scholarly journals Geometrical manipulation of complex supramolecular tessellations by hierarchical assembly of amphiphilic platinum(II) complexes

2021 ◽  
Vol 118 (6) ◽  
pp. e2022829118
Author(s):  
Jason Koon-Lam Poon ◽  
Zhen Chen ◽  
Sammual Yu-Lut Leung ◽  
Ming-Yi Leung ◽  
Vivian Wing-Wah Yam
Keyword(s):  
Phase Separation ◽  
Self Assembly ◽  
Soft Materials ◽  
Topological Transition ◽  
Structural Hierarchy ◽  
Hierarchical Assembly ◽  
Metal Metal ◽  
Archimedean Tiling ◽  
Simple Molecules ◽  
Order Increase

Here we report complex supramolecular tessellations achieved by the directed self-assembly of amphiphilic platinum(II) complexes. Despite the twofold symmetry, these geometrically simple molecules exhibit complicated structural hierarchy in a columnar manner. A possible key to such an order increase is the topological transition into circular trimers, which are noncovalently interlocked by metal···metal and π–π interactions, thereby allowing for cofacial stacking in a prismatic assembly. Another key to success is to use the immiscibility of the tailored hydrophobic and hydrophilic sidechains. Their phase separation leads to the formation of columnar crystalline nanostructures homogeneously oriented on the substrate, featuring an unusual geometry analogous to a rhombitrihexagonal Archimedean tiling. Furthermore, symmetry lowering of regular motifs by design results in an orthorhombic lattice obtained by the coassembly of two different platinum(II) amphiphiles. These findings illustrate the potentials of supramolecular engineering in creating complex self-assembled architectures of soft materials.

DNA-based self-assembly of nanostructures

2017 ◽  
Author(s):  
Joshua D. Carter ◽  
Chenxiang Lin ◽  
Yan Liu ◽  
Hao Yan ◽  
Thomas H. LaBean
Keyword(s):  
Self Assembly ◽  
Materials Science ◽  
Directed Assembly ◽  
Building Blocks ◽  
Hierarchical Assembly ◽  
Synthetic Dna ◽  
Nanoscale Manufacturing ◽  
Covalently Linked ◽  
Design Construction ◽  
Proteins And Peptides

This article examines the DNA-based self-assembly of nanostructures. It first reviews the development of DNA self-assembly and DNA-directed assembly, focusing on the main strategies and building blocks available in the modern molecular construction toolbox, including the design, construction, and analysis of nanostructures composed entirely of synthetic DNA, as well as origami nanostructures formed from a mixture of synthetic and biological DNA. In particular, it considers the stepwise covalent synthesis of DNA nanomaterials, unmediated assembly of DNA nanomaterials, hierarchical assembly, nucleated assembly, and algorithmic assembly. It then discusses DNA-directed assembly of heteromaterials such as proteins and peptides, gold nanoparticles, and multicomponent nanostructures. It also describes the use of complementary DNA cohesion as 'smart glue' for bringing together covalently linked functional groups, biomolecules, and nanomaterials. Finally, it evaluates the potential future of DNA-based self-assembly for nanoscale manufacturing for applications in medicine, electronics, photonics, and materials science.

Dispersion, Phase Separation, and Self-Assembly of Polymer-Grafted Nanorod Composites

2017 ◽  
Vol 50 (21) ◽  
pp. 8816-8826 ◽  
Author(s):  
Vaishnavi Gollanapalli ◽  
Anirudh Manthri ◽  
Uma K. Sankar ◽  
Mukta Tripathy
Keyword(s):  
Phase Separation ◽  
Self Assembly ◽  
Dispersion Phase

scholarly journals Chirality, Gelation Ability and Crystal Structure: Together or Apart? Alkyl Phenyl Ethers of Glycerol as Simple LMWGs

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 732
Author(s):  
Alexander A. Bredikhin ◽  
Aidar T. Gubaidullin ◽  
Zemfira A. Bredikhina ◽  
Robert R. Fayzullin ◽  
Olga A. Lodochnikova
Keyword(s):  
Self Assembly ◽  
Chiral Recognition ◽  
Soft Materials ◽  
Gelling Agent ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Types ◽  
Low Molecular Weight Gelators ◽  
Phenyl Ethers

Chiral recognition plays an important role in the self-assembly of soft materials, in particular supramolecular organogels formed by low molecular weight gelators (LMWGs). Out of 14 pairs of the studied racemic and enantiopure samples of alkyl-substituted phenyl ethers of glycerol, only eight enantiopure diols form the stable gels in nonane. The formation of gels from solutions was studied by polarimetry, and their degradation with the formation of xerogels was studied by the PXRD method. The revealed crystalline characteristics of all studied xerogels corresponded to those for crystalline samples of the parent gelators. In addition to those previously investigated, crystalline samples of enantiopure para-n-alkylphenyl glycerol ethers [alkyl = pentyl (5), hexyl (6), heptyl (7), octyl (8), nonyl (9)] and racemic 3-(3,5-dimethylphenoxy)propane-1,2-diol (rac-14) have been examined by single crystal X-ray diffraction analysis. Among 22 samples of compounds 1-14 studied by SC-XRD, seven different types of supramolecular motifs are identified, of which only two are realized in crystals of supramolecular gelators. An attempt was made to relate the ability to gel formation with the characteristics of the supramolecular motif of a potential gelling agent, and the frequency of formation of the motif, required for gelation, with the chiral characteristics of the sample.

scholarly journals Thermodynamics of structured fluids. Hard science for soft materials

2000 ◽  
Vol 72 (10) ◽  
pp. 1819-1834 ◽  
Author(s):  
John M. Prausnitz
Keyword(s):  
Self Assembly ◽  
Theoretical Calculations ◽  
Soft Materials ◽  
Confined Space ◽  
Molecular Physics ◽  
Fluid Structure ◽  
Light Emitting ◽  
Structured Fluids ◽  
Recent Developments ◽  
Narrow Space

At liquid-like densities, molecules of complex fluids can assume a variety of structures (or positions) in space; when the molecules contain many atoms as, for example, in polymers, that variety becomes very large. Further, when confined to a narrow space, it is possible to achieve structures that are not normally observed. Thanks to recent advances in statistical mechanics and molecular physics, and thanks to increasingly fast computers, it is now possible to calculate a fluid's structure, that is, the positions of molecules at equilibrium under given conditions. Calculation of fluid structure is useful because thermodynamic properties depend strongly on that structure, leading to possible applications for new materials. Three examples illustrate some recent developments; each example is presented only schematically (with a minimum of equations) to indicate the physical basis of the mathematical description. The first example considers the effect of branching on self-assembly (micellization) of copolymers (with possible long-range applications in medicine). The second and third examples consider the effect of confinement on fluid structure: first, crystallization in a narrow, confined space to produce a desired crystal structure (with possible applications for light-emitting diodes) and second, suppression of micellization of a diblock copolymer in a thin film (with possible application in lithography). Whenever possible, theoretical calculations are compared with experimental results.

scholarly journals Water vapor induced self-assembly of islands/honeycomb structure by secondary phase separation in polystyrene solution with bimodal molecular weight distribution

2021 ◽  
Author(s):  
Maciej Łojkowski ◽  
Adrian Chlanda ◽  
Emilia Choińska ◽  
Wojciech Swieszkowski
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Self Assembly ◽  
Secondary Phase ◽  
Honeycomb Structure ◽  
Polymer Chains ◽  
Molecular Weights ◽  
Secondary Phase Separation

<p>The formation of complex structures in thin films is of interest in many fields. Segregation of polymer chains of different molecular weights is a well-known process. However, here, polystyrene with bimodal molecular weight distribution, but no additional chemical modification was used. It was proven that at certain conditions, the phase separation occurred between two fractions of bimodal polystyrene/methyl ethyl ketone solution. The films were prepared by spin-coating, and the segregation between polystyrene phases was investigated by force spectroscopy. Next, water vapour induced secondary phase separation was investigated. The introduction of moist airflow induced the self-assembly of the lower molecular weight into islands and the heavier fraction into a honeycomb. As a result, an easy, fast, and effective method of obtaining island/honeycomb morphologies was demonstrated. The possible mechanisms of the formation of such structures were discussed.</p>

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