Zeolite Nanocrystals

Zhang, Yahong; Ren, Nan; Tang, Yi

doi:10.1016/b978-0-444-53189-6.00017-2

Cited by 9 publications

(7 citation statements)

References 211 publications

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“…However, when the size of zeolite crystals is decreased to nanoscale, their external surface areas increase dramatically so that their surface-related properties are remarkably exhibited, such as adjustable surface charge, hydrophilicity/hydrophobicity, and surface ion-exchangeability. These rich surface properties would provide attractive parameters for the exploration of adsorption and reaction of bulky biomolecules . In our previous studies, nanozeolite particles were found to possess amazing protein and peptide adsorption amounts, and different nanozeolite materials displayed different adsorption capacities due to their various surface characteristics. – Moreover, the interactions between nanozeolites and protein molecules could be well adjusted by varying the frameworks and surface properties of nanozeolites, – which can be supported by a big family of more than 150 zeolite types with different frameworks and morphologies.…”

Section: Introductionmentioning

confidence: 99%

Crystal Plane- and Size-Dependent Protein Adsorption on Nanozeolite

Zhang

Ren

et al. 2009

J. Phys. Chem. C

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In this study, nanozeolites LTL with different exposed crystal planes and sizes were synthesized as excellent model material to study the effects of the crystal plane and size of the nanozeolite on the protein adsorption behaviors. A larger protein adsorption amount is observed on the smaller nanocrystals due to their larger surface area. More importantly, it is found that the (001) crystal plane with a 12-membered ring channel array has a larger contribution for protein adsorption on zeolite LTL nanocrystals than the other two dimensions with a very small pore opening (1.5 Å). It is proposed that the difference of protein adsorption on various crystal planes could be attributed to abundant exposed pore openings on the top (bottom) surface and curved surface of the side surface in columned nanozeolites LTL. This fact shows that the nanoscaled topography is also an important factor determining protein adsorption on the surface of nanozeolites, and efforts in the future should be focused on the synthesis of nanozeolites LTL with abundant exposed (001) planes. This observation will provide a new view for bioapplication and design of crystalline nanomaterials.

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Section: Introductionmentioning

confidence: 99%

Crystal Plane- and Size-Dependent Protein Adsorption on Nanozeolite

Zhang

Ren

et al. 2009

J. Phys. Chem. C

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“…This quest has driven numerous activities in academics and industry in the past decade to design catalytically active microporous−mesoporous zeolite systems. Usually, cost- and time-intensive templating strategies or difficult postsynthetic modifications have been applied to achieve mesoporosity in these catalyst systems. − Generally, several strategies for the introduction of mesoporosity can be distinguished, including (i) soft templates in the form of surfactants or polymers, (ii) hard templates such as carbon- or resin-beads, or (iii) preformed biotemplates acting as scaffolds during synthesis, which are finally removed by subsequent calcination to leave their mesoporous imprint. Recently, even three-dimensionally ordered mesopores were beautifully arranged in a zeolitic matrix.…”

Section: Introductionmentioning

confidence: 99%

One-Step Synthesis of Hierarchical Zeolite Beta via Network Formation of Uniform Nanocrystals

et al. 2011

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A hierarchical mesoporous network of zeolite beta with very high micropore as well as mesopore volume was synthesized without the need of a porogen at near 100% yield in the form of easily retrievable micrometer-sized particles. This was achieved by a dense-gel synthesis utilizing steam-assisted conversion (SAC) to induce a burst of nucleation. During the first phase of the synthesis, individual, evenly sized zeolite beta nanoparticles are formed that subsequently condense into a porous network displaying uniform mesopores. The final product consists of hierarchical self-sustaining macroscopic zeolite aggregates assembled from 20 nm crystalline domains of zeolite beta. The small size of the zeolite crystals in the resulting materials gives rise to mesopores with dominant pore sizes of about 13 nm. Large surface areas between 630 and 750 m(2)/g and total pore volumes up to 0.9 mL/g were obtained without sacrificing the microporosity (usually larger than 0.20 mL/g). Crystallization conditions were optimized for different Si/Al ratios between 10 and 33. A complete conversion into hierarchical zeolite beta was achieved in only a few hours at 170-180 °C if the amount of water present during the steam-assisted conversion was adequately adjusted. This dense gel steam conversion process proves to be a highly efficient strategy for fabricating hierarchical zeolite beta networks in a single step.

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“…Si + (2 + y)H 2 O = SiO 2 ·yH 2 O + 2H 2 (6) In the case of total conversion of PS (see Scheme 1 for the reaction stoichiometry) the volume of H 2 should be higher than The volume of hydrogen extracted in the first 30 min of treatment at room temperature usually corresponds to 85-95% of general H 2 output at room temperature (compare Fig. 4 and Table 1 values).…”

Section: Hydrogen Desorption Kinetics At Reaction With Watermentioning

confidence: 96%

“…The insertion of metal or metal oxide into a porous solid could create a material with significantly different physical and chemical properties, thus creating a so-called meso-porous composite [1][2][3][4][5][6][7]. Since the pores of this material are exposed to air, an interaction between the pore walls and particles takes place, as well as between the free surface of the particles and ambient gases.…”

Section: Introductionmentioning

confidence: 99%