المؤلفون: Elena Serrano, Javier Garcia-Martinez, Juan Carlos Martínez, Noemi Linares, Erika de Oliveira Jardim

المساهمون: Universidad de Alicante. Departamento de Química Inorgánica, Laboratorio de Nanotecnología Molecular (NANOMOL)

المصدر: Crystal Growth & Design. 20:515-520

مصطلحات موضوعية: Hierarchical architectures, Química Inorgánica, Materials science, 010405 organic chemistry, Cationic polymerization, General Chemistry, 010402 general chemistry, Condensed Matter Physics, Consecutive surfactant-templating, 01 natural sciences, 0104 chemical sciences, Chemical engineering, Pulmonary surfactant, Basic solution, Scientific method, Zeolites, General Materials Science

الوصف: Intracrystalline mesoporosity can be conveniently introduced in zeolites using cationic surfactants in a mild basic solution –a process known as surfactant-templating. However, this technique is limited to small-headed and single-chain surfactants because they need to diffuse through the narrow micropores of the zeolite, which limits the potential of this approach. Herein, we show that the mesoporosity generated in zeolites with small-headed and single-chain surfactants, such as CTAB, provides enough accessibility to allow the use of bulky surfactants that otherwise cannot enter the structure of the zeolite. Moreover, in this contribution, a USY zeolite has been successively treated with cationic surfactants of different chain lengths (C12 to C22) proving that the mesopores introduced in the zeolite can be efficiently widened and narrowed by consecutive treatments with surfactants of the suitable size. Finally, the use of consecutive surfactant-templating opens up the possibility of using surfactants of different packing parameters to produce new hierarchical architectures in zeolites. The authors thank the synchrotron ALBA (2018022824) and Spanish MINECO-AEI/FEDER (CTQ2015-74494-JIN and RTI2018-099504-B-C21). E. Serrano and N. Linares acknowledges the University of Alicante (refs UATALENTO 16-03 and 17-05, respectively).

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::bf102523b61675f565063b2d967015bbTest
https://doi.org/10.1021/acs.cgd.9b01180Test

المؤلفون: Matthias Thommes, Aida Grau-Atienza, Alexander Sachse, Erika de Oliveira Jardim, Noemi Linares, Javier Garcia-Martinez

المساهمون: Universidad de Alicante. Departamento de Química Inorgánica, Laboratorio de Nanotecnología Molecular (NANOMOL)

المصدر: Crystal Growth & Design. 17:4289-4305

مصطلحات موضوعية: Materials science, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Micelle, chemistry.chemical_compound, Pulmonary surfactant, Bromide, Molecule, General Materials Science, Zeolite, Dissolution, Química Inorgánica, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Intracrystalline mesoporosity, 0104 chemical sciences, chemistry, Chemical engineering, Transmission electron microscopy, Basic solution, Zeolites, Surfactant-templating, 0210 nano-technology

الوصف: Novel insights into the surfactant-templating process leading to the formation of tailored intracrystalline mesoporosity in USY zeolite are presented in the light of the changes in the textural, morphological, and chemical properties of this zeolite produced during its treatment in a basic solution of cetyltrimethylammonium bromide (CTAB). The inability of analogous surfactants with bulkier heads to produce mesoporosity suggests that individual CTAB molecules can actually enter the zeolite through its microporosity. Once inside, the surfactant molecules self-assemble to produce the micelles responsible for the formation of mesoporosity causing the expansion of the zeolite crystals, as evidenced by He pycnometry measurements. The analysis of ultramicrotomed samples by transmission electron microscopy evidenced the formation of uniform intracrystalline mesoporosity throughout the entire crystals. In order to investigate an alternative method, namely, the dissolution and reassembly of zeolites, this was performed in USY leading to the formation of composite materials, which are distinctly different from the zeolite with intracrystalline mesoporosity obtained by surfactant-templating. Finally, it was proved that the presence of mesoporosity in the initial zeolite is not needed for the surfactant-templating to occur. This was verified by surfactant-templating of a NaY zeolite, which does not present the large mesopores found in USY. Authors acknowledge the CAPITA project WAVES (EP7-NMP-266543) and Rive Technology for financial support.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a3886961e92e72e6eeabfceb12e4d9deTest
https://doi.org/10.1021/acs.cgd.7b00619Test

المؤلفون: Yonghong Ni, Lei Zhang, Kaiming Liao, Xian-Wen Wei

المصدر: Crystal Growth & Design. 8:3636-3640

مصطلحات موضوعية: Nanotechnology, General Chemistry, Condensed Matter Physics, Hydrothermal circulation, chemistry.chemical_compound, chemistry, Chemical engineering, Bromide, Basic solution, General Materials Science, Hexamethylenetetramine, Selected area diffraction, High-resolution transmission electron microscopy, Powder diffraction, Nanoneedle

الوصف: In this paper, we report the successful synthesis of well-aligned single crystalline NiHPO3·H2O nanoneedle bundles on a large scale via a facile hydrothermal route, employing NiSO4·6H2O and NaH2PO2 as the reactants in the presence of NH3·H2O, hexamethylenetetramine (HMT), and cetyltrimethylammonium bromide (CTAB). The reaction was carried out at 150 °C for 24 h. Generally, in basic solution, H2PO2− is often used as a reductant, but it can also decompose into HPO32− and P3− ions due to dismutation. Namely, the redox and dismutation reactions are competitive. Since the formation of Ni-HMT-NH3 complex reduced the potential of the Ni2+/Ni pair in our work, the dismutation reaction of H2PO2− ions was predominant. This led to the production of NiHPO3·H2O due to the smaller solubility. The as-obtained product was characterized by X-ray powder diffraction (XRD), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and field emission scanning electron microscopy (SEM...

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::be613f0bab0b59cf88031e836da7e2b8Test
https://doi.org/10.1021/cg800193jTest

المؤلفون: Allan S. Myerson, In Sung Lee, Ki Tae Kim, Alfred Y. Lee

المصدر: Crystal Growth & Design. 8:108-113

مصطلحات موضوعية: Aqueous solution, Chemistry, Inorganic chemistry, technology, industry, and agriculture, Evaporation, Substrate (chemistry), General Chemistry, Condensed Matter Physics, eye diseases, law.invention, symbols.namesake, Chemical engineering, law, Basic solution, Glycine, Monolayer, symbols, General Materials Science, Crystallization, Raman spectroscopy

الوصف: This study demonstrates the effect of the solution pH on the polymorphic outcome of glycine by evaporation-driven crystallization from aqueous solution. More than 2000 solution droplets under identical conditions were generated using a patterned self-assembled monolayers (SAMs) substrate. Each droplet on the substrate serves as an independent crystallization trial. Glycine nucleated inside the droplets through solvent evaporation, and their polymorphic forms were identified via Raman microscopy. Three different polymorphic forms of glycine (α-, β-, and γ-forms) simultaneously crystallized at all conditions employed. The probability of producing the thermodynamically stable γ-glycine from acidic (pH 3.40) or basic solution (pH 10.10) droplets significantly increased when compared with neutral aqueous solution (pH ∼ 6.00) droplets.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::d43ecb7e668a8c6b2cb3ab48dc17654cTest
https://doi.org/10.1021/cg700890mTest

المؤلفون: Lan Xiang, Huajie Liu, Yong Jin

المصدر: Crystal Growth & Design. 6:283-286

مصطلحات موضوعية: Coprecipitation, Stereochemistry, Chemistry, Infrared spectroscopy, General Chemistry, Condensed Matter Physics, Hydrothermal circulation, law.invention, Thermogravimetry, Crystallinity, Chemical engineering, law, Basic solution, Hydrothermal synthesis, General Materials Science, Crystallization

الوصف: The influence of hydrothermal treatment on the crystallinity and discharge capability of Al-substituted α-Ni(OH)2 was discussed in this paper. α-Ni(OH)2 with 15% Al substitution prepared at room te...

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::eae0e04bb0c15c49715f61efddf47d5aTest
https://doi.org/10.1021/cg050119pTest

المؤلفون: Cong-Min Ji, Hui-Juan Yang, Vassilis Tangoulis, Hui-Zhong Kou, Chongchao Zhao, Ai-Li Cui

المصدر: Crystal Growth & Design. 9:4607-4609

مصطلحات موضوعية: Crystallography, chemistry.chemical_compound, Nickel, Nuclear magnetic resonance, Spin states, chemistry, Basic solution, Pyridine, chemistry.chemical_element, General Materials Science, General Chemistry, Self-assembly, Condensed Matter Physics

الوصف: In a basic solution of Ni(ClO4)2·6H2O and pyridine-2-amidoxime (H2pyaox), tetranuclear [Ni4(Hpyaox)2(pyaox)2]2+ fragments are formed that self-assemble to generate single-, double-, or triple-decker clusters [Ni4(Hpyaox)2(pyaox)2(Him)4](ClO4)2 (1), [Ni8(Hpyaox)4(pyaox)4(H2O)4](ClO4)2·H2O·CH3CN (2), [Ni12(Hpyaox)6(pyaox)6(H2O)2(N3)2](ClO4)4·8H2O·CH3CN (3). Magnetic studies show that the compounds possess high-spin ground states.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::c2b280f37ae160b9cf38909765421b16Test
https://doi.org/10.1021/cg900975yTest

المؤلفون: Hiroaki Imai, Tetsuo Kawano

المصدر: Crystal Growth & Design. 6:1054-1056

مصطلحات موضوعية: Nanostructure, Aqueous solution, Chemistry, Nucleation, Nanoparticle, Mineralogy, Crystal growth, General Chemistry, Condensed Matter Physics, Chemical engineering, Basic solution, General Materials Science, Nanorod, Wurtzite crystal structure

الوصف: Nanoscale ZnO grains and rods having various aspect ratios were selectively synthesized through acidic and basic routes, respectively, in an aqueous system at 60 °C. Equiaxial nanograins were obtained by the addition of NaOH into an acidic solution of ZnSO4 (acidic route). On the other hand, nanorods with an aspect ratio ∼12 were prepared by the introduction of ZnSO4 into a basic solution of NaOH (basic route). The aspect ratio of ZnO nanoparticles was changed by the preparation routes, whereas the final pH of the solutions was the same. The variation of pH in the reaction system influenced the density of homogeneous nucleation and the crystal growth along the c axis. The morphological control of one-dimensional ZnO particulate materials with nanosized diameters and lengths was successfully achieved using the simple mixing techniques.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::2b176eafaae1bc3896384a42b08e04b8Test
https://doi.org/10.1021/cg050338aTest