scholarly journals Tolerance to structural disorder and tunable mechanical behavior in self-assembled superlattices of polymer-grafted nanocrystals

2017 ◽  
Vol 114 (11) ◽  
pp. 2836-2841 ◽  
Author(s):  
X. Wendy Gu ◽  
Xingchen Ye ◽  
David M. Koshy ◽  
Shraddha Vachhani ◽  
Peter Hosemann ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Self Assembly ◽  
Structural Disorder ◽  
Structural Features ◽  
Structural Defects ◽  
Critical Parameters ◽  
Recent Developments ◽  
Self Assembled ◽  
Elastic And Plastic Deformation

Large, freestanding membranes with remarkably high elastic modulus (>10 GPa) have been fabricated through the self-assembly of ligand-stabilized inorganic nanocrystals, even though these nanocrystals are connected only by soft organic ligands (e.g., dodecanethiol or DNA) that are not cross-linked or entangled. Recent developments in the synthesis of polymer-grafted nanocrystals have greatly expanded the library of accessible superlattice architectures, which allows superlattice mechanical behavior to be linked to specific structural features. Here, colloidal self-assembly is used to organize polystyrene-grafted Au nanocrystals at a fluid interface to form ordered solids with sub-10-nm periodic features. Thin-film buckling and nanoindentation are used to evaluate the mechanical behavior of polymer-grafted nanocrystal superlattices while exploring the role of polymer structural conformation, nanocrystal packing, and superlattice dimensions. Superlattices containing 3–20 vol % Au are found to have an elastic modulus of ∼6–19 GPa, and hardness of ∼120–170 MPa. We find that rapidly self-assembled superlattices have the highest elastic modulus, despite containing significant structural defects. Polymer extension, interdigitation, and grafting density are determined to be critical parameters that govern superlattice elastic and plastic deformation.

Bioactive clusters promoting cell penetration and nucleic acid complexation for drug and gene delivery applications: from designed to self-assembled and responsive systems

2016 ◽  
Vol 52 (23) ◽  
pp. 4257-4273 ◽  
Author(s):  
Eline Bartolami ◽  
Camille Bouillon ◽  
Pascal Dumy ◽  
Sébastien Ulrich
Keyword(s):  
Nucleic Acid ◽  
Gene Delivery ◽  
Nucleic Acids ◽  
Self Assembly ◽  
The Self ◽  
Cell Penetration ◽  
Responsive Systems ◽  
Recent Developments ◽  
Self Assembled ◽  
Drug And Gene Delivery

Recent developments in the (self-)assembly of cationic clusters promoting nucleic acids complexation and cell penetration open the door to applications in drug and gene delivery.

Interplay between H-bonding and interpenetration in an aqueous copper(ii)–aminoalcohol–pyromellitic acid system: self-assembly synthesis, structural features and catalysis

2018 ◽  
Vol 47 (46) ◽  
pp. 16674-16683 ◽  
Author(s):  
Tiago A. Fernandes ◽  
Marina V. Kirillova ◽  
Vânia André ◽  
Alexander M. Kirillov
Keyword(s):  
Self Assembly ◽  
Coordination Compounds ◽  
Building Blocks ◽  
Structural Features ◽  
Acid System ◽  
Pyromellitic Acid ◽  
Self Assembled

Two new copper(ii) coordination compounds were self-assembled from N-methyldiethanolamine and pyromellitic acid as principal building blocks; their structural and catalytic features were investigated.

scholarly journals The Versatile Manipulations of Self-Assembled Proteins in Vaccine Design

2021 ◽  
Vol 22 (4) ◽  
pp. 1934
Author(s):  
Que Dan Nguyen ◽  
Kosuke Kikuchi ◽  
Basudev Maity ◽  
Takafumi Ueno
Keyword(s):  
Self Assembly ◽  
Structural Features ◽  
Biological Molecules ◽  
Future Perspectives ◽  
Protein Assemblies ◽  
Viral Pathogens ◽  
Subunit Vaccines ◽  
Small Proteins ◽  
Recent Developments ◽  
Proteins And Peptides

Protein assemblies provide unique structural features which make them useful as carrier molecules in biomedical and chemical science. Protein assemblies can accommodate a variety of organic, inorganic and biological molecules such as small proteins and peptides and have been used in development of subunit vaccines via display parts of viral pathogens or antigens. Such subunit vaccines are much safer than traditional vaccines based on inactivated pathogens which are more likely to produce side-effects. Therefore, to tackle a pandemic and rapidly produce safer and more effective subunit vaccines based on protein assemblies, it is necessary to understand the basic structural features which drive protein self-assembly and functionalization of portions of pathogens. This review highlights recent developments and future perspectives in production of non-viral protein assemblies with essential structural features of subunit vaccines.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

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

MRS Advances ◽  
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.

Self-Assembly of a Chiral Cubic Three-Connected Net from the High Symmetry Molecules C60 and SnI4

2020 ◽  
Author(s):  
Daniel B. Straus ◽  
Robert J. Cava
Keyword(s):  
Organic Synthesis ◽  
Self Assembly ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
High Symmetry ◽  
Molecular Chirality ◽  
Chiral Materials ◽  
Self Assembled ◽  
Chiral Centers

The design of new chiral materials usually requires stereoselective organic synthesis to create molecules with chiral centers. Less commonly, achiral molecules can self-assemble into chiral materials, despite the absence of intrinsic molecular chirality. Here, we demonstrate the assembly of high-symmetry molecules into a chiral van der Waals structure by synthesizing crystals of C<sub>60</sub>(SnI<sub>4</sub>)<sub>2</sub> from icosahedral buckminsterfullerene (C<sub>60</sub>) and tetrahedral SnI4 molecules through spontaneous self-assembly. The SnI<sub>4</sub> tetrahedra template the Sn atoms into a chiral cubic three-connected net of the SrSi<sub>2</sub> type that is held together by van der Waals forces. Our results represent the remarkable emergence of a self-assembled chiral material from two of the most highly symmetric molecules, demonstrating that almost any molecular, nanocrystalline, or engineered precursor can be considered when designing chiral assemblies.

scholarly journals Nano- and Micropatterning on Optical Fibers by Bottom-Up Approach: The Importance of Being Ordered

2021 ◽  
Vol 11 (7) ◽  
pp. 3254
Author(s):  
Marco Pisco ◽  
Francesco Galeotti
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Self Assembly ◽  
Ordered Structures ◽  
Bottom Up ◽  
Photonic Structures ◽  
Fiber Technology ◽  
Optical Fiber Probes ◽  
Fiber Probes ◽  
Self Assembled

The realization of advanced optical fiber probes demands the integration of materials and structures on optical fibers with micro- and nanoscale definition. Although researchers often choose complex nanofabrication tools to implement their designs, the migration from proof-of-principle devices to mass production lab-on-fiber devices requires the development of sustainable and reliable technology for cost-effective production. To make it possible, continuous efforts are devoted to applying bottom-up nanofabrication based on self-assembly to decorate the optical fiber with highly ordered photonic structures. The main challenges still pertain to “order” attainment and the limited number of implementable geometries. In this review, we try to shed light on the importance of self-assembled ordered patterns for lab-on-fiber technology. After a brief presentation of the light manipulation possibilities concerned with ordered structures, and of the new prospects offered by aperiodically ordered structures, we briefly recall how the bottom-up approach can be applied to create ordered patterns on the optical fiber. Then, we present un-attempted methodologies, which can enlarge the set of achievable structures, and can potentially improve the yielding rate in finely ordered self-assembled optical fiber probes by eliminating undesired defects and increasing the order by post-processing treatments. Finally, we discuss the available tools to quantify the degree of order in the obtained photonic structures, by suggesting the use of key performance figures of merit in order to systematically evaluate to what extent the pattern is really “ordered”. We hope such a collection of articles and discussion herein could inspire new directions and hint at best practices to fully exploit the benefits inherent to self-organization phenomena leading to ordered systems.

scholarly journals Self-assembled interpenetrating networks by orthogonal self assembly of surfactants and hydrogelators

2009 ◽  
Vol 143 ◽  
pp. 345 ◽  
Author(s):  
Aurelie M. Brizard ◽  
Marc C. A. Stuart ◽  
Jan H. van Esch
Keyword(s):  
Self Assembly ◽  
Interpenetrating Networks ◽  
Self Assembled

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....

Self-assembled luminescent cholate gels induced by a europium ion in deep eutectic solvents

Soft Matter ◽  
2021 ◽  
Author(s):  
Meng Sun ◽  
Qintang Li ◽  
Xiao Chen
Keyword(s):  
Self Assembly ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Sodium Cholate ◽  
The Self ◽  
Europium Ion ◽  
Self Assembled

Luminescent gels have been successfully fabricated through the self-assembly of sodium cholate and a europium ion in choline chloride-based deep eutectic solvents.

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