ChemInform Abstract: Evaluation of Pore Structure Parameters of MCM‐41 Catalyst Supports and Catalysts by Means of Nitrogen and Argon Adsorption.

Ravikovitch, Peter I.; Wei, Di; Chueh, Wei-Te; Haller, Gary L.; Neimark, Alexander V.

doi:10.1002/chin.199731034

Cited by 12 publications

(16 citation statements)

References 1 publication

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“…This method was selected over the BJH method, which generally underestimates silica pore size by about 1 nm. 67 The introduction of amine groups reduced the mean pore diameter, BET surface area, and pore volume, consistent with the incorporation of the amine groups in the pores of particles. Micron-sized nonporous silica particles were also amine-modified.…”

Section: Resultssupporting

confidence: 56%

Relating Mobility of dsRNA in Nanoporous Silica Particles to Loading and Release Behavior

Zhou

Nadeau

Khan

et al. 2021

ACS Appl. Bio Mater.

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Nanoparticle delivery of polynucleic acids traditionally relies on the modulation of surface interactions to achieve loading and release. This work investigates the additional role of confinement in mobility of dsRNA (84 and 282 base pair (bp) sequences of Spodoptera frugiperda) as a function of silica nanopore size (nonporous, 3.9, 8.0, and 11.3 nm). Amine-functionalized nanoporous silica microspheres (NPSMs, ∼10 μm) are used to directly visualize the loading and exchange of fluorescently labeled dsRNA. Porous particles are fully accessible to both lengths of dsRNA by passive diffusion, except for 282 bp dsRNA in 3.9 nm pores. The stiffness of dsRNA suggests that encapsulation occurs by threading into nanopores, which is inhibited when the ratio of dsRNA length to pore size is large. The mobility of dsRNA at the surface and in the core of NPSMs, as measured by fluorescence recovery after photobleaching, is similar. The mobility increases with pore size (from 0.0002 to 0.001 μm2/s for 84 bp dsRNA in 3.9–11.3 nm pores) and decreases with the length of dsRNA. However, when the dsRNA is unable to load into the pores (on nonporous particles and for 282 bp dsRNA in 3.9 nm pores), surface mobility is not detectable. The pore structure appears to serve as a “source” to provide a mobile network of dsRNA at the particle surface. The importance of mobility is demonstrated by exchange experiments, where NPSMs saturated with mobile dsRNA can exchange dsRNA with the surrounding solution, while immobile dsRNA is not exchanged. These results indicate that nanoparticle synthesis techniques that provide pores large enough to take up polynucleic acids internally (and not simply on the external surface of the particle) can be harnessed to design polynucleic acid/nanoporous silica combinations for controlled mobility as a path forward toward effective nanocarriers.

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Section: Resultssupporting

confidence: 56%

Relating Mobility of dsRNA in Nanoporous Silica Particles to Loading and Release Behavior

Zhou

Nadeau

Khan

et al. 2021

ACS Appl. Bio Mater.

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“…The total pore volumes were estimated from the adsorbed amount at the relative pressure of P/P 0 = 0.98 and the pore size distributions were obtained from the adsorption branch of the isotherms, using the nonlocal density function theory (NLDFT) method. 32 Elemental compositions were obtained using a JEOL JSM-6390LV scanning electron microscope (SEM) operated at 20 kV. Data acquisition was performed using a 100 s accumulation time.…”

Section: Methodsmentioning

confidence: 99%

Template-Directed Assembly of Metal–Chalcogenide Nanocrystals into Ordered Mesoporous Networks

et al. 2015

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Although great progress in the synthesis of porous networks of metal and metal oxide nanoparticles with highly accessible pore surface and ordered mesoscale pores has been achieved, synthesis of assembled 3D mesostructures of metal-chalcogenide nanocrystals is still challenging. In this work we demonstrate that ordered mesoporous networks, which comprise well-defined interconnected metal sulfide nanocrystals, can be prepared through a polymer-templated oxidative polymerization process. The resulting self-assembled mesostructures that were obtained after solvent extraction of the polymer template impart the unique combination of light-emitting metal chalcogenide nanocrystals, three-dimensional open-pore structure, high surface area, and uniform pores. We show that the pore surface of these materials is active and accessible to incoming molecules, exhibiting high photocatalytic activity and stability, for instance, in oxidation of 1-phenylethanol into acetophenone. We demonstrate through appropriate selection of the synthetic components that this method is general to prepare ordered mesoporous materials from metal chalcogenide nanocrystals with various sizes and compositions.

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“…Typically, DFT calculations predict slightly larger pore sizes. 32,33 The mesoporous silica scaffolds are named MS-d, where d denotes the BJH pore diameter in nanometers.…”

Section: ■ Introductionmentioning

confidence: 99%

Phase Behavior and Ion Dynamics of Nanoconfined LiBH₄ in Silica

Lambregts

Eck²,

Suwarno

et al. 2019

J. Phys. Chem. C

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The increasing demand for high capacity yet safe storage of renewable energy calls for the development of all-solid-state batteries. A major hurdle in this development is the identification of new suitable types of solid-state electrolytes. Nanoconfined lithium borohydride is a solid-state electrolyte candidate due to its high lithium-ion mobility at ambient temperatures. The origin of the high lithium-ion mobility is not fully understood, however. We studied nanocomposites of lithium borohydride and nanoporous silica Santa Barbara Amorphous-15 (SBA-15) with different pore sizes, using 1H, 6,7Li, and 11B solid-state NMR at various temperatures, to get in-depth insights into the phase behavior and ion dynamics of lithium borohydride in the silica pores. The results allow us to formulate a detailed dynamic model for lithium borohydride confined in SBA-15; bulklike LiBH4 is separated from the pore walls by an amorphous, highly dynamic LiBH4 fraction displaying both Li+ and BH4 – diffusion even at ambient temperatures. As shown by 11B temperature-jump exchange NMR, this dynamic fraction increases as a function of temperature. Li+ exchange between the bulklike and “dynamic” LiBH4 fraction is slow at ambient temperatures, but at elevated temperatures (≥90 °C), above the phase transition of the bulklike fraction, lithium ions rapidly diffuse through both LiBH4 fractions and exchange between these confined fractions at rates approaching the megahertz time scale.

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ChemInform Abstract: Evaluation of Pore Structure Parameters of MCM‐41 Catalyst Supports and Catalysts by Means of Nitrogen and Argon Adsorption.

Cited by 12 publications

References 1 publication

Relating Mobility of dsRNA in Nanoporous Silica Particles to Loading and Release Behavior

Relating Mobility of dsRNA in Nanoporous Silica Particles to Loading and Release Behavior

Template-Directed Assembly of Metal–Chalcogenide Nanocrystals into Ordered Mesoporous Networks

Phase Behavior and Ion Dynamics of Nanoconfined LiBH₄ in Silica

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ChemInform Abstract: Evaluation of Pore Structure Parameters of MCM‐41 Catalyst Supports and Catalysts by Means of Nitrogen and Argon Adsorption.

Cited by 12 publications

References 1 publication

Relating Mobility of dsRNA in Nanoporous Silica Particles to Loading and Release Behavior

Relating Mobility of dsRNA in Nanoporous Silica Particles to Loading and Release Behavior

Template-Directed Assembly of Metal–Chalcogenide Nanocrystals into Ordered Mesoporous Networks

Phase Behavior and Ion Dynamics of Nanoconfined LiBH4 in Silica

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Product

Resources

About

Phase Behavior and Ion Dynamics of Nanoconfined LiBH₄ in Silica