scholarly journals Light-directed trapping of metastable intermediates in a self-assembly process

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Joonsik Seo ◽  
Joonyoung F. Joung ◽  
Sungnam Park ◽  
Young Ji Son ◽  
Jaegeun Noh ◽  
...  
Keyword(s):  
Self Assembly ◽  
Alkyl Chain ◽  
Perylene Diimide ◽  
Chemical Compositions ◽  
Assembly Process ◽  
Supramolecular Framework ◽  
Tubular Structures ◽  
Significant Information ◽  
Self Assembling ◽  
General Method

AbstractSelf-assembly is a dynamic process that often takes place through a stepwise pathway involving formation of kinetically favored metastable intermediates prior to generation of a thermodynamically preferred supramolecular framework. Although trapping intermediates in these pathways can provide significant information about both their nature and the overall self-assembly process, it is a challenging venture without altering temperature, concentrations, chemical compositions and morphologies. Herein, we report a highly efficient and potentially general method for “trapping” metastable intermediates in self-assembly processes that is based on a photopolymerization strategy. By employing a chiral perylene-diimide possessing a diacetylene containing an alkyl chain, we demonstrated that the metastable intermediates, including nanoribbons, nanocoils and nanohelices, can be effectively trapped by using UV promoted polymerization before they form thermodynamic tubular structures. The strategy developed in this study should be applicable to naturally and synthetically abundant alkyl chain containing self-assembling systems.

MOLECULE-UP FABRICATION AND MANIPULATION OF LIPID NANOTUBES

2002 ◽  
Vol 01 (05n06) ◽  
pp. 465-469 ◽  
Author(s):  
TOSHIMI SHIMIZU ◽  
GEORGE JOHN ◽  
AKIHIRO FUKAGAWA ◽  
KOHZO ITO ◽  
HIROSHI FRUSAWA
Keyword(s):  
Optical Tweezers ◽  
Self Assembly ◽  
Flexural Rigidity ◽  
Combinatorial Approach ◽  
Tubular Structures ◽  
Self Assembling ◽  
Degree Of Unsaturation ◽  
Hydrophobic Chain ◽  
Rational Control ◽  
Lipid Nanotube

Self-assembling behavior of both a cardanol-appended glycolipid mixture and the fractionated four components has been examined in aqueous solutions. The cardanyl glucoside mixture differing in the degree of unsaturation in the hydrophobic chain was found to self-assemble in water to form open-ended nanotube structures with 10–15 nm inner diameters. The pure saturated homologue produced twisted helical ribbons through self-assembly, whereas the monoene derivative gave tubular structures. The rational control of helical and tubular morphologies has been achieved by a combinatorial approach through the binary self-assembly of the saturated and monoene derivatives. The flexural rigidity of a single lipid nanotube was first evaluated using optical tweezers manipulation and then compared with that of natural microtubules.

scholarly journals Free-standing supramolecular hydrogel objects by reaction-diffusion

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Matija Lovrak ◽  
Wouter E. J. Hendriksen ◽  
Chandan Maity ◽  
Serhii Mytnyk ◽  
Volkert van Steijn ◽  
...  
Keyword(s):  
Structure Formation ◽  
Self Assembly ◽  
Reaction Diffusion ◽  
Building Blocks ◽  
Assembly Process ◽  
Supramolecular Hydrogel ◽  
Free Standing ◽  
Spatial Control ◽  
Self Assembling ◽  
Vast Range

Abstract Self-assembly provides access to a variety of molecular materials, yet spatial control over structure formation remains difficult to achieve. Here we show how reaction–diffusion (RD) can be coupled to a molecular self-assembly process to generate macroscopic free-standing objects with control over shape, size, and functionality. In RD, two or more reactants diffuse from different positions to give rise to spatially defined structures on reaction. We demonstrate that RD can be used to locally control formation and self-assembly of hydrazone molecular gelators from their non-assembling precursors, leading to soft, free-standing hydrogel objects with sizes ranging from several hundred micrometres up to centimeters. Different chemical functionalities and gradients can easily be integrated in the hydrogel objects by using different reactants. Our methodology, together with the vast range of organic reactions and self-assembling building blocks, provides a general approach towards the programmed fabrication of soft microscale objects with controlled functionality and shape.

Self-Assembling Microspheres from Charged Functional Polyelectrolytes and Small-Molecule Counterions

2004 ◽  
Vol 823 ◽  
Author(s):  
Brandon Mckenna ◽  
Henrik Birkedal ◽  
Michael H. Bartl ◽  
Timothy J. Deming ◽  
Galen D. Stucky
Keyword(s):  
Amino Acids ◽  
Confocal Microscopy ◽  
Self Assembly ◽  
Fluorescent Labeling ◽  
Vesicle Formation ◽  
Assembly Process ◽  
Covalent Crosslinking ◽  
Self Assembling ◽  
Minimum Number ◽  
Sphere Formation

AbstractMicrometer-sized spheres have been found to assemble from homopolymer electrolytes and small, multivalent counterions in water. In contrast to previous efforts, these vesicles do not use preformed templates, do not require block copolymers, and do not necessarily employ nanoparticles. We have investigated the requirements for vesicle formation with regards to both components of the assembly. Self-assembly occurs with a variety of poly-amino acids and counterions, all of which require a minimum number of charged groups to promote non-covalent crosslinking. We show how the assembly process is controlled by pH and how, in consequence, the pKa's of the reactants can be used to reliably predict sphere formation. By varying the nature of the small counterions, we have determined the requirements for assemblies. The assemblies have been further investigated using confocal microscopy and fluorescent labeling of the different components.

Small-angle X-ray scattering structural study of the nanofiber self-assembly process in supramolecular gels based on glucopyranosides

2014 ◽  
Vol 47 (4) ◽  
pp. 1284-1297 ◽  
Author(s):  
Marlon F. Abreu ◽  
Denise R. dos Santos ◽  
Carlos E. N. Gatts ◽  
Rosana Giacomini ◽  
Sergio L. Cardoso ◽  
...  
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Alkyl Chain ◽  
Hydroxyl Group ◽  
Assembly Process ◽  
Scanning Calorimetry ◽  
Oh Groups ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

This paper reports a study of the supramolecular self-assembly process of low molecular mass organic gelators in the formation of nanofiber networks. Methyl 4,6-O-benzylidene-α-D-glucopyranoside derivative compounds were designed to investigate the effect of substituents on the molecules' self-assembly properties. Gelators were prepared using two different substituent groups at position 4 of the aromatic ring: an electron-donating series (with n-alkoxyl groups) and an electron-withdrawing series (with n-alkoxycarbonyl groups), where n = 2, 3, 4, 8 and 16 C atoms. The gelation process in several gelator concentrations was studied in polar and apolar organic solvents. Differential scanning calorimetry revealed that the gelation temperature increases with the molar concentration and decreases with alkyl chain size in both series of gelators. Scanning electron microscopy images of the xerogel showed cylindrical aggregates. In situ small-angle X-ray scattering analysis corroborated a model of self-assembly based on one-dimensional nanofiber growth in a two-phase gel system, while X-ray powder diffraction revealed partial crystallization for the gelator compounds and for some gel samples. The infrared analyses of gels indicated that molecules undergo a self-assembly process via hydrogen bonding, suggesting that both OH groups are involved for samples of the n-alkoxycarbonyl series. On the other hand, the n-alkoxyl series aggregation process depends on the size of the alkyl chain. The compound with the smallest group, n-propoxyl, also undergoes self-assembly using both OH groups. Conversely, the rest of the n-alkoxyl series uses only one hydroxyl group.

scholarly journals Self-Assembly of Short Elastin-like Amphiphilic Peptides: Effects of Temperature, Molecular Hydrophobicity and Charge Distribution

Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 202 ◽  
Author(s):  
Meiwen Cao ◽  
Yang Shen ◽  
Yu Wang ◽  
Xiaoling Wang ◽  
Dongxiang Li
Keyword(s):  
Charge Distribution ◽  
Self Assembly ◽  
Temperature Increase ◽  
The Self ◽  
Assembly Process ◽  
Amphiphilic Peptides ◽  
Self Assembling ◽  
Amphiphilic Peptide ◽  
Effects Of Temperature ◽  
Thermo Sensitivity

A novel type of self-assembling peptides has been developed by introducing the basic elastomeric β-turn units of elastin protein into the amphiphilic peptide molecules. The self-assembly behaviors of such peptides are affected by the overall molecular hydrophobicity, charge distribution and temperature. The molecules with higher hydrophobicity exhibit better self-assembling capability to form long fibrillar nanostructures. For some peptides, the temperature increase can not only promote the self-assembly process but also change the self-assembly routes. The self-assembly of the peptides with two charges centralized on one terminal show higher dependence on temperature than the peptides with two charges distributed separately on the two terminals. The study probes into the self-assembly behaviors of short elastin-like peptides and is of great help for developing novel self-assembling peptides with thermo sensitivity.

scholarly journals Gas barrier enhancement of uncharged apolar polymeric films by self-assembling stratified nano-composite films

RSC Advances ◽  
2019 ◽  
Vol 9 (19) ◽  
pp. 10938-10947 ◽  
Author(s):  
Ali Akbar Motedayen ◽  
Mohammadreza Rezaeigolestani ◽  
Carole Guillaume ◽  
Valérie Guillard ◽  
Nathalie Gontard
Keyword(s):  
Self Assembly ◽  
Hydrophobic Interactions ◽  
Composite Films ◽  
The Self ◽  
Polymeric Films ◽  
Assembly Process ◽  
Gas Barrier ◽  
Nano Composite ◽  
Self Assembling ◽  
First Time

The gas (O2 and CO2) permeability of an innovative stratified PE–organoclay (LLDPE/OMMT) nano-enabled composite films was studied for the first time and related to the self-assembly process driven by hydrophobic interactions.

scholarly journals Self-Assembly of Tail Tube Protein of Bacteriophage vB_EcoS_NBD2 into Extremely Long Polytubes in E. coli and S. cerevisiae

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 208 ◽  
Author(s):  
Aliona Špakova ◽  
Eugenijus Šimoliūnas ◽  
Raminta Batiuškaitė ◽  
Simonas Pajeda ◽  
Rolandas Meškys ◽  
...  
Keyword(s):  
Self Assembly ◽  
Tail Length ◽  
Cell Protein ◽  
Tubular Structures ◽  
E Coli ◽  
Physical Conditions ◽  
Self Assembling ◽  
Phage Proteins ◽  
Purification Protocol

Nucleotides, peptides and proteins serve as a scaffold material for self-assembling nanostructures. In this study, the production of siphovirus vB_EcoS_NBD2 (NBD2) recombinant tail tube protein gp39 reached approximately 33% and 27% of the total cell protein level in Escherichia coli and Saccharomyces cerevisiae expression systems, respectively. A simple purification protocol allowed us to produce a recombinant gp39 protein with 85%–90% purity. The yield of gp39 was 2.9 ± 0.36 mg/g of wet E. coli cells and 0.85 ± 0.33 mg/g for S. cerevisiae cells. The recombinant gp39 self-assembled into well-ordered tubular structures (polytubes) in vivo in the absence of other phage proteins. The diameter of these structures was the same as the diameter of the tail of phage NBD2 (~12 nm). The length of these structures varied from 0.1 µm to >3.95 µm, which is 23-fold the normal NBD2 tail length. Stability analysis demonstrated that the polytubes could withstand various chemical and physical conditions. These polytubes show the potential to be used as a nanomaterial in various fields of science.

scholarly journals Directed Self-Assembly of Polystyrene Nanospheres by Direct Laser-Writing Lithography

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 280
Author(s):  
Eleonora Cara ◽  
Federico Ferrarese Lupi ◽  
Matteo Fretto ◽  
Natascia De Leo ◽  
Mauro Tortello ◽  
...  
Keyword(s):  
Self Assembly ◽  
Large Scale ◽  
The Self ◽  
Assembly Process ◽  
Systematic Assessment ◽  
Self Assembling ◽  
Polystyrene Nanospheres ◽  
Direct Laser ◽  
Novel Method ◽  
Spinning Speed

In this work, we performed a systematic study on the effect of the geometry of pre-patterned templates and spin-coating conditions on the self-assembling process of colloidal nanospheres. To achieve this goal, large-scale templates, with different size and shape, were generated by direct laser-writer lithography over square millimetre areas. When deposited over patterned templates, the ordering dynamics of the self-assembled nanospheres exhibits an inverse trend with respect to that observed for the maximisation of the correlation length ξ on a flat surface. Furthermore, the self-assembly process was found to be strongly dependent on the height (H) of the template sidewalls. In particular, we observed that, when H is 0.6 times the nanospheres diameter and spinning speed 2500 rpm, the formation of a confined and well ordered monolayer is promoted. To unveil the defects generation inside the templates, a systematic assessment of the directed self-assembly quality was performed by a novel method based on Delaunay triangulation. As a result of this study, we found that, in the best deposition conditions, the self-assembly process leads to well-ordered monolayer that extended for tens of micrometres within the linear templates, where 96.2% of them is aligned with the template sidewalls.

scholarly journals Self-assembling iron oxyhydroxide/oxide tubular structures: laboratory-grown and field examples from Rio Tinto

2016 ◽  
Vol 472 (2195) ◽  
pp. 20160466 ◽  
Author(s):  
Laura M. Barge ◽  
Silvana S. S. Cardoso ◽  
Julyan H. E. Cartwright ◽  
Ivria J. Doloboff ◽  
Erika Flores ◽  
...  
Keyword(s):  
Self Assembly ◽  
Scaling Analysis ◽  
Iron Oxyhydroxide ◽  
Tubular Structures ◽  
Iron Mineral ◽  
Self Assembling ◽  
Rio Tinto ◽  
Yield Information ◽  
Chemical Gardens ◽  
Río Tinto

Rio Tinto in southern Spain has become of increasing astrobiological significance, in particular for its similarity to environments on early Mars. We present evidence of tubular structures from sampled terraces in the stream bed at the source of the river, as well as ancient, now dry, terraces. This is the first reported finding of tubular structures in this particular environment. We propose that some of these structures could be formed through self-assembly via an abiotic mechanism involving templated precipitation around a fluid jet, a similar mechanism to that commonly found in so-called chemical gardens. Laboratory experiments simulating the formation of self-assembling iron oxyhydroxide tubes via chemical garden/chemobrionic processes form similar structures. Fluid-mechanical scaling analysis demonstrates that the proposed mechanism is plausible. Although the formation of tube structures is not itself a biosignature, the iron mineral oxidation gradients across the tube walls in laboratory and field examples may yield information about energy gradients and potentially habitable environments.

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