Regulating Charge Carrier Dynamics in Stable Perovskite Nanorods for Photo-Induced Atom Transfer Radical Polymerization.

Semiconducting nanocrystals have attracted world-wide research interest in artificial photosynthesis due to their appealing properties and enticing potentials in converting solar energy into valuable chemicals. Compared to 0D nanoparticles, 1D nanorods afford long-distance charge carriers separation and extended charge carriers lifetime due to the release of quantum confinement in axial direction. Herein, stable CsPbBr3 nanorods of distinctive dimensions are crafted without altering their properties and morphology via grafting hydrophobic polystyrene (PS) chains through a post-synthesis ligand exchange process. The resulting PS-capped CsPbBr3 nanorods exhibit a series of enhanced stabilities against UV irradiation, elevated temperature, and polar solvent, making them promising candidates for photo-induced atom transfer radical polymerization (ATRP). Tailoring the surface chemistry and dimension of the PS-capped CsPbBr3 nanorods endows stable, but variable reaction kinetics in the photo-induced ATRP of methyl methacrylate. The trapping-detrapping process of photogenerated charge carriers lead to extended lifetime of charge carriers in lengthened CsPbBr3 nanorods, contributing to a facilitated reaction kinetics of photo-induced ATRP. Therefore, by leveraging such stable PS-capped CsPbBr3 nanorods, the effects of surface chemistry and charge carriers dynamics on its photocatalytic performance are scrutinized, providing fundamental understandings for designing next-generation efficient nanostructured photocatalyst in artificial photosynthesis and solar energy conversion.

Precise Regulation in Chain-Edge Structural Microenvironments of 1D Covalent Organic Frameworks for Photocatalysis.

Covalent organic frameworks (COFs) constitute a promising research topic for photocatalytic reactions, but the rules and conformational relationships of 1D COFs are poorly defined. Herein, the chain edge structure is designed by precise modulation at the atomic level, and the 1D COFs bonded by C, O, and S elements is directionally prepared for oxygen-tolerant photoinduced electron transfer-atom transfer radical polymerization (PET-ATRP) reactions. It is demonstrated that heteroatom-type chain edge structures (─O─, ─S─) lead to a decrease in intra-plane conjugation, which restricts the effective transport of photogenerated electrons along the direction of the 1D strip. In contrast, the all-carbon type chain edge structure (─C─) with higher intra-plane conjugation not only reduces the energy loss of photoexcited electrons but also enhances the carrier density, which exhibits the optimal photopolymerization performance. This work offers valuable guidance in the exploitation of 1D COFs for high photocatalytic performance. This work offers valuable guidance in the exploitation of 1D COFs for high photocatalytic performance.

Plenty of Space in the Backbone: Radical Ring-Opening Polymerization.

Radical polymerization is the most widely applied technique in both industry and fundamental science. However, its major drawback is that it typically yields polymers with non-functional, non-degradable all-carbon backbones-a limitation that radical ring-opening polymerization (rROP) allows to overcome. The last decade has seen a surge in rROP, primarily focused on creating degradable polymers. This pursuit has resulted in the creation of the first readily degradable materials through radical polymerization. Recent years have witnessed innovations in new monomers that address previous design limitations, such as ring strain and reactivity ratios. Furthermore, advances in integrating rROP with reversible deactivation radical polymerization (RDRP) have facilitated the incorporation of complex, customizable chemical payloads into the main polymer chain. This short review discusses the latest developments in monomer design with a focused analysis of their limitations in a broader historical context. Recently evolving strategies for compatibility of rROP monomers with RDRP are discussed, which are key to precision polymer synthesis. The latest chemistry surveyed expands the horizon beyond mere hydrolytic degradation. Now is the time to explore the chemical potential residing in the previously inaccessible polymer backbone.

In-situ polymerized solid/quasi-solid polymer electrolyte for lithium-metal batteries: recent progress and perspectives.

In pursuit of high energy density, lithium metal batteries (LMBs) are undoubtedly the best choice. However, leakage and inevitable dendrite growth in liquid electrolytes seriously hinder its practical application. Solid/quasi-solid state electrolytes have emerged as an answer to solve the above issues. Especially, polymer electrolytes with excellent interface compatibility, high flexibility, and ease of machining have become a research hotspot for LMBs. Nevertheless, the interface contact between polymer electrolyte and inorganic electrode materials and the low ionic conductivity restrict its development. On account of these, in situ polymerized polymer electrolyte is proposed. Polymer solid electrolytes produced through in situ polymerization promote robust interface contact between the electrolyte and electrode while simplifying the preparation steps. This review summarized the latest research progress in in situ polymerized solid electrolytes for LMBs. These electrolytes were divided into three parts according to their polymerization methods: thermally induced polymerization, chemical initiator polymerization, ionizing radiation polymerization, and so on. Furthermore, we concluded the major challenges and future trends of in situ polymerized solid electrolytes for LMBs. It's hoped that this review will provide meaningful guidance on designing high-performance polymer solid electrolytes for LMBs.

Reversible Addition-Fragmentation Chain-Transfer Polymerization in Supercritical CO2: A Review.

The development of cleaner, more environmentally friendly processes in polymerization technology is crucial due to the prevalent use of volatile organic solvents (VOCs), which are harmful and toxic. Future regulations are likely to limit or ban VOCs. This review explores the use of supercritical solvents, specifically supercritical CO2 (scCO2), in polymerization processes. The study focuses on reversible addition-fragmentation chain-transfer (RAFT) induced homo-polymerization of various monomers using specific chain transfer agents (CTAs) in scCO2. RAFT polymerization, a reversible deactivation radical polymerization (RDRP) polymerization, relies heavily on the choice of CTA, which significantly influences the dispersity and molar mass of the resulting polymers. Stabilizers are also crucial in controlling product specifications for polymerizations in supercritical CO2, except for fluor-based polymers, although they must be removed and preferably recycled to ensure product purity and sustainability. The review notes that achieving high molar mass through RAFT polymerization in scCO2 is challenging due to solubility limits, which lead to polymer precipitation. Despite this, RAFT polymerization in scCO2 shows promise for sustainable, circular production of low molar mass polymers, although these cannot yet be fully considered green products.

Development of pH-responsive Hydrogel from Copolymers of Artemisia vulgaris Seed Mucilage, Mucin, and poly(methacrylate) for Controlled Delivery of Acyclovir Sodium.

To cope with the constraints of conventional drug delivery systems, site-specific drug delivery systems are the major focus of researchers. The present research developed water-swellable, pH-responsive methacrylic acid-based hydrogel scaffolds of Artemisia vulgaris seed mucilage with mucin and loaded with acyclovir sodium as a model drug. The developed hydrogel discs are evaluated for diverse parameters. Drug loading efficiency in all formulations ranges from 63% to 75%. The hydrogels exhibited pH-dependent swelling, displaying optimum swelling in a phosphate buffer (pH 7.4), and insignificant swelling in an acidic buffer (pH 1.2), in addition, they responded well to electrolyte concentrations. The sol-gel fraction is estimated ranging from 60 to 95%. Dissolution studies unveiled sustained drug release for 24 h in a phosphate buffer of pH 7.4, exhibiting zero-order release kinetics. Moreover, FTIR spectra confirmed the drug-excipient compatibility. SEM photomicrographs revealed a rough and porous surface of hydrogel discs with several pores and channels. The PXRD diffractograms exposed the amorphous nature of the polymeric blends. The findings of acute toxicity studies proved the developed hydrogel network is biocompatible. Therefore, these outcomes connote the newly created network as a smart delivery system, able to dispatch acyclovir sodium into the intestinal segment for a prolonged period.

Preparation of Water-Soluble Polyion Complex (PIC) Micelles with pH-Responsive Carboxybetaine Block.

A dual zwitterionic diblock copolymer (M100C100) consisting of poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC, M) and poly(3-((2-(methacryloyloxy)ethyl) dimethylammonio) propionate) (PCBMA, C) is synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. A double hydrophilic diblock copolymer (M100S100) consist of PMPC and anionic poly(3-sulfopropyl methacrylate potassium salt) (PMPS, S) is synthesized via RAFT. The degrees of polymerization of each block are 100. The charges of PMPC are neutralized intramolecularly. At neutral pH, the charges in PCBMA are also neutralized intramolecularly due to its carboxybetaine structure. Under acidic conditions, PCBMA exhibits polycation behavior as the pendant carboxy groups become protonated, forming cationic tertiary amine groups. PMPS shows permanent anionic nature independent of pH. Charge neutralized mixture of cationic M100C100 and anionic M100S100 in acidic aqueous solution forms water-soluble polyion complex (PIC) micelle owing to electrostatic attractive interactions. The core is composed of the cationic PCBMA and anionic PMPS blocks, with the PMPC blocks serving as shells that covered the core surface, forming spherical core-shell PIC micelles. Above pH 4 the pendant carboxy groups in PCBMA undergo deprotonation, transitioning to a zwitterionic state, thereby eliminating the cationic charge in PCBMA. Therefore, above pH 4 the PIC micelles are dissociated due to the disappearance of the charge interactions.

Photo-Deactivation Strategy for Switchable ATRP with the Assistance of Molecular Switches.

Light irradiation is an external stimulus, rapidly developed in switchable atom transfer radical polymerization (ATRP) via photo-activation methods in recent years. Herein, a photo-deactivation strategy is introduced to regulate ATRP with the assistance of photoswitchable hexaarylbiimidozole (HABI). Under visible light irradiation and in the presence of HABI, ATRP is greatly decelerated or quenched depending on the concentration of HABI. Interestingly, with visible light off, ATRP can proceed smoothly and follow a first-order kinetics. Moreover, photo-switchable ATRP alternatively with light off and on is demonstrated. Besides, the mechanism of photo-deactivation ATRP involving radical quenching is proposed in the presence of HABI.

Hydrophobic Aerogels from Vinyl Polymers Derived from Radical Polymerization: Proof-of-Concept.

Hydrophilicity is one important drawback of bio-based aerogels. To overcome this issue, a novel approach for the preparation of mesoporous, water repellent aerogels is introduced, which combines synthesis of cross-linked bio-based copolymers from methacrylate copolymerizations, followed by solvent exchange and supercritical drying steps. The influence of monomers with different nonpolar ester groups (methyl, vanillin, tetrahydrofurfuryl) on textural properties and water contact angles of the dry products is assessed. Final aerogels show generally high overall porosities (≈96%), low densities (0.07-0.11 g cm-3) as well as fine, mainly mesoporous networks, and specific surface areas in the range of 120-240 m2 g-1. Hereby, choice of the methacrylate ester groups results in differences of the resulting pore-size distributions. Water repellency tests show stable static water contact angles in the hydrophobic range (≈100°) achieved for the substrate containing the vanillin ester group. On the contrary the other substrates absorb water quickly, which indicates a decisive role of the ester group. The presented approach opens up a new pathway to bio-based aerogels with intrinsic hydrophobicity. It is suggested that the properties are tailored by the choice of the monomer structure, hence enabling further adaption and optimization of the products.

Polyhedral Vinyl Polymer Particles Synthesized Via Solvent-Free Radical Polymerization.

Liquid marbles (LMs) with a cubic shape are created by using various vinyl monomers as an inner liquid and polymer plates with mm size as a stabilizer. The relationship between the surface tension of the vinyl monomers and formability of the LMs is investigated. LMs can be fabricated using vinyl monomers with surface tensions of 42.7-40.3 mN m-1. The cubic polymer particles are successively synthesized via free-radical polymerizations by irradiation of the cubic LMs with UV light in a solvent-free manner. In addition, controlling the number of polymer plates per one LM, the shape of the plate or the coalescence of the LMs can lead to production of polymer particles with desired forms (e.g., Platonic and rectangular solids) that correspond to the shapes of the original LMs.

Block Copolymers of Polyolefins with Polyacrylates: Analyzing and Improving the Blocking Efficiencies Using MILRad/ATRP Approach.

Despite their industrial ubiquity, polyolefin-polyacrylate block copolymers are challenging to synthesize due to the distinct polymerization pathways necessary for respective blocks. This study utilizes MILRad, metal-organic insertion light-initiated radical polymerization, to synthesize polyolefin-b-poly(methyl acrylate) copolymer by combining palladium-catalyzed insertion-coordination polymerization and atom transfer radical polymerization (ATRP). Brookhart-type Pd complexes used for the living polymerization of olefins are homolytically cleaved by blue-light irradiation, generating polyolefin-based macroradicals, which are trapped with functional nitroxide derivatives forming ATRP macroinitiators. ATRP in the presence of Cu(0), that is, supplemental activators and reducing agents , is used to polymerize methyl acrylate. An increase in the functionalization efficiency of up to 71% is demonstrated in this study by modifying the light source and optimizing the radical trapping condition. Regardless of the radical trapping efficiency, essentially quantitative chain extension of polyolefin-Br macroinitiator with acrylates is consistently demonstrated, indicating successful second block formation.

Preparation of Block Copolymer Self-Assemblies via Pisa in a Non-Polar Medium Based on RCMP.

Polymerization-induced self-assembly (PISA) is conducted in a non-polar medium (n-dodecane) via reversible complexation-mediated polymerization (RCMP). Stearyl methacrylate (SMA) is used to synthesize a macroinitiator, and subsequent block polymerization of benzyl methacrylate (BzMA) from the macroinitiator in n-dodecane afforded a PSMA-PBzMA block copolymer, where PSMA is poly(stearyl methacrylate) and PBzMA is poly(benzyl methacrylate). Because PSMA is soluble but PBzMA is insoluble in n-dodecane, the block copolymer formed a self-assembly during the block polymerization (PISA). Spherical micelles, worms, and vesicles are obtained, depending on the degrees of polymerization of PSMA and PBzMA. "One-pot" PISA is also attained; namely, BzMA is directly added to the reaction mixture of the macroinitiator synthesis, and PISA is conducted in the same pot without purification of the macroinitiator. The spherical micelle and vesicle structures are also fixed using a crosslinkable monomer during PISA. RCMP-PISA is highly attractive as it is odorless and metal-free. The "one-pot" synthesis does not require the purification of the macroinitiator. RCMP-PISA can provide a practical approach to synthesize self-assemblies in non-polar media.

Quasi-Chromophores Segregated by Single-Chain Nanoparticles of Fluorinated Zwitterionic Random Copolymers Showing Remarkably Enhanced Fluorescence Emission Capable of Fluorescent Cell Imaging.

Organic and polymer fluorescent nanomaterials are a frontier research focus. Here in this work, a series of fluorinated zwitterionic random copolymers end-attached with a quasi-chromophoric group of pyrene or tetraphenylethylene (TPE) are well synthesized via atom transfer radical polymerization with activators regenerated by electron transfer (ARGET ATRP). Those random copolymers with total degree of polymerization 100 or 200 are able to produce fluorescent single-chain nanoparticles (SCNPs) through intra-chain self-folding assembly with quite uniform diameters in the range of 10-20 nm as characterized by dynamic light scattering and transmission electron microscopy. By virtue of the segregation or confinement effect, both SCNPs functionalized with pyrene or TPE group are capable of emitting fluorescence, with pyrene tethered SCNPs exhibiting stronger fluorescence emission reaching the highest quantum yield ≈20%. Moreover, such kind of fluorescent SCNPs manifest low cytotoxicity and good cell imaging performance for Hela cells. The creation of fluorescent SCNPs through covalently attached one quasi-chromophore to the end of one fluorinated zwitterionic random copolymer provides an alternative strategy for preparing polymeric luminescence nanomaterials, promisingly serving as a new type of fluorescent nanoprobes for biological imaging applications.

T790M mutation upconversion fluorescence biosensor via mild ATRP strategy and site-specific DNA cleavage of restriction endonuclease.

A unique combination of a specific nucleic acid restriction endonuclease (REase) and atom transfer radical polymerization (ATRP) signal amplification strategy was employed for the detection of T790M mutations prevalent in the adjuvant diagnosis of lung cancer. REase selectively recognizes and cleaves T790M mutation sites on double-stranded DNA formed by hybridization of a capture sequence and a target sequence. At the same time, the ATRP strategy resulted in the massive aggregation of upconverted nanoparticles (UCNPs), which significantly improved the sensitivity of the biosensor. In addition, the UCNPs have excellent optical properties and can eliminate the interference of autofluorescence in the samples, thus further improving the detection sensitivity. The proposed upconversion fluorescent biosensor is characterized by high specificity, high sensitivity, mild reaction conditions, fast response time, and a detection limit as low as 0.14 fM. The performance of the proposed biosensor is comparable to that of clinical PCR methods when applied to clinical samples. This work presents a new perspective for assisted diagnosis in the pre-intervention stage of tumor diagnostics in the early stage of precision oncology treatments.

Selective adsorption and identification of penicillin G sodium in milk by molecularly imprinted polymer doped carbon dot.

A carbon dot (CD) was prepared by o-phenylenediamine and water, which showed bright yellow fluorescence under ultraviolet light irradiation (λ = 580 nm), and verified good fluorescence quenching effect on penicillin G sodium (Png-Na). Using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and Png-Na as a template, a kind of composite microsphere combining CD and molecularly imprinted polymer (MIP) was synthesized by surface-initiated atomic transfer radical polymerization (SI-ATRP). For reasons of comparison, we also prepared MIP without CD and non-imprinted polymers (NIPs). Through static and dynamic adsorption experiments, the maximum adsorption capacity was 47.05 mg g-1 and the equilibrium time was 30 min. High-performance liquid chromatography (HPLC) was utilized to determine the content of Png-Na in the spiked milk samples. A sensitive, rapid, and simple method for determination of Png-Na in food samples was developed. The utilized approach enabled the quantification of Png-Na within the concentration range 20-1000 µg L-1 (with a limit of detection of 5 µg L-1). The recoveries achieved were in the range 93.3-98.2%, with a relative standard deviation of 1.2-4.2%. The results demonstrated that CD@MIP possessed the capability of specific adsorption and fluorescence detection of Png-Na, enabling simultaneous detection and enrichment of Png-Na in real samples.

The Triumph of the Spin Chemistry of Fullerene C60 in the Light of Its Free Radical Copolymerization with Vinyl Monomers.

The spin theory of fullerenes is taken as a basis concept to virtually exhibit a peculiar role of C60 fullerene in the free radical polymerization of vinyl monomers. Virtual reaction solutions are filled with the initial ingredients (monomers, free radicals, and C60 fullerene) as well as with the final products of a set of elementary reactions, which occurred in the course of the polymerization. The above objects, converted to the rank of digital twins, are considered simultaneously under the same conditions and at the same level of the theory. In terms of the polymerization passports of the reaction solutions, a complete virtual picture of the processes considered is presented.

4-Vinyl Guaiacol: A Key Intermediate for Biobased Polymers.

In order to contribute to the shift from petro-based chemistry to biobased chemistry, necessary to minimize the environmental impacts of the chemical industry, 2-methoxy-4-vinylphenol (4-vinyl guaiacol, 4VG) was used to synthesize a platform of biobased monomers. Thus, nine biobased monomers were successfully prepared. The synthesis procedures were investigated through the green metrics calculations in order to quantify the sustainability of our approaches. Their radical homopolymerization in toluene solution initiated by 2,2'-azobis(2-methylpropionitrile) (AIBN) was studied and the effect of residual 4VG as a radical inhibitor on the kinetics of polymerization was also explored. The new homopolymers were characterized by proton nuclear magnetic resonance (1H-NMR) spectroscopy, size exclusion chromatography and thermal analyses (dynamical scanning calorimetry DSC, thermal gravimetric analysis TGA). By varying the length of the alkyl ester or ether group of the 4VG derivatives, homopolymers with Tg ranging from 117 °C down to 5 °C were obtained. These new biobased monomers could be implemented in radical copolymerization as substitutes to petro-based monomers to decrease the carbon footprint of the resulting copolymers for various applications.

A Versatile Approach for the Synthesis of Antimicrobial Polymer Brushes on Natural Rubber/Graphene Oxide Composite Films via Surface-Initiated Atom-Transfer Radical Polymerization.

A simple strategy was adopted for the preparation of an antimicrobial natural rubber/graphene oxide (NR/GO) composite film modified through the use of zwitterionic polymer brushes. An NR/GO composite film with antibacterial properties was prepared using a water-based solution-casting method. The composited GO was dispersed uniformly in the NR matrix and compensated for mechanical loss in the process of modification. Based on the high bromination activity of α-H in the structure of cis-polyisoprene, the composite films were brominated on the surface through the use of N-bromosuccinimide (NBS) under the irradiation of a 40 W tungsten lamp. Polymerization was carried out on the brominated films using sulfobetaine methacrylate (SBMA) as a monomer via surface-initiated atom transfer radical polymerization (SI-ATRP). The NR/GO composite films modified using polymer brushes (PSBMAs) exhibited 99.99% antimicrobial activity for resistance to Escherichia coli and Staphylococcus aureus. A novel polymer modification strategy for NR composite materials was established effectively, and the enhanced antimicrobial properties expand the application prospects in the medical field.

Tailored Fluorosurfactants through Controlled/Living Radical Polymerization for Highly Stable Microfluidic Droplet Generation.

Droplet-based microfluidics represents a disruptive technology in the field of chemistry and biology through the generation and manipulation of sub-microlitre droplets. To avoid droplet coalescence, fluoropolymer-based surfactants are commonly used to reduce the interfacial tension between two immiscible phases to stabilize droplet interfaces. However, the conventional preparation of fluorosurfactants involves multiple steps of conjugation reactions between fluorinated and hydrophilic segments to form multiple-block copolymers. In addition, synthesis of customized surfactants with tailored properties is challenging due to the complex synthesis process. Here, we report a highly efficient synthetic method that utilizes living radical polymerization (LRP) to produce fluorosurfactants with tailored functionalities. Compared to the commercialized surfactant, our surfactants outperform in thermal cycling for polymerase chain reaction (PCR) testing, and exhibit exceptional biocompatibility for cell and yeast culturing in a double-emulsion system. This breakthrough synthetic approach has the potential to revolutionize the field of droplet-based microfluidics by enabling the development of novel designs that generate droplets with superior stability and functionality for a wide range of applications.

One-Pot Reversible Complexation-Mediated Polymerization (RCMP) from Benzylic Alcohols for Facile Access to Polymer-Grafted Lignin.

One-pot synthesis of methacrylic and acrylic polymers from benzylic alcohols (R-OH) used as initiating moieties was developed. R-OH was converted to alkyl iodide (R-I), and the generated R-I was used as an initiator without purification or isolation in the subsequent reversible complexation mediated polymerization (RCMP), leading to one-pot RCMP from R-OH. As a useful application, this technique was exploited for one-pot polymer-grafting from lignin that is the second most abundant renewable carbon-source on earth and bears benzylic alcohols. The direct initiation from lignin eliminates tedious initiator attachment and purification, offering a facile access to polymer-grafted lignin. The obtained polymer-grafted lignin was utilized to form an efficient UV-absorbing film with high transparency in visible region. One-pot RCMP may serve as a practical method to obtain value-added functional lignin-polymer composites.