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Dynamic chemistry utilizing both covalent and noncovalent bonds provides valid protocols in manipulating properties of self‐assemblies and functions. Here we employ dynamic chemistry to realize multiple‐route control over supramolecular chirality up to five states. N‐protected fluorinated phenylalanine in the carboxylate state self‐assembled into achiral nanoparticles ascribed to the amphiphilicity. Protonation promoted one‐dimensional growth into helices with shrunk hydrophilicity, which in the presence of disulfide pyridine undergo chirality inversion promoted by the hydrogen bonding‐directed coassembly. Further interacting with the water‐soluble reductant cleavages the disulfide bond to initiate the rearrangement of coassemblies with a chirality inversion as well. Finally, by tuning the pH environments, aromatic nucleophilic substitution reaction between reduced products and perfluorinated phenylalanine occurs, giving distinct chiral nanoarchitectures with emerged luminescence and circularly polarized luminescence. We thus realized a particular five‐state control by combining dynamic chemistry at one chiral compound, which greatly enriches the toolbox in fabricating responsive chiroptical materials. [ABSTRACT FROM AUTHOR]

Dynamic chemistry utilizing both covalent and noncovalent bonds provides valid protocols in manipulating properties of self‐assemblies and functions. Here we employ dynamic chemistry to realize multiple‐route control over supramolecular chirality up to five states. N‐protected fluorinated phenylalanine in the carboxylate state self‐assembled into achiral nanoparticles ascribed to the amphiphilicity. Protonation promoted one‐dimensional growth into helices with shrunk hydrophilicity, which in the presence of disulfide pyridine undergo chirality inversion promoted by the hydrogen bonding‐directed coassembly. Further interacting with the water‐soluble reductant cleavages the disulfide bond to initiate the rearrangement of coassemblies with a chirality inversion as well. Finally, by tuning the pH environments, aromatic nucleophilic substitution reaction between reduced products and perfluorinated phenylalanine occurs, giving distinct chiral nanoarchitectures with emerged luminescence and circularly polarized luminescence. We thus realized a particular five‐state control by combining dynamic chemistry at one chiral compound, which greatly enriches the toolbox in fabricating responsive chiroptical materials. [ABSTRACT FROM AUTHOR]

Many studies on the basis of cholesteric liquid crystal (CLC) have focused on dynamic optical changes utilizing photochemical reactions raising helical pitch variations. However, the conventional dyes doped in CLC system often show reversible isomerization such as trans‐cis, E‐Z, and open‐close forms that hampers the fixation of desired color cues. Here, a cyanostilbene‐based reactive mesogen (CSRM) for phototunable and subsequently polymerizable smart CLC paints is newly designed and synthesized. The structural color of the CLC paint can be precisely manipulated in remote controllable manner by inducing a photochemical reaction of CSRM. Due to the irreversible isomerization behaviors of CSRM, the constructed periodic structures with different helical pitches are intactly fixed via in situ photopolymerization under 460 nm light. In addition, the combination of helical nanostructures and cyanostilbene luminophore produces a circularly polarized light emission. The dissymmetry factor of circularly polarized luminescence is dependent on the photoregulated helical nanostructures in CLC films. The decoupled system of triple photofunctionality in a single component of chirophotonic crystalline material is applied to develop advanced optical information storages. [ABSTRACT FROM AUTHOR]

Examples of anisotropic movement paired with helical geometry abound in the animal and plant kingdoms are used for a variety of reasons, such as diverse social signaling directed at conspecifics or camouflage to avoid predation. Inspired by these natural phenomena, a smart sensor is developed with a chiroptical 3D actuator that can fold, bend, and twist in response to external stimuli, reflecting light of specific wavelengths, and possessing circular polarization properties. Chirophotonic crystal actuators are constructed with an asymmetric Janus structure and are fabricated by self‐assembly, screen printing, and in situ photopolymerization. The optically active layer consists of cholesteric liquid crystal polymer, and the mechanically active layer is composed of a polymeric gel thin film. The programmed in‐planar and out‐of‐planar asymmetric Janus structures control the directionality of various shapes morphing from 2D to 3D. Finite element simulations allow to predict the shape changes associated with these chirophotonic crystal actuators: flower blooming, tendril climbing, eagle hunting, ant lifting, and inchworm moving motions. By utilizing the chirophotonic crystal actuator, a reusable and portable methanol‐laced water identifier is developed. [ABSTRACT FROM AUTHOR]

Examples of anisotropic movement paired with helical geometry abound in the animal and plant kingdoms are used for a variety of reasons, such as diverse social signaling directed at conspecifics or camouflage to avoid predation. Inspired by these natural phenomena, a smart sensor is developed with a chiroptical 3D actuator that can fold, bend, and twist in response to external stimuli, reflecting light of specific wavelengths, and possessing circular polarization properties. Chirophotonic crystal actuators are constructed with an asymmetric Janus structure and are fabricated by self‐assembly, screen printing, and in situ photopolymerization. The optically active layer consists of cholesteric liquid crystal polymer, and the mechanically active layer is composed of a polymeric gel thin film. The programmed in‐planar and out‐of‐planar asymmetric Janus structures control the directionality of various shapes morphing from 2D to 3D. Finite element simulations allow to predict the shape changes associated with these chirophotonic crystal actuators: flower blooming, tendril climbing, eagle hunting, ant lifting, and inchworm moving motions. By utilizing the chirophotonic crystal actuator, a reusable and portable methanol‐laced water identifier is developed. [ABSTRACT FROM AUTHOR]

ABC triblock copolymers with frustrated interactions of χACN ≪ χABN ~ χBCN confined in nanopores with A‐block‐attracting surfaces can self‐assemble into helical morphologies, where the B blocks form helical domains wrapping around C‐core cylinders within the A shell. It has been suggested that the number of helical strands (m) increases as the volume fraction of C block (fC) decreases, while the increasing m is restricted because C blocks forming domains cannot maintain a cylindrical shape as fC gradually decreases, and the B block domains transform from helical structures to toroidal domains. To prevent the restriction of increasing m, in the current study we added C homopolymers into nanopores. For a given triblock copolymer with (χABN, χBCN, χACN) = (80, 80, 20) and (fA, fB, fC) = (0.7, 0.1, 0.2), varying the concentration (ϕH) and the chain length (γ) of the C homopolymers, as well as the diameter (D) of the nanopores, we constructed different two‐dimensional phase diagrams with respect to two of these control parameters using self‐consistent field theory. A number of helical structures with strands ranging from 1 to 6 are predicted. Our calculations indicate that m increases with increasing γ and D and decreasing ϕH. The theoretical results demonstrate that blending of homopolymer with one given triblock terpolymer could provide an efficient route to fabricate different complex helical nanostructures. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Designing broadband enhanced chirality is of strong interest to the emerging fields of chiral chemistry and sensing, or to control the spin orbital momentum of photons in recently introduced nanophotonic chiral quantum and classical optical applications. However, chiral light‐matter interactions have an extremely weak nature, are difficult to control and enhance, and cannot be made tunable or broadband. In addition, planar ultrathin nanophotonic structures to achieve strong, broadband, and tunable chirality at the technologically important visible to ultraviolet spectrum still remain elusive. Here, these important problems are tackled by experimentally demonstrating and theoretically verifying spectrally tunable, extremely large, and broadband chiroptical response by nanohelical metamaterials. The reported new designs of all‐dielectric and dielectric‐metallic (hybrid) plasmonic metamaterials permit the largest and broadest ever measured chiral Kuhn's dissymmetry factor achieved by a large‐scale nanophotonic structure. In addition, the strong circular dichroism of the presented bottom‐up fabricated optical metamaterials can be tuned by varying their dimensions and proportions between their dielectric and plasmonic helical subsections. The currently demonstrated ultrathin optical metamaterials are expected to provide a substantial boost to the developing field of chiroptics leading to significantly enhanced and broadband chiral light‐matter interactions at the nanoscale. [ABSTRACT FROM AUTHOR]

Self-assembled structures with circularly polarized luminescence (CPL) have attracted great attention in recent years. π-conjugated N-terminal amino acids with chiral amino acid residues and luminophores are capable of forming selfassembled structures at hierarchical levels, whereby chirality can be transferred to the macroscopic scale with easily modulated CPL properties. Due to the presence of multiple noncovalent binding sites, including hydrogen bonding and aromatic interactions, π-conjugated N-terminal amino acids are emerging core candidates for incorporation into multicomponent self-assembled architectures, accomplishing rational control over supramolecular chirality as well as showing rich chiroptical properties. In this Minireview, we provide a brief summary of multiple-component coassembled systems comprising π-conjugated N-terminal amino acids, small organic species and metal ions. The synthesis of helical structures and manipulation of supramolecular chirality by controlling the selfassembled species is introduced, and the CPL properties of multiple-component π-conjugated N-terminal amino acids are also briefly summarized. [ABSTRACT FROM AUTHOR]

Self‐sorting, simultaneous, and orthogonal operations during the self‐assembly of complex mixtures are commonly observed for biological species but rare in artificial systems. In this study, we designed two gelators (LPF and LPFEG) containing the same chiral phenylalanine core but different achiral peripheral substituents to give hydrogels with opposite supramolecular handedness. When the two hydrogels were mixed, double‐network nanofibers with opposite handedness were formed by spontaneous high‐order organization and self‐sorting of the two gelators. The chiroptical activity of the double‐network hydrogels could be tuned by varying the molar ratio of LPF and LPFEG in the mixture, thus showing that the two gelators were highly independent of each other. Enhanced mechanical properties were observed for the interpenetrating networks when the LPF/LPFEG molar ratio was 3:7, with a more than fourfold increase in both the storage (G′) and loss modulus (G′′) relative to those of the individual hydrogels. [ABSTRACT FROM AUTHOR]

Protein allostery, a chemical‐to‐mechanical effect that can precisely regulate protein structure, exists in many proteins. Herein, we demonstrate that protein allostery can be used to drive self‐assembly for the construction of tunable protein architectures. Calmodulin (CaM) was chosen as a model allosteric protein. Ca2+‐mediated contraction of CaM to a closed state can activate CaM and its ligand to self‐assemble into a 1D protein helical microfilament. Conversely, relaxation of CaM to the open state can unwind and further dissociate the helical assemblies. Fine regulation of the protein conformation by tuning the external Ca2+ level allows us to obtain various protein helical nanostructures with tunable helicity. This study offers a new approach toward chemomechanically controlled protein self‐assembly. [ABSTRACT FROM AUTHOR]

Keywords: chiroptical property; helical nanostructures; photoisomerization; photopolymerization; smart paints EN chiroptical property helical nanostructures photoisomerization photopolymerization smart paints 1 1 1 03/21/23 20230315 NES 230315 In article number 2202707, Kwang-Un Jeong and co-workers present chiroptical smart paints using cyanostilbene-based reactive mesogens. Chiroptical property, helical nanostructures, photoisomerization, photopolymerization, smart paints The helical nanostructures in the developed paint are precisely controlled and fixed by UV light and subsequent blue light irradiation. [Extracted from the article]

Keywords: helical nanostructures; heterogeneous assembly; selective reflection; smart sensors; soft actuators EN helical nanostructures heterogeneous assembly selective reflection smart sensors soft actuators 1 1 1 01/20/23 20230116 NES 230116 B Chiroptical 3D Actuators b In article number 2210680, Kwang-Un Jeong, Seung-Yeol Jeon, Dae-Yoon Kim, and co-workers develop chiroptical 3D smart actuators by assembling cholesteric liquid crystals onto a polymeric gel thin film. Helical nanostructures, heterogeneous assembly, selective reflection, smart sensors, soft actuators The newly developed chiroptical 3D smart actuators can be applied to soft robots and sensors. [Extracted from the article]

Helical nanostructures, heterogeneous assembly, selective reflection, smart sensors, soft actuators Keywords: helical nanostructures; heterogeneous assembly; selective reflection; smart sensors; soft actuators EN helical nanostructures heterogeneous assembly selective reflection smart sensors soft actuators 1 1 1 11/03/23 20230111 NES 230111 B Chiroptical 3D Actuators b In article number 2210680, Kwang-Un Jeong, Seung-Yeol Jeon, Dae-Yoon Kim, and co-workers develop chiroptical 3D smart actuators by assembling cholesteric liquid crystals onto a polymeric gel thin film. The newly developed chiroptical 3D smart actuators can be applied to soft robots and sensors. [Extracted from the article]

Among various metal oxide semiconductors, hematite ( α-FeO) is a considerable candidate for solar energy applications due to its moderate bandgap, good chemical stability and lower cost. However, hematite has a low diffusion length of charge carriers and low photocurrent generation efficiency restricting its widespread applications. In this work, we have studied the improvement of light absorption properties of a hematite thin film by adjoining the film by an array of silver helical nanostructures. Different forms of normal and conical nanohelices are fabricated using glancing angle deposition method. The helical nanostructures are fixed to a substrate and then are covered by a thin film of hematite nanoparticles. Measurement of UV-Vis spectra of the fabricated thin films indicates the remarkable broadband enhancement of the light absorption properties in the visible and near infrared regions. The improvement is more broadband for conical nanohelices than the normal ones. The experiments have also been supplemented by consistence finite element numerical calculations. Both the experiment and the simulation confirm improvement of the light absorption of the hematite thin film by about 45 and 52 % using normal and helical Ag nanostructures, respectively. [ABSTRACT FROM AUTHOR]

Self-assembly of chiral amphiphiles with π-conjugated tectons into one-dimensional helical nanostructures offers great potential applications in the biological, physical, and material sciences. In this review, the recent development of supramolecular self-assembly of chiral amphiphiles with π-conjugated tectons has been discussed on the basis of experimental exploration by elegantly utilizing cooperative noncovalent forces such as π-π stacking, hydrophobic interaction, hydrogen bond and electrostatic interaction, and the potential applications of these self-assembled helical nanostructures in chiral recognition, asymmetric catalysis, electrical conduction, switchable interfaces and soft template for the fabrication of one-dimensional hard materials are described by a representative example. Meanwhile, some scientific and technical challenges in the development of supramolecular self-assembly of chiral amphiphiles with π-conjugated tectons are also presented. It is hoped that this review can summarize the strategies for self-assembling soft nanomaterials by using chiral amphiphiles with π-conjugated tectons, and also as a guideline for design functional nanomaterials for various potential applications. [ABSTRACT FROM AUTHOR]

Helical Nanostructures: Broadband Enhanced Chirality with Tunable Response in Hybrid Plasmonic Helical Metamaterials (Adv. Funct. In article number 2010329, Ufuk Kilic, Christos Argyropoulos, and co-workers tackle these important problems by experimentally demonstrating and theoretically verifying spectrally tunable, extremely large, and broadband circular dichroism from new hybrid dielectric and plasmonic nanohelical metamaterial configurations operating at the technologically important visible to ultra-violet spectrum. Keywords: chirality; helical nanostructures; metamaterials; plasmonics EN chirality helical nanostructures metamaterials plasmonics 1 1 1 05/20/21 20210517 NES 210517 Chiral light-matter interactions have an extremely weak nature, are difficult to be controlled and enhanced, and cannot be made tunable or broadband. [Extracted from the article]