Liquid-like Nanoparticle Organic Hybrid Materials Research Articles

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.

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.

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.

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.

CO2 selective separation of Pebax-based mixed matrix membranes (MMMs) accelerated by silica nanoparticle organic hybrid materials (NOHMs)

Liquid-like nanoparticle organic hybrid materials (NOHMs) hold great promise in CO2 capture due to tailored nanostructures and functionalities. Herein, we demonstrate a facile and generic method to enhance CO2 selective separation of Pebax-based MMMs by NOHMs. NOHMs with core/corona/canopy structure based on silica with different particle size (120 nm, 220 nm and 380 nm) were prepared, respectively. The basic physicochemical properties of NOHMs and MMMs were examined. Excellent interface compatibility is obtained due to the peculiar property of liquid-like NOHMs in resolving nanoparticles agglomeration. More importantly, CO2-philic moieties (EO segments) in canopy (polyetheramine M2070) endow MMMs with a superior CO2 selective separation. The effect of NOHMs content on mixed gases permeation were systemically investigated. Remarkably, the optimum CO2 permeability reached 246.7 Barrer and a satisfied CO2/N2 selectivity of 66.4 for membrane (P-NOHMs-120-(15)) was obtained, which were increased by 267.1% and 76.1% compared with pristine Pebax membrane, respectively. Moreover, Grand Canonical Monte Carlo (GCMC) molecular simulation was used to investigate how NOHMs improve CO2 selective separation by analyzing interaction parameters (interaction energy, density field distribution and isosteric heat). Finally, the enhanced CO2 selective separation sites were determined. The CO2 selective separation accelerated by NOHMs proposed in present work provides ingenious inspiration for the development of novel fillers in MMMs due to the tailored nanostructures of NOHMs.

Selective separation of CO2 using novel mixed matrix membranes based on Pebax and liquid-like nanoparticle organic hybrid materials

Pebax1657 is known as a promising polymeric membrane material for CO2 separation. In order to further improve its gas separation performance, different polymers containing ethylene oxide (EO) groups are incorporated into the Pebax1657 matrix to form mixed matrix membranes (MMMs). Liquid-like nanoparticle organic hybrid materials (NOHM-I-HPE, “I” stands for “ionic bond” and “HPE” refers to polyetheramine (“PE”) with a high (“H”) ether group content), which are made of polyetheramine chains tethered onto functionalized silica nanoparticles, have shown high solubility of CO2. In this study, the homogenous NOHM-I-HPE/Pebax1657 MMMs with different NOHM-I-HPE loadings are prepared and investigated. The results indicate that the addition of NOHM-I-HPE leads to a decrease in glass transition temperature of Pebax1657 and an increase in EO content of the MMMs. Influences of NOHM-I-HPE content on CO2, N2 and CH4 permeations are investigated at 23 °C and 1 bar. For the NOHM-I-HPE loading ranging from 0 to 60 wt%, solubility coefficients of the MMMs for CO2 greatly increase from 1.16 to 3.84 cm3 (STP)/(cm3·bar), while those for CH4 and N2 only increase from 0.078 to 0.094 cm3 (STP)/(cm3·bar) and from 0.013 to 0.026 cm3 (STP)/(cm3·bar), respectively. Although the CO2/N2 selectivity slightly decreases with an increase in the NOHM-I-HPE loading, the CO2/CH4 selectivity is improved in the newly developed NOHM-I-HPE/Pebax1657 MMMs. These results indicate that the NOHM-I-HPE/Pebax1657 MMMs are very promising candidates for selective CO2 separation for various energy related applications.

Improving the Damping Properties of Nanocomposites by Monodispersed Hybrid POSS Nanoparticles: Preparation and Mechanisms.

In this work, a series of heptaphenyl siloxane trisilanol/polyhedral oligomeric silsesquioxane (T7-POSS) modified by polyols with different molecular weights were synthesized into liquid-like nanoparticle–organic hybrid materials using the grafted-from method. All grafted POSS nanoparticles changed from solid powders to liquid at room temperature. Polyurethane (PU) nanocomposites with POSS contents ranging from 1.75 to 9.72 wt % were prepared from these liquefied polyols-terminated POSS with polyepichlorohydrin (POSS–PECH). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the morphology of the POSS–PECH/PU nanocomposites. The results showed that the polyol-terminated POSS particles overcame the nanoagglomeration effect and evenly disperse in the polymeric matrix. The damping factor (tan δ) of resultant nanocomposites increased from 0.90 to 1.16, while the glass transition temperature decreased from 15.8 to 9.4 °C when POSS contents increased from 0 to 9.75 wt %. The gel content, tensile strength and Fourier transform infrared (FTIR) analyses demonstrated that the molecular thermal movement ability of the polyurethane (PU) matrix increased with increasing POSS hybrid content. Therefore, the improvement of the damping properties of the composites was mainly due to the friction-related losses occurring in the interface region between the nanoparticles and the matrix.

Liquid-like CNT/SiO2nanoparticle organic hybrid materials as fillers in mixed matrix composite membranes for enhanced CO2-selective separation

Liquid-like nanoparticle organic hybrid materials with core/canopy/corona were used as fillers in Pebax-1657 matrix to fabricate mixed-matrix membranes. The effect of composite core composition on CO2/N2separation performance was systematically investigated.

Selective Separation of Co<Sub>2</Sub> Using Novel Mixed Matrix Membranes Based on Pebax and Liquid-Like Nanoparticle Organic Hybrid Materials

Pebax1657 is known as a promising polymeric membrane material for CO2 separation. In order to further improve its gas separation performance, different polymers containing ethylene oxide (EO) groups were incorporated into the Pebax1657 matrix to form mixed matrix membranes. Liquid-like nanoparticle organic hybrid materials (NOHM-I-HPE, “I” stands for “ionic bond” and “HPE” refers to polyetheramine (“PE”) with a high (“H”) ether group content), which were made of polyetheramine chains tethered onto functionalized silica nanoparticles, have shown high solubility of CO2. In this study, the homogenous NOHM-I-HPE/Pebax1657 mixed matrix membranes with different NOHM-IHPE loadings were prepared and investigated. The results of differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS) indicated that the addition of NOHM-I-HPE resulted in a decrease in glass transition temperature of Pebax1657 and an increase in EO content of the mixed matrix membrane. Single gas permeabilities of CO2, N2 and CH4 at 23 °C and 1 bar were measured using the time-lag method. For the NOHM-I-HPE loading ranging from 0 to 60 wt.%, solubility coefficients of the mixed matrix membranes for CO2 greatly increased from 1.16 to 3.84 cm3 (STP)/(cm3·bar), while those for CH4 and N2 only slightly increased from 0.078 to 0.094 cm3 (STP)/(cm3·bar) and from 0.013 to 0.026 cm3 (STP)/(cm3·bar), respectively. CO2 permeability increased four times compared to the pure Pebax1657 membrane after the incorporation of 60 wt.% NOHM-I-HPE in Pebax1657. Although the CO2/N2 selectivity slightly decreased with an increase in the NOHM-I-HPE loading, the CO2/CH4 selectivity was improved in the newly developed NOHM-IHPE/Pebax1657 mixed matrix membranes. These results indicate that the NOHM-I-HPE/Pebax1657 mixed matrix membranes are very promising candidates for selective CO2 separation for various energy related applications.

Synthesis of liquid-like trisilanol isobutyl-POSS NOHM and its application in capturing CO2

The trisilanol isobutyl polyhedral oligomeric silsesquioxane(POSS) was fabricated into liquid-like nanoparticle organic hybrid materials(NOHMs) with γ-(2,3-epoxypropoxy)propytrimethoxysilane as corona and polyetheramine M2070 as canopy, and the product was called liquid-like POSS NOHM. The liquid-like POSS NOHM has a low viscosity at room temperature without any solvent and the mass fraction of trisilanol isobutyl POSS was 23.38%. The liquid-like POSS NOHM shows great CO2 capturing property with a capacity of 2.108 mmol/g(pCO2=6 MPa). The physical adsorption increased obviously with the pressure going up and it may make a difference between liquid-like POSS NOHMs and traditional monoethamolamine(MEA) based CO2 absorbent. The recycle property was also studied. The NOHM behaved as fresh product even after 10 cycles.

Effect of canopy structures and their steric interactions on CO2 sorption behavior of liquid-like nanoparticle organic hybrid materials

Download options Please wait... Supplementary files Supplementary information PDF (325K) Article information DOI https://doi.org/10.1039/C3RA46801A Article type Communication Submitted 18 Nov 2013 Accepted 02 Jan 2014 First published 06 Jan 2014 Download Citation RSC Adv., 2014,4, 8723-8726 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Effect of canopy structures and their steric interactions on CO2 sorption behavior of liquid-like nanoparticle organic hybrid materials Y. Park, C. Petit, P. Han and A. Alissa Park, RSC Adv., 2014, 4, 8723 DOI: 10.1039/C3RA46801A To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Youngjune Park Camille Petit Patrick Han Ah-Hyung Alissa Park

Design and Characterization of Liquidlike POSS-Based Hybrid Nanomaterials Synthesized via Ionic Bonding and Their Interactions with CO2

Liquidlike nanoparticle organic hybrid materials (NOHMs) were designed and synthesized by ionic grafting of polymer chains onto nanoscale silica units called polyhedral oligomeric silsesquioxane (POSS). The properties of these POSS-based NOHMs relevant to CO2 capture, in particular thermal stability, swelling, viscosity, as well as their interactions with CO2, were investigated using thermogravimetric analyses, differential scanning calorimetry, and NMR and ATR FT-IR spectroscopies. The results indicate that POSS units significantly enhance the thermal stability of the hybrid materials, and their porous nature also contributes to the overall CO2 capture capacity of NOHMs. The viscosity of the synthesized NOHMs was comparable to those reported for ionic liquids, and rapidly decreased as the temperature increased. The sorption of CO2 in POSS-based NOHMs also reduced their viscosities. The swelling behavior of POSS-based NOHMs was similar to that of previously studied nanoparticle-based NOHMs, and this generally resulted in less volume increase in NOHMs compared to their corresponding polymers for the same amount of CO2 loading.

Effect of water on the physical properties and carbon dioxide capture capacities of liquid-like Nanoparticle Organic Hybrid Materials and their corresponding polymers

Binary systems composed of liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) and the secondary fluid (i.e., water) were prepared, and their thermal stabilities, densities, viscosities, and CO2 absorption capacities were investigated. Recent work has suggested NOHMs as an alternative CO2 capture media with interesting chemical and physical tunability. Anhydrous CO2 capture solvents often degrade when they are exposed to water, while flue gas generally contains about 8–16% water. Thus, this study was conducted to investigate the effect of water on the NOHMs’ properties relevant to CO2 capture as well as the chemical and thermal stabilities of H2O-loaded NOHMs. It was found that water acted as an antisolvent of NOHMs, and therefore, caused a decreased CO2 capture capacity. On the other hand, the results indicated that while water did not affect the NOHMs’ thermal stability, it significantly helped lowering their density and viscosity. In order to investigate the effect of intermolecular interactions among two fluids on the density and viscosity, the excess volumes and viscosity deviations were calculated and correlated with Redlich–Kister equations. The trends revealed the existence of strong intermolecular interactions between water molecules and the poly(ethlyne glycol) component of NOHMs, which may have caused the drastic decrease in the NOHMs’ viscosity with the addition of water.

Effect of SO2 on CO2 Capture Using Liquid-like Nanoparticle Organic Hybrid Materials

Liquid-like nanoparticle organic hybrid materials (NOHMs), consisting of silica nanoparticles with a grafted polymeric canopy, were synthesized. Previous work on NOHMs has revealed that CO2 capture behaviors in these hybrid materials can be tuned by modifying the structure of the polymeric canopy. Because SO2, which is another acidic gas found in flue gas, would also interact with NOHMs, this study was designed to investigate its effect on CO2 capture in NOHMs. In particular, CO2 capture capacities as well as swelling and CO2 packing behaviors of NOHMs were analyzed using thermogravimetric analyses and Raman and attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopies before and after exposure of NOHMs to SO2. It was found that the SO2 absorption in NOHMs was only prominent at high SO2 levels (i.e., 3010 ppm; Ptot = 0.4 MPa) far exceeding the typical SO2 concentration in flue gas. As expected, the competitive absorption between SO2 and CO2 for the same absorption sites (i.e., ether and amine groups) resulted in a decreased CO2 capture capacity of NOHMs. The swelling of NOHMs was not notably affected by the presence of SO2 within the given concentration range (Ptot = 0–0.68 MPa). On the other hand, SO2, owing to its Lewis acidic nature, interacted with the ether groups of the polymeric canopy and, thus, changed the CO2 packing behaviors in NOHMs.

Spectroscopic Investigation of the Canopy Configurations in Nanoparticle Organic Hybrid Materials of Various Grafting Densities during CO2 Capture

Novel liquid-like nanoparticle organic hybrid materials (NOHMs) made of polyetheramine chains tethered onto functionalized silica nanoparticles were synthesized and characterized before and after exposure to CO2 using NMR, Raman, and ATR FT-IR spectroscopies in order to investigate the effect of the grafting densities on the NOHM canopy structure. Considering the promising tunable properties for CO2 capture of NOHMs, this study was conducted to provide important structural information to better design NOHMs for CO2 capture. In order to minimize the CO2 absorption via enthalpic effect and provide a more accurate assessment of the structural effects, the NOHMs were synthesized without task-specific groups. A greater chain ordering and decreased intermolecular interactions were observed in NOHMs compared to the unbound polymer. This was attributed to the specific structural arrangement of the frustrated canopy. The distinct configuration of grafted polymer chains caused different CO2 packing and CO2-induced ...

Effects of Bonding Types and Functional Groups on CO2 Capture using Novel Multiphase Systems of Liquid-like Nanoparticle Organic Hybrid Materials

Novel liquid-like nanoparticle organic hybrid materials (NOHMs) which possess unique features including negligible vapor pressure and a high degree of tunability were synthesized and their physical and chemical properties as well as CO(2) capture capacities were investigated. NOHMs can be classified based on the synthesis methods involving different bonding types, the existence of linkers, and the addition of task-specific functional groups including amines for CO(2) capture. As a canopy of polymeric chains was grafted onto the nanoparticle cores, the thermal stability of the resulting NOHMs was improved. In order to isolate the entropy effect during CO(2) capture, NOHMs were first prepared using polymers that do not contain functional groups with strong chemical affinity toward CO(2). However, it was found that even ether groups on the polymeric canopy contributed to CO(2) capture in NOHMs via Lewis acid-base interactions, although this effect was insignificant compared to the effect of task-specific functional groups such as amine. In all cases, a higher partial pressure of CO(2) was more favorable for CO(2) capture, while a higher temperature caused an adverse effect. Multicyclic CO(2) capture tests confirmed superior recyclability of NOHMs and NOHMs also showed a higher selectivity toward CO(2) over N(2)O, O(2) and N(2).

Investigation of CO2 capture mechanisms of liquid-like nanoparticle organic hybrid materials via structural characterization

Nanoparticle organic hybrid materials (NOHMs) have been recently developed that comprise an oligomeric or polymeric canopy tethered to surface-modified nanoparticles via ionic or covalent bonds. It has already been shown that the tunable nature of the grafted polymeric canopy allows for enhanced CO(2) capture capacity and selectivity via the enthalpic intermolecular interactions between CO(2) and the task-specific functional groups, such as amines. Interestingly, for the same amount of CO(2) loading NOHMs have also exhibited significantly different swelling behavior compared to that of the corresponding polymers, indicating a potential structural effect during CO(2) capture. If the frustrated canopy species favor spontaneous ordering due to steric and/or entropic effects, the inorganic cores of NOHMs could be organized into unusual structural arrangements. Likewise, the introduction of small gaseous molecules such as CO(2) could reduce the free energy of the frustrated canopy. This entropic effect, the result of unique structural nature, could allow NOHMs to capture CO(2) more effectively. In order to isolate the entropic effect, NOHMs were synthesized without the task-specific functional groups. The relationship between their structural conformation and the underlying mechanisms for the CO(2) absorption behavior were investigated by employing NMR and ATR FT-IR spectroscopies. The results provide fundamental information needed for evaluating and developing novel liquid-like CO(2) capture materials and give useful insights for designing and synthesizing NOHMs for more effective CO(2) capture.