAS removal. The best-performing material, functionalized with a fluorinated alkylammonium (PPN-6-FNDMB), selectively adsorbs PFAS with high capacity (up to 4.0 mmol/g) and rapid kinetics (equilibrium reached in <30 s). Furthermore, PPN-6-FNDMB outperforms several commercial adsorbents, achieving near-complete removal of 21 different PFAS from a groundwater sample collected at a US Air Force base. The PFAS could subsequently be desorbed from PPN-6-FNDMB, concentrating them by a factor of over 50 times. The recycled PPN-6-FNDMB could then be reused with minimal losses in long-chain PFAS adsorption capacity over four cycles.

Pezoulas, Ethan R↗
DOE OSTI2018

Improving CO2 capture performance by incorporating functionalized materials in porous polymer networks

The Zhou group has developed a novel PPN based CO2 capture sorbent based on a melamine-formaldehyde resin. By incorporating an alkylamine within the basic framework we can achieve uptakes in excess of 10%wt. We have developed an alternative method of improving the cycling capacity of these PPN systems through the incorporation of dopant molecules. The dopant molecule, cyanuric acid, results in a material that only loses 4% of its uptake capacity over 30 cycles as opposed to a 20% loss without the dopant.

porous polymer network, alkylamines, post-combusti↗