Nonclassical Crystal Growth Research Articles

Zeta Potential and Size Analysis of Zeolitic Imidazolate Framework-8 Nanocrystals Prepared by Surfactant-Assisted Synthesis.

The crystal nucleation and growth mechanism of monodispersed metal-organic framework nanoparticles were studied using time-resolved light dynamic, electrokinetic, and powder X-ray diffraction methods. We confirmed that zeolitic imidazolate framework-8 (ZIF-8) nanocrystals follow a nonclassical crystal growth pathway, where a fast nucleation occurs with dense liquid clusters or nanocrystals forming spontaneously when two precursors are mixed. We also explored the zeta potential and solvodynamic size changes of ZIF-8 prepared by a surfactant-assisted synthesis. Three modulators, including 1-methylimidazole (1-mIm), tris(hydroxymethyl)aminomethane (THAM), and (1-hexadecyl)trimethylammonium bromide (CTAB), were studied. We found that 1-mIm dramatically increases the rate of nucleation of ZIF-8. With an increasing amount of 1-mIm, which functions as a coordination modulator, the size increases, and the zeta potential of ZIF-8 decreases. Whereas THAM, as both a coordination and a deprotonation modulator, increases the size and zeta potential of ZIF-8 simultaneously, CTAB, as a long alkyl cationic surfactant, mainly adsorbs on the surface of ZIF-8, and the zeta potential of the formed ZIF-8 is controlled by the amount of CTAB in solution compared with its critical micelle concentration. Overall, we reveal that the modulator type and concentration can be used to control the size and zeta potential of the dispersed ZIF-8 nanocrystals in a colloid system. The experiments also enable identification of the nucleation and crystal growth processes of ZIF-8. The findings will be applicable to other nanocrystals in colloid systems, which are used for heterogeneous catalysis and guest molecular loadings.

Kinetics of Oriented Attachment of Mica Crystals.

Oriented attachment (OA), that is, the coalescence of crystals through attachment on coaligned crystal faces, is a nonclassical crystal growth process. Before attachment, a mesocrystal consisting of coaligned parallel crystals but with liquid separating them was observed. Fundamental questions such as why OA is kinetically favored and whether a mesocrystal stage is a prerequisite for OA are raised. Through combining brute-force molecular dynamics simulations and path samplings based on extensive umbrella simulations, we address these questions with a case study on the OA of a mica nanocrystal onto a mica crystal substrate in water. Brute-force simulations show that if two mica crystals are attached but largely misaligned, coalignment hardly appears. Thus, if OA is possible, then coalignment must appear before the attachment between crystals. Electrophoresis of the nanocrystal toward the substrate surface is spontaneous, but mesocrystal formation is occasional, also shown by brute-force simulations. Free energies along different pathways show that OA is spontaneous and kinetically favored over non-OA, and a mesocrystal formation is just a bifurcation in the pathway. OA is through a pathway in which the nanocrystal is tilted with respect to the substrate. Part of the nanocrystal is attached to the substrate first, and then, OA is gradually completed. Once a mesocrystal is occasionally formed, then a jump event is needed for the nanocrystal to get back to the OA pathway. The sampling technique here can hopefully guide the design of nanostructured materials facilitated by OA.

HKUST-1 MOF nanoparticles: a non-classical crystallization route in supercritical CO2.

Reducing MOF particles to the nanoscale size range is beneficial due to their increased surface-to-volume ratio, higher defects exposing metals and ligands, and short diffusion path. While great efforts have been made to reduce the particle sizes by controlling the reaction kinetics or terminating the particle growth, large-scale, rapid synthesis of MOF nanoparticles (NPs) remains a challenge. Here, we report supercritical (sc) CO2-assisted synthesis of HKUST-1 NPs in a continuous flow reactor, which yielded pure and thermally stable MOFs with median sizes of 110-250 nm and BET surface areas of 1610-1890 m2 g-1 under 10 seconds synthesis time. ScCO2 and ethanol with a molar ratio of 9 : 1 are used as co-solvents for the fast nucleation of HKUST-1 and crystal formation. A typical dry yield of 53.7 wt% is achieved with 0.1 M Cu precursor under mild conditions at 75 °C and 13 MPa. The space-time yields and surface area production rates are 5668 kg m-3 d-1 and 1.0 × 1010 m2 m-3 d-1. Particle size and morphology analyses indicate that aggregation of nascent structures occurs in the aerosolized state, leading to a non-classical crystal growth mechanism and enabling multiple pathways for tuning the synthesis process. With the ability to recycle CO2, solvents, and unreacted precursors, the method can be used for the scalable production of MOFs.

Nonclassical Crystal Growth of Supramolecular Polymers in Aqueous Medium.

A mechanistic understanding of the principles governing the hierarchical organization of supramolecular polymers offers a paradigm for tailoring synthetic molecular architectures at the nano to micrometric scales. Herein, the unconventional crystal growth mechanism of a supramolecular polymer of superbenzene(coronene)-diphenylalanine conjugate (Cr-FFOEt ) is demonstrated. 3D electron diffraction (3D ED), a technique underexplored in supramolecular chemistry, is effectively utilized to gain a molecular-level understanding of the gradual growth of the initially formed poorly crystalline hairy, fibril-like supramolecular polymers into the ribbon-like crystallites. The further evolution of these nanosized flat ribbons into microcrystals by oriented attachment and lateral fusion is probed by time-resolved microscopy and electron diffraction. The gradual morphological and structural changes reveal the nonclassical crystal growth pathway, where the balance of strong and weak intermolecular interactions led to a structure beyond the nanoscale. The role of distinct π-stacking and H-bonding interactions that drive the nonclassical crystallization process of Cr-FFOEt supramolecular polymers is analyzed in comparison to analogous molecules, Py-FFOEt and Cr-FF forming helical and twisted fibers, respectively. Furthermore, the Cr-FFOEt crystals formed through nonclassical crystallization are found to improve the functional properties.

Nonclassical crystal growth and growth rate hysteresis observed during the growth of curcumin in impure solutions

Partially dissolved crystals of curcumin grow faster and exhibit an accelerated growth rate hysteresis.

Vacancy infilling during the crystallization of Fe-deficient hematite: An in situ synchrotron X-ray diffraction study of non-classical crystal growth

Abstract The crystallization of hematite from precursor ferrihydrite was studied using time-resolved, angle-dispersive synchrotron X-ray diffraction in aqueous solutions at pH 10 and 11 and at temperatures ranging from 80 to 170 °C. Rietveld analyses revealed a non-classical crystallization pathway involving vacancy infilling by Fe as defective hematite nanocrystals evolved. At 90 °C and pH 11, incipient hematite particles exhibited an Fe site occupancy as low as 0.68(2), and after 30 min, Fe occupancy plateaued at 0.84(1), achieving a metastable steady state with a composition corresponding to “hydrohematite.” During crystal growth, unit-cell volume increased with an increase in Fe occupancy. The increase in Fe occupancy in hydrohematite was accomplished by deprotonation, resulting in a shortening of the long Fe-O(H) bonds and decreased distortion of the octahedral sites. Once the occupancy stabilized, the unit-cell volume contracted following further nanoparticle growth. Our study documented various synthetic routes to the formation of “hydrohematite” with an Fe vacancy of 10–20 mol% in the final product. The structure refined for synthetic hydrohematite at 90 °C and pH 11 closely matched that of natural hydrohematite from Salisbury, Connecticut, with a refined Fe occupancy of 0.83(2). Dry heating this natural hydrohematite generated anhydrous, stoichiometric hematite, again by continuous infilling of vacancies. The transformation initiated at 150 °C and was complete at 700 °C, and it was accompanied by the formation of a minor amorphous phase that served as a reservoir for Fe during the inoculation of the defective crystalline phase.

(NH4)3FeF6 mesocrystals grown by electric field-assisted in situ dissolution and the reaction of anodic iron oxides.

(NH4)3FeF6 mesocrystalline octahedrons are formed by in situ dissolution and the reaction of anodic iron oxides, followed by a non-classical crystal growth process involving electrical polarization and subsequent alignment of primary (NH4)3FeF6 particles under an external electric field. The obtained (NH4)3FeF6 can be converted to nano-micro hierarchical α-Fe2O3 octahedrons by thermal annealing.

In-situ evolution of anodic TiO2 nanotubes to ammonium oxofluorotitanate mesocrystals and their conversion to mesocrystalline TiO2

3D ordered superstructures of mesocrystalline NH4TiOF3 and (NH4)2TiOF4 are synthesized via in-situ evolution from anodic TiO2 nanotube arrays grown on the Ti metal substrate under high current density. As revealed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy characterizations, the obtained NH4TiOF3 and (NH4)2TiOF4 mesocrystals consist of well aligned nanoparticle subunits at atomic level and can be converted to TiO2 (anatase) mesocrystals with their original exterior shapes retained upon thermal annealing. Close examination suggests that NH4TiOF3 and (NH4)2TiOF4 mesocrystals form via a nonclassical crystal growth process involving fast oriented aggregation of particles assisted by electric field-dipole interaction.

Reply to Comment on “A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires”

RETURN TO ISSUEPREVCommentsNEXTReply to Comment on “A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires”Alexander B. BardAlexander B. BardDepartment of Chemistry, University of Washington, Seattle, Washington 98195, United StatesMore by Alexander B. Bardhttps://orcid.org/0000-0002-9000-3277, Xuezhe ZhouXuezhe ZhouDepartment of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United StatesMore by Xuezhe Zhou, Xiaojing XiaXiaojing XiaDepartment of Molecular Engineering and Science, University of Washington, Seattle, Washington 98195, United StatesMore by Xiaojing Xiahttps://orcid.org/0000-0003-2713-6891, Guomin ZhuGuomin ZhuPhysical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesDepartment of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United StatesMore by Guomin Zhu, Matthew B. LimMatthew B. LimDepartment of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United StatesMore by Matthew B. Limhttps://orcid.org/0000-0001-6129-9876, Seung Min KimSeung Min KimInstitute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905, Republic of KoreaMore by Seung Min Kimhttps://orcid.org/0000-0002-4474-0145, Matthew C. JohnsonMatthew C. JohnsonDepartment of Biochemistry, University of Washington, Seattle, Washington 98195, United StatesMore by Matthew C. Johnson, Justin M. KollmanJustin M. KollmanDepartment of Biochemistry, University of Washington, Seattle, Washington 98195, United StatesMore by Justin M. Kollman, Matthew A. MarcusMatthew A. MarcusAdvanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United StatesMore by Matthew A. Marcus, Steven R. SpurgeonSteven R. SpurgeonEnergy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesMore by Steven R. Spurgeonhttps://orcid.org/0000-0003-1218-839X, Daniel E. PereaDaniel E. PereaEnvironmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesMore by Daniel E. Pereahttps://orcid.org/0000-0003-3789-4039, Arun DevarajArun DevarajPhysical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesMore by Arun Devaraj, Jaehun ChunJaehun ChunPhysical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesMore by Jaehun Chunhttps://orcid.org/0000-0002-2291-6496, James J. De YoreoJames J. De YoreoPhysical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesDepartment of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United StatesDepartment of Chemistry, University of Washington, Seattle, Washington 98195, United StatesMore by James J. De Yoreohttps://orcid.org/0000-0002-9194-6699, and Peter J. Pauzauskie*Peter J. PauzauskieDepartment of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United StatesPhysical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United StatesDepartment of Chemistry, University of Washington, Seattle, Washington 98195, United States*(P.J.P.) Email: [email protected]More by Peter J. Pauzauskiehttps://orcid.org/0000-0002-1554-5949Cite this: Chem. Mater. 2021, 33, 10, 3862–3864Publication Date (Web):May 14, 2021Publication History Received19 November 2020Revised12 February 2021Published online14 May 2021Published inissue 25 May 2021https://doi.org/10.1021/acs.chemmater.0c04469Copyright © 2021 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1174Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (765 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Yttrium,Anions,Sodium,Mathematical methods,Phase transitions Get e-Alerts

Comment on “A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires”

RETURN TO ISSUEPREVCommentsNEXTComment on “A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires”Pavel P. Fedorov*Pavel P. FedorovProkhorov General Physics Institute of the Russian Academy of Sciences, Moscow 119991, Russia*Email: [email protected]More by Pavel P. Fedorovhttp://orcid.org/0000-0002-2918-3926Cite this: Chem. Mater. 2021, 33, 10, 3859–3861Publication Date (Web):May 12, 2021Publication History Received8 April 2020Revised16 September 2020Published online12 May 2021Published inissue 25 May 2021https://doi.org/10.1021/acs.chemmater.0c01515Copyright © 2021 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1169Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (3 MB) Get e-AlertsSUBJECTS:Chemical composition,Crystallization,Anions,Crystal structure,Phase transitions Get e-Alerts

Wide-area multilayered self-assembly of fluorapatite nanorods vertically oriented on a substrate as a non-classical crystal growth.

Oriented attachment of homogeneously shaped nanoblocks, such as nanocubes and nanorods, is attracting attention as a fundamental process of non-classical crystal growth to produce specific ordered architectures of functional materials. Although lateral alignments of horizontally oriented nanorod are commonly observed at the air-liquid and liquid-solid interfaces in dispersion systems, the accumulation of vertically oriented nanorods on a substrate has rarely been produced in a wide area over a millimeter-sized flat surface. Here, we achieved homogeneous stacking of vertical fluorapatite nanorods with a large aspect ratio (∼6) in a toluene-hexane mixture system through a gradual decrease in the dispersibility. Micrometer-thick flat films in which the c direction of fluorapatite nanorods was arranged perpendicularly to the surface were deposited on a substrate with a diameter of over 20 mm. The wide-area accumulation of vertical nanorods occurs through the self-assembly of laterally arranged clusters of nanorods covered with a stabilizing agent and subsequent gentle sedimentation on the substrate surface.

Molecular Crystal Microcapsules: Formation of Sealed Hollow Chambers via Surfactant‐Mediated Growth

Hollow organic molecular cocrystals comprised of 9-methylanthracene-1,2,4,5-tetracyanobenzene (9MA-TCNB) and naphthalene-1,2,4,5-tetracyanobenzene (NAPH-TCNB) were fabricated using a surfactant-mediated co-reprecipitation method. The crystals exhibit a narrow size distribution that can be easily tuned by varying the concentration of surfactant and incubation temperature. The rectangular crystals possess symmetrical twinned cavities with an estimated storage volume on the order of 10-10 L. An aqueous dye solution can be incorporated into the cavities during crystal growth and stored inside for up to several hours, confirming the sealed nature of the hollow chambers. Our results demonstrate that it is possible to harness non-classical crystal growth to fabricate organic molecular crystals with novel topologies.

Size Evolution and Composition of the Intermediate Phase During Nonclassical Protein Crystal Growth from Solution

We propose here that the intermediate nucleation phase identified in a certain case of protein crystal growth actually consists of two distinct parts: a low density and higher density phase. A theo...

A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires

Sodium yttrium fluoride (NaYF4) is an important upconverting material with many potential uses in chemistry, materials science, and biology, which can be synthesized hydrothermally in both cubic (α...

Covalent organic framework mesocrystals through dynamic modulator manipulated mesoscale self-assembly of imine macrocycle precursors

Framework crystallization is an unresolved challenge in the chemistry of covalent organic frameworks (COFs) due to the poorly controlled simultaneous polymerization and crystallization processes. Here, we report the first morphogenesis of COF mesocrystals with two-dimensional hexagonal p6m symmetry through the combination of alkyl amine as a dynamic modulator and 2,4,6- triformylresorcinol imine as an asymmetrical building block. The amine modulator depresses the lateral growth of 2D sheets, and the slow kinetics combined with the asymmetrical conformation of 2,4,6-triformylresorcinol imine lead to the formation of transient imine macrocycles, which further undergo mesoscale self-assembly into nanotubular structures. The nanotubular structures tend to join together into rod-like bundles with ordered hexagonal rods, which finally grow into uniform hexagonal COF mesocrystals. The present strategy opens a nonclassical nucleation and crystal growth approach to create COFs with unexplored mesocrystal structures, which further extends the scope of crystalline framework materials and provides a new strategy for crystal morphogenesis.

Non-classical crystal growth on a hydrophobic substrate: learning from bivalve nacre

The hydrophobic substrate has an effect on the non-classical crystallization of nacreous aragonite crystals.

Connection of crystal faceting with the mechanism of its formation

The observed formation of nano- and microcrystals devoid of faceting in low-temperature processes of their formation can be associated with the implementation of a non-classical crystal growth mechanism by aggregation and oriented splicing of particles. The observation is illustrated on CaF2 examples.

Retraction of "Solid-to-Solid Crystallization of Organic Thin Films: Classical and Nonclassical Pathways".

[This retracts the article DOI: 10.1021/acsomega.8b00153.].

Oriented Attachment Revisited: Does a Chemical Reaction Occur?

Summary Oriented attachment (OA) growth has shown great significance in the development of crystal growth theory over the past decade, which is generally acknowledged as a physical process. Here, we report a different OA growth manner, which involves not only the physical nanoparticle attachment but also the chemical reaction between nanoparticles and ions. It is demonstrated that with the participation of NaHCO3 and NH4HCO3, micron-sized sheets of NaY(CO3)2·6H2O and (NH4)Y(CO3)2·H2O can be formed from Y2(CO3)3·2H2O nanoparticles through a chemical-reaction-directed OA. In contrast to the conventional OA process, this OA growth can produce single-crystalline substances whose crystallographic structures and chemical constituents are different (usually more complicated) from those of precursor nanoparticles. Such an OA mechanism shows applicability in a number of salts. Our findings not only extend the territory of the non-classical aggregation-based crystal growth mode but also provide a feasible approach for creating functional materials with complex architectures.

Direct growth of SnO2 nanocrystallites on electrochemically exfoliated graphene for lithium storage

Abstract As a new generation of high quality graphene, electrochemically exfoliated graphene is an ideal platform for constructing integrated high-performance nanocomposites as advanced electrode materials for energy storage and conversion devices. To take on a challenge of direct growth of nanoparticles on electrochemically exfoliated graphene with limited oxygen-containing functional groups and its hydrophobic nature, a systematic study is carried out on growth of SnO2 nanocrystallites on the surface of electrochemically exfoliated graphene. The results indicate that these nanocrystals can efficiently grow on the functional group-free surface of electrochemically exfoliated graphene, if the precursor molecules can polymerize into larger molecules and aggregate on electrochemically exfoliated graphene followed by decomposition and phase transformation into the final metal oxide nanocrystallites. Some key factors affecting this non-classical crystal growth are investigated. Addition of a small amount of water in a polar aprotic solvent to stimulate polymerization of the precursor molecules and a solvothermal treatment to facilitate decomposition of the disordered aggregates of the polymerized precursors are crucial to the growth of nanocrystals on electrochemically exfoliated graphene. The improved electrical conductivity and structural stability of the hybrids may promote the performance of the materials in various applications, such as exceptional lithium storage capability.