scholarly journals Self-assembly and mesophase formation in a non-ionic chromonic liquid crystal: insights from bottom-up and top-down coarse-grained simulation models

Soft Matter ◽  
2020 ◽  
Vol 16 (41) ◽  
pp. 9488-9498
Author(s):  
Thomas D. Potter ◽  
Martin Walker ◽  
Mark R. Wilson
Keyword(s):  
Aqueous Solution ◽  
Liquid Crystal ◽  
Self Assembly ◽  
Simulation Models ◽  
Coarse Grained ◽  
Top Down ◽  
Bottom Up ◽  
Mesophase Formation

New coarse-grained models are introduced for a non-ionic chromonic molecule, TP6EO2M, in aqueous solution.

scholarly journals Multiscale additive manufacturing of polymers using 3D photo-printable self-assembling ionic liquid monomers

2019 ◽  
Vol 4 (3) ◽  
pp. 580-585 ◽  
Author(s):  
Bineh G. Ndefru ◽  
Bryan S. Ringstrand ◽  
Sokhna I.-Y. Diouf ◽  
Sönke Seifert ◽  
Juan H. Leal ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Additive Manufacturing ◽  
Self Assembly ◽  
Low Cost ◽  
Low Resolution ◽  
Top Down ◽  
Bottom Up ◽  
Cost Approach ◽  
Self Assembling ◽  
Nanoscale Features

Combining bottom-up self-assembly with top-down 3D photoprinting affords a low cost approach for the introduction of nanoscale features into a build with low resolution features.

Dealing with Multiple Models in System Dynamics

2014 ◽  
Vol 3 (4) ◽  
pp. 17-35 ◽  
Author(s):  
Willem L. Auping ◽  
Erik Pruyt ◽  
Jan H. Kwakkel
Keyword(s):  
System Dynamics ◽  
Simulation Models ◽  
Dynamics Simulation ◽  
Multiple Models ◽  
Top Down ◽  
Bottom Up ◽  
New Approach ◽  
Behavioural Patterns ◽  
Copper Availability

This paper introduces an approach to compare simulation runs from multiple System Dynamics simulation models. Three dynamic hypotheses regarding the uncertain evolutions of long-term copper availability are introduced and used to illustrate the new approach. They correspond to three different perspectives on the copper system (global top-down, global bottom-up, and regional top-down). Although each of these models allows to generate a wealth of behavioural patterns, the focus in this paper is on the differences in trajectories caused by different models for identical values of shared parameters and identical settings of other assumptions, not on differences in behavioural patterns caused by each of the models. Hence, differences in trajectories between the three models are identified, quantified, and classified based on a quantified measure of difference. For these models, small differences between the trajectories are only found in stable runs, while the alternative perspectives are largely responsible for medium to large differences. Hence, it is concluded that multiple dynamic hypotheses may have to be modelled when dealing with uncertain issues.

Block Copolymer Films Hierarchical Assembly in Confinement

2007 ◽  
Vol 364-366 ◽  
pp. 437-441
Author(s):  
Yong Zhi Cao ◽  
Shen Dong ◽  
Ying Chun Liang ◽  
Tao Sun ◽  
Yong Da Yan
Keyword(s):  
Block Copolymer ◽  
Self Assembly ◽  
Structural Control ◽  
Computer Control ◽  
The Self ◽  
Top Down ◽  
Bottom Up ◽  
Dimensional Precision ◽  
Periodic Arrays ◽  
Copolymer Films

Ultrathin block copolymer films are promising candidates for bottom-up nanotemplates in hybrid organic-inorganic electronic, optical, and magnetic devices. Key to many future applications is the long range ordering and precise placement of the phase-separated nanoscale domains. In this paper, a combined top-down/bottom-up hierarchical approach is presented on how to fabricate massive arrays of aligned nanoscale domains by means of the self-assembly of asymmetric poly (styrene-block-ethylene/butylenes-block-styrene) (SEBS) tirblock copolymers in confinement. The periodic arrays of the poly domains were orientated via the introduction of AFM micromachining technique as a tool for locally controlling the self-assembly process of triblock copolymers by the topography of the silicon nitride substrate. Using the controlled movement of 2- dimensional precision stage and the micro pressure force between the tip and the surface by computer control system, an artificial topographic pattern on the substrate can be fabricated precisely. Coupled with solvent annealing technique to direct the assembly of block copolymer, this method provides new routes for fabricating ordered nanostructure. This graphoepitaxial methodology can be exploited in hybrid hard/soft condensed matter systems for a variety of applications. Moreover, Pairing top-down and bottom-up techniques is a promising, and perhaps necessary, bridge between the parallel self-assembly of molecules and the structural control of current technology.

scholarly journals Self-assembly of liquid crystal block copolymer PEG-b-smectic polymer in pure state and in dilute aqueous solution

2009 ◽  
Vol 143 ◽  
pp. 235 ◽  
Author(s):  
Bing Xu ◽  
Rafael Piñol ◽  
Merveille Nono-Djamen ◽  
Sandrine Pensec ◽  
Patrick Keller ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Liquid Crystal ◽  
Block Copolymer ◽  
Self Assembly ◽  
Pure State ◽  
Dilute Aqueous Solution ◽  
Crystal Block

scholarly journals The Bipolar Logic of Feedforward and Feedback Circuits

2021 ◽  
Author(s):  
Arturo Tozzi
Keyword(s):  
Visual Recognition ◽  
Coarse Grained ◽  
William Of Ockham ◽  
Top Down ◽  
Object Persistence ◽  
Bottom Up ◽  
Bipolar Mode ◽  
External Sources ◽  
Drug Resistant Epilepsy ◽  
Work Up

Instead of the conventional 0 and 1 values, bipolar reasoning uses -1, 0, +1 to describe double-sided judgements in which neutral elements are halfway between positive and negative evaluations (e.g., “uncertain” lies between “impossible” and “totally sure”). We discuss the state-of-the-art in bipolar logics and recall two medieval forerunners, i.e., William of Ockham and Nicholas of Autrecourt, who embodied a bipolar mode of thought that is eminently modern. Starting from the trivial observation that “once a wheat sheaf is sealed and tied up, the packed down straws display the same orientation”, we work up a new theory of the bipolar nature of networks, suggesting that orthodromic (i.e., feedforward, bottom-up) projections might be functionally coupled with antidromic (i.e., feedback, top-down) projections via the mathematical apparatus of presheaves/globular sets. When an entrained oscillation such as a neuronal spike propagates from A to B, changes in B might lead to changes in A, providing unexpected antidromic effects. Our account points towards the methodological feasibility of novel neural networks in which message feedback is guaranteed by backpropagation mechanisms endowed in the same feedforward circuits. Bottom-up/top-down transmission at various coarse-grained network levels provides fresh insights in far-flung scientific fields such as object persistence, memory reinforcement, visual recognition, Bayesian inferential circuits and multidimensional activity of the brain. Implying that axonal stimulation by external sources might backpropagate and modify neuronal electric oscillations, our theory also suggests testable previsions concerning the optimal location of transcranial magnetic stimulation’s coils in patients affected by drug-resistant epilepsy.

scholarly journals Thermodynamics of the self-assembly of non-ionic chromonic molecules using atomistic simulations. The case of TP6EO2M in aqueous solution

Soft Matter ◽  
2015 ◽  
Vol 11 (4) ◽  
pp. 680-691 ◽  
Author(s):  
Anna Akinshina ◽  
Martin Walker ◽  
Mark R. Wilson ◽  
Gordon J. T. Tiddy ◽  
Andrew J. Masters ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Aqueous Solution ◽  
Liquid Crystal ◽  
Molecular Dynamics Simulations ◽  
Self Assembly ◽  
The Self ◽  
Atomistic Simulations ◽  
Aggregation Behaviour ◽  
Dynamics Simulations

Molecular dynamics simulations of non-ionic triphenylene-based chromonic liquid crystal molecules demonstrate self-assembly of the molecules into stacks and “quasi-isodesmic” aggregation behaviour.

Block Copolymer Lithography: Merging “Bottom-Up” with “Top-Down” Processes

MRS Bulletin ◽  
2005 ◽  
Vol 30 (12) ◽  
pp. 952-966 ◽  
Author(s):  
Craig J. Hawker ◽  
Thomas P. Russell
Keyword(s):  
Self Assembly ◽  
Polymer Chains ◽  
Top Down ◽  
Bottom Up ◽  
Robust Solution ◽  
Size Scale ◽  
Design And Synthesis ◽  
Manufacturing Techniques ◽  
Future Demands ◽  
Alternative Routes

AbstractAs the size scale of device features becomes ever smaller, conventional lithographic processes become increasingly more difficult and expensive, especially at a minimum feature size of less than 45 nm. Consequently, to achieve higher-density circuits, storage devices, or displays, it is evident that alternative routes need to be developed to circumvent both cost and manufacturing issues.An ideal process would be compatible with existing technological processes and manufacturing techniques; these strategies, together with novel materials, could allow significant advances to be made in meeting both short-term and long-term demands for higher-density, faster devices. The self-assembly of block copolymers (BCPs), two polymer chains covalently linked together at one end, provides a robust solution to these challenges. As thin films, immiscible BCPs self-assemble into a range of highly ordered morphologies where the size scale of the features is only limited by the size of the polymer chains and are, therefore, nanoscopic.While self-assembly alone is sufficient for a number of applications in fabricating advanced microelectronics, directed, self-orienting, self-assembly processes are also required to produce complex devices with the required density and addressability of elements to meet future demands. Both strategies require the design and synthesis of polymers that have well-defined characteristics such that the necessary fine control over the morphology, interfacial properties, and simplicity of processes can be realized. By combining tailored self-assembly processes (a “bottom-up” approach) with microfabrication processes (a “top-down” approach), the ever-present thirst of the consumer for faster, better, and cheaper devices can be met in very simple, yet robust, ways. The integration of novel chemistries with the manipulation of self-assembly will be treated in this article.

Directed Self-assembly of 2-Dimensional Mesoblocks Using Top-Down/Bottom-Up Design

2005 ◽  
pp. 154-166 ◽  
Author(s):  
Geoff Poulton ◽  
Ying Guo ◽  
Geoff James ◽  
Phil Valencia ◽  
Vadim Gerasimov ◽  
...  
Keyword(s):  
Self Assembly ◽  
Top Down ◽  
Bottom Up

Special Issue on Texturing Processes and Attainable Functionalities

2016 ◽  
Vol 10 (1) ◽  
pp. 3-3
Author(s):  
Nobuyuki Moronuki
Keyword(s):  
Self Assembly ◽  
Special Issue ◽  
Top Down ◽  
Bottom Up ◽  
Energy Beam ◽  
Surface Functionality ◽  
Material Deposition ◽  
Wide Range ◽  
Lotus Leaves ◽  
Optical Applications

Regular micro/nanostructures or textures provide such functions as optical or friction properties, but neither texture design nor the texturing process has been well developed. Functional texture is often inspired by natural designs, with the microstructure on the surface of lotus leaves or the nanostructure on the bottoms of geckos’ feet often cited as examples. “Biomimetic” has become a keyword in state-of-the-art technologies. Processes are also important because functional textures require a wide range of structural dimensions, from nanometers to micrometers. Top-down processes such as cutting or energy beam processing are often used and are based on the copying principle. Bottom-up processes include the self-assembly of particles and the anodic oxidation of aluminum. As the principle behind bottom-up processes is completely different from that behind top-down processes, special attention is warranted. Furthermore, material deposition can effect drastic changes in surface functionality. This special issue features nine papers, including eight studies and one review paper, classified into the following topics: - Biomimetic design of functions - Top-down or cutting texturing processes - Bottom-up or self-organization texturing processes - Measurement system for textures - Optical applications - Optical applications - Adhesive applications - Biomedical applications These papers present the latest advances in texturing processes, functional design, and realization or demonstration. Learning more about these advances will enable readers toshare their knowledge and experience in technologies, development, and potential texturing applications. In closing, I would like to express my sincere gratitude to the authors and reviewers for their interesting and enlightening contributions to this special issue.

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