As one of the most widely used commodity plastics, poly(vinyl chloride) (PVC) is extensively used worldwide, yet is difficult to recycle and is often discarded immediately after use. Its end‐of‐life ...treatment often generates toxic hydrogen chloride and dioxins that pose a critical threat to ecosystems. To address this challenge, the mechanochemical degradation of PVC into water‐soluble biocompatible products is presented herein. Oxirane mechanophores are strategically introduced into the polymeric backbone via sequential dechlorination followed by epoxidation. The oxirane mechanophore in the polymer backbone undergoes a force‐induced heterolytic ring‐opening to carbonyl ylide intermediates, which eventually generates acetals during the course of the reaction. The subsequent hydrolysis of the backbone acetals affords the scission of the polymeric chain into water‐soluble low‐molecular‐weight fragments. Combined with its low cytotoxicity and phytotoxicity, this solvent‐free mechanochemical degradation process offers a green alternative for the degradation of PVC.
The mechanochemical degradation of poly(vinyl chloride) (PVC) into water‐soluble biocompatible products is demonstrated. The solid‐state mechanochemical dechlorination followed by epoxidation offers a more environmentally friendly alternative to the traditional solution‐based reaction. This work exploits the force‐induced heterolytic oxirane ring‐opening which aids PVC degradation into smaller fragments upon hydrolysis.
Introduction of asymmetry into a supramolecular system via external chiral stimuli can contribute to the understanding of the intriguing homochirality found in nature. Circularly polarized light ...(CPL) is regarded as a chiral physical force with right‐ or left‐handedness. It can induce and modulate supramolecular chirality due to preferential interaction with one enantiomer. Herein, this review focuses on the photon‐to‐matter chirality transfer mechanisms at the supramolecular level. Thus, asymmetric photochemical reactions are reviewed, and the creation of a chiral bias upon CPL irradiation is discussed. Furthermore, the possible mechanisms for the amplification and propagation of the bias into the supramolecular level are outlined based on the nature of the photochromic building block. Representative examples, including azobenzene derivatives, polydiacetylene, bicyclic ketone, polyfluorenes, Cn‐symmetric molecules, and inorganic nanomaterials, are presented.
The detailed mechanisms for supramolecular chirality driven by a chiral bias upon circularly polarized light irradiation are outlined. In particular, this review presents three possible mechanisms of chiral amplification process from photochromic building blocks to supramolecular chiral structures: stereoregular packing/polymerization, photoderacemization, and asymmetric photodestruction/production.
Smart fabrics and interactive textiles have attracted great interest as a newly emergent material because of their multifunctional capabilities. Herein, a highly robust wireless flexible strain ...sensor on the basis of commercial textile by the integration of functional hybrid carbon nanomaterials and piezoresistive material is fabricated. Specifically, a solution‐processable spray‐assisted coating approach that enables the creation of a uniform coating over a large area of fabrics is employed. The textile‐based strain sensor exhibits a highly stable and immediate response over a wide range of bending curvatures and structural properties of ZnO nanowires because of their different deflection behaviors. The wearing performance with attaching on commercial fabrics is further demonstrated. The as‐prepared sensor responds well to diverse body motions with accurate detection of strain magnitude and even extends its viability in wireless remote sensing by connecting to a wireless transmitter. The novel approach for the modification of textiles with functional nanomaterials may provide a feasible approach for the production of textile‐based electronics without employing any sophisticated fabrication processes, and it further exploits the diverse functionalities by utilizing various sensing components.
A highly robust flexible strain sensor is fabricated through a facile integration of functional nanomaterials into a textile platform. It well demonstrates not only a rapid response to diverse body motions but also different strain sensing behaviors depending on geometrical features of ZnO nanostructure. Furthermore, the capability of the textile‐based sensor is extended to remote monitoring by configuration with wireless transmitter.
The charge separation efficiency of water oxidation photoanodes is modulated by depositing polyelectrolyte multilayers on their surface using layer‐by‐layer (LbL) assembly. The deposition of the ...polyelectrolyte multilayers of cationic poly(diallyldimethylammonium chloride) and anionic poly(styrene sulfonate) induces the formation of interfacial dipole layers on the surface of Fe2O3 and TiO2 photoanodes. The charge separation efficiency is modulated by tuning their magnitude and direction, which in turn can be achieved by controlling the number of bilayers and type of terminal polyelectrolytes, respectively. Specifically, the multilayers terminated with anionic poly(styrene sulfonate) exhibit a higher charge separation efficiency than those with cationic counterparts. Furthermore, the deposition of water oxidation molecular catalysts on top of interfacial dipole layers enables more efficient photoelectrochemical water oxidation. The approach exploiting the polyelectrolyte multilayers for improving the charge separation efficiency is effective regardless of pH and types of photoelectrodes. Considering the versatility of the LbL assembly, it is anticipated that this study will provide insights for the design and fabrication of efficient photoelectrodes.
Interfacial dipole layers for efficient charge separation are deposited on the desired water‐oxidation photoanode via layer‐by‐layer assembly of oppositely charged polyelectrolytes. The charge separation efficiency can be modulated by controlling the direction and magnitude of interfacial dipoles with the number of polyelectrolyte layers and types of terminal polyelectrolytes, regardless of the pH and types of photoanodes.
Growing environmental concern has increased the demand for clean energy, and various technologies have been developed to utilize renewable energy sources. With the development of highly efficient ...energy conversion and storage systems, fundamental studies on the electrochemistry of electrodes are critical because the functionality of most of these systems relies on interfacial electrochemical reactions that occur on the surfaces of the electrodes. In this context, efficient electrode design methods are required to study specific electrochemical principles and the mechanisms of interfacial reactions on the surface of electrodes.Compared with other electrode fabrication methods, layer-by-layer (LbL) assembly is a simple, inexpensive, and versatile process for producing highly ordered multilayer thin-film electrodes from a diverse array of materials. LbL-assembled multilayer electrodes exhibit distinct electrochemical properties compared with electrodes created via other fabrication methods because of the nanoscale control of the composition and structures of electrodes afforded by LbL assembly. LbL assembly can generate unique nanoarchitectures from a multiplicity of electroactive components to investigate the detailed electrochemical mechanisms within the electrode, allowing for investigations of the internal-architecture-dependent electrochemical properties within the electrodes. As electrochemical LbL research has progressed over the last 10 years, our group has performed pioneering studies on the fundamental electrochemical properties of multilayer electrodes fabricated via LbL assembly for diverse energy applications. In this Account, we aim to outline the fundamental electrochemistry occurring at the nanoscale level on multilayer thin-film LbL electrodes using our work to illustrate these concepts, including the dependence of the electrochemistry on the thickness and architecture of multilayer electrodes, competition between mass and charge transfer, and control over the ion-permeation selectivity and interfacial dipole moments in multilayer electrodes. We anticipate that our approach to LbL-assembled electrodes will be of great interest and provide an attractive platform for the investigation of fundamental multilayer thin-film electrochemistry. We also believe that it will provide guidelines for research efforts toward future electrode engineering.
An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced ...by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation.
Plastic packaging effectively protects foods from mechanical, microbial, and chemical damage, but oxygen can still permeate these plastics, degrading foods. Improving the gas barrier usually requires ...metallic or halogenated polymeric coatings; however, both cause environmental concerns and metallic coatings block visible light and electromagnetic signals. This paper reports a design of a highly flexible, visible light and radio frequency transparent coating on commercial poly(ethylene terephthalate) (PET) film. Nanoscale blending was achieved between negatively charged cellulose nanofibers and positively charged chitin nanowhiskers by employing spray-assisted layer-by-layer assembly. Synergetic interplay between these highly crystalline nanomaterials results in a flexible film with superior barrier characteristics. The oxygen transmission rate was below 0.5 mL m–2 day–1. Moreover, this coating maintains its performance even when exposed to common hazards such as bending stress and hydration. The coating also notably reduces the haziness of PET with a negligible loss of transparency and provides effective inhibition of antibacterial growth. This “crab-on-a-tree” nanocoating holds high potential for biorenewable and optical and radio frequency transparent packaging applications.
As the demand for next-generation electronics is increasing, organic and polymer-based semiconductors are in the spotlight as suitable materials owing to their tailorable structures along with ...flexible properties. Especially, polyimide (PI) has been widely utilised in electronics because of its outstanding mechanical and thermal properties and chemical resistance originating from its crystallinity, conjugated structure and π-π interactions. PI has recently been receiving more attention in the energy storage and conversion fields due to its unique redox activity and charge transfer complex structure. In this review, we focus on the design of PI structures with improved electrochemical and photocatalytic activities for use as redox-active materials in photo- and electrocatalysts, batteries and supercapacitors. We anticipate that this review will offer insight into the utilisation of redox-active PI-based polymeric materials for the development of future electronics.
This review covers redox-active polyimides in energy conversion and storage applications along with the recent progress in the synthetic methods and topological control used to produce polyimides.
Despite its abundance, water is not widely used as a medium for organic reactions. However, under geothermal conditions, water exhibits unique physicochemical properties, such as viscosity and a ...dielectric constant, and the ionic product become similar to those of common organic solvents. We have synthesized highly crystalline polyimide‐based covalent organic frameworks (PICs) under geomimetic hydrothermal conditions. By exploiting triphenylene‐2,3,6,7,10,11‐hexacarboxylic acid in combination with various aromatic diamines, PICs with various pore dimensions and crystallinities were synthesized. XRD, FT‐IR, and DFT calculations revealed that the solubility of the oligomeric intermediates under hydrothermal conditions affected the stacking structures of the crystalline PICs. Furthermore, the synthesized PICs demonstrate promising potential as an anode material in lithium‐ion batteries owing to its unique redox‐active properties and high surface area.
Polyimide‐based COFs were synthesized via a geomimetic hydrothermal reaction, yielding materials having various pore dimensions and crystal structures. The solubility of the oligomeric intermediates under hydrothermal conditions affected the growth mechanism and reaction pathway, which determined the 3D stacking structures of the polyimide‐based COFs.
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