scholarly journals Shaping colloidal bananas to reveal biaxial, splay-bend nematic, and smectic phases

Science ◽  
2020 ◽  
Vol 369 (6506) ◽  
pp. 950-955
Author(s):  
Carla Fernández-Rico ◽  
Massimiliano Chiappini ◽  
Taiki Yanagishima ◽  
Heidi de Sousa ◽  
Dirk G. A. L. Aarts ◽  
...  
Keyword(s):  
Phase Behavior ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Functional Materials ◽  
Building Blocks ◽  
Develop Model ◽  
Smectic Phases ◽  
Particle Level ◽  
Nematic Phases ◽  
The Impact

Understanding the impact of curvature on the self-assembly of elongated microscopic building blocks, such as molecules and proteins, is key to engineering functional materials with predesigned structure. We develop model “banana-shaped” colloidal particles with tunable dimensions and curvature, whose structure and dynamics are accessible at the particle level. By heating initially straight rods made of SU-8 photoresist, we induce a controllable shape deformation that causes the rods to buckle into banana-shaped particles. We elucidate the phase behavior of differently curved colloidal bananas using confocal microscopy. Although highly curved bananas only form isotropic phases, less curved bananas exhibit very rich phase behavior, including biaxial nematic phases, polar and antipolar smectic-like phases, and even the long-predicted, elusive splay-bend nematic phase.

scholarly journals Self-Assembly of Shape-Tunable Oblate Colloidal Particles into Orientationally Ordered Crystals, Glassy Crystals and Plastic Crystals

Soft Matter ◽  
2021 ◽  
Author(s):  
Jiawei Lu ◽  
Xiangyu Bu ◽  
Xinghua Zhang ◽  
Bing Liu
Keyword(s):  
Crystal Structures ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Building Blocks ◽  
Fundamental Question ◽  
The Self ◽  
Plastic Crystals ◽  
Self Assembled ◽  
Glassy Crystals ◽  
The Relationship

The shapes of colloidal particles are crucial to the self-assembled superstructures. Understanding the relationship between the shapes of building blocks and the resulting crystal structures is an important fundamental question....

A Dynamic Route to Structure and Function: Recent Advances in Imine-Based Organic Nanostructured Materials

2013 ◽  
Vol 66 (1) ◽  
pp. 9 ◽  
Author(s):  
Yi Liu ◽  
Zhan-Ting Li
Keyword(s):  
Self Assembly ◽  
Reaction System ◽  
Functional Materials ◽  
Building Blocks ◽  
The Self ◽  
Interlocked Molecules ◽  
Functional Aspects ◽  
Imine Bond ◽  
And Function ◽  
Dynamic Route

The chemistry of imine bond formation from simple aldehyde and amine precursors is among the most powerful dynamic covalent chemistries employed for the construction of discrete molecular objects and extended molecular frameworks. The reversible nature of the C=N bond confers error-checking and proof-reading capabilities in the self-assembly process within a multi-component reaction system. This review highlights recent progress in the self-assembly of complex organic molecular architectures that are enabled by dynamic imine chemistry, including molecular containers with defined geometry and size, mechanically interlocked molecules, and extended frameworks and polymers, from building blocks with preprogrammed steric and electronic information. The functional aspects associated with the nanometer-scale features not only place these dynamically constructed nanostructures at the frontier of materials sciences, but also bring unprecedented opportunities for the discovery of new functional materials.

scholarly journals Straightforward Preparation of Supramolecular Janus Nanorods by Hydrogen Bonding of End-Functionalized Polymers

2020 ◽  
Author(s):  
Shuaiyuan Han ◽  
Sandrine Pensec ◽  
Cédric Lorthioir ◽  
Jacques Jestin ◽  
Jean-Michel Guigner ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Functional Materials ◽  
Phase Segregation ◽  
Building Blocks ◽  
Functionalized Polymers ◽  
Nanometer Range ◽  
One Dimensional ◽  
Oil In Water ◽  
First Time

Janus cylinders are one-dimensional colloids that have two faces with different compositions and functionalities and are useful as building blocks for advanced functional materials. Such anisotropic objects are difficult to prepare with nanometric dimensions. Here we describe a robust and versatile strategy to form micrometer long Janus nanorods with diameters in the 10-nanometer range, by self-assembly in water of end-functionalized polymers. For the first time, the Janus topology is not a result of the phase segregation of incompatible polymer arms, but is driven by the interactions between unsymmetrical and complementary hydrogen bonded stickers. It is therefore independent of the actual polymers used and works even for compatible polymers. To illustrate their applicative potential, we show that these Janus nanorods can efficiently stabilize oil-in-water emulsions.

scholarly journals Diverse protein assembly driven by metal and chelating amino acids with selectivity and tunability

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Minwoo Yang ◽  
Woon Ju Song
Keyword(s):  
Amino Acids ◽  
Self Assembly ◽  
Protein Structures ◽  
Functional Materials ◽  
Building Blocks ◽  
Unnatural Amino Acid ◽  
Metal Coordination ◽  
Specific Chemical ◽  
Natural Building ◽  
Kinetics Of

AbstractProteins are versatile natural building blocks with highly complex and multifunctional architectures, and self-assembled protein structures have been created by the introduction of covalent, noncovalent, or metal-coordination bonding. Here, we report the robust, selective, and reversible metal coordination properties of unnatural chelating amino acids as the sufficient and dominant driving force for diverse protein self-assembly. Bipyridine-alanine is genetically incorporated into a D3 homohexamer. Depending on the position of the unnatural amino acid, 1-directional, crystalline and noncrystalline 2-directional, combinatory, and hierarchical architectures are effectively created upon the addition of metal ions. The length and shape of the structures is tunable by altering conditions related to thermodynamics and kinetics of metal-coordination and subsequent reactions. The crystalline 1-directional and 2-directional biomaterials retain their native enzymatic activities with increased thermal stability, suggesting that introducing chelating ligands provides a specific chemical basis to synthesize diverse protein-based functional materials while retaining their native structures and functions.

scholarly journals The Assembly of Porphyrin Systems in Well-Defined Nanostructures: An Update

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4307 ◽  
Author(s):  
Gabriele Magna ◽  
Donato Monti ◽  
Corrado Di Natale ◽  
Roberto Paolesse ◽  
Manuela Stefanelli
Keyword(s):  
Self Assembly ◽  
Energy Transport ◽  
Functional Materials ◽  
Building Blocks ◽  
Spatial Arrangement ◽  
Transport Processes ◽  
Internal Electric Field ◽  
Porphyrin Derivatives ◽  
Molecular Building Blocks ◽  
The Individual

The interest in assembling porphyrin derivatives is widespread and is accounted by the impressive impact of these suprastructures of controlled size and shapes in many applications from nanomedicine and sensors to photocatalysis and optoelectronics. The massive use of porphyrin dyes as molecular building blocks of functional materials at different length scales relies on the interdependent pair properties, consisting of their chemical stability/synthetic versatility and their quite unique physicochemical properties. Remarkably, the driven spatial arrangement of these platforms in well-defined suprastructures can synergically amplify the already excellent properties of the individual monomers, improving conjugation and enlarging the intensity of the absorption range of visible light, or forming an internal electric field exploitable in light-harvesting and charge-and energy-transport processes. The countless potentialities offered by these systems means that self-assembly concepts and tools are constantly explored, as confirmed by the significant number of published articles related to porphyrin assemblies in the 2015–2019 period, which is the focus of this review.

A design path for the hierarchical self-assembly of patchy colloidal particles

Soft Matter ◽  
2015 ◽  
Vol 11 (19) ◽  
pp. 3913-3919 ◽  
Author(s):  
E. Edlund ◽  
O. Lindgren ◽  
M. Nilsson Jacobi
Keyword(s):  
Self Assembly ◽  
Colloidal Particles ◽  
Building Blocks

Patchy colloidal particles are promising candidates for building blocks in directed self-assembly.

Self-assembly of water-soluble silver nanoclusters: superstructure formation and morphological evolution

Nanoscale ◽  
2017 ◽  
Vol 9 (48) ◽  
pp. 19191-19200 ◽  
Author(s):  
Jinglin Shen ◽  
Zhi Wang ◽  
Di Sun ◽  
Guokui Liu ◽  
Shiling Yuan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Morphological Evolution ◽  
Functional Materials ◽  
Building Blocks ◽  
Water Soluble ◽  
Silver Nanoclusters ◽  
Efficient Approach ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Supramolecular self-assembly, based on non-covalent interactions, has been employed as an efficient approach to obtain various functional materials from nanometer-sized building blocks, in particular, [Ag6(mna)6]6−, mna = mercaptonicotinate (Ag6-NC).

scholarly journals Unveiling the Key Templates in the Self-Assembly of Gigantic Molybdenum Blue Wheels

2018 ◽  
Author(s):  
Weimin Xuan ◽  
Robert Pow ◽  
Qi Zheng, ◽  
Nancy Watfa ◽  
De-Liang Long ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electrostatic Interactions ◽  
Structural Evolution ◽  
Functional Materials ◽  
Building Blocks ◽  
Underlying Mechanism ◽  
The Self ◽  
Supramolecular Systems ◽  
Structure Directing Agent ◽  
Molybdenum Blue

Template synthesis is a powerful and useful approach to build a variety of functional materials and complicated supramolecular systems. Systematic study on how templates structurally evolve from basic building blocks and then affect the templated self-assembly is critical to understand the underlying mechanism and gain more guidance for designed assembly but remains challenging. Here we describe the templated self-assembly of a series of gigantic Mo Blue (MB) clusters 1-4 using L-ornithine as structure-directing agent. L-ornithine is essential for the formation of such kind of template⊂host assemblies by providing directional forces of hydrogen bonding and electrostatic interactions. Based on the structural relationship between encapsulated templates of {Mo8} (1), {Mo17} (2) and {Mo36} (4), a plausible pathway of the structural evolution of templates is proposed, thus giving more insight on the templated self-assembly of Mo Blue clusters.

scholarly journals Using Photoactive N-Heterocyclic Carbenes Monolayers to Identify the Influence of Surface Proximity on Photoswitching Activity

2020 ◽  
Author(s):  
Shahar Dery ◽  
Israel Alshanski ◽  
Evgeniy Mervinetsky ◽  
Daniel Feferman ◽  
Shlomo Yitzchaik ◽  
...  
Keyword(s):  
Surface Potential ◽  
Self Assembly ◽  
Functional Materials ◽  
Imidazole Ring ◽  
Structural Flexibility ◽  
Vertical Orientation ◽  
Order Of Magnitude ◽  
Adsorption Geometry ◽  
Photoinduced Changes ◽  
The Impact

<p>Self-assembly of photoresponsive molecules is a robust technology for reversibly tuning the chemical and electronic properties of functional materials. In most systems the photoactive group is separated from the surface by a spacer and thus the photo-responsiveness does not benefit from interactions with the metal. Herein, the impact of metal photoactive-group interactions on photoswitchability and surface potential were probed by self-assembly of N-heterocyclic carbene molecules (NHCs) that were functionalized with stilbene group directly on their imidazole ring. Stilbene-NHCs that were adsorbed on weakly interacting Au surface accumulated a vertical orientation, as identified by FTIR measurements. This positioning enabled structural flexibility and high photoisomerization efficiency that induced reversible changes in surface potential. Stilbene-NHCs that were anchored on Pt film accumulated flat-lying adsorption geometry due to strong metal-adsorbate interactions. These interactions limited the structural flexibility of the stilbene groups and induced deteriorated photoswitchability that led to lower photoinduced changes in surface potential. While stronger metal-adsorbate interactions hindered the photo-induced isomerization yield of stilbene, these interactions prompted the <i>cis</i>-to-<i>trans</i> thermal-induced isomerization rate, which was an order of magnitude higher on Pt than on Au. </p>

Impact of Wet-Dry Cycling on the Phase Behavior and Compartmentalization Properties of Complex Coacervates

2020 ◽  
Author(s):  
Hadi Fares ◽  
Alexander Marras ◽  
Jeffrey Ting ◽  
Matthew Tirrell ◽  
Christine Keating
Keyword(s):  
Phase Diagram ◽  
Phase Behavior ◽  
Self Assembly ◽  
Building Blocks ◽  
Early Earth ◽  
Local Concentration ◽  
Acid System ◽  
Initial Composition ◽  
Molecular Building Blocks ◽  
Polyelectrolyte Solutions

<div>Wet-dry cycling on the early Earth is thought to have facilitated production of molecular building blocks of life, but thus far its impact on self-assembly and compartmentalization of resulting (macro)molecules has been limited. We investigated dehydration/rehydration of complex coacervates, which are membraneless compartments formed by phase separation of polyelectrolyte solutions, and suggested as protocell models. Depending on initial composition of a poly(diallyldimethylammonium)/poly(acrylic acid) system, drying enabled formation or disassembly of coacervate droplets. In compartments surviving tenfold dehydration, partitioning of a fluorescent RNA oligonucleotide decreased, while its local concentration inside the coacervates remained nearly constant, despite increasing tenfold globally. RNA mobility was also enhanced as the system dehydrated. These changes can be understood as resulting from drying induced compositional movements on the phase diagram, with increased ionic strength being particularly important in determining coacervate properties. These results showed that wet-dry cycling can alter the phase behavior and protocell-relevant functions of complex coacervates.</div>

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