Self-Assembly of Two Unit Cells into a Nanodomain Structure Containing Five-Fold Symmetry

2018 ◽  
Vol 9 (15) ◽  
pp. 4373-4378 ◽  
Author(s):  
Hongbo Xie ◽  
Hucheng Pan ◽  
Yuping Ren ◽  
Shineng Sun ◽  
Liqing Wang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Unit Cells ◽  
Nanodomain Structure

Microfabrication for Packaged Biomolecular Unit Cells

2013 ◽  
Author(s):  
Mary-Anne Nguyen ◽  
Andy Sarles
Keyword(s):  
Self Assembly ◽  
Material System ◽  
Stimuli Responsive ◽  
Critical Feature ◽  
Liquid Phases ◽  
Unit Cells ◽  
Droplet Interface Bilayer ◽  
Polymeric Substrates ◽  
Original Amount

This paper focuses on developing a closed fluidic environment for packaging biomolecular unit cells, which consists of a synthetic lipid bilayer and other biomolecules contained in a near solid-state material with two regions that contain hydrophobic oil (i.e. nonpolar solvent) surrounding aqueous droplets. This research provides a stepping-stone towards an autonomic biomolecular material system, whereby a packaged system will allow for precise droplet interface bilayer (DIB) formation without the interference of outside contamination for long-term applications. Also, substrate materials need to maintain droplets and preserve the self-assembly and stimuli-responsive properties of biomolecules within the unit cell. A critical feature of an encapsulating material is that it does not absorb either of the liquid phases required to form DIBs. Oil depletion tests within sealed, polymeric substrates show that polydimethylsiloxane (PDMS) absorbs full volume of injected hexadecane in approximately 27 hours. However, polyurethane substrates maintain the original amount of oil injected even after several weeks. Bilayer lifetime is also monitored within an environment in which the oil is also depleting. The results of this test show the longevity of a DIB to be shorter than oil lifetime. The lipid-encased droplets disconnect after approximately 10 hours, when there is only approximately <60% amount of oil present. In addition, an initial microfluidic substrate is designed such that a single T-junction intersection can be used to form monodisperse droplets within a primary oil-filled channel and a downstream increase in channel width can be used to connect droplets to form DIBs.

Self-assembled plasmonic metamaterials

Nanophotonics ◽  
2013 ◽  
Vol 2 (3) ◽  
pp. 211-240 ◽  
Author(s):  
Stefan Mühlig ◽  
Alastair Cunningham ◽  
José Dintinger ◽  
Toralf Scharf ◽  
Thomas Bürgi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Degrees Of Freedom ◽  
Building Blocks ◽  
Spatial Arrangement ◽  
Plasmonic Nanostructures ◽  
Bottom Up ◽  
Unit Cells ◽  
Amorphous Structures ◽  
Self Assembled ◽  
Novel Applications

AbstractNowadays for the sake of convenience most plasmonic nanostructures are fabricated by top-down nanofabrication technologies. This offers great degrees of freedom to tailor the geometry with unprecedented precision. However, it often causes disadvantages as well. The structures available are usually planar and periodically arranged. Therefore, bulk plasmonic structures are difficult to fabricate and the periodic arrangement causes undesired effects, e.g., strong spatial dispersion is observed in metamaterials. These limitations can be mitigated by relying on bottom-up nanofabrication technologies. There, self-assembly methods and techniques from the field of colloidal nanochemistry are used to build complex functional unit cells in solution from an ensemble of simple building blocks, i.e., in most cases plasmonic nanoparticles. Achievable structures are characterized by a high degree of nominal order only on a short-range scale. The precise spatial arrangement across larger dimensions is not possible in most cases; leading essentially to amorphous structures. Such self-assembled nanostructures require novel analytical means to describe their properties, innovative designs of functional elements that possess a desired near- and far-field response, and entail genuine nanofabrication and characterization techniques. Eventually, novel applications have to be perceived that are adapted to the specifics of the self-assembled nanostructures. This review shall document recent progress in this field of research. Emphasis is put on bottom-up amorphous metamaterials. We document the state-of-the-art but also critically assess the problems that have to be overcome.

Supramolecular structures formed by the self assembly of ionic fullerenes in binary liquid mixtures

2007 ◽  
Vol 22 (11) ◽  
pp. 3029-3035 ◽  
Author(s):  
Tohru Shiga ◽  
Tomoyoshi Motohiro
Keyword(s):  
Self Assembly ◽  
Liquid Mixtures ◽  
Binary Liquid Mixtures ◽  
Supramolecular Structures ◽  
The Self ◽  
Laser Raman Spectroscopy ◽  
Raman Spectroscopic ◽  
Laser Raman ◽  
Binary Liquid ◽  
Unit Cells

The self assembly of C60-N, N′-dimethylpyrrolidinium iodide (C60-DMePyI) in binary liquid mixtures has been investigated. C60-DMePyI self-organized into nanosheets in a mixture of toluene and iodomethane, and aggregated to form nanofibers in toluene. The dimensions of the nanosheets were several micrometers in length and about 100 nm in thickness. Scanning electron microscope observations indicated that a large number of nanorods having a diameter of about 20-nm formed matted nanosheets. When iodomethane alone was used as a solvent, supramolecular structures such as nanofibers and nanosheets were not produced. Structural analyses of the C60-DMePyI aggregates were carried out by laser Raman spectroscopy and x-ray diffraction (XRD). The Raman spectroscopic results suggested that an ordered chain of successive polyiodine units was formed in all the supramolecular aggregates. The XRD studies showed that the crystal systems of the nanosheets and nanofibers were monoclinic, though with different unit cells.

scholarly journals Confinement of surface spinners in liquid metamaterials

2019 ◽  
Vol 116 (51) ◽  
pp. 25424-25429 ◽  
Author(s):  
Jean-Baptiste Gorce ◽  
Hua Xia ◽  
Nicolas Francois ◽  
Horst Punzmann ◽  
Gregory Falkovich ◽  
...  
Keyword(s):  
Self Assembly ◽  
Wave Amplitude ◽  
Optical Lattices ◽  
Standing Waves ◽  
Adjacent Cell ◽  
Nonuniform Flow ◽  
Surface Flows ◽  
Half Wavelength ◽  
Unit Cells ◽  
Generate Surface

We show that rotating particles at the liquid–gas interface can be efficiently manipulated using the surface-wave analogue of optical lattices. Two orthogonal standing waves generate surface flows of counter-rotating half-wavelength unit cells, the liquid interface metamaterial, whose geometry is controlled by the wave phase shift. Here we demonstrate that by placing active magnetic spinners inside such metamaterials, one makes a powerful tool which allows manipulation and self-assembly of spinners, turning them into vehicles capable of transporting matter and information between autonomous metamaterial unit cells. We discuss forces acting on a spinner carried by a nonuniform flow and show how the forces confine spinners to orbit inside the same-sign vortex cells of the wave-driven flow. Reversing the spin, we move the spinner into an adjacent cell. By changing the spinning frequency or the wave amplitude, one can precisely control the spinner orbit. Multiple spinners within a unit cell self-organize into stable patterns, e.g., triangles or squares, orbiting around the center of the cell. Spinners having different frequencies can also be confined, such that the higher-frequency spinner occupies the inner orbit and the lower-frequency one circles on the outer orbit, while the orbital motions of both spinners are synchronized.

Self-assembly protocol design for periodic multicomponent structures

Soft Matter ◽  
2015 ◽  
Vol 11 (46) ◽  
pp. 8930-8938 ◽  
Author(s):  
William M. Jacobs ◽  
Daan Frenkel
Keyword(s):  
General Theory ◽  
Self Assembly ◽  
Protocol Design ◽  
Unit Cells ◽  
Assembly Pathways

We propose a general theory to design self-assembly pathways for addressable crystals with complex, multicomponent unit cells.

scholarly journals Optical vector field rotation and switching with near-unity transmission by fully developed chiral photonic crystals

2021 ◽  
Vol 118 (16) ◽  
pp. e2021304118
Author(s):  
Chun-Wei Chen ◽  
Iam Choon Khoo
Keyword(s):  
Photonic Crystals ◽  
Self Assembly ◽  
High Performance ◽  
Vector Fields ◽  
Continuous Wave ◽  
Rotatory Power ◽  
Polarization Rotation ◽  
Chiral Photonic Crystals ◽  
Unit Cells ◽  
Size Interaction

State-of-the-art nanostructured chiral photonic crystals (CPCs), metamaterials, and metasurfaces have shown giant optical rotatory power but are generally passive and beset with large optical losses and with inadequate performance due to limited size/interaction length and narrow operation bandwidth. In this work, we demonstrate by detailed theoretical modeling and experiments that a fully developed CPC, one for which the number of unit cells N is high enough that it acquires the full potentials of an ideal (N → ∞) crystal, will overcome the aforementioned limitations, leading to a new generation of versatile high-performance polarization manipulation optics. Such high-N CPCs are realized by field-assisted self-assembly of cholesteric liquid crystals to unprecedented thicknesses not possible with any other means. Characterization studies show that high-N CPCs exhibit broad transmission maxima accompanied by giant rotatory power, thereby enabling large (>π) polarization rotation with near-unity transmission over a large operation bandwidth. Polarization rotation is demonstrated to be independent of input polarization orientation and applies equally well on continuous-wave or ultrafast (picosecond to femtosecond) pulsed lasers of simple or complex (radial, azimuthal) vector fields. Liquid crystal–based CPCs also allow very wide tuning of the operation spectral range and dynamic polarization switching and control possibilities by virtue of several stimuli-induced index or birefringence changing mechanisms.

scholarly journals Auxetic Two-Dimensional Nanostructures from DNA

2020 ◽  
Author(s):  
Ruixin Li ◽  
Haorong Chen ◽  
Jong Hyun Choi
Keyword(s):  
Self Assembly ◽  
Md Simulations ◽  
Dna Origami ◽  
Coarse Grained ◽  
Two Dimensional ◽  
Materials Chemistry ◽  
Dna Nanostructures ◽  
Unit Cells ◽  
Materials Used ◽  
Architectured Materials

ABSTRACTArchitectured materials exhibit negative Poisson’s ratios and enhanced mechanical properties compared with regular materials. Their auxetic behaviors should emerge from periodic cellular structures regardless of the materials used. The majority of such metamaterials are constructed by top-down approaches and macroscopic with unit cells of microns or larger. On the other extreme, there are molecular-scale auxetics including naturally-occurring crystals which are not designable. There is a gap from few nanometers to microns, which may be filled by bottom-up biomolecular self-assembly. Here we demonstrate two-dimensional auxetic nanostructures using DNA origami. Structural reconfiguration experiments are performed by strand displacement and complemented by mechanical deformation studies using coarse-grained molecular dynamics (MD) simulations. We find that the auxetic properties of DNA nanostructures are mostly defined by geometrical designs, yet materials’ chemistry also plays an important role. From elasticity theory, we introduce a set of design principles for auxetic DNA metamaterials, which should find diverse applications.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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.

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