Transmutable Colloidal Crystals and Active Phase Separation via Dynamic, Directed Self-Assembly with Toggled External Fields

ACS Nano ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 764-771 ◽  
Author(s):  
Zachary M. Sherman ◽  
James W. Swan
Keyword(s):  
Phase Separation ◽  
Self Assembly ◽  
Colloidal Crystals ◽  
Active Phase ◽  
External Fields

A Novel Technique for Large-Scale Fabrication of 3D Colloidal Crystals: Suspending Self-Assembly in Water Medium (SSAM)

2021 ◽  
Author(s):  
Zhengting Zhang ◽  
Guiyun Yi ◽  
Xiaodong Wang ◽  
Peng Li ◽  
Zhuoyan Wan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Large Scale ◽  
Colloidal Crystals ◽  
Water Medium ◽  
Novel Technique

scholarly journals Influence of Phase Composition and Pretreatment on the Conversion of Iron Oxides into Iron Carbides in Syngas Atmospheres

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 773
Author(s):  
Aleks Arinchtein ◽  
Meng-Yang Ye ◽  
Michael Geske ◽  
Marvin Frisch ◽  
Ralph Kraehnert
Keyword(s):  
Phase Composition ◽  
Iron Oxide ◽  
Self Assembly ◽  
Iron Carbide ◽  
Active Phase ◽  
Physicochemical Analysis ◽  
Carbide Formation ◽  
Iron Carbides ◽  
Carbide Phases ◽  
Higher Hydrocarbons

CO2 Fischer–Tropsch synthesis (CO2–FTS) is a promising technology enabling conversion of CO2 into valuable chemical feedstocks via hydrogenation. Iron–based CO2–FTS catalysts are known for their high activities and selectivities towards the formation of higher hydrocarbons. Importantly, iron carbides are the presumed active phase strongly associated with the formation of higher hydrocarbons. Yet, many factors such as reaction temperature, atmosphere, and pressure can lead to complex transformations between different oxide and/or carbide phases, which, in turn, alter selectivity. Thus, understanding the mechanism and kinetics of carbide formation remains challenging. We propose model–type iron oxide films of controlled nanostructure and phase composition as model materials to study carbide formation in syngas atmospheres. In the present work, different iron oxide precursor films with controlled phase composition (hematite, ferrihydrite, maghemite, maghemite/magnetite) and ordered mesoporosity are synthesized using the evaporation–induced self–assembly (EISA) approach. The model materials are then exposed to a controlled atmosphere of CO/H2 at 300 °C. Physicochemical analysis of the treated materials indicates that all oxides convert into carbides with a core–shell structure. The structure appears to consist of crystalline carbide cores surrounded by a partially oxidized carbide shell of low crystallinity. Larger crystallites in the original iron oxide result in larger carbide cores. The presented simple route for the synthesis and analysis of soft–templated iron carbide films will enable the elucidation of the dynamics of the oxide to carbide transformation in future work.

Dispersion, Phase Separation, and Self-Assembly of Polymer-Grafted Nanorod Composites

2017 ◽  
Vol 50 (21) ◽  
pp. 8816-8826 ◽  
Author(s):  
Vaishnavi Gollanapalli ◽  
Anirudh Manthri ◽  
Uma K. Sankar ◽  
Mukta Tripathy
Keyword(s):  
Phase Separation ◽  
Self Assembly ◽  
Dispersion Phase

Self-assembly of latex particles for colloidal crystals

Particuology ◽  
2011 ◽  
Vol 9 (6) ◽  
pp. 559-565 ◽  
Author(s):  
Zhirong Li ◽  
Jingxia Wang ◽  
Yanlin Song
Keyword(s):  
Self Assembly ◽  
Colloidal Crystals ◽  
Latex Particles

Interfacial polymer phase segregation and self-assembly of square colloidal crystals

Soft Matter ◽  
2012 ◽  
Vol 8 (25) ◽  
pp. 6684 ◽  
Author(s):  
Matthew M. Shindel ◽  
Szu-Wen Wang ◽  
Ali Mohraz
Keyword(s):  
Self Assembly ◽  
Colloidal Crystals ◽  
Phase Segregation ◽  
Polymer Phase

scholarly journals Synthesis of magnetic mesoporous titania colloidal crystals through evaporation induced self-assembly in emulsion as effective and recyclable photocatalysts

2015 ◽  
Vol 17 (41) ◽  
pp. 27653-27657 ◽  
Author(s):  
Jeffrey E. Chen ◽  
Hong-Yuan Lian ◽  
Saikat Dutta ◽  
Saad M. Alshehri ◽  
Yusuke Yamauchi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Self Assembly ◽  
Colloidal Crystal ◽  
Colloidal Crystals ◽  
Mesoporous Titania ◽  
Evaporation Induced Self Assembly

This study illustrates the directed self-assembly of mesoporous TiO2 with magnetic properties due to its colloidal crystal structure with Fe3O4.

scholarly journals Water vapor induced self-assembly of islands/honeycomb structure by secondary phase separation in polystyrene solution with bimodal molecular weight distribution

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Secondary Phase ◽  
Honeycomb Structure ◽  
Polymer Chains ◽  
Molecular Weights ◽  
Secondary Phase Separation

<p>The formation of complex structures in thin films is of interest in many fields. Segregation of polymer chains of different molecular weights is a well-known process. However, here, polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. It was proven that at certain conditions, the phase separation occurred between two fractions of bimodal polystyrene/methyl ethyl ketone solution. The films were prepared by spin-coating, and the segregation between polystyrene phases was investigated by force spectroscopy. Next, water vapour induced secondary phase separation was investigated. The introduction of moist airflow induced the self-assembly of the lower molecular weight into islands and the heavier fraction into a honeycomb. As a result, an easy, fast, and effective method of obtaining island/honeycomb morphologies was demonstrated. The possible mechanisms of the formation of such structures were discussed.</p>

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