scholarly journals Surface-triggered cascade reactions between DNA linkers direct the self-assembly of colloidal crystals of controllable thickness

Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5450-5459 ◽  
Author(s):  
Pritam Kumar Jana ◽  
Bortolo Matteo Mognetti
Keyword(s):  
Self Assembly ◽  
Colloidal Crystals ◽  
Cascade Reactions ◽  
The Self ◽  
Particle Interactions ◽  
Functionalized Surfaces ◽  
Layer Deposition

Functionalized surfaces direct colloidal layer deposition by enhancing particle–particle interactions.

Large-Scale Self-Assembly in Weakly-Flocculated Suspensions

2019 ◽  
Vol 4 (1) ◽  
pp. 68-74
Author(s):  
Aleš Dakskobler ◽  
Matjaz Valant
Keyword(s):  
Self Assembly ◽  
Shear Force ◽  
Large Scale ◽  
Hard Spheres ◽  
Colloidal Crystals ◽  
The Self ◽  
Spherical Particles ◽  
Particle Interactions ◽  
Concentrated Suspensions ◽  
Average Angle

Background: Studies on the formation of colloidal crystals in concentrated suspensions have mainly been based on dispersed suspensions with a repulsive inter-particle potential of hard or nearly hard spheres. The self-assembly in weakly-flocculated suspensions has still been unrealized. Here, we report on the formation of ordered structures in concentrated suspensions of nearly-hard spherical particles with weakly-attractive inter-particle interactions that are an order of magnitude higher than the particles’ thermal energy. Methods: In our case, the self-assembly in such suspensions is not thermodynamically driven, but an external shear force must be applied. The driving force for the particles’ ordering is an increase in the inter-particle interactions. This manifests itself in a decrease in the average angle between the interparticle interaction direction and the applied shear stress direction. Results: For a successful ordering into a large-scale closed packed assembly, the external shear force must not exceed the inter-particle attractive interaction for the minimum possible average angle (as in the closed packed structures) but be high enough to enable the particles to move in the highly loaded suspension. Conclusion: The developed method for the self-assembly of the weakly flocculated systems can be applied very generally e.g. a control over a composition of heterogeneous colloidal crystals, manufacturing of the large-scale photonic crystals or preparation of very densely packed compacts of particles needed for the production of sintered ceramics.

scholarly journals Self-Assembly of Ternary Particles for Tough Colloidal Crystals with Vivid Structure Colors

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Binfu Bao ◽  
Duo Liu ◽  
Youyou Yang ◽  
Zhehong Shen ◽  
Bo You
Keyword(s):  
Carbon Black ◽  
Self Assembly ◽  
Large Scale ◽  
Colloidal Crystals ◽  
The Self ◽  
Natural Conditions ◽  
Practical Applications ◽  
Structural Colors ◽  
Crystal Films ◽  
Nanosilica Particles

Self-assembly of colloidal spheres is the most frequently used method for structural colors, but the chroma of the structural colors is usually so low that people cannot observe it under natural conditions. This paper presents a facile method for fabrications of vivid structural colors by doping carbon black into the self-assembly of colloidal polymer spheres and nanosilica particles. This approach can generate very gorgeous structural colors which can be very easily seen under natural conditions. The fabrication conditions for the self-assembly of composite dispersions of polymer/silica/carbon black were optimized to obtain colloidal crystals with vivid colors. Thus, robust mechanical properties, large-scale, and brilliant structural colors can guarantee the obtained crystal films to find practical applications, which are demonstrated by the fact that the successful applications of structural colors beautify the original simple and tedious surface of bamboo strand board (BSB).

Fabrication of Colloidal Crystals on Different Patterned Silicon Substrates by Self-Assembly Method

2013 ◽  
Vol 850-851 ◽  
pp. 92-95
Author(s):  
Yong Wan ◽  
Zhong Yu Cai ◽  
Ming Hui Jia ◽  
Chao Li ◽  
Wan Qin Yang
Keyword(s):  
Self Assembly ◽  
Colloidal Suspension ◽  
Colloidal Crystals ◽  
The Self ◽  
Surface Pattern ◽  
Silicon Substrates ◽  
Assembly Process ◽  
Assembly Method ◽  
Microsphere Size ◽  
Influent Factors

Silica and polystyrene (PS) microspheres assembled on two quite different patterned silicon substrates, cross-like pillar pattern and eye-like pattern, respectively. The results indicated that the surface pattern imposes a predetermined lattice orientation in colloidal crystals (CCs). Other influent factors, such as microsphere size, the altitude of pattern and the concentration of colloidal suspension, may also play an important role on the self-assembly process.

Recent advances in the self-assembly of polynuclear metal–selenium and –tellurium compounds from 14–16 reagents

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Alexander M. Polgar ◽  
John F. Corrigan
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Controlled Synthesis ◽  
Metal Chalcogenides ◽  
Group 14 ◽  
Ancillary Ligands ◽  
Metal Atoms ◽  
Functionalized Surfaces ◽  
Group 14 Elements ◽  
Background Material

Abstract The use of reagents containing bonds between group 14 elements and Se or Te for the self-assembly of polynuclear metal–chalcogen compounds is covered. Background material is briefly reviewed and examples from the literature are highlighted from the period 2007–2017. Emphasis is placed on the different classes of 14–16 precursors and their application in the targeted synthesis of metal–chalcogen compounds. The unique properties arising from the combination of specific 14–16 precursors, metal atoms, and ancillary ligands are also described. Selected examples are chosen to underline the progress in (i) controlled synthesis of heterometallic (ternary) chalcogen clusters, (ii) chalcogen clusters with organic functionalized surfaces, and (iii) crystalline open-framework metal chalcogenides.

Controlling the self-assembly of magnetic nanoparticles by competing dipolar and isotropic particle interactions

2014 ◽  
Vol 436 ◽  
pp. 83-89 ◽  
Author(s):  
Manuela Hod ◽  
Celin Dobbrow ◽  
Mukanth Vaidyanathan ◽  
Debanjan Guin ◽  
Lhoussaine Belkoura ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Self Assembly ◽  
The Self ◽  
Particle Interactions

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

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