Entropy-Induced Self-Assembly of Colloidal Crystals with High Reflectivity and Narrow Reflection Bandwidth

Cracks and defects, which could result in lower reflectivity and larger full width at half maximum (FWHM), are the major obstacles for obtaining highly ordered structures of colloidal crystals (CCs). The high-quality CCs with high reflectivity (more than 90%) and 9.2 nm narrow FWHM have been successfully fabricated using a fixed proportion of a soft matter system composed of silica particles (SPs), polyethylene glycol diacrylate (PEGDA), and ethanol. The influences of refractivity difference, volume fractions, and particle dimension on FWHM were illuminated. Firstly, we clarified the influences of the planar interface and the bending interface on the self-assembly. The CCs had been successfully fabricated on the planar interface and presented unfavorable results on the bending interface. Secondly, a hard sphere system consisting of SPs, PEGDA, and ethanol was established, and the entropy-driven phase transition mechanism of a polydisperse system was expounded. The FWHM and reflectivity of CCs showed an increasing trend with increasing temperature. Consequently, high-quality CCs were obtained by adjusting temperatures (ordered structure formed at 90 °C and solidified at 0 °C) based on the surface phase rule of the system. We acquired a profound understanding of the principle and process of self-assembly, which is significant for preparation and application of CCs such as optical filters.

Download Full-text

Influence of growth parameters on the fabrication of high-quality colloidal crystals via a controlled evaporation self-assembly method

Thin Solid Films ◽

10.1016/j.tsf.2010.02.062 ◽

2010 ◽

Vol 518 (18) ◽

pp. 5083-5090 ◽

Cited By ~ 26

Author(s):

G.Q. Liu ◽

Z.S. Wang ◽

Y.H. Ji

Keyword(s):

Self Assembly ◽

Growth Parameters ◽

Colloidal Crystals ◽

High Quality ◽

Assembly Method

Download Full-text

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

Scientific Reports ◽

10.1038/s41598-021-90310-7 ◽

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.

Download Full-text

Introducing high-quality planar defects into colloidal crystals via self-assembly at the air/water interface

10.1117/12.2075937 ◽

2015 ◽

Author(s):

Kuo Zhong ◽

Pieter-Jan Demeyer ◽

Xingping Zhou ◽

Olga Kruglova ◽

Niels Verellen ◽

...

Keyword(s):

Self Assembly ◽

Colloidal Crystals ◽

Water Interface ◽

High Quality ◽

Planar Defects ◽

Air Water Interface

Download Full-text

Fabricación y caracterización óptica de cristales coloidales de alta calidad formados por esferas de SiO2 de 225 nm de diámetro con empaquetamiento fcc crecidos por el método convectivo de auto-ensamblado de deposición vertical.

Universitas Scientiarum ◽

10.11144/javeriana.sc15-2.faoc ◽

2010 ◽

Vol 15 (2) ◽

pp. 150 ◽

Cited By ~ 3

Author(s):

Octavio Alejandro Castañeda-Uribe ◽

Juan Carlos Salcedo-Reyes ◽

Henry Alberto Méndez-Pinzón ◽

Aura Marina Pedroza-Rodríguez

Keyword(s):

Photonic Crystals ◽

Self Assembly ◽

Volume Fraction ◽

Colloidal Crystals ◽

Optical Characterization ◽

Bragg Diffraction ◽

Face Centered Cubic ◽

High Quality ◽

Assembly Method ◽

Face Centered

Objective: Fabrication and optical characterization of close-packed 225 nm SiO2 -based colloidal crystals. Materials and methods: The vertical convective self-assembly method is used to grow high-quality 225 nm close-packed SiO2-based colloidal crystals. An annealing process (550°C) is made in order to improve the mechanical stability of the sample. Optical characterization is done by angle-resolved transmission spectroscopy (A-RTS) and structural characterization by Scanning Electron Microscopy (SEM). Results: Both, A-RTS and SEM, show that with the vertical convective self-assembly method, with the appropriate parameters of temperature of evaporation (60°C), volume fraction of the colloidal suspension (0.2% w/w) and acidity (pH=6), highly ordered close packed face centered cubic (fcc) SiO2 based colloidal crystals are obtained. Conclusions: The growth of high-quality (long range order and defect-free) face centered cubic opal-based photonic crystals is reported. Key words: Photonic crystals, colloidal crystals, artificial opals, vertical convective deposition method, Bragg diffraction

Download Full-text

Corrigendum to “Influence of growth parameters on the fabrication of high-quality colloidal crystals via a controlled evaporation self-assembly method” [Thin Solid Films 518 (2010) 5083–5090]

Thin Solid Films ◽

10.1016/j.tsf.2016.01.013 ◽

2016 ◽

Vol 599 ◽

pp. 194

Author(s):

G.Q. Liu ◽

Z.S. Wang ◽

Y.H. Ji

Keyword(s):

Self Assembly ◽

Growth Parameters ◽

Colloidal Crystals ◽

High Quality ◽

Thin Solid Films ◽

Solid Films ◽

Assembly Method

Download Full-text

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

Crystal Growth & Design ◽

10.1021/acs.cgd.1c00461 ◽

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

Download Full-text

Novel Erythrocyte-like Graphene Microspheres with High Quality and Mass Production Capability via Electrospray Assisted Self-Assembly

Scientific Reports ◽

10.1038/srep03327 ◽

2013 ◽

Vol 3 (1) ◽

Cited By ~ 17

Author(s):

Yayang Tian ◽

Guan Wu ◽

Xike Tian ◽

Xiaoming Tao ◽

Wei Chen

Keyword(s):

Self Assembly ◽

Mass Production ◽

High Quality ◽

Production Capability

Download Full-text

Topological liquid crystal superstructures as structured light lasers

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2110839118 ◽

2021 ◽

Vol 118 (49) ◽

pp. e2110839118

Author(s):

Miha Papič ◽

Urban Mur ◽

Kottoli Poyil Zuhail ◽

Miha Ravnik ◽

Igor Muševič ◽

...

Keyword(s):

Self Assembly ◽

Soft Matter ◽

Structured Light ◽

Topological Defects ◽

Photonic Devices ◽

Light Polarization ◽

Self Healing ◽

Fabry Perot ◽

Self Assembled ◽

External Stimuli

Liquid crystals (LCs) form an extremely rich range of self-assembled topological structures with artificially or naturally created topological defects. Some of the main applications of LCs are various optical and photonic devices, where compared to their solid-state counterparts, soft photonic systems are fundamentally different in terms of unique properties such as self-assembly, self-healing, large tunability, sensitivity to external stimuli, and biocompatibility. Here we show that complex tunable microlasers emitting structured light can be generated from self-assembled topological LC superstructures containing topological defects inserted into a thin Fabry–Pérot microcavity. The topology and geometry of the LC superstructure determine the structuring of the emitted light by providing complex three-dimensionally varying optical axis and order parameter singularities, also affecting the topology of the light polarization. The microlaser can be switched between modes by an electric field, and its wavelength can be tuned with temperature. The proposed soft matter microlaser approach opens directions in soft matter photonics research, where structured light with specifically tailored intensity and polarization fields could be designed and implemented.

Download Full-text