Nanoparticle Organic Hybrid Materials Research Articles

Magnetically recoverable nanoparticle organic hybrid materials as kinetic hydrate inhibitors

Gas hydrates pose significant risks in the oil and gas industry because of their tendency to form blockages in transportation pipelines under low-temperature and high-pressure conditions. Conventional thermodynamic hydrate inhibitors require high dosages, with associated substantial costs and environmental concerns. Kinetic hydrate inhibitors (KHIs), which operate at much lower dosages, offer a more sustainable solution but are often limited by environmental compatibility and recovery problems. In this study, we introduce a novel class of magnetically recoverable KHIs utilizing nanoparticle organic hybrid materials (NOHMs), named NOHM-I-PNIPAM, featuring a tunable Fe3O4 core-SiO2 shell structure with poly(N-isopropylacrylamide) (PNIPAM) as the organic component. The chemical properties of NOHM-I-PNIPAM were characterized using TEM, FT-IR, and XPS. The hydrate kinetic inhibition performance was evaluated with a CH4 (90 %) + C2H6 (7 %) + C3H8 (3 %). Various grafting densities of PNIPAM on NOHMs and weight fractions of NOHM-I-PNIPAM were used to explore NOHM-I-PNIPAM’s role in the formation kinetics of natural gas hydrates under different cooling rates. Notably, the NOHM-I-PNIPAM (1.0), when utilized at a 2 wt% dosage, exhibited the most effective inhibition performance in terms of the onset temperature of CH4 (90 %) + C2H6 (7 %) + C3H8 (3 %) hydrate. Considering the effective concentration of PNIPAM in NOHM-I-PNIPAM, the inhibition performance was found to be comparable to that of conventional PNIPAM. Results showed that NOHM-I-PNIPAM is a promising KHI due to its combined properties of magnetic separation and comparable kinetic inhibition performance. Experimentally, NOHM-I-PNIPAM demonstrated stability over long-term cycles and was effectively magnetically separated. Hence, we believe that this work can provide valuable insights into the potential of NOHMs as recoverable and reusable KHIs for industrial applications for flow assurance.

Carbon capture in polymer-based electrolytes.

Nanoparticle organic hybrid materials (NOHMs) have been proposed as excellent electrolytes for combined CO2 capture and electrochemical conversion due to their conductive nature and chemical tunability. However, CO2 capture behavior and transport properties of these electrolytes after CO2 capture have not yet been studied. Here, we use a variety of nuclear magnetic resonance (NMR) techniques to explore the carbon speciation and transport properties of branched polyethylenimine (PEI) and PEI-grafted silica nanoparticles (denoted as NOHM-I-PEI) after CO2 capture. Quantitative 13C NMR spectra collected at variable temperatures reveal that absorbed CO2 exists as carbamates (RHNCOO- or RR'NCOO-) and carbonate/bicarbonate (CO32-/HCO3-). The transport properties of PEI and NOHM-I-PEI studied using 1H pulsed-field-gradient NMR, combined with molecular dynamics simulations, demonstrate that coulombic interactions between negatively and positively charged chains dominate in PEI, while the self-diffusion in NOHM-I-PEI is dominated by silica nanoparticles. These results provide strategies for selecting adsorbed forms of carbon for electrochemical reduction.

Interfacial-interaction induced modifications in segmental dynamics and free volume of the poly(ethyleneimine) canopy in nanoparticle-organic hybrid materials: an investigation by temperature dependent broadband dielectric and positron annihilation spectroscopy.

Broadband dielectric spectroscopy, positron annihilation lifetime spectroscopy and differential scanning calorimetry are used to investigate the molecular dynamics, free volume and thermal behaviour of a poly(ethyleneimine), PEI, canopy in liquid-like nanoparticle-organic hybrid materials (NOHMs) consisting of alumina nanoparticles and nanorods as inorganic nanocores. It is confirmed that the highly branched PEI canopy in liquid-like NOHMs possesses an ordered structure having less entanglements of the side chains as compared to neat PEI. The size of the free volumes associated with the PEI canopy for nanoparticle- and nanorod-based NOHMs is larger and smaller, respectively, as compared to neat PEI. The time scales characterizing the segmental dynamics and side chain relaxations of the canopy in the nanorod-based NOHM are slowed down drastically as compared to the nanoparticle-based NOHM and neat PEI. These results confirm that the shape of the inorganic cores plays a deterministic role toward the structural arrangement (free volume) and segmental dynamics of the canopy polymer in liquid-like NOHMs.

Elucidating the assembly of nanoparticle organic hybrid materials (NOHMs) near an electrode interface with varying potential using neutron reflectivity.

A critical concern regarding electrolyte formulation in an electrochemical environment is the impact of the interaction of the multiple components (i.e., supporting electrolyte or additive) with the electrode surface. Recently, liquid-like neat Nanoparticle Organic Hybrid Materials (NOHMs) have been considered as an electrolyte component to improve the transport of redox-active species to the electrode surface. However, the structure and assembly of the NOHMs near the electrode surface is unknown and could significantly impact the electrode-electrolyte interface. Hence, we have investigated the depth profile of polyetheramine (HPE) polymer and NOHM-I-HPE (nanoparticles with ionically bonded HPE polymer) in deuterated water (D2O) in the presence of two different salts (KHCO3 and ZnCl2) near two different electrode surfaces using neutron reflectometry. Moreover, the depth profile of the NOHM-I-HPE near the electrode surface in a potential has also been studied with in situ reflectivity experiments. Our results indicate that a change in the chemical structure/hydrophilicity of the electrode surface does not significantly impact the ordering of HPE polymer or NOHM-I-HPE near the surface. This study also indicates that the NOHM-I-HPE particles form a clear layer near the electrode surface immediately above an adsorbed layer of free polymer on the electrode surface. The addition of salt does not impact the layering of NOHM-I-HPE, though it does alter the conformation of the polymer grafted to the nanoparticle surface and free polymer sequestered near the surface. Finally, the application of negative potential results in an increased amount of free polymer near the electrode surface. Correlating the depth profile of free polymer and NOHM-I-HPE particles with the electrochemical performance indicates that this assembly of free polymer near the electrode surface in NOHM-I-HPE solutions contributes to the higher current density of the system. Therefore, this holistic study offers insight into the importance of the assembly of NOHM-I-HPE electrolyte and free polymer near the electrode surface in an electrochemical milieu on its performance.

Encapsulation of Nanoparticle Organic Hybrid Materials within Electrospun Hydrophobic Polymer/Ceramic Fibers for Enhanced CO2 Capture (Adv. Funct. Mater. 32/2023)

Encapsulation of Nanoparticle Organic Hybrid Materials within Electrospun Hydrophobic Polymer/Ceramic Fibers for Enhanced CO₂ Capture (Adv. Funct. Mater. 32/2023)

Kinetic and thermodynamic property study of electrostatic-assisted porous liquids, nanofluids and nanoparticle organic hybrid materials by molecular dynamics simulation

Despite similar components, electrostatic–assisted porous liquids, nanofluids and nanoparticle organic hybrid materials have different stability, thermodynamic and kinetic characteristics, mainly because of different preparation methods and core contents. In this work, porous liquids proved to be fluid at near room temperature and exist stably by molecular dynamics simulations. In contrast, nanoparticles of nanofluids tended to aggregate from one another because of the strong interaction between nanoparticles when the canopies were squeezed out. In addition, simulation results demonstrated that the degree of polymerization, core size and grafting density had distinct effects on glass transition temperature, dispersion and viscosity, which were brought by a combination of factors, including solid content and intramolecular / intermolecular entanglement.

Encapsulation of Nanoparticle Organic Hybrid Materials within Electrospun Hydrophobic Polymer/Ceramic Fibers for Enhanced CO2 Capture

AbstractLiquid‐like nanoparticle organic hybrid materials (NOHMs) consisting of a silica core with ionically grafted branched polyethyleneimine chains (referred to as NIPEI) are encapsulated within submicron‐scale polyacrylonitrile (PAN)/polymer‐derived‐ceramic electrospun fibers. The addition of a room‐temperature curable, liquid‐phase organopolysilazane (OPSZ) ceramic precursor to the PAN/NOHM solution enhances the internal dispersion of NOHMs and forms a thin ceramic sheath layer on the fiber exterior, shielding the hydrophilic NIPEI to produce near‐superhydrophobic non‐woven fiber mats with contact angles exceeding 140°. 60:40 loadings of NOHMs to PAN/OPSZ can be reliably achieved with low OPSZ percentages required, and up to 4:1 NOHM:polymer loadings are possible before losing hydrophobicity. These fibers demonstrate up to ≈2 mmol CO2 g−1 fiber capture capacities in a pure CO2 atmosphere through the nonwoven fibrous networks and the permeability of the OPSZ shell. The hybrid fibers additionally show enhanced capture kinetics under pure CO2 and 400 ppm CO2 conditions, indicating their promising application as a direct air capture platform.

Highly Tunable Syngas Product Ratios Enabled by Novel Nanoscale Hybrid Electrolytes Designed for Combined CO2 Capture and Electrochemical Conversion

AbstractCoupling renewable energy with the electrochemical conversion of CO2 to chemicals and fuels has been proposed as a strategy to achieve a new circular carbon economy and help mitigate the effects of anthropogenic CO2 emissions. Liquid‐like Nanoparticle Organic Hybrid Materials (NOHMs) are composed of polymers tethered to nanoparticles and are previously explored as CO2 capture materials and electrolyte additives. In this study, two types of aqueous NOHM‐based electrolytes are prepared to explore the effect of CO2 binding energy (i.e., chemisorption versus physisorption) on CO2 electroreduction over a silver nanoparticle catalyst for syngas production. Poly(ethylenimine) (PEI) and Jeffamine M2070 (HPE) are ionically tethered to SiO2 nanoparticles to form the amine‐containing NOHM‐I‐PEI and ether‐containing NOHM‐I‐HPE, respectively. At less negative cathode potentials, PEI and NOHM‐I‐PEI‐based electrolytes produce CO at higher rates than 0.1 molal. KHCO3 due to favorable catalyst‐electrolyte interactions. Whereas at more negative potentials, H2 production is favored because of the carbamate electrochemical inactivity. Conversely, HPE and NOHM‐I‐HPE‐based electrolytes display poor CO2 reduction performance at less negative potentials. At more negative potentials, their performance approached that of 0.1 molal. KHCO3, highlighting how the polymer functional groups of NOHMs can be strategically selected to produce value‐added products from CO2 with highly tunable compositions.

Synthesis of novel Al2O3 nanoparticle organic hybrid materials for enhancing the CO2-separation performance of prepared Al2O3-NOHMs/Pebax mixed matrix membrane

In this study, a novel liquid-like nanoparticle organic hybrid materials (NOHMs) is synthesized, in which Al2O3 was used as core, called as Al2O3-NOHMs, and it has been used for the first time to improve the performance of mixed matrix membranes (MMMs) for CO2 capture. In addition, the Al2O3-NOHMs with core/corona/canopy structure observed by TEM possess unique enthalpy effect and entropy effect, which can break through the trade-off effect of membrane separation process. According to gas separation permeation tests, the Al2O3-NOHMs/Pebax mixed matrix membranes with 2 wt% Al2O3-NOHMs showed higher CO2 permeability of 137.15 Barrer and CO2/N2 selectivity of 77.8 compared with neat Pebax membranes, and surpassed 2008 Robeson upper bound. Hence, this novel NOHMs is a very promising alternative to prepare MMMs for CO2 capture.

(Vittorio de Nora Award) Electrolytes: Discovery to Fundamentals, and Fundamentals to Discovery

I am humbled to be among the prominent scientist, engineers, and inventors who have been past ECS Vittorio De Nora Awardees. I have met with Professor De Nora on several occasions, and will share some anecdotes of these encounters throughout my presentation and give some historical perspectives. As you can imagine, because of my personal encounters with Professor De Nora and my long-time affiliation with the ECS, this Award is special to me. In this presentation I will talk about three different types of electrolyte systems that we have addressed over the years.One of my earlier projects was researching the performance factors of the all iron flow battery. This approach to energy storage was actually a direct outcome of Professor De Nora’s push to develop a large flow battery at the Diamond Shamrock Corporation. The effort was driven by the need for large-scale energy storage for power plant load leveling. Of course, the motivation of the all iron approach was that it is a simple redox system with the prospective for low cost and sustainable reactants. We published our experimental findings in 1981 in JES1. After a long hiatus of work on this system, it started to become of interest again about a decade ago with labs and companies pursuing this chemistry. We then introduced the concept of a slurry electrode for the all-iron flow battery, and pursued its development. The slurry electrode/electrolyte system facilitated the design to separate power capacity from energy capacity. I will talk about some of the key experimental observations and analysis with the slurry electrode, and the future prospects for an all-iron slurry energy storage system.The second system I will discuss is the proton conducting high temperature polymer membrane of PBI doped with phosphoric acid, which we introduced in the early 1990s2. Similar to the discovery of the DSA electrode invented by Henri Beer (1980 Vittorio De Nora Awardee) which De Nora is credited for commercializing, the PBI/PA system is an example of chance discovery. The PBI/PA discovery motivated several decades of research, and now is a commercial product. I will tell the story about the origin of the concept (with Professor Ernest Yeager, the 1995 Vittorio De Nora Awardee) and its discovery, and then summarize some of the advances made over the years.Finally, I will talk about the most recent research on electrolytes that I am involved in. There has been a long standing need for advancing the fundamental science for the discovery of new electrolytes for electrochemical energy storage systems including redox flow batteries and electrochemical capacitors; and also for electrochemical processes and devices such as energy conversion, metal deposition, separations and sensors. For example, by specifically designing new electrolytes with higher concentrations of electrochemically active species, low flammability and tunable transport properties, substantial improvements could be realized in (i) energy and power density, (ii) safety and reductions in environmental impact, and (iii) performance of energy storage systems. Our current research focus is on developing the fundamental underpinnings of three materials approaches: deep eutectic solvents (DESs), microemulsions, and nanoparticle organic hybrid materials (NOHMS). I will describe these three materials systems which have molecular and messo-scale structure that influence transport and interfacial properties. The goal of our activity is to develop an understanding of (i) structure-property relationships, (ii) transport mechanisms, (iii) interfacial electrode-electrolyte structure and its evolution, (iv) electron and ion transfer reactions in these structured materials systems, and (v) how these structures and properties can be tailored at the atomistic level to advance performance in electrochemical energy storage systems and electrochemical processes. In order to accomplish this goal, we have assembled a research team consisting of key researchers, students, and postdocs from seven academic institutions and one national lab, all having unique and specialized expertise and facilities. This team forms the DOE Emerging Frontier Research Center on Breakthrough Electrolytes for Energy Storage (EFRC-BEES)3. In this talk, I will address a couple of the approaches we are taking and what we learned about these materials systems as electrolytes4.Finally, I would like to thank the many colleagues and friends who have collaborated with and supported me over the past four to five decades, and especially all of my students and postdocs that I had the pleasure to work with.

Mechanistic Study of Controlled Zinc Electrodeposition Behaviors Facilitated by Nanoscale Electrolyte Additives at the Electrode Interface.

Nanoparticle organic hybrid materials (NOHMs) are liquid-like materials composed of an inorganic core to which a polymeric canopy is ionically tethered. NOHMs have unique properties including negligible vapor pressure, high oxidative thermal stability, and the ability to bind to reactive species of interest due to the tunability of their polymeric canopy. This makes them promising multifunctional materials for a wide range of energy and environmental technologies, including electrolyte additives for electrochemical energy storage (e.g., flow batteries) and the electrochemical conversion of CO2 to chemicals and fuels. Due to their unique transport behaviors in fluid systems, an understanding of the near-electrode surface behavior of NOHMs in electrolyte solutions and their effect on electrochemical reactions is still lacking. In this work, the complexation of zinc (Zn) by NOHMs with an ionically tethered polyetheramine canopy (HPE) (NOHM-I-HPE) was studied using attenuated total reflectance Fourier transform infrared and Carbon-13 nuclear magnetic resonance spectroscopy. Additionally, various electrochemical techniques were employed to discern the role of NOHM-I-HPE during zinc electrodeposition, and the results were compared to those of the electrochemical system containing untethered HPE polymers. Our findings confirmed that NOHM-I-HPE and HPE reversibly complex zinc in the aqueous electrolyte. NOHM-I-HPE and HPE were found to block some of the electrode active sites, reducing the overall current density during electrodeposition, while facilitating the formation of smooth zinc deposits, as revealed by surface imaging and diffraction techniques. Observed variations in the current density responses and the degree of passivation created by the NOHM-I-HPE and HPE adsorbed on the electrode surface revealed that their different packing behaviors at the electrode-electrolyte interface influence the zinc deposition mechanism. The presence of the nanoparticle and ordering offered by the NOHMs as well as the structured conformation of the polymeric canopy allowed the formation of void spaces and free volumes for enhanced transport behaviors. These findings provided insights into how structured electrolyte additives such as NOHMs can allow for advancements in electrolyte design for controlled deposition of metal species from energy-dense electrolytes or for other electrochemical reactions.

Nanoscale Hybrid Electrolytes with Viscosity Controlled Using Ionic Stimulus for Electrochemical Energy Conversion and Storage.

As renewable energy is rapidly integrated into the grid, the challenge has become storing intermittent renewable electricity. Technologies including flow batteries and CO2 conversion to dense energy carriers are promising storage options for renewable electricity. To achieve this technological advancement, the development of next generation electrolyte materials that can increase the energy density of flow batteries and combine CO2 capture and conversion is desired. Liquid-like nanoparticle organic hybrid materials (NOHMs) composed of an inorganic core with a tethered polymeric canopy (e.g., polyetheramine (HPE)) have a capability to bind chemical species of interest including CO2 and redox-active species. In this study, the unique response of NOHM-I-HPE-based electrolytes to salt addition was investigated, including the effects on solution viscosity and structural configurations of the polymeric canopy, impacting transport behaviors. The addition of 0.1 M NaCl drastically lowered the viscosity of NOHM-based electrolytes by up to 90%, reduced the hydrodynamic diameter of NOHM-I-HPE, and increased its self-diffusion coefficient, while the ionic strength did not alter the behaviors of untethered HPE. This study is the first to fundamentally discern the changes in polymer configurations of NOHMs induced by salt addition and provides a comprehensive understanding of the effect of ionic stimulus on their bulk transport properties and local dynamics. These insights could be ultimately employed to tailor transport properties for a range of electrochemical applications.

Insights into the Enhanced Oxidative Thermal Stability of Nanoparticle Organic Hybrid Materials Developed for Carbon Capture and Energy Storage

Insights into the Enhanced Oxidative Thermal Stability of Nanoparticle Organic Hybrid Materials Developed for Carbon Capture and Energy Storage

Encapsulation of highly viscous CO2 capture solvents for enhanced capture kinetics: Modeling investigation of mass transfer mechanisms

The encapsulation of highly viscous liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) inside a gas permeable polymer to form SIPs (Solvent Impregnated Polymers) significantly enhanced the CO2 capture kinetics of NOHMs, leading to a remarkable 50-fold increase in CO2 flux compared to the neat NOHMs. To understand the mechanism for enhanced CO2 mass transfer within these hybrid materials, kinetic modeling of CO2 uptake into SIPs containing polyethylenimine functionalized NOHMs, denoted NPEI-SIP, was conducted. CO2 mass transfer into NPEI-SIP films was found to conform, both qualitatively and quantitatively, with a diffusion-controlled moving front model. The diffusion-controlled model was also used to simulate CO2 uptake within a fixed bed containing polydisperse NPEI-SIP particles, and this model accurately predicted experimentally measured breakthrough curves at 25 °C and 50 °C. The 50-fold increase in gas flux was shown to be a consequence of the very large CO2 permeability within the polymer–solvent composite. The increase in gas flux is also dependent on the diffusion–reaction regime in which the chemical solvent operates, and the largest improvement will occur when immobilizing solvents, such as NOHMs, which operate in the instantaneous-reaction regime. The CO2 capacity (~3 mol CO2/kg) and saturation time (~5 min) of 430 μm SIP particles were comparable to popular CO2 chemisorption materials such as amine grafted silicates, in spite of the slow kinetics of NOHM-I-PEI in liquid form (CO2 saturation time ~24 h for a 1 mm thin film).

Dynamic Mixing Behaviors of Ionically Tethered Polymer Canopy of Nanoscale Hybrid Materials in Fluids of Varying Physical and Chemical Properties.

An emerging area of sustainable energy and environmental research is focused on the development of novel electrolytes that can increase the solubility of target species and improve subsequent reaction performance. Electrolytes with chemical and structural tunability have allowed for significant advancements in flow batteries and CO2 conversion integrated with CO2 capture. Liquid-like nanoparticle organic hybrid materials (NOHMs) are nanoscale fluids that are composed of inorganic nanocores and an ionically tethered polymeric canopy. NOHMs have been shown to exhibit enhanced conductivity making them promising for electrolyte applications, though they are often challenged by high viscosity in the neat state. In this study, a series of binary mixtures of NOHM-I-HPE with five different secondary fluids, water, chloroform, toluene, acetonitrile, and ethyl acetate, were prepared to reduce the fluid viscosity and investigate the effects of secondary fluid properties (e.g., hydrogen bonding ability, polarity, and molar volume) on their transport behaviors, including viscosity and diffusivity. Our results revealed that the molecular ratio of secondary fluid to the ether groups of Jeffamine M2070 (λSF) was able to describe the effect that secondary fluid has on transport properties. Our findings also suggest that in solution, the Jeffamine M2070 molecules exist in different nanoscale environments, where some are more strongly associated with the nanoparticle surface than others, and the conformation of the polymer canopy was dependent on the secondary fluid. This understanding of the polymer conformation in NOHMs can allow for the better design of an electrolyte capable of capturing and releasing small gaseous or ionic species.

Solvent Impregnated Polymers Loaded with Liquid‐Like Nanoparticle Organic Hybrid Materials for Enhanced Kinetics of Direct Air Capture and Point Source CO2 Capture

AbstractHybrid CO2 capture materials, solvent impregnated polymers (SIPs), are developed based on a simple and scalable encapsulation technique to enhance CO2 capture kinetics of water‐lean solvents with high viscosity. Liquid‐like nanoparticle organic hybrid materials functionalized with polyethylenimine (NOHM‐I‐PEI) are incorporated into a shell material and UV‐cured to produce gas‐permeable solid sorbents with uniform NOHMs loading (NPEI‐SIPs). The CO2 capture kinetics of NPEI‐SIPs show a remarkable 50‐fold increase compared to that of neat NOHM‐I‐PEI due to a large increase in the NOHMs‐CO2 interfacial surface area provided by the SIP design. The optimum NOHM‐I‐PEI loading and sorption temperature are found to be ≈49 wt% and 50 °C, respectively, and NPEI‐SIPs exhibit great thermal stability over 20 CO2 capture/sorbent regeneration temperature swing cycles. The pseudoequilibrium CO2 loadings of NPEI‐SIPs under humid conditions are as high as 3.1 mmol CO2 g−1NPEI − SIPs for 15 vol% CO2 (postcombustion capture) and 1.7 mmol CO2 g−1NPEI − SIPs for 400 ppm (direct air capture). These findings suggest that NPEI‐SIPs can effectively capture CO2 from a wide range of CO2 concentrations including direct air capture while allowing the flexible design of CO2 capture reactors by combining the benefits of liquid solvents and solid sorbents.

Localized and Collective Dynamics in Liquid-like Polyethylenimine-Based Nanoparticle Organic Hybrid Materials

Broadband dielectric spectroscopy, rheology, and nuclear magnetic resonance spectroscopy are employed to study molecular dynamics in a nanoparticle organic hybrid material (NOHMs) system comprising...

Tandem and Hybrid Processes for Carbon Dioxide Utilization

Sean Overa received a B.S. in chemical engineering from the University of South Carolina and is currently a chemical engineering PhD student in the Jiao group at the University of Delaware. His research is on electrochemical processes and reactor design, with a focus in two-step electrochemical conversion of CO₂. Primarily his work has focused on the production, design, and scale-up of zero-gap electrolyzers for conversion of CO₂ and CO to multi-carbon products. Tony Feric received a B.S. in chemical engineering from the University of Maryland, College Park and is currently a chemical engineering PhD student in the Park group at Columbia University. His research is focused on the design and development of novel nanoparticle organic hybrid materials (NOHMs) for CO₂ capture and electrochemical conversion to value-added products. More specifically, he is exploring their dynamics in solution, evaluating their stability under different processing conditions and understanding their unique interactions at the electrode-electrolyte interface. Ah-Hyung (Alissa) Park is the Lenfest Professor in applied climate science of Earth and environmental engineering & chemical engineering at Columbia University and is the director of the Lenfest Center for Sustainable Energy. Her research focuses on sustainable energy and materials conversion pathways with emphasis on integrated Carbon capture, utilization, and storage (CCUS). Park has led a number of global and national discussions on CCUS including the Mission Innovation Workshop on CCUS (2017) and the National Petroleum Council CCUS Report (2019). She is a Fellow of the American Association for the Advancement of Science, American Chemical Society, and Royal Society of Chemistry. Feng Jiao received a B.S. in chemistry from Fudan University and a PhD in chemistry from University of St Andrews. After a postdoctoral training at Lawrence Berkeley National Laboratory, Dr. Jiao joined the University of Delaware as a faculty member in 2010. He is now the Robert Grasselli Development Professor of Chemical and Biomolecular Engineering and serves as the director of the Center for Catalytic Science & Technology. The Jiao group focuses primarily on nanostructured materials, electrocatalysis, and carbon dioxide utilization.

Spectroscopic Investigation of Entropic Canopy-Canopy Interactions of Nanoparticle Organic Hybrid Materials.

Nanoparticle organic hybrid materials (NOHMs) are self-suspended liquid-like nanoparticle-based functional materials consisting of a surface-functionalized inorganic nanocore and oligomeric or polymeric chains. They often exhibit complex intermolecular and intramolecular interactions among their constituents, resulting in versatile physicochemical characteristics that range from glassy solids to solvent-free nanoparticle fluids. A variety of applications involving NOHMs have been investigated thus far, including thermal management fluids, lubricants, magnetic fluids, nanocomposites, electrolytes, water treatment and biomass pretreatment chemicals, and CO2 capture solvents. In particular, NOHMs have recently been recognized as a promising CO2 capture and utilization medium. To capture CO2 more effectively, a variety of specific functional groups of strong chemical affinity to CO2 can be added to the polymeric canopy (enthalpic contribution), and various steric considerations induced by attractive/repulsive interactions among the nanocores and canopies can be introduced (entropic contribution). These occur while maintaining negligible vapor pressure and enhanced thermal stability. Here, we investigated the canopy dynamics of NOHMs with different-sized SiO2 nanocores, aiming to reveal the hidden nature of the entropic interaction occurring in NOHMs. Pulse-field gradient nuclear magnetic resonance spectroscopy (with 1H) was employed to investigate the canopy dynamics of the NOHMs synthesized using 7, 12, and 22 nm SiO2 particles, and these results were compared with those from a ternary mix of all three sizes of SiO2 nanocores. The self-diffusion coefficient and thermal diffusivity were also evaluated.

Electrochemistry of Nanoscale Hybrid Materials (NOHM) Complexes

Nanoparticle organic hybrid materials, also known as NOHMs, are composite particles formed by polymers grafted (either ionically or covalently) onto surface-modified inorganic nanoparticles. The unique structure and liquid-like properties of such material have promoted the interest on its application as an electrolyte with the potential to capture and carry nonpolar electroactive species.In this work two types of NOHMs are considered. Both systems comprise silica cores ionically grafted with polymer tails. The polymer tails correspond to polyethylimine for the NOHM-I-PEI, and to polyetheramine with a sulfonic acid linker for the NOHM-I-HPE.Cyclic voltammetry was used to investigate the interaction of NOHM-I-PEI and NOHM-HPE with copper. NOHM-I-PEI showed a significant pH influence, with peak inhibition occurring at high pH. The protonation behavior of PEI and NOHM-I-PEI was explored (Figure 1). CV results suggest a strong binding of the copper ions and a potential competition between protons and metal ions. Copper hydroxide formation can also occur at higher pH. In contrast, onset potential shift was observed in presence of NOHM-I-HPE.These studies are complemented by exploration through Electron Paramagnetic Resonance (EPR) and Nuclear Magnetic Resonance (NMR). Through EPR, the nature of the ion in solution can be explored. On the other hand, 13C T1 relaxation of the NOHM-based electrolyte at different compositions provide information on the dynamics of the grafted polymers in solution Figure 1