Consequences of Convex Nanopore Chemistry on Confined Water Dynamics

Jackson, Grayson L.; Kim, Sung‐A; Jayaraman, Ashish; Diallo, Souleymane; Mahanthappa, Mahesh K.

doi:10.1021/acs.jpcb.9b10176

Cited by 6 publications

(3 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found that a KWW function provides a reasonable description of our data as the distribution of branch lengths along the polymer backbone of the PEI and variation in the local functional group environment should result in inhomogeneous contributions to dynamics, similar to many other systems where the KWW relationship has been employed. 33,34 The stretching exponent, β, in our fits was allowed to float between 0.5 and 1 in the fitting procedure but converged at the lower limit of 0.5 (typical for heterogeneous polymer systems 35 ) for the spectra obtained at 325 K (Figure S5). We show the trend in β vs Q without these limits in place for a few samples in Figure S5 where values continue to converge around 0.5.…”

Section: ■ Methodsmentioning

confidence: 99%

Measuring the Influence of CO₂ and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO₂ from the Environment

Baumann,

Yamada,

Ito

et al. 2024

Chem. Mater.

View full text Add to dashboard Cite

Aminopolymer sorbents are leading candidates for extracting CO 2 directly from the atmosphere under ambient conditions. For effective carbon capture, this requires not only that the CO 2 actively binds with amine groups of the polymer under low gas concentrations but also that it readily diffuses through the sorbent media to access as many of the amine binding sites as possible. Unfortunately, high reactivity and diffusivity tend to be mutually exclusive properties when it comes to small molecule transport within a polymer, posing a significant materials design challenge. While many reports to date focus on chemical additives or engineering strategies to tackle this trade-off, only a few studies have seriously investigated the underlying chemical and physical properties of the sorbent polymer as a function of its interaction with the relevant sorbate molecules. In this study, we investigate the interplay of polymer-sorbate reactivity and diffusive dynamics of both H 2 O and CO 2 in branched polyethylenimine (PEI) using quasielastic neutron scattering (QENS), infrared spectroscopy, gravimetric uptake, and mechanical dissipation measurements as a function of atmospheric dosing conditions. We uncover an intriguing and previously unreported discrepancy in the diffusive dynamics of PEI dosed with CO 2 and H 2 O vapor at the microscopic and macroscopic length scales. At the macroscopic scale, our mechanical dissipation measurements show that while the exposure to H 2 O vapor alone always plasticizes the dynamics of PEI, the absorption of CO 2 , either in the presence of H 2 O or not, leads to a mechanical stiffening of the PEI. Interestingly, this response differs at the microscopic scale where the diffusive dynamics of the H 2 O-and/or CO 2 -dosed samples as quantified by QENS are always enhanced relative to the undosed PEI. This dynamic facilitation is greatest in the presence of H 2 O vapor alone, consistent with H 2 O strongly plasticizing the dynamics of PEI. However, the simultaneous exposure to both H 2 O and CO 2 leads to a stiffening of the QENS dynamics at the microscopic scale relative to the hydrated state, signifying local interactions between the CO 2 and the polymer. Under these conditions, we also observe a greater amount of CO 2 absorbed into the PEI film that is simultaneously exposed to both H 2 O and CO 2 as compared to the film exposed to just CO 2 , further evidencing a complicated three-way interaction between the H 2 O, CO 2 , and PEI. These results are discussed in terms of an absorption process that involves the formation of carbamate ions, the generation of ionic cross-link junctions in the PEI, and changes in the local hydration level of the polymer around the ions. To establish the importance of the carbamate ions in this process, we utilize a methylation reaction to modify the PEI and convert all of the primary and secondary amines into tertiary amines that are incapable of forming carbamates. This considerably diminishes the role of hydrogen bonding in the PEI, enhances the microscopic dy...

show abstract

Section: ■ Methodsmentioning

confidence: 99%

Measuring the Influence of CO₂ and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO₂ from the Environment

Baumann,

Yamada,

Ito

et al. 2024

Chem. Mater.

View full text Add to dashboard Cite

show abstract

“…The inter-diffusion of aqueous salts confined in mesoporous silica in contact with bulk water was also determined by following the depletion of salt concentration from monolithic samples using visible spectroscopy [306][307][308], or by measuring the increasing electrical conductivity of the water phase [296]. There are also 2123 some studies of self-diffusion of water confined in other 2124 materials, such as activated carbon [309], metal-organic 2125 nanotubes [310], and convex pores of alkylsulfonate 2126 amphiphiles [311], while the diffusion of ions confined 2127 in water nanofilms and nanodroplets was analyzed by 2128 synchrotron X-ray microprobe [312] and dielectric spec-2129 troscopy [313], respectively.…”

Section: Transport Properties Of Water and Ions Under Confinement: An...mentioning

confidence: 99%

Structure and dynamics of nanoconfined water and aqueous solutions

et al. 2021

View full text Add to dashboard Cite

This review is devoted to discussing recent progress on the structure, thermodynamic, reactivity, and dynamics of water and aqueous systems confined within different types of nanopores, synthetic and biological. Currently, this is a branch of water science that has attracted enormous attention of researchers from different fields interested to extend the understanding of the anomalous properties of bulk water to the nanoscopic domain. From a fundamental perspective, the interactions of water and solutes with a confining surface dramatically modify the liquid's structure and, consequently, both its thermodynamical and dynamical behaviors, breaking the validity of the classical thermodynamic and phenomenological description of the transport properties of aqueous systems. Additionally, man-made nanopores and porous materials have emerged as promising solutions to challenging problems such as water purification, biosensing, nanofluidic logic and gating, and energy storage and conversion, while aquaporin, ion channels, and nuclear pore complex nanopores regulate many biological functions such as the conduction of water, the generation of action potentials, and the storage of genetic material. In this work, the more recent experimental and molecular simulations advances in this exciting and rapidly evolving field will be reported and critically discussed.

show abstract

“…These diverse properties of confined water open a new door to materials science and may play an important role in the future development of biology. For more details concerning the intriguing properties of confined water and its impact on materials properties, consider refs – .…”

Section: Introductionmentioning

confidence: 99%

Confined Water Dynamics in the Scaffolds of Polylactic Acid

Ishikawa,

Borges,

Mourão

et al. 2024

ACS Omega

View full text Add to dashboard Cite

Resorbable polylactic acid (PLA) ultrathin fibers have been applied as scaffolds for tissue engineering applications due to their micro-and nanoporous structure that favor cell adhesion, besides inducing cell proliferation and upregulating gene expression related to tissue regeneration. Incorporation of multiwalled carbon nanotubes into PLA fibers has been reported to increase the mechanical properties of the scaffold, making them even more suitable for tissue engineering applications. Ideally, scaffolds should be degraded simultaneously with tissue growth. Hydration and swelling are factors related to scaffold degradation. Hydration would negatively impact the mechanical properties since PLA shows hydrolytic degradation. Water absorption critically affects the catalysis and allowance of the hydrolysis reactions. Moreover, either mass transport and chemical reactions are influenced by confined water, which is an unexplored subject for PLA micro-and nanoporous fibers. Here, we probe and investigate confined water onto highly porous PLA microfibers containing few amounts of incorporated carbon nanotubes by Fourier transform infrared (FTIR) spectroscopy. A hydrostatic pressure was applied to the fibers to enhance the intermolecular interactions between water molecules and C�O groups from polyester bonds, which were evaluated over the wavenumber between 1600 and 2000 cm −1 . The analysis of temperature dependence of FTIR spectra indicated the presence of confined water which is characterized by a non-Arrhenius to Arrhenius crossover at T 0 = 190 K for 1716 and 1817 cm −1 carbonyl bands of PLA. These bands are sensitive to a hydrogen bond network of confined water. The relevance of our finding relies on the challenge detecting confined water in hydrophobic cavities as in the PLA one. To the best of our knowledge, we present the first report referring the presence of confined water in a hydrophobic scaffold as PLA for tissue engineering. Our findings can provide new opportunities to understand the role of confined water in tissue engineering applications. For instance, we argue that PLA degradation may be affected the most by confined water. PLA degradation involves hydrolytic and enzymatic degradation reactions, which can both be sensitive to changes in water properties.

show abstract

Consequences of Convex Nanopore Chemistry on Confined Water Dynamics

Cited by 6 publications

References 79 publications

Measuring the Influence of CO₂ and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO₂ from the Environment

Measuring the Influence of CO₂ and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO₂ from the Environment

Structure and dynamics of nanoconfined water and aqueous solutions

Confined Water Dynamics in the Scaffolds of Polylactic Acid

Contact Info

Product

Resources

About

Consequences of Convex Nanopore Chemistry on Confined Water Dynamics

Cited by 6 publications

References 79 publications

Measuring the Influence of CO2 and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO2 from the Environment

Measuring the Influence of CO2 and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO2 from the Environment

Structure and dynamics of nanoconfined water and aqueous solutions

Confined Water Dynamics in the Scaffolds of Polylactic Acid

Contact Info

Product

Resources

About

Measuring the Influence of CO₂ and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO₂ from the Environment

Measuring the Influence of CO₂ and Water Vapor on the Dynamics in Polyethylenimine To Understand the Direct Air Capture of CO₂ from the Environment