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 STUDY OF THE FORMATION OF MESOPOROUS TiO2 USING ISOPROPOXIDE PRECURSORS UNDER LESS WATER CONDITIONS

2010 ◽  
Vol 5 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Indriana Kartini ◽  
Gao Qing Lu
Keyword(s):  
Self Assembly ◽  
Isopropyl Alcohol ◽  
Molar Ratio ◽  
Mesoporous Titania ◽  
Synthesis Parameters ◽  
Water Conditions ◽  
Evaporation Induced Self Assembly ◽  
Added Water ◽  
Templating Synthesis

The role of the synthesis parameters (the molar ratio of template, isopropyl alcohol, acetylacetone, and water with respect to titanium(IV) tetraisopropoxide) has been thoroughly investigated to understand their effects on the mesostructures and the formation of crystalline phases of mesoporous titania xerogels in less water condition (no added water) at 60 oC. The resultant mesoporous titania are more likely to have worm-hole like structure as the dominant stable structure. The template appears to play no significant role in structure directing at mesophase level. However, increasing the amount of the template delays the formation of anatase crystalline phase   Keywords: mesoporous titania, templating synthesis, anatase, evaporation-induced self-assembly

The Effects of Surfactants on the Morphology of Colloidal Crystals in Self-assembly

2006 ◽  
Vol 942 ◽  
Author(s):  
Zuocheng Zhou ◽  
Qin Li ◽  
Likui Wang ◽  
Xiusong Zhao
Keyword(s):  
Crystal Structure ◽  
Surface Tension ◽  
Contact Angle ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Colloidal Suspension ◽  
Sodium Dodecyl ◽  
Colloidal Crystals ◽  
Phase Contact ◽  
Surfactant Solutions

AbstractIn this research, sodium dodecyl sulfates (SDS) and N-cetyl-n,n,n-trimethyammonium bromide (CTAB) surfactant solutions are used as solvents of polystyrene (PS) colloidal suspension during the fabrication of colloidal crystals. The effects of the surfactant on the quality and the morphology of the colloidal crystals are studied. It was found that surfactants not only change the charge of PS colloidal particles, but also significantly changed the surface tension and the 3 phase contact angle of the suspension with respect to the glass substrate, in turn they change the thickness of the formed crystal as well as the crystal structure. The derived knowledge will be potentially useful in clarifying the mechanisms involved in the formation of colloidal crystals.

scholarly journals Evaporation-induced self-assembly synthesis of Ni-doped mesoporous SnO2 thin films with tunable room temperature magnetic properties

2017 ◽  
Vol 5 (22) ◽  
pp. 5517-5527 ◽  
Author(s):  
Junpeng Fan ◽  
Miguel Guerrero ◽  
Adrián Carretero-Genevrier ◽  
Maria Dolors Baró ◽  
Santiago Suriñach ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Self Assembly ◽  
Room Temperature ◽  
Ferromagnetic Properties ◽  
Evaporation Induced Self Assembly ◽  
Sno2 Thin Films ◽  
Controlled Doping ◽  
Mesoporous Sno2

Controlled doping of mesoporous SnO2 thin films with Ni2+ during evaporation induced self-assembly (EISA) synthesis enables room-temperature ferromagnetic properties.

Assembling ultra-thick and crack-free colloidal crystals via an isothermal heating evaporation induced self-assembly method

2012 ◽  
Vol 358 (12-13) ◽  
pp. 1611-1616 ◽  
Author(s):  
Qingsong Jiang ◽  
Chan Li ◽  
Shugang Shi ◽  
Degang Zhao ◽  
Lun Xiong ◽  
...  
Keyword(s):  
Self Assembly ◽  
Colloidal Crystals ◽  
Isothermal Heating ◽  
Assembly Method ◽  
Evaporation Induced Self Assembly

scholarly journals Preparation, Properties, and Self-Assembly Behavior of PTFE-Based Core-Shell Nanospheres

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Katia Sparnacci ◽  
Diego Antonioli ◽  
Simone Deregibus ◽  
Michele Laus ◽  
Giampaolo Zuccheri ◽  
...  
Keyword(s):  
Particle Size ◽  
Self Assembly ◽  
Colloidal Crystal ◽  
Colloidal Crystals ◽  
Direct Consequence ◽  
Core Shell ◽  
Precise Control ◽  
Assembly Behavior ◽  
Shell Particles ◽  
High Degree

Nanosized PTFE-based core-shell particles can be prepared by emulsifier-free seed emulsion polymerization technique starting from spherical or rod-like PTFE seeds of different size. The shell can be constituted by the relatively high Tg polystyrene and polymethylmethacrylate as well as by low Tg polyacrylic copolymers. Peculiar thermal behavior of the PTFE component is observed due to the high degree of PTFE compartmentalization. A very precise control over the particle size can be exerted by properly adjusting the ratio between the monomers and the PTFE seed. In addition, the particle size distribution self-sharpens as the ratio monomer/PTFE increases. Samples with uniformity ratios suited to build 2D and 3D colloidal crystals are easily prepared. In particular, 2D colloidal crystal of spheres leads to very small 2D nanostructuration, useful for the preparation of masks with a combination of nanosphere lithography and reactive ion etching. 3D colloidal crystals were also obtained featuring excellent opal quality, which is a direct consequence of the monodispersity of colloids used for their growth.

Synthesis and Characterization of Magnetic Mesoporous Ɣ-FE2O3/SIO2

2014 ◽  
Vol 879 ◽  
pp. 128-133
Author(s):  
Nur Shuhada Shaari ◽  
Suhaina Mohd Ibrahim ◽  
Farinaa Md Jamil ◽  
Zuhana Ahmad Zubir ◽  
A.M. Abdullah ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Iron Oxide ◽  
Self Assembly ◽  
Quantum Interference ◽  
Silica Matrix ◽  
Synthesis And Characterization ◽  
Vibrating Sample Magnetometer ◽  
Superconducting Quantum Interference Device ◽  
Evaporation Induced Self Assembly

Magneticmesoporousɣ-Fe2O3/SiO2 synthesized using an evaporation-induced self-assembly (EISA) approach. The non-ionictriblock copolymer P123 was used as surfactant template with various amounts of iron oxide (1.8g-2.4g) and varied during the synthesis. Characterizations of the surface area and magnetic properties for prepared materials were done using N2-sorption analyses, and a superconducting quantum interference device interfaced with a vibrating sample magnetometer (SQUID-VSM) respectively. From this study, N2-sorption analysis indicated that most of the ɣ-Fe2O3domains of several nanometres were embedded in the silica matrix. In addition, the obtained magneticmesoporouscomposite which contains 2.3g amount ofiron oxide has revealedhigher magnetism saturation value of (4.564 emu/g) compared to other prepared samples which been evaluated by VSM analysis.

scholarly journals Accelerated annealing of colloidal crystal monolayers by means of cyclically applied electric fields

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Peng-Kai Kao ◽  
Bryan J. VanSaders ◽  
Sharon C. Glotzer ◽  
Michael J. Solomon
Keyword(s):  
Electric Fields ◽  
Self Assembly ◽  
Colloidal Crystal ◽  
Orientational Order ◽  
Particle Interaction ◽  
Colloidal Crystals ◽  
Quantitative Relationship ◽  
Melting Time ◽  
Local Defect ◽  
High Quality

AbstractExternal fields are commonly applied to accelerate colloidal crystallization; however, accelerated self-assembly kinetics can negatively impact the quality of crystal structures. We show that cyclically applied electric fields can produce high quality colloidal crystals by annealing local disorder. We find that the optimal off-duration for maximum annealing is approximately one-half of the characteristic melting half lifetime of the crystalline phase. Local six-fold bond orientational order grows more rapidly than global scattering peaks, indicating that local restructuring leads global annealing. Molecular dynamics simulations of cyclically activated systems show that the ratio of optimal off-duration for maximum annealing and crystal melting time is insensitive to particle interaction details. This research provides a quantitative relationship describing how the cyclic application of fields produces high quality colloidal crystals by cycling at the fundamental time scale for local defect rearrangements; such understanding of dynamics and kinetics can be applied for reconfigurable colloidal assembly.

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