Self-assembly process under a solid-state reaction of β-Si3N4/austenitic stainless-steel composites: stirring conditions and material texture

2021 ◽  
pp. 002199832110573
Author(s):  
Fumio Munakata ◽  
Kazuya Ookubo ◽  
Mariko Takeda ◽  
Yoshihiro Sato ◽  
Yuka Mizukami ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Solid State ◽  
Solid State Reaction ◽  
Self Assembly ◽  
The Self ◽  
Assembly Process ◽  
Diffusion Limited Aggregation ◽  
Material Texture ◽  
Microstructural Morphology ◽  
Additive Particle

In the self-assembly process of β-Si3N4 (SN)/316L stainless-steel (SUS316L) composite materials tailored via sintering of powder mixtures, the formation of a SN agglomerate resulting from condensation–dispersion reactions during the stirring of SN/SUS316L was found to play an important role in improving the thermal conductivity. Moreover, the obtained SN secondary particle groups connected to form a network through diffusion-limited aggregation. In particular, it was shown that the sample prepared at the milling speed of 150 r/min has a similar particle group area (about 1.38 μm2) to that at 120 r/min, but a higher κ (increased from 9.5 W m−1 K−1 to 11.5 W m−1 K−1). To quantitatively evaluate the microstructural morphology of the texture of the self-assembled composite material, global parameters τ( q) and D q and local parameters α( q) and f( α) were determined via multifractal analysis. These characteristics of the anisotropy, dispersion, and cohesiveness of the particle network in the material texture could be analyzed together with the capacity dimension D0, information dimension D1 (configuration entropy), correlation dimension D2, and α( q) (related to internal energy). The results suggest that α( q) reflects the differences in the cohesion of the additive particle agglomeration that constitutes the self-assembly process under the solid-state reaction.

scholarly journals Chondroitin-based nanoplexes as peptide delivery systems – Investigations into the self-assembly process, solid-state and extended release characteristics

2015 ◽  
Vol 93 ◽  
pp. 242-253 ◽  
Author(s):  
Anita Umerska ◽  
Krzysztof Jan Paluch ◽  
Maria Jose Santos-Martinez ◽  
Carlos Medina ◽  
Owen I. Corrigan ◽  
...  
Keyword(s):  
Solid State ◽  
Self Assembly ◽  
Extended Release ◽  
Delivery Systems ◽  
Peptide Delivery ◽  
The Self ◽  
Assembly Process

Multifractal characteristics of the self-assembly material texture of β-Si3N4/SUS316L austenitic stainless steel composites

2021 ◽  
Vol 853 ◽  
pp. 156570
Author(s):  
Fumio Munakata ◽  
Mariko Takeda ◽  
Kazuhiro Nemoto ◽  
Kazuya Ookubo ◽  
Yoshihiro Sato ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Self Assembly ◽  
The Self ◽  
Material Texture

scholarly journals Self-Assembled Nanomaterials Based on Complementary Sn(IV) and Zn(II)-Porphyrins, and Their Photocatalytic Degradation for Rhodamine B Dye

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3598
Author(s):  
Nirmal K. Shee ◽  
Hee-Joon Kim
Keyword(s):  
Aqueous Solution ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Self Assembly ◽  
The Self ◽  
Assembly Process ◽  
Absorption Bands ◽  
Ligand Coordination ◽  
Rhodamine B Dye ◽  
Metal Ligand

A series of porphyrin triads (1–6), based on the reaction of trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP) with six different phenoxy Zn(II)-porphyrins (ZnLn), was synthesized. The cooperative metal–ligand coordination of 3-pyridyl nitrogens in the SnP with the phenoxy Zn(II)-porphyrins, followed by the self-assembly process, leads to the formation of nanostructures. The red-shifts and remarkable broadening of the absorption bands in the UV–vis spectra for the triads in CHCl3 indicate that nanoaggregates may be produced in the self-assembly process of these triads. The emission intensities of the triads were also significantly reduced due to the aggregation. Microscopic analyses of the nanostructures of the triads reveal differences due to the different substituents on the axial Zn(II)-porphyrin moieties. All these nanomaterials exhibited efficient photocatalytic performances in the degradation of rhodamine B (RhB) dye under visible light irradiation, and the degradation efficiencies of RhB in aqueous solution were observed to be 72~95% within 4 h. In addition, the efficiency of the catalyst was not impaired, showing excellent recyclability even after being applied for the degradation of RhB in up to five cycles.

scholarly journals Metal Oxide-Related Dendritic Structures: Self-Assembly and Applications for Sensor, Catalysis, Energy Conversion and Beyond

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1686
Author(s):  
Ruohong Sui ◽  
Paul A. Charpentier ◽  
Robert A. Marriott
Keyword(s):  
Metal Oxide ◽  
Energy Conversion ◽  
Self Assembly ◽  
Hierarchical Structures ◽  
The Self ◽  
Assembly Process ◽  
Electronic Noses ◽  
Dendritic Nanostructures ◽  
Energy Conversion And Storage ◽  
The Aesthetic

In the past two decades, we have learned a great deal about self-assembly of dendritic metal oxide structures, partially inspired by the nanostructures mimicking the aesthetic hierarchical structures of ferns and corals. The self-assembly process involves either anisotropic polycondensation or molecular recognition mechanisms. The major driving force for research in this field is due to the wide variety of applications in addition to the unique structures and properties of these dendritic nanostructures. Our purpose of this minireview is twofold: (1) to showcase what we have learned so far about how the self-assembly process occurs; and (2) to encourage people to use this type of material for drug delivery, renewable energy conversion and storage, biomaterials, and electronic noses.

Controllable Synthesis of Cobalt Porphyrin Nanocrystals through Micelle Confinement Self-Assembly

MRS Advances ◽  
2020 ◽  
Vol 5 (42) ◽  
pp. 2147-2155
Author(s):  
Sudi Chen ◽  
Xitong Ren ◽  
Shufang Tian ◽  
Jiajie Sun ◽  
Feng Bai
Keyword(s):  
Self Assembly ◽  
Water Oxidation ◽  
Separation Efficiency ◽  
Noncovalent Interactions ◽  
Building Blocks ◽  
The Self ◽  
Hexagonal Prism ◽  
Assembly Process ◽  
Surfactant Micelles ◽  
Cobalt Porphyrin

AbstractThe self-assembly of optically active building blocks into functional nanocrystals as high-activity photocatalysts is a key in the field of photocatalysis. Cobalt porphyrin with abundant catalytic properties is extensively studied in photocatalytic water oxidation and CO2 reduction. Here, we present the fabrication of cobalt porphyrin nanocrystals through a surfactant-assisted interfacial self-assembly process using Co-tetra(4-pyridyl) porphyrin as building block. The self-assembly process relies on the combined noncovalent interactions such as π-π stacking and axial Co-N coordination between individual porphyrin molecules within surfactant micelles. Tuning different reaction conditions (temperature, the ratio of co-solvent DMF) and types of surfactant, various nanocrystals with well-defined 1D to 3D morphologies such as nanowires, nanorods and nano hexagonal prism were obtained. Due to the ordered accumulation of molecules, the nanocrystals exhibit the properties of the enhanced capability of visible light capture and can conduce to improve the transport and separation efficiency of the photogenerated carriers, which is important for photocatalysis. Further studies of photocatalytic CO2 reduction are being performed to address the relationship between the size and shape of the nanocrystals with the photocatalytic activity.

scholarly journals Modification of a Single Atom Affects the Physical Properties of Double Fluorinated Fmoc-Phe Derivatives

2021 ◽  
Vol 22 (17) ◽  
pp. 9634
Author(s):  
Moran Aviv ◽  
Dana Cohen-Gerassi ◽  
Asuka A. Orr ◽  
Rajkumar Misra ◽  
Zohar A. Arnon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Physical Properties ◽  
Self Assembly ◽  
Deep Understanding ◽  
Building Blocks ◽  
The Self ◽  
Single Atom ◽  
Supramolecular Organization ◽  
Assembly Process ◽  
Wide Range

Supramolecular hydrogels formed by the self-assembly of amino-acid based gelators are receiving increasing attention from the fields of biomedicine and material science. Self-assembled systems exhibit well-ordered functional architectures and unique physicochemical properties. However, the control over the kinetics and mechanical properties of the end-products remains puzzling. A minimal alteration of the chemical environment could cause a significant impact. In this context, we report the effects of modifying the position of a single atom on the properties and kinetics of the self-assembly process. A combination of experimental and computational methods, used to investigate double-fluorinated Fmoc-Phe derivatives, Fmoc-3,4F-Phe and Fmoc-3,5F-Phe, reveals the unique effects of modifying the position of a single fluorine on the self-assembly process, and the physical properties of the product. The presence of significant physical and morphological differences between the two derivatives was verified by molecular-dynamics simulations. Analysis of the spontaneous phase-transition of both building blocks, as well as crystal X-ray diffraction to determine the molecular structure of Fmoc-3,4F-Phe, are in good agreement with known changes in the Phe fluorination pattern and highlight the effect of a single atom position on the self-assembly process. These findings prove that fluorination is an effective strategy to influence supramolecular organization on the nanoscale. Moreover, we believe that a deep understanding of the self-assembly process may provide fundamental insights that will facilitate the development of optimal amino-acid-based low-molecular-weight hydrogelators for a wide range of applications.

Study of the reaction mechanism between electroless Ni–P and Sn and its effect on the crystallization of Ni–P

2003 ◽  
Vol 18 (1) ◽  
pp. 4-7 ◽  
Author(s):  
Y. C. Sohn ◽  
Jin Yu ◽  
S. K. Kang ◽  
W. K. Choi ◽  
D. Y. Shih
Keyword(s):  
Reaction Mechanism ◽  
Solid State ◽  
Solid State Reaction ◽  
Crystallization Temperature ◽  
Low Temperatures ◽  
Transformation Temperature ◽  
The Self ◽  
Heat Of Reaction ◽  
Solder Reaction ◽  
Electroless Ni

The reaction mechanism between electroless Ni–P and Sn was investigated to understand the effects of Sn on solder reaction-assisted crystallization at low temperatures as well as self-crystallization of Ni–P at high temperatures. Ni3Sn4 starts to form in a solid-state reaction well before Sn melts. Heat of reaction for Ni3Sn4 was measured during the Ni–P and Sn reaction (241.2 J/g). It was found that the solder reaction not only promotes crystallization at low temperatures by forming Ni3P in the P-rich layer but also facilitates self-crystallization of Ni–P by reducing the transformation temperature and heat of crystallization. The presence of Sn reduces the self-crystallization temperature of Ni–P by about 10 °C. The heat of crystallization also decreases with an increased Sn thickness.

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