Topological liquid crystal superstructures as structured light lasers

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.

scholarly journals Aqueous interfacial gels assembled from small molecule supramolecular polymers

2017 ◽  
Vol 8 (2) ◽  
pp. 1350-1355 ◽  
Author(s):  
Alexander S. Groombridge ◽  
Aniello Palma ◽  
Richard M. Parker ◽  
Chris Abell ◽  
Oren A. Scherman
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
Self Assembly ◽  
Hyperbranched Polymer ◽  
Soft Matter ◽  
Supramolecular Polymers ◽  
Supramolecular Network ◽  
Self Healing ◽  
Liquid Interfaces ◽  
Stimuli Responsive

The successful self-assembly of a stimuli-responsive aqueous supramolecular hyperbranched polymer from small molecules and the macrocyclic host cucurbit[8]uril (CB[8]) is reported. This self-healing supramolecular network can act as a soft matter barrier at liquid–liquid interfaces.

4. Gelification and soapiness

2020 ◽  
pp. 63-90
Author(s):  
Tom McLeish
Keyword(s):  
Brownian Motion ◽  
Self Assembly ◽  
Soft Matter ◽  
Intermolecular Forces ◽  
Two Dimensional ◽  
Important Distinction ◽  
One Dimensional ◽  
The Third ◽  
Self Assembled ◽  
Weak Intermolecular Forces

‘Gelification and soapiness’ looks at the third class of soft matter: ‘self-assembly’. Like the colloids of inks and clays, and the polymers of plastics and rubbers, ‘self-assembled’ soft matter also emerges as a surprising consequence of Brownian motion combined with weak intermolecular forces. Like them, it also leads to explanations of a very rich world of materials and phenomena, such as gels, foams, soaps, and ultimately to many of the structures of biological life. There is an important distinction that needs to be made between one-dimensional and two-dimensional self-assembly.

scholarly journals Periodic assembly of nanoparticle arrays in disclinations of cholesteric liquid crystals

2017 ◽  
Vol 114 (9) ◽  
pp. 2137-2142 ◽  
Author(s):  
Yunfeng Li ◽  
Elisabeth Prince ◽  
Sangho Cho ◽  
Alinaghi Salari ◽  
Youssef Mosaddeghian Golestani ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Soft Matter ◽  
Cholesteric Liquid Crystal ◽  
Topological Defects ◽  
Spatial Inhomogeneity ◽  
Cholesteric Phase ◽  
Anisotropic Surface ◽  
Linear Defects

An important goal of the modern soft matter science is to discover new self-assembly modalities to precisely control the placement of small particles in space. Spatial inhomogeneity of liquid crystals offers the capability to organize colloids in certain regions such as the cores of the topological defects. Here we report two self-assembly modes of nanoparticles in linear defects-disclinations in a lyotropic colloidal cholesteric liquid crystal: a continuous helicoidal thread and a periodic array of discrete beads. The beads form one-dimensional arrays with a periodicity that matches half a pitch of the cholesteric phase. The periodic assembly is governed by the anisotropic surface tension and elasticity at the interface of beads with the liquid crystal. This mode of self-assembly of nanoparticles in disclinations expands our ability to use topological defects in liquid crystals as templates for the organization of nanocolloids.

scholarly journals Review of Contemporary Self-Assembled Systems for the Controlled Delivery of Therapeutics in Medicine

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 278
Author(s):  
Laura Osorno ◽  
Alyssa Brandley ◽  
Daniel Maldonado ◽  
Alex Yiantsos ◽  
Robert Mosley ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Self Assembly ◽  
Deep Understanding ◽  
Drug Bioavailability ◽  
Medical Needs ◽  
Self Assembling ◽  
Amphiphilic Molecules ◽  
Self Assembled ◽  
Assembly Behavior ◽  
External Stimuli

The novel and unique design of self-assembled micro and nanostructures can be tailored and controlled through the deep understanding of the self-assembly behavior of amphiphilic molecules. The most commonly known amphiphilic molecules are surfactants, phospholipids, and block copolymers. These molecules present a dual attraction in aqueous solutions that lead to the formation of structures like micelles, hydrogels, and liposomes. These structures can respond to external stimuli and can be further modified making them ideal for specific, targeted medical needs and localized drug delivery treatments. Biodegradability, biocompatibility, drug protection, drug bioavailability, and improved patient compliance are among the most important benefits of these self-assembled structures for drug delivery purposes. Furthermore, there are numerous FDA-approved biomaterials with self-assembling properties that can help shorten the approval pathway of efficient platforms, allowing them to reach the therapeutic market faster. This review focuses on providing a thorough description of the current use of self-assembled micelles, hydrogels, and vesicles (polymersomes/liposomes) for the extended and controlled release of therapeutics, with relevant medical applications. FDA-approved polymers, as well as clinically and commercially available nanoplatforms, are described throughout the paper.

Liquid-crystal metasurfaces: Self-assembly for versatile optical functionality

2022 ◽  
Author(s):  
Irina V. Kasyanova ◽  
Maxim V. Gorkunov ◽  
Serguei P. Palto
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Fluid Phase ◽  
Photonic Devices ◽  
Light Diffraction ◽  
Applied Potential ◽  
Surface Alignment ◽  
Optical Functions ◽  
External Stimuli

Abstract Liquid crystals subjected to modulated surface alignment assemble into metasurface-type structures capable of various flat-optical functionalities, including light diffraction and focusing, deflection and splitting. Remaining in a fluid phase, they are susceptible to external stimuli, and, in particular, can be efficiently controled by low voltages. We overview the existing approaches to the design and fabrication of liquid-crystal metasurfaces, highlight their realized optical functions and discuss the applied potential in emerging photonic devices.

scholarly journals Tunable self-assembled Casimir microcavities and polaritons

2021 ◽  
Author(s):  
Timur Shegai ◽  
Battulga Munkhbat ◽  
Adriana Canales ◽  
Betül Kücüköz ◽  
Denis Baranov
Keyword(s):  
Self Assembly ◽  
Separation Distance ◽  
Van Der Waals Interactions ◽  
Visible Range ◽  
Light Pressure ◽  
Ordered Structures ◽  
Molecular Systems ◽  
Micro Scale ◽  
Fabry Perot ◽  
Self Assembled

Abstract Spontaneous formation of ordered structures – self-assembly – is ubiquitous in nature and observed on different length scales, ranging from atomic and molecular systems to micro-scale objects and living matter. Self-ordering in molecular and biological systems typically involves short-range hydrophobic and van der Waals interactions. Here, we introduce an approach to micro-scale self-assembly based on the joint action of attractive Casimir and repulsive electrostatic forces arising between charged metallic nanoflakes in a solution. This system forms a self-assembled optical Fabry-Perot microcavity with a fundamental mode in the visible range (long-range separation distance ca. 100-200 nm) and a tunable equilibrium configuration. Furthermore, by placing an excitonic material in the microcavity region, we are able to realize hybrid light-matter states (polaritons), whose properties, such as the coupling strength and the eigenstate composition, can be controlled in real-time by the concentration of ligand molecules in the solution and light pressure. These Casimir microcavities can find future use as sensitive and tunable platforms for a variety of applications, including opto-mechanics, nanomachinery, and cavity-induced polaritonic chemistry.

scholarly journals Light-Driven Pitch Tuning of Self-Assembled Hierarchical Gratings

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 326
Author(s):  
Yuan-Hang Wu ◽  
Sai-Bo Wu ◽  
Chao Liu ◽  
Qing-Gui Tan ◽  
Rui Yuan ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Soft Matter ◽  
Cholesteric Liquid Crystal ◽  
Functional Materials ◽  
Wave Pattern ◽  
Photonic Devices ◽  
Archimedean Spiral ◽  
First Order ◽  
Diffraction Angle ◽  
Self Assembled

Gratings are of vital importance in modern optics. Self-assembled cholesteric liquid crystal (CLC) gratings have attracted intensive attention due to their easy fabrication and broad applications. However, simultaneously achieving arbitrary patterning and delicate tuning of CLC gratings remains elusive. Here, light-driven pitch tuning is accomplished in hierarchical gratings formed in a molecular switch doped CLC. We fabricate a checkerboard hierarchical CLC grating for a demonstration, whose pitch is optically tuned from 4.6 µm to 10.7 µm. Correspondingly, the first-order diffraction angle continuously changes from 9.4° to 4.8° and a significant polarization selectivity is also observed. In addition, hierarchical CLC gratings with triangular wave pattern, Archimedean spiral, and radial stripes are also demonstrated. This work creates new opportunities for soft-matter-based intelligent functional materials and advanced photonic devices.

Defect Engineering in Self-Assembled 3D Photonic Crystals

2007 ◽  
Vol 121-123 ◽  
pp. 377-380
Author(s):  
Qing Feng Yan ◽  
Zuo Cheng Zhou ◽  
Fa Bing Su ◽  
X.S. Zhao
Keyword(s):  
Photonic Crystals ◽  
Self Assembly ◽  
Chemical Vapor ◽  
Directed Assembly ◽  
Photonic Devices ◽  
Defect Engineering ◽  
Scale Line ◽  
Fabrication Procedure ◽  
Line Defects ◽  
Self Assembled

This work describes the combination of photolithography and self-assembly methods for fabrication of 3D photonic crystals (PCs) with well-defined micron-scale line defects embedded in the PCs. Line defects with different dimensions, shapes, and compositions have been introduced into the 3D PCs by choosing different photoresists, masks, and template-directed assembly techniques. Infiltration of carbon using high-temperature chemical vapor deposition (CVD) technique showed that the fabrication procedure offers an ideal approach to functional 3D photonic devices from self-assembled photonic crystals.

Defect Engineering in Self-Assembled 3D Photonic Crystals

2007 ◽  
Vol 121-123 ◽  
pp. 57-60
Author(s):  
Qing Feng Yan ◽  
Zuo Cheng Zhou ◽  
Fa Bing Su ◽  
X.S. Zhao
Keyword(s):  
Photonic Crystals ◽  
Self Assembly ◽  
Chemical Vapor ◽  
Directed Assembly ◽  
Photonic Devices ◽  
Defect Engineering ◽  
Scale Line ◽  
Fabrication Procedure ◽  
Line Defects ◽  
Self Assembled

This work describes the combination of photolithography and self-assembly methods for fabrication of 3D photonic crystals (PCs) with well-defined micron-scale line defects embedded in the PCs. Line defects with different dimensions, shapes, and compositions have been introduced into the 3D PCs by choosing different photoresists, masks, and template-directed assembly techniques. Infiltration of carbon using high-temperature chemical vapor deposition (CVD) technique showed that the fabrication procedure offers an ideal approach to functional 3D photonic devices from self-assembled photonic crystals.

scholarly journals Fmoc-diphenylalanine-based hydrogels as a potential carrier for drug delivery

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 458-468
Author(s):  
Ranjoo Choe ◽  
Seok Il Yun
Keyword(s):  
Drug Delivery ◽  
Self Assembly ◽  
Release Mechanism ◽  
Self Healing ◽  
Polyamidoamine Dendrimer ◽  
Diffusion Controlled ◽  
Self Assembled ◽  
High Concentrations ◽  
Β Sheet ◽  
Biphasic Profile

AbstractSelf-assembled hydrogels from 9-fluorenylmethoxycarbonyl-modified diphenylalanine (Fmoc-FF) peptides were evaluated as potential vehicles for drug delivery. During self-assembly of Fmoc-FF, high concentrations of indomethacin (IDM) drugs were shown to be incorporated into the hydrogels. The β-sheet arrangement of peptides was found to be predominant in Fmoc-FF–IDM hydrogels regardless of the IDM content. The release mechanism for IDM displayed a biphasic profile comprising an initial hydrogel erosion-dominated stage followed by the diffusion-controlled stage. Small amounts of polyamidoamine dendrimer (PAMAM) added to the hydrogel (Fmoc-FF 0.5%–IDM 0.5%–PAMAM 0.03%) resulted in a more prolonged IDM release compared with Fmoc-FF 0.5%–IDM 0.5% hydrogel. Furthermore, these IDM-loaded hydrogels demonstrated excellent thixotropic response and injectability, which make them suitable candidates for use as injectable self-healing matrices for drug delivery.

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