Transformation of self-assembly of a TTF derivative at the 1-phenyloctane/HOPG interface studied by STM—from a nanoporous network to a linear structure

Nanoscale ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 1652-1657 ◽  
Author(s):  
Jing Xu ◽  
Xunwen Xiao ◽  
Ke Deng ◽  
Qingdao Zeng
Keyword(s):  
Self Assembly ◽  
Linear Structure ◽  
Hexagonal Network

When dissolved in 1-phenyloctane, EDTTF could co-assemble with TCDB to form a hexagonal network and would transform into a linear structure.

FORMATION AND HARD MAGNETIC PROPERTIES OF A HEXAGONAL NETWORK OF NICKEL FERRITE NANOPARTICLES

2006 ◽  
Vol 20 (26) ◽  
pp. 1645-1651
Author(s):  
JIAFU CHEN ◽  
YU YE ◽  
QIANWANG CHEN
Keyword(s):  
Network Structure ◽  
Self Assembly ◽  
Nickel Ferrite ◽  
Ferrite Nanoparticles ◽  
Magnetic Feature ◽  
Bulk Materials ◽  
Nickel Ferrite Nanoparticles ◽  
Carbon Coated ◽  
Hard Magnetic Properties ◽  
Hexagonal Network

A novel hexagonal network structure formed by self-assembly of discrete nickel ferrite nanoparticles on a carbon-coated Cu grid is reported. Each hexagon consists of about 22 discrete nanoparticles with sizes from 120 to 250 nm. The side of the regular hexagon contains 4–6 discrete nanoparticles. The sample displays a large coercivity of 622.6 Oe, exhibiting a hard magnetic feature different from those of the corresponding bulk materials, and is closely related to the hexagonal network structure of nickel ferrite nanoparticles.

Observation and modeling of conformational molecular structures driving the self-assembly of tri-adamantyl benzene on Ag(111)

2016 ◽  
Vol 18 (30) ◽  
pp. 20281-20289 ◽  
Author(s):  
Bastien Calmettes ◽  
Nicolas Estrampes ◽  
Christophe Coudret ◽  
Thomas J. Roussel ◽  
Jordi Faraudo ◽  
...  
Keyword(s):  
Self Assembly ◽  
Molecular Structures ◽  
The Self ◽  
Stm Image ◽  
Hexagonal Network

A STM image of the hexagonal network of tri-adamantyl benzene molecules on Ag(111).

scholarly journals New Insights on the Self-Assembly of Bio-sourced Block Copolymer MH-b-PS in Aqueous Solutions: Nanocorals, Cubosomes & Nanocubes

2021 ◽  
Author(s):  
Yomen Atassi ◽  
Redouane Borsali
Keyword(s):  
Aqueous Solution ◽  
Block Copolymer ◽  
Aqueous Solutions ◽  
Self Assembly ◽  
Room Temperature ◽  
Linear Structure ◽  
The Self ◽  
Fine Tuning ◽  
Experimental Parameters ◽  
First Time

Polymer self-assembly in solution still constitutes a simple methodology for the preparation of elegant yet sophisticated nanomaterials. This work aims at presenting how the fine tuning of the experimental parameters of the nanoprecipitation process can lead to a variety of novel morphologies ranging from nanocorals through cubosomes to nanocubes. A carbohydrate dibloc copolymer with a simple and linear structure MH1.2k-b-PS2.3 has been used as a model to illustrate the formation of these new self-assemblies. This is the first time that nanocube morphology has been generated using this type of bio-sourced co-polymer in aqueous solution and at room temperature.

Synthetic DNA filaments: from design to applications

2018 ◽  
Vol 399 (7) ◽  
pp. 773-785 ◽  
Author(s):  
Wolfgang Pfeifer ◽  
Barbara Saccà
Keyword(s):  
Self Assembly ◽  
Rational Design ◽  
Bending Strength ◽  
Molecular Model ◽  
Persistence Length ◽  
Linear Structure ◽  
Theoretical Models ◽  
Structural Features ◽  
Cellular Adhesion ◽  
Active Motion

Abstract Natural filaments, such as microtubules and actin filaments, are fundamental components of the cell. Despite their relatively simple linear structure, filaments play a number of crucial roles in living organisms, from scaffolding to cellular adhesion and motility. The mechanical properties of natural filaments mostly rely on the structural features of the component units and on the way they are connected together, thus providing an ideal molecular model for emulation purposes. In this review, we describe the progresses done in this field using DNA for the rational design of synthetic filamentous-like materials with tailored structural and physical characteristics. We firstly survey the strategies that have been adopted until now for the construction of individual DNA building components and their programmable self-assembly into linear oligomeric structures. We then describe the theoretical models of polymer elasticity applied to calculate the bending strength of DNA filaments, expressed in terms of persistence length. Finally, we report some of the most exciting examples of truly biomimetic DNA filaments, which are capable of mimicking not only the sophisticated structural features of their natural counterparts but also their responsiveness to external stimuli, thus resulting in active motion and growing networks between distant loci.

scholarly journals Solvent-Dependent Self-Assembly of 4,7-Dibromo-5,6-bis(octyloxy)benzo[c][1,2,5] Thiadiazole on Graphite Surface by Scanning Tunneling Microscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bao Zha ◽  
Xinrui Miao ◽  
Yijing Li ◽  
Pei Liu ◽  
Kai Miao ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
Lamellar Structure ◽  
Octanoic Acid ◽  
Linear Structure ◽  
Halogen Bonding ◽  
The Self ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Solvent Molecules

Solvent effect on self-assembly of 4,7-dibromo-5,6-bis(octyloxy)benzo[c][1,2,5] thiadiazole (DBT) on a highly oriented graphite (HOPG) surface was investigated by scanning tunneling microscopy (STM) by using 1-phenyloctane, 1-octanoic acid, and 1-octanol as the solvents. Two different patterns were obtained in 1-phenyloctane and 1-octanoic acid, suggesting that the self-assembly of DBT was solvent dependent. At the 1-phenyloctane/HOPG interface, a linear structure was revealed due to the intermolecular halogen bonding. When 1-octanoic acid and 1-octanol are used as the solvents, the coadsorption of solvent molecules resulting from the hydrogen bonding between DBT and solvent made an important contribution to the formation of a lamellar structure. The results demonstrate that solvents could affect the molecular self-assembly according to the variational intermolecular interactions.

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.

Video real-time imaging of artificial membranes during freeze-drying by cryo-electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 16-17
Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price
Keyword(s):  
Real Time ◽  
Self Assembly ◽  
Freeze Drying ◽  
Video Capture ◽  
Drying Process ◽  
Artificial Membranes ◽  
The Past ◽  
Cryo Electron Microscopy ◽  
Spherical Structures ◽  
Capture Techniques

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.

Biomimetic materials: An introduction

1992 ◽  
Vol 50 (2) ◽  
pp. 1020-1021 ◽  
Author(s):  
M. Sarikaya ◽  
J. T. Staley ◽  
I. A. Aksay
Keyword(s):  
Self Assembly ◽  
Structural Control ◽  
Hierarchical Structures ◽  
Ceramic Composites ◽  
Advanced Materials ◽  
Length Scale ◽  
Spider Webs ◽  
Biomimetic Materials ◽  
Synthetic Materials ◽  
All Ceramic

Biomimetics is an area of research in which the analysis of structures and functions of natural materials provide a source of inspiration for design and processing concepts for novel synthetic materials. Through biomimetics, it may be possible to establish structural control on a continuous length scale, resulting in superior structures able to withstand the requirements placed upon advanced materials. It is well recognized that biological systems efficiently produce complex and hierarchical structures on the molecular, micrometer, and macro scales with unique properties, and with greater structural control than is possible with synthetic materials. The dynamism of these systems allows the collection and transport of constituents; the nucleation, configuration, and growth of new structures by self-assembly; and the repair and replacement of old and damaged components. These materials include all-organic components such as spider webs and insect cuticles (Fig. 1); inorganic-organic composites, such as seashells (Fig. 2) and bones; all-ceramic composites, such as sea urchin teeth, spines, and other skeletal units (Fig. 3); and inorganic ultrafine magnetic and semiconducting particles produced by bacteria and algae, respectively (Fig. 4).

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.

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