Concept Of Self-assembly Research Articles

Controlling the Morphology in Electrostatic Self-Assembly via Light.

Electrostatic self-assembly of macroions is an emerging area with great potential in the development of nanoscale functional objects, where photo-irradiation responsiveness can either elevate or suppress the self-assembly. The ability to control the size and shape of macroion assemblies would greatly facilitate the fabrication of desired nano-objects that can be harnessed in various applications such as catalysis, drug delivery, bio-sensors, and actuators. Here, we demonstrate that a polyelectrolyte with a size of 5 nm and multivalent counterions with a size of 1 nm can produce well-defined nanostructures ranging in size from 10-1000 nm in an aqueous environment by utilizing the concept of electrostatic self-assembly and other intermolecular non-covalent interactions including dipole-dipole interactions. The pH- and photoresponsiveness of polyelectrolytes and azo dyes provide diverse parameters to tune the nanostructures. Our findings demonstrate a facile approach to fabricating and manipulating self-assembled nanoparticles using light and neutron scattering techniques.

On the Mechanical Concept of Self-Assembly of Nanomaterials

On the Mechanical Concept of Self-Assembly of Nanomaterials

On the Mechanical Concept of Self-Assembly of Nanomaterials

The article presents the mechanical concept of self-assembly of nanoparticles. It is assumed that nanoparticles are deformable stamps in a plane dynamic contact problem, lying on the boundary of a multilayer deformable medium. The constant vibration in the microcosm is caused by the oscillatory mode by the energy of phonons and magnons. Earlier, in the works of the authors, the mechanical concept of self-organization of nanoparticles was presented. It is based on high-frequency resonance, which causes the formation of standing waves. They localize the available aggregates of nanoparticles on the crest of standing waves. The self-assembly of nanoparticles is based on resonance, previously predicted by Academician I. I. Vorovich and inherent only in deformable dies in contact problems on a multilayer medium. Deformable nanoparticles are modeled by fractals representing packed block elements described by the Helmholtz equation. The resonance of the deformable dies allows the capture of nanoparticles, dictated by the Coulomb forces of attraction. It is shown that the combination of two fractals generates a new fractal with a combined carrier, and in the case of multiple association, a fragment of a nanomaterial is obtained. To implement the study, for the first time it was possible to construct a high-precision approximate solution of a plane contact problem on the action of a stamp of any finite size on a multilayer base. This result is dictated by the need for an analytical construction of the theory of self-assembly of nanomaterials.

Origami-Inspired Fabrication of High-Performance Wafer-Level Packaged Three-Dimensional Radio-Frequency Inductors

Planar radio-frequency (RF) on-chip inductors suffer from large electromagnetic losses, stemming from the low resistivity silicon substrate. Though it is well-known that 3-dimensional (3D) MEMS-based RF inductors offer significant performance enhancement by reducing the substrate proximity effects, they are prone to mechanical failures and often come without any appropriate packaging, leading to reliability issues. Herein, we report an approach to fabricate highly robust packaged 3D RF inductors, while relying on the concept of stress-induced self-assembly. By leveraging the large residual stresses in evaporated chromium thin films at low thicknesses (below 50 nm), we assemble the planar copper coils coated with chromium nano-layers into out-of-plane folded RF inductors, directly improving their <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$</tex-math> </inline-formula> -factor. Through measurements, we show more than three-fold ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 300%) improvement in the inductor <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$</tex-math> </inline-formula> -factor after the bending. Considering the inherent fragility of suspended inductors, we then add a dedicated wafer-level polymer packaging to our inductors, to improve their mechanical robustness. Specifically, we coat a thick SU-8 layer using a quasi-static volumetric dispensing process, to embed the inductors without deforming them. Upon baking, the polymer layer solidifies, making the buried inductors extremely rigid. We show that though our inductors have <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$</tex-math> </inline-formula> -factors similar to existing MEMS inductors, their low design complexity and high strength gained via polymer packaging make them stand out among the others. This packaging technique essentially paves the way for the widespread commercialization of suspended inductors, which has been hindered in the past by their poor mechanical reliability. 2023-0018

Multi-Functionalization of Solid Support via Zn(II)-Mediated Chirality-Directed Self-Assembly

Establishing a strategy for realizing programmed self-assembly is critical in manufacturing materials with functional hybrid structures. In this work, we introduce a robust methodology for enabling multi-component self-assembly using the concept of chirality-directed self-assembly. A specific combination of heterochiral Zn(II) methylene bis(oxazoline) (BOX) complexes can be selectively generated when combinations of enantiomers of chiral BOX ligands are mixed in the presence of Zn(Oac)2. The resulting Zn(II) BOX complexes, unlike non-covalent bonds, are highly stable and stay intact at elevated temperatures, yet can be reversibly disintegrated under mild conditions using EDTA. This approach can be easily applied to multi-functionalize various solid supports enabling the one-pot generation of multi-functional hybrid structures.

Emergence of layered nanoscale mesh networks through intrinsic molecular confinement self-assembly.

Block copolymer self-assembly is a powerful tool for two-dimensional nanofabrication; however, the extension of this self-assembly concept to complex three-dimensional network structures is limited. Here we report a simple method to experimentally generate three-dimensional layered mesh morphologies through intrinsic molecular confinement self-assembly. We designed triblock bottlebrush polymers with two Janus domains: one perpendicular and one parallel to the polymer backbone. The former enforces a lamellar superstructure that intrinsically confines the intralayer self-assembly of the latter, giving rise to a mesh-like monoclinic (54°) M15 network substructure with excellent long-range order, as well as a tetragonal (90°) T131 mesh. Numerical simulations show that the spatial constraints exerted on the polymer backbone drive the assembly of M15 and yield T131 in the strong segregation regime. This work demonstrates that intrinsic molecular confinement is a viable path to bottom-up assembly of new geometrical phases of soft matter, extending the capabilities of block copolymer nanofabrication.

Do chemists control plane packing, i.e. two-dimensional self-assembly, at all scales?

With the help of mathematics, we rationalize general concepts of self-assembly of molecules, nanoobjects, micron-sized colloids, and even millimetric shapes.

ОТ СОБЫТИЙ ЯЗЫКА К ЯЗЫКУ СОБЫТИЙ

The article presents the background of the author’s concept of selfassembly of the plot. The proximity of the language of demonological stories to the spoken language requires special attention to the text, to its linguistic semantics. The linguosemantic approach to the analysis of texts, which was justified by the author, is demonstrated by the example of the concept of “to lead the water”, widely represented in mythological stories. A lot of predicative compounds were found that implement semantic transitions between two lexico-semantic nests. It is shown that the analyzed narratives are based on the actualization of intra-linguistic, potential predications (“language events”) into predicative syntagmasmythological motifs (“language of events”). The search for an answer to the question of how interactions arising in the language between different levels of the language system (intra-language predications between secondary and primary meanings of words, between literal and metaphorical meanings of idiomatic expressions, etc.) are transformed into text-building constructs led to the emergence of the concept of selfassembly of the plot.

Enzymatically-active nanoparticles to direct the self-assembly of peptides in hydrogel with a 3D spatial control

Hydroxypropylmethylcellulose grafted with silanol groups (Si-HPMC) hydrogels are employed as 3D scaffolds to encapsulate phosphatase-modified silica nanoparticles (AP@NPs). Such hybrid materials are catalytically active when enzyme susbtrates are diffusing through the material. Using the enzyme-assisted self-assembly concept, the tripeptide Fmoc-FFY is generated in situ in close vicinity of AP@NPs thanks to the phosphate hydrolysis of the diffusing precursor Fmoc-FFpY. The self-assembly of Fmoc-FFY is spatially concomitant to the presence of AP@NPs. In the Si-HPMC host hydrogel, AP@NPs aggregate and thus limit their diffusion in the material. This feature is used to localize at the micrometre scale the self-assembly within the material: AP@NPs are injected in a defined 3D area within the Si-HPMC gel using an adapted microsyringe. The diffusion of precursor Fmoc-FFpY toward this region leads to a Fmoc-FFY self-assembly exclusively there, an impossible strategy using free AP. Thus, this work allows to spatially control the enzyme-assisted self-assembly of peptides within host materials as an alternative approach for the design of hierarchically structured materials.

Enzyme-Instructed Self-Assembly of Peptides: From Concept to Representative Applications.

Enzyme-instructed self-assembly, integrating enzymatic reaction and molecular self-assembly, has drawn noticeable attention over the last decade with the intension of being used in valuable applications. Recent advances in the field make it possible to spatiotemporally control peptide self-assembly in cellular milieu, broadening the potential applications of peptide assemblies to cancer therapy and subcellular delivery. In this review, the concept of enzyme-instructed self-assembly of peptide, containing enzymatic trigger and spatiotemporal control, is described. Representative applications in cells are also discussed, followed by an outlook on the field of enzyme-instructed self-assembly.

Chirality-driven self-assembly: application toward renewable/exchangeable resin-immobilized catalysts.

Resin-immobilized catalysts were prepared through chirality-driven self-assembly. The method allows the resin-immobilized catalyst to be regenerated under mild conditions and in situ catalyst exchange to be carried out quantitatively. The uniqueness of the methodology was demonstrated by the preparation of a catalyst for TEMPO oxidation as well as a two-step sequential TEMPO oxidation/aldol condensation sequence enabled by facile catalyst exchange.

Inside Back Cover: Hierarchical Superstructures by Combining Crystallization‐Driven and Molecular Self‐Assembly (Angew. Chem. Int. Ed. 40/2021)

Hierarchical fir-tree-like superstructures have been realized by Holger Schmalz, Hans-Werner Schmidt, and co-workers in the Communication on page 21767, by utilizing the unique corona structure of patchy worm-like micelles for the directed molecular self-assembly of a 1,3,5-benzenetricarboxamide. The combination of crystallization-driven and molecular self-assembly concepts can give access to a large variety of fibrillar superstructures with potential applications in filtration or catalysis.

Patchy Micelles with a Crystalline Core: Self-Assembly Concepts, Properties, and Applications.

Crystallization-driven self-assembly (CDSA) of block copolymers bearing one crystallizable block has emerged to be a powerful and highly relevant method for the production of one- and two-dimensional micellar assemblies with controlled length, shape, and corona chemistries. This gives access to a multitude of potential applications, from hierarchical self-assembly to complex superstructures, catalysis, sensing, nanomedicine, nanoelectronics, and surface functionalization. Related to these applications, patchy crystalline-core micelles, with their unique, nanometer-sized, alternating corona segmentation, are highly interesting, as this feature provides striking advantages concerning interfacial activity, functionalization, and confinement effects. Hence, this review aims to provide an overview of the current state of the art with respect to self-assembly concepts, properties, and applications of patchy micelles with crystalline cores formed by CDSA. We have also included a more general discussion on the CDSA process and highlight block-type co-micelles as a special type of patchy micelle, due to similarities of the corona structure if the size of the blocks is well below 100 nm.

"Concentration-in-Control" self-assembly concept at the liquid-solid interface challenged.

Self-assembled molecular networks (SAMNs) on surfaces evoke a lot of interest, both from a fundamental as well as application point of view. When formed at the liquid–solid interface, precise control over different polymorphs can be achieved by simply adjusting the concentration of molecular building blocks in solution. Significant influence of solute concentration on self-assembly behavior has been observed, whether the self-assembly behavior is controlled by either van der Waals forces or hydrogen bonding interactions. In both cases, high- and low-density supramolecular networks have been observed at high and low solute concentrations, respectively. In contrast to this “concentration-in-control” self-assembly concept here we report an atypical concentration dependent self-assembly behavior at a solution–solid interface. At the interface between heptanoic acid (HA) and highly oriented pyrolytic graphite (HOPG), we show, using scanning tunneling microscopy (STM), the formation of a low-density porous network at high solute concentrations, and a high-density compact network at low solute concentrations. This intriguing inverse concentration dependent self-assembly behavior has been attributed to the preaggregation of solute molecules in the heptanoic acid solution as revealed by UV-vis spectroscopy. The observed results have been correlated to the molecular density of self-assembled monolayers attained at the HA/HOPG interface.

Intramolecular Cyclization-Induced Crystallization-Driven Self-Assembly of an Amorphous Poly(amic acid)

We propose a new concept of intramolecular cyclization-induced crystallization-driven self-assembly (ICI-CDSA) based on an amorphous poly(amic acid) (PAA). Nanobundles with high crystallinity were ...

Poly(N-vinylpyrrolidone) Antimalaria Conjugates of Membrane-Disruptive Peptides.

The concepts of polymer-peptide conjugation and self-assembly were applied to antimicrobial peptides (AMPs) in the development of a targeted antimalaria drug delivery construct. This study describes the synthesis of α-acetal, ω-xanthate heterotelechelic poly(N-vinylpyrrolidone) (PVP) via reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization, followed by postpolymerization deprotection to yield α-aldehyde, ω-thiol heterotelechelic PVP. A specific targeting peptide, GSRSKGT, for Plasmodium falciparum-infected erythrocytes was used to sparsely decorate the α-chain ends via reductive amination while cyclic decapeptides from the tyrocidine group were conjugated to the ω-chain end via thiol-ene Michael addition. The resultant constructs were self-assembled into micellar nanoaggregates whose sizes and morphologies were determined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The in vitro activity and selectivity of the conjugates were evaluated against intraerythrocytic P. falciparum parasites.

DNA Self-Assembly Mediated by Programmable Soft-Patchy Interactions.

Adding shape and interaction anisotropy to a colloidal particle offers exquisitely tunable routes to engineer a rich assortment of complex-architected structures. Inspired by the hierarchical self-assembly concept with block copolymers and DNA liquid crystals and exploiting the unique assembly properties of DNA, we report here the construction and self-assembly of DNA-based soft-patchy anisotropic particles with a high degree of modularity in the system's design. By programmable positioning of thermoresponsive polymeric patches on the backbone of a stiff DNA duplex with linear and star-shaped architecture, we reversibly drive the DNA from a disordered ensemble to a diverse array of long-range ordered multidimensional nanostructures with tunable lattice spacing, ranging from lamellar to bicontinuous double-gyroid and double-diamond cubic morphologies, through the alteration of temperature. Our results demonstrate that the proposed hierarchical self-assembly strategy can be applied to any kind of DNA nanoarchitecture, highlighting the design principles for integration of self-assembly concepts from the physics of liquid crystals, block copolymers, and patchy colloids into the continuously growing interdisciplinary research field of structural DNA nanotechnology.

Cylindrical Zwitterionic Particles via Interpolyelectrolyte Complexation on Molecular Polymer Brushes.

The fabrication of macromolecular architectures with high aspect ratio and well-defined internal and external morphologies remains a challenge. The combination of template chemistry and self-assembly concepts to construct peculiar polymer architectures via a bottom-up approach is an emerging approach. In this study, a cylindrical template-namely a core-shell molecular polymer brush-and linear diblock copolymers (DBCP) associate to produce high aspect ratio polymer particles via interpolyelectrolyte complexation. Induced, morphological changes are studied using cryogenic transmission electron and atomic force microscopy, while the complexation is further followed by isothermal titration calorimetry and ξ-potential measurements. Depending on the nature of the complexing DBCP, distinct morphological differences can be achieved. While polymers with a non-ionic block lead to internal compartmentalization, polymers featuring zwitterionic domains lead to a wrapping of the brush template.

Meta-DNA structures.

DNA origami has emerged as a highly programmable method to construct customized objects and functional devices in the 10-100 nm scale. Scaling up the size of the DNA origami would enable many potential applications, which include metamaterial construction and surface-based biophysical assays. Here we demonstrate that a six-helix bundle DNA origami nanostructure in the submicrometre scale (meta-DNA) could be used as a magnified analogue of single-stranded DNA, and that two meta-DNAs that contain complementary 'meta-base pairs' can form double helices with programmed handedness and helical pitches. By mimicking the molecular behaviours of DNA strands and their assembly strategies, we used meta-DNA building blocks to form diverse and complex structures on the micrometre scale. Using meta-DNA building blocks, we constructed a series of DNA architectures on a submicrometre-to-micrometre scale, which include meta-multi-arm junctions, three-dimensional (3D) polyhedrons, and various 2D/3D lattices. We also demonstrated a hierarchical strand-displacement reaction on meta-DNA to transfer the dynamic features of DNA into the meta-DNA. This meta-DNA self-assembly concept may transform the microscopic world of structural DNA nanotechnology.

Efficient catalytic elimination of COS and H2S by developing ordered mesoporous carbons with versatile base N sites via a calcination induced self-assembly route

Catalytic elimination of highly toxic COS and H2S from industrial resources plays a crucial role in terms of production safety and environmental protection. We report here novel calcination induced self-assembly concept to the fast synthesis of ordered mesoporous carbons with structural base N sites (A-N-OMC-Ts, where T stands for carbonization temperature) without using any solvent and catalysts. The A-N-OMC-Ts show large BET surface areas (∼1538 m2/g), ordered mesoporosity, and the base N sites exhibit versatile structures (e.g. pyridine and pyrrole, 2.03–3.77 wt%). As a result, A-N-OMC-Ts show excellent activities in hydrolysis of COS to H2S, and the H2S can be efficiently captured (∼10.5 mmol/g, 0 °C, 1 bar, IAST selectivity H2S/N2 = 4963, 75 °C) and oxidized into elemental sulfur by A-N-OMC-Ts. The complete elimination of COS and H2S over A-N-OMC-Ts was performed at ambient conditions (50 °C for COS; 150 °C for H2S, and Ea = 32.29 kJ/mol), much better than that of g-C3N4 (150 °C, H2S conversion < 10%, Ea = 42.11 kJ/mol). These performances are outstanding among the metal-free catalysts reported previously. A plausible mechanistic scenario involves the synergistic effect of pyridinic and pyrrolic N as well as the intermediate H2O2 was proposed by us. Coupled the cleavage of H-S bond and S release that accelerate the desulfuration rate.