Supramolecular self assembly of a monomeric copper(II) complex of N-salicylidene-2-methoxyaniline forming three-dimensional closed and open channels

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.

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

MRS Advances ◽

10.1557/adv.2020.349 ◽

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.

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Energy Loss in Steep Open Channels with Step-Pools

Water ◽

10.3390/w13010072 ◽

2020 ◽

Vol 13 (1) ◽

pp. 72

Author(s):

Suresh Kumar Thappeta ◽

S. Murty Bhallamudi ◽

Venu Chandra ◽

Peter Fiener ◽

Abul Basar M. Baki

Keyword(s):

Energy Loss ◽

Flow Rate ◽

Recirculation Zone ◽

Three Dimensional ◽

Nonlinear Function ◽

Open Channels ◽

Geometrical Parameters ◽

Transition Flow ◽

Cumulative Energy ◽

Zone Velocity

Three-dimensional numerical simulations were performed for different flow rates and various geometrical parameters of step-pools in steep open channels to gain insight into the occurrence of energy loss and its dependence on the flow structure. For a given channel with step-pools, energy loss varied only marginally with increasing flow rate in the nappe and transition flow regimes, while it increased in the skimming regime. Energy loss is positively correlated with the size of the recirculation zone, velocity in the recirculation zone and the vorticity. For the same flow rate, energy loss increased by 31.6% when the horizontal face inclination increased from 2° to 10°, while it decreased by 58.6% when the vertical face inclination increased from 40° to 70°. In a channel with several step-pools, cumulative energy loss is linearly related to the number of step-pools, for nappe and transition flows. However, it is a nonlinear function for skimming flows.

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Polymer cyclization for the emergence of hierarchical nanostructures

Nature Communications ◽

10.1038/s41467-021-24222-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Chaojian Chen ◽

Manjesh Kumar Singh ◽

Katrin Wunderlich ◽

Sean Harvey ◽

Colette J. Whitfield ◽

...

Keyword(s):

Self Assembly ◽

Three Dimensional ◽

Hierarchical Structures ◽

Structural Similarity ◽

Vital Role ◽

Nanomaterial Synthesis ◽

Wide Range ◽

Linear Poly ◽

Polymer Folding ◽

Dynamics Simulations

AbstractThe creation of synthetic polymer nanoobjects with well-defined hierarchical structures is important for a wide range of applications such as nanomaterial synthesis, catalysis, and therapeutics. Inspired by the programmability and precise three-dimensional architectures of biomolecules, here we demonstrate the strategy of fabricating controlled hierarchical structures through self-assembly of folded synthetic polymers. Linear poly(2-hydroxyethyl methacrylate) of different lengths are folded into cyclic polymers and their self-assembly into hierarchical structures is elucidated by various experimental techniques and molecular dynamics simulations. Based on their structural similarity, macrocyclic brush polymers with amphiphilic block side chains are synthesized, which can self-assemble into wormlike and higher-ordered structures. Our work points out the vital role of polymer folding in macromolecular self-assembly and establishes a versatile approach for constructing biomimetic hierarchical assemblies.

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Direct Patterning and Spontaneous Self-Assembly of Graphene Oxide via Electrohydrodynamic Jet Printing for Energy Storage and Sensing

Micromachines ◽

10.3390/mi11010013 ◽

2019 ◽

Vol 11 (1) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Bin Zhang ◽

Jaehyun Lee ◽

Mincheol Kim ◽

Naeeung Lee ◽

Hyungdong Lee ◽

...

Keyword(s):

Graphene Oxide ◽

Energy Storage ◽

Self Assembly ◽

High Performance ◽

Three Dimensional ◽

Chemical Properties ◽

Layer By Layer ◽

Energy Storage Devices ◽

Laminar Structure ◽

Jet Printing

The macroscopic assembly of two-dimensional materials into a laminar structure has received considerable attention because it improves both the mechanical and chemical properties of the original materials. However, conventional manufacturing methods have certain limitations in that they require a high temperature process, use toxic solvents, and are considerably time consuming. Here, we present a new system for the self-assembly of layer-by-layer (LBL) graphene oxide (GO) via an electrohydrodynamic (EHD) jet printing technique. During printing, the orientation of GO flakes can be controlled by the velocity distribution of liquid jet and electric field-induced alignment spontaneously. Closely-packed GO patterns with an ordered laminar structure can be rapidly realized using an interfacial assembly process on the substrates. The surface roughness and electrical conductivity of the LBL structure were significantly improved compared with conventional dispensing methods. We further applied this technique to fabricate a reduced graphene oxide (r-GO)-based supercapacitor and a three-dimensional (3D) metallic grid hybrid ammonia sensor. We present the EHD-assisted assembly of laminar r-GO structures as a new platform for preparing high-performance energy storage devices and sensors.

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