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A comparative study of the copolymerization of racemic propylene oxide (PO) with CO2 catalyzed by racemic (salcy)CoX (salcy = N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-diaminocyclohexane; X = perfluorobenzoate (OBzF5) or 2,4-dinitrophenoxy (DNP)) in the presence of a [PPN]Cl ([PPN] = bis(triphenylphosphine)iminium) cocatalyst is performed in bulk at 21 °C and a 2.5 MPa pressure of CO2. The increase in the nucleophilicity of an attacking anion results in the increase in the copolymerization rate. Racemic (salcy)CoX provides a high selectivity of the copolymerization, which can be higher than 99%, and the living polymerization mechanism. Poly(propylene carbonate) (PPC) with bimodal molecular weight distribution (MWD) is formed throughout copolymerization. Both modes are living and are characterized by low dispersity, while their contribution to MWD depends on the nature of the attacking anion. The racemic (salcy)CoDNP/[PPN]DNP system is found to be preferable for the production of PPC with a high yield and selectivity. [ABSTRACT FROM AUTHOR]

Biosensors stand at the forefront of innovation in critical fields such as medicine, food safety, and environmental monitoring, offering precise detection of specific biomarkers. Among these, polymer-based biosensors have emerged as powerful tools, evolving from inert materials to intricately tailored structures capable of precise molecular binding. Electrospinning, a prominent fabrication method, offers a cost-effective approach for developing diagnostic kits, pushing the boundaries of biosensors with exceptionally low analyte detection limits. However, the reliance on commercial polymers restricts the versatility of electrospun nanofibers due to the fixed properties and limited functionalization options of off-the-shelf materials. These constraints prevent the tailoring of nanofibers to meet specific or diverse needs, as their molecular structure and surface functionalities are not easily adjustable. A promising solution is integrating Controlled Radical Polymerization (CRP) with electrospinning. CRP provides precise control over polymer properties, enabling the creation of nanofibers with customized functionalities for various applications. This approach combines the benefits of electrospinning, such as high surface area-to-volume ratios, with the advanced capabilities of CRP to enhance the selectivity and sensitivity of biosensors. This review represents recent advancements in biosensors, covering acquisition, characterization, and applications, with a focal point on the role of functional polymers. Exploring biosensor architecture, electrospinning principles, controlled polymer synthesis, CRP techniques, and polymer topologies, the manuscript also discusses challenges and future prospects, including microfluidic integration, multi-detection capabilities, machine learning, and the development of wearable biosensors. [ABSTRACT FROM AUTHOR]

The nanocomposites of ferroferric oxide (Fe3O4) with polyhydroxyurethane (PHU) were fabricated via a physical mixing approach. This process involved grafting poly(N‐vinyl pyrrolidone) (PVPy) chains onto the surfaces of Fe3O4 nanoparticles via surface‐initiated living radical polymerization. The PVPy‐grafted Fe3O4 nanoparticles were directly incorporated into the precursors of PHUs [i.e., bis(cyclic carbonate) and a trifunctional amine] and the mixtures were cured at high temperatures to form organic–inorganic composites. This method ensured that Fe3O4 nanoparticles were finely dispersed within the PHU matrix through the strong intermolecular hydrogen bonding between PVPy and PHU. Compared to plain PHU network, the nanocomposites had enhanced thermomechanical properties, including higher glass transition temperatures (Tg's) and improved tensile mechanical properties. The inclusion of Fe3O4 nanoparticles also enhanced the shape memory properties of the PHU networks, improving shape recovery rates, fixity of transient shapes, and recovery of the original shapes. In addition, the nanocomposites demonstrated paramagnetic and photothermal properties and the photothermal behavior enabled a non‐contact control of shape recovery. Highlights: Poly(N‐vinyl pyrrolidone)‐grafted Fe3O4 nanoparticles were synthesized.Nanocomposites of PHU with Fe3O4 were prepared via a physical blending approach.Incorporation of Fe3O4 resulted in improved thermomechanical properties.The nanocomposites had the photothermal properties. [ABSTRACT FROM AUTHOR]

Polymer materials suffer mechano-oxidative deterioration or degradation in the presence of molecular oxygen and mechanical forces. In contrast, aerobic biological activities combined with mechanical stimulus promote tissue regeneration and repair in various organs. A synthetic approach in which molecular oxygen and mechanical energy synergistically initiate polymerization will afford similar robustness in polymeric materials. Herein, aerobic mechanochemical reversible-deactivation radical polymerization was developed by the design of an organic mechano-labile initiator which converts oxygen into activators in response to ball milling, enabling the reaction to proceed in the air with low-energy input, operative simplicity, and the avoidance of potentially harmful organic solvents. In addition, this approach not only complements the existing methods to access well-defined polymers but also has been successfully employed for the controlled polymerization of (meth)acrylates, styrenic monomers and solid acrylamides as well as the synthesis of polymer/perovskite hybrids without solvent at room temperature which are inaccessible by other means. Polymer materials suffer mechano-oxidative deterioration or degradation in the presence of molecular oxygen and mechanical forces. Here the authors demonstrate a synthetic approach in which molecular oxygen and mechanical energy synergistically initiate polymerization and affords robustness in polymeric materials. [ABSTRACT FROM AUTHOR]

Topological growth control allows to produce a narrow distribution of outgrown colloidal rods with defined and adjustable length. We use an external magnetic field to assemble paramagnetic colloidal spheres into colloidal rods of a chosen length. The rods reside above a metamorphic hexagonal magnetic pattern. The periodic repetition of specific loops of the orientation of an applied external field renders paramagnetic colloidal particles and their assemblies into active bipeds that walk on the pattern. The metamorphic patterns allow the robust and controlled polymerization of single colloids to bipeds of a desired length. The colloids are exposed to this fixed external control loop that causes multiple simultaneous responses: Small bipeds and single colloidal particles interpret the external magnetic loop as an order to walk toward the active zone, where they assemble and polymerize. Outgrown bipeds interpret the same loop as an order to walk away from the active zone. The topological transition occurs solely for the growing biped and nothing is changed in the environment nor in the magnetic control loop. As in many biological systems the decision of a biped that reached its outgrown length to walk away from the reaction site is made internally, not externally. Topological growth control can produce colloidal rods with specific, adjustable lengths. Using an external magnetic field and metamorphic patterns, authors assemble paramagnetic colloidal spheres into walking bipeds, whose length determines their movement towards or away from an active zone. [ABSTRACT FROM AUTHOR]

Atom transfer radical polymerization (ATRP) with dual photoredox/copper catalysis combines the advantages of photo-ATRP and photoredox-mediated ATRP, utilizing visible light and ensuring broad monomer scope and solvent compatibility while minimizing side reactions. Despite its popularity, challenges include high photocatalyst (PC) loadings (10 to 1000 ppm), requiring additional purification and increasing costs. In this study, we discover a PC that functions at the sub-ppm level for ATRP through mechanism-driven PC design. Through studying polymerization mechanisms, we find that the efficient polymerizations are driven by PCs whose ground state oxidation potential—responsible for PC regeneration—play a more important role than their excited state reducing power, responsible for initiation. This is verified by screening PCs with varying redox potentials and triplet excited state generation capabilities. Based on these findings, we identify a highly efficient PC, 4DCDP-IPN, featuring moderate excited state reducing power and a maximized ground state oxidation potential. Employing this PC at 50 ppb, we synthesize poly(methyl methacrylate) with high conversion, narrow molecular weight distribution, and high chain-end fidelity. This system exhibits oxygen tolerance and supports large-scale reactions under ambient conditions. Our findings, driven by the systematic PC design, offer meaningful insights for controlled radical polymerizations and metallaphotoredox-mediated syntheses beyond ATRP. Atom transfer radical polymerization with dual photoredox/copper catalysis often requires high photocatalyst loadings. Herein the authors report a photocatalyst that functions at the sub-ppm level for controlled radical polymerizations, focusing on a design strategy aimed at photocatalyst regeneration. [ABSTRACT FROM AUTHOR]

Functional polymers play an important role in various biomedical applications. From many choices, poly(2-isopropenyl-2-oxazoline) (PIPOx) represents a promising reactive polymer with great potential in various biomedical applications. PIPOx, with pendant reactive 2-oxazoline groups, can be readily prepared in a controllable manner via several controlled/living polymerization methods, such as living anionic polymerization, atom transfer radical polymerization (ATRP), reversible addition–fragmentation transfer (RAFT) or rare earth metal-mediated group transfer polymerization. The reactivity of pendant 2-oxazoline allows selective reactions with thiol and carboxylic group-containing compounds without the presence of any catalyst. Moreover, PIPOx has been demonstrated to be a non-cytotoxic polymer with immunomodulative properties. Post-polymerization functionalization of PIPOx has been used for the preparation of thermosensitive or cationic polymers, drug conjugates, hydrogels, brush-like materials, and polymer coatings available for drug and gene delivery, tissue engineering, blood-like materials, antimicrobial materials, and many others. This mini-review covers new achievements in PIPOx synthesis, reactivity, and use in biomedical applications. [ABSTRACT FROM AUTHOR]

The recovery process in bipolar disorder is a subjective and multidimensional experience that seeks to develop new meanings and purposes for living a satisfying life despite the limitations imposed by the disorder. Thus, this qualitative study aimed to explore the perceptions of recovery and the meanings attributed by individuals undergoing treatment for bipolar disorder to the elements considered relevant in this process. Semi-structured interviews with open-ended questions were conducted to explore the experiences and perspectives of recovery in individuals undergoing treatment for bipolar disorder. Grounded Theory was used as the method for qualitative analysis. The study included 26 participants aged between 18 and 65 years. Based on the analysis of participant reports, we identified two main themes: living with the illness and what it means to be in recovery. The perception of recovery is an individual process and can differ from the medical model. Participants suggest that accepting the diagnosis of bipolar disorder and finding meaning in life are essential to their recovery. They also describe how mental health professionals can facilitate or hinder this process. Understanding patients' perceptions can facilitate access to healthcare services and treatment adherence. [ABSTRACT FROM AUTHOR]

In the forefront of advanced materials, ultra-high molecular weight (UHMW) polymers, renowned for their outstanding mechanical properties, have found extensive applications across various domains. However, their production has encountered a significant challenge: the attainment of UHMW polymers with a low dispersity (Ɖ). Herein, we introduce the pioneering technique of ultrasound (US) initiated polymerization, which has garnered attention for its capability to successfully polymerize a multitude of monomers. This study showcases the synthesis of UHMW polymers with a comparatively low Ɖ (≤ 1.1) within a remarkably short duration (~ 15 min) through the amalgamation of emulsion polymerization and high-frequency ultrasound-initiated polymerization. Particularly noteworthy is the successful copolymerization of diverse monomers, surpassing the molecular weight and further narrowing the Ɖ compared to their respective homopolymers. Notably, this includes monomers like vinyl acetate, traditionally deemed unsuitable for controlled polymerization. The consistent production and uniform dispersion of radicals during ultrasonication have been identified as key factors facilitating the swift fabrication of UHMW polymers with exceptionally low Ɖ. Ultra-high molecular weight (UHMW) polymers exhibit exceptional mechanical properties and have found extensive applications, however, it remains challenging to produce them with a low dispersity. Here, the authors develop ultrasound-initiated copolymerization of diverse monomers, generating UHMW polymers with low dispersity within 15 min. [ABSTRACT FROM AUTHOR]

I nnovative strides in polymer synthesis have led to the successful living anionic polymerization of styrene-olefin triblock copolymers, yielding varying molecular weights and a remarkably narrow dispersity (Đ) in cyclohexane solvent at 45°C, initiated by n-butyllithium. The novel approach employs anionic polymerization, augmented by the aid of a coupling agent known as 1,12-dibromododecane. Unlike traditional alcohol-based methods employed in polystyrene synthesis, this coupling agent, introduced at the end of the reaction, grafts two living macro-styrene chains with the dodecane chain, effectively acting as the pivotal second component in the formation of the triblock copolymer. Extensive experimentation pinpointed 45°C as the optimal temperature for anionic copolymerization in cyclohexane solvent. The comprehensive analysis, encompassing 13C NMR, ¹H NMR, FTIR spectroscopy, and GPC, confirms the successful synthesis of styrene-dodecane-styrene triblock copolymer. The NMR results illustrate successful molecular structures, while GPC attests to the precision, showing a narrow Đ of below 1.2. This pioneering approach not only underscores the efficiency of anionic polymerization in the synthesis of styreneolefin-styrene triblock copolymer using termination strategy but also promises extensive implications in material science and industrial applications. [ABSTRACT FROM AUTHOR]

This comprehensive review provides a detailed examination of controlled polymerization in the development of nanogels‐based microfluidic devices. Here, we have explored the integration of atom transfer radical polymerization (ATRP) and reversible addition‐fragmentation chain transfer (RAFT) techniques within microfluidic platforms for the synthesis of nanogels. The synergistic combination of ATRP and RAFT with microfluidics has emerged as a powerful tool for precise control over polymerization reactions, enabling the fabrication of well‐defined, multifunctional nanogels with tailored properties. The review begins with a thorough introduction to the principles of ATRP and RAFT, highlighting their respective advantages in controlled radical polymerization. Subsequently, it elucidates the principles of microfluidics and its profound impact on polymerization processes. The merging of these techniques enables precise control over reaction kinetics, monomer conversions, and molecular weight distributions, facilitating the synthesis of nanogels with unprecedented precision and reproducibility. Furthermore, this review delves into the chemical mechanisms underlying ATRP and RAFT reactions in microfluidic environments, emphasizing the role of various initiators, catalysts, and chain transfer agents. Special attention is given to the impact of microscale flow conditions on reaction kinetics and polymer structure. In addition, the review discusses emerging trends in the field, such as the incorporation of novel monomers and the exploration of environmentally benign reaction conditions. Highlights: The controlled polymerization is the mechanism by which we can obtain tailormade material.The nanogel synthesis must ensure the gelation to be in confined dimensions here microfluidics plays key role. [ABSTRACT FROM AUTHOR]

Fluorinated polymers are important materials in everyday life; however, most monomers of widely used fluoropolymers are gaseous, and their polymerization is difficult in an ordinary laboratory. Therefore, partially fluorinated polymers have recently been reported. As an easy-to-handle fluorine-containing monomer, α-trifluoromethylstyrene (TFMST) can be used to produce partially fluorinated polymers with trifluoromethyl groups in the main chain; however, TFMST does not homopolymerize, and there are limited reports on its copolymerization with styrene (ST). In this study, we applied the controlled radical polymerization method, which is effective for the polymerization of ST, to the copolymerization of TFMST and ST. We also showed that nitroxide-mediated polymerization is effective. The content ratio of TFMST in the TFMST–ST copolymer can be controlled between 10% and 40% by changing its monomer ratio. Additionally, the polymerization of TFMST and ST with substituents was performed to increase structural variations. The thermal stability as well as water and oil repellency of the synthesized polymers with different composition ratios and substituents were also evaluated. [ABSTRACT FROM AUTHOR]

Background: Catalysis represents a critical field that greatly contributes to human living, technology, economic growth and the environment. Compact catalysts have frequently been applied in manufacturing a range of substances and fuels, thus essentially subsidising income and good living. Catalysts offer significant ecological profits, such as catalytic transformers, fuel cell technology, chemical production and environmental cleaning in automobiles. Still, the use of catalysts is anticipated to raise due to the need to discover ecologically responsive production pathways and affordable products. Since its discovery, catalysis has played a vital role in a range of fields, from industrial production, sustainable energy strategy and environmental cleaning to the pharmaceutical industry. The discovery and use of catalysts mark a critical aspect in chemistry due to the raising need for greater output plus effectiveness in industry and cleaner production. Despite their importance, the invention of catalysts remained a challenge as it relied on trial-and-error tactics. Customarily, catalysts were developed using various tiresome, time-wasting and usually one-at-a-time techniques characterised and screened for activity and modified until no extra improvements were necessary. However, with the advancement in science and technology, catalyst discovery has been made more accessible and faster through combinatorial techniques. Combinatorial experimentation technologies in chemistry are a fast emerging field that includes the formulation and fast creation of a combination of material libraries and parallel screening for particular chemical or physical characteristics of concern in a general economical and compelling style. These techniques in heterogeneous catalysis are essential for the quick invention of catalysts and for improving the available ones. The rapid and economic invention of catalysts and optimisation of the available ones attract much industrial interest. Short conclusion: The present review uncovers catalysis development, progress, history and some applications. The latest developments and challenges associated with using high throughput experimentation techniques in synthesising, optimising, discovering and screening catalysts are discussed. A high throughput experimentation approach is potential in catalysis and is promising. [ABSTRACT FROM AUTHOR]

The term "in vivo ("in the living") chemistry" refers to chemical reactions that take place in a complex living system such as cells, tissue, body liquids, or even in an entire organism. In contrast, reactions that occur generally outside living organisms in an artificial environment (e.g., in a test tube) are referred to as in vitro. Over the past decades, significant contributions have been made in this rapidly growing field of in vivo chemistry, but it is still not fully understood, which transformations proceed efficiently without the formation of by‐products or how product formation in such complex environments can be characterized. Potential applications can be imagined that synthesize drug molecules directly within the cell or confer new cellular functions through controlled chemical transformations that will improve the understanding of living systems and develop new therapeutic strategies. The guiding principles of this contribution are twofold: 1) Which chemical reactions can be translated from the laboratory to the living system? 2) Which characterization methods are suitable for studying reactions and structure formation in complex living environments? [ABSTRACT FROM AUTHOR]

Highly resistant to reduction nitroxides open new opportunities for structural studies of biological macromolecules in their native environment inside living cells and for functional imaging of pH and thiols, enzymatic activity and redox status in living animals. 3,4-Disubstituted nitroxides of 2,2,5,5-tetraethylpyrrolidine and pyrroline series with a functional group for binding to biomolecules and a polar moiety for higher solubility in water and for more rigid attachment via additional coordination to polar sites were designed and synthesized. The EPR spectra, lipophilicities, kinetics of the reduction in ascorbate-containing systems and the decay rates in liver homogenates were measured. The EPR spectra of all 3,4-disubstituted pyrrolidine nitroxides showed additional large splitting on methylene hydrogens of the ethyl groups, while the spectra of similar pyrroline nitroxides were represented with a simple triplet with narrow lines and hyperfine structure of the nitrogen manifolds resolved in oxygen-free conditions. Both pyrrolidine and pyrroline nitroxides demonstrated low rates of reduction with ascorbate, pyrrolidines being a bit more stable than similar pyrrolines. The decay of positively charged nitroxides in the rat liver homogenate was faster than that of neutral and negatively charged radicals, with lipophilicity, rate of reduction with ascorbate and the ring type playing minor role. The EPR spectra of N,N-dimethyl-3,4-bis-(aminomethyl)-2,2,5,5-tetraethylpyrrolidine-1-oxyl showed dependence on pH with pKa = 3, ΔaN = 0.055 mT and ΔaH = 0.075 mT. [ABSTRACT FROM AUTHOR]

Cationic polymers have been identified as a promising type of antibacterial molecules, whose bioactivity can be tuned through structural modulation. Recent studies suggest that the placement of the cationic groups close to the core of the polymeric architecture rather than on appended side chains might improve both their bioactivity and selectivity for bacterial cells over mammalian cells. However, antibacterial main-chain cationic polymers are typically synthesized via polycondensations, which do not afford precise and uniform molecular design. Therefore, accessing main-chain cationic polymers with high degrees of molecular tunability hinges upon the development of controlled polymerizations tolerating cationic motifs (or cation progenitors) near the propagating species. Herein, we report the synthesis and ring-opening metathesis polymerization (ROMP) of N-methylpyridinium- fused norbornene monomers. The identification of reaction conditions leading to a well-controlled ROMP enabled structural diversification of the main-chain cationic polymers and a study of their bioactivity. This family of polyelectrolytes was found to be active against both Gram-negative (Escherichia coli) and Gram-positive (Methicillin-resistant Staphylococcus aureus) bacteria with minimal inhibitory concentrations as low as 25 μg/mL. Additionally, the molar mass of the polymers was found to impact their hemolytic activity with cationic polymers of smaller degrees of polymerization showing increased selectivity for bacteria over human red blood cells. [ABSTRACT FROM AUTHOR]

Photoinduced reversible deactivation radical polymerization (photo‐RDRP) or photoinduced controlled/living radical polymerization has emerged as a versatile and powerful technique for preparing functional and advanced polymer materials under mild conditions by harnessing light energy. While UV and visible light (λ = 400–700 nm) are extensively employed in photo‐RDRP, the utilization of near‐infrared (NIR) wavelengths (λ = 700–2500 nm) beyond the visible region remains relatively unexplored. NIR light possesses unique properties, including enhanced light penetration, reduced light scattering, and low biomolecule absorption, thereby providing opportunities for applying photo‐RDRP in the fields of manufacturing and medicine. This comprehensive review categorizes all known NIR light‐induced RDRP (NIR‐RDRP) systems into four mechanism‐based types: mediation by upconversion nanoparticles, mediation by photocatalysts, photothermal conversion, and two‐photon absorption. The distinct photoinitiation pathways associated with each mechanism are discussed. Furthermore, this review highlights the diverse applications of NIR‐RDRP reported to date, including 3D printing, polymer brush fabrication, drug delivery, nanoparticle synthesis, and hydrogel formation. By presenting these applications, the review underscores the exceptional capabilities of NIR‐RDRP and offers guidance for developing high‐performance and versatile photopolymerization systems. Exploiting the unique properties of NIR light unlocks new opportunities for synthesizing functional and advanced polymer materials. [ABSTRACT FROM AUTHOR]

The construction of polymer-based mimicry on cell surface to manipulate cell behaviors and functions offers promising prospects in the field of biotechnology and cell therapy. However, precise control of polymer grafting sites is essential to successful implementation of biomimicry and functional modulation, which has been overlooked by most current research. Herein, we report a biological site-selected, in situ controlled radical polymerization platform for living cell surface engineering. The method utilizes metabolic labeling techniques to confine the growth sites of polymers and designs a Fenton-RAFT polymerization technique with cytocompatibility. Polymers grown at different sites (glycans, proteins, lipids) have different membrane retention time and exhibit differential effects on the recognition behaviors of cellular glycans. Of particular importance is the achievement of in situ copolymerization of glycomonomers on the outermost natural glycan sites of cell membrane, building a biomimetic glycocalyx with distinct recognition properties. Constructing polymer-based mimics on the surface of cells has potential to manipulate cell behavior, but precise control of grafting sites is challenging. Here, the authors report a method for site selected radical polymerization on cell surfaces by metabolic labelling. [ABSTRACT FROM AUTHOR]

Biodegradable polymer-based therapeutics have recently become essential drug delivery biomaterials for various bioactive compounds. Biodegradable and biocompatible polymer-based biomaterials fulfill the requirements of these therapeutics because they enable to obtain polymer biomaterials with optimized blood circulation, pharmacokinetics, biodegradability, and renal excretion. Herein, we describe an adaptable polymerization platform employed for the synthesis of long-circulating, stimulus-sensitive and biodegradable biomaterials, therapeutics, or theranostics. Four chain transfer agents (CTA) were designed and successfully synthesized for the reversible addition-fragmentation chain transfer polymerization, allowing the straightforward synthesis of hydrolytically biodegradable structures of block copolymers-based biomaterials. The controlled polymerization using the CTAs enables controlling the half-life of the hydrolytic degradation of polymer precursors in a wide range from 5 h to 21 days. Moreover, the antitumor drug pirarubicin (THP) was successfully conjugated to the polymer biomaterials via a pH-sensitive hydrazone bond for in vitro and in vivo experiments. Polymer conjugates demonstrated superior antitumor efficacy compared to basic linear polymer-based conjugates. Notably, the biodegradable systems, even though those with degradation in the order of hours were selected, increased the half-life of THP in the bloodstream almost two-fold. Indeed, the presented platform design enables the main chain-end specific attachment of targeting ligands or diagnostic molecules. The adaptable polymerization platform design allows tuning of the biodegradability rate, stimuli-sensitive drug bonding, and optimized pharmacokinetics to increase the therapy outcome and system targeting, thus allowing the preparation of targeted or theranostic polymer conjugates. Biodegradable and biocompatible polymer-based biomaterials are recognized as potential future bioactive nanomedicines. To advance the development of such biomaterials, we developed polymerization platforms utilizing tailored chain transfer agents allowing the straightforward synthesis of hydrolytically degradable polymer biomaterials with tuned biodegradability from hours to several days. The platform allows for the synthesis of long-circulating, stimulus-sensitive and biodegradable biomaterial serving as drug carriers or theranostics. The therapeutic potential was validated by preparation of polymer biomaterials containing pirarubicin, anticancer drug, bound via pH sensitive bond and by showing prolonged blood circulation and increased antitumor activity while keeping the drug side effects low. This work paves the way for future development of biodegradable polymer biomaterials with advanced properties in drug delivery. [Display omitted] [ABSTRACT FROM AUTHOR]

In this present work, a new kind of sulfurized hydrodesulfurization catalyst was synthesized via the hydrothermal treatment of MoS2, NiCO3·2Ni(OH)2·4H2O, and Al2O3 precursors, followed by annealing under a H2 atmosphere, which does not require a sulfurization process compared to traditional preparation methods. The influence of the annealing temperature and the type of Al2O3 precursor on the interactions between MoS2 and Al2O3 were studied using X-ray fluorescence spectroscopy, X-ray diffraction, N2 adsorption–desorption, Raman spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results indicated an increase in the number of stacked layers of the MoS2 catalyst, accompanied by a decrease in the degree of decoration of Ni atoms onto MoS2 nanoslabs, as a result of the strengthened MoS2–Al2O3 interaction. Subsequently, the efficiency of hydrodesulfurization (HDS) was evaluated using dibenzothiophene as a representative reactant, while establishing a correlation between the structure of the catalyst and its performance. The catalysts, using pseudo-boehmite as the precursor and calcined at 500 °C, synthesized by calcining pseudo-boehmite as the precursor for Al2O3 at a temperature of 500 °C and possessing suitable metal–support interactions, exhibited a reduced number of MoS2 stacking layers and lateral dimensions, along with an optimal decoration degree of Ni atoms, thereby resulting in the highest level of HDS activity. [ABSTRACT FROM AUTHOR]

Natural materials are composed of a limited number of molecular building blocks and their exceptional properties are governed by their hierarchical structure. However, this level of precision is unattainable with current state‐of‐the‐art materials for 3D printing. Herein, new self‐assembled printable materials based on block copolymers (BCPs) enabling precise control of the nanostructure in 3D are presented. In particular, well‐defined BCPs consisting of poly(styrene) (PS) and a polymethacrylate‐based copolymer decorated with printable units are selected as suitable self‐assembled materials and synthesized using controlled radical polymerization. The synthesized library of BCPs are utilized as printable formulations for the fabrication of complex 3D microstructures using two‐photon laser printing. By fine‐tuning the BCP composition and solvent in the formulations, the fabrication of precise 3D nano‐ordered structures is demonstrated for the first time. A key point of this work is the achievement of controlled nano‐order within the entire 3D structures. Thus, imaging of the cross‐sections of the 3D printed samples is performed, enabling the visualization also from the inside. The presented versatile approach is expected to create new avenues for the precise design of functional polymer materials suitable for high‐resolution 3D printing exhibiting tailor‐made nanostructures. [ABSTRACT FROM AUTHOR]

A method for the synthesis of CDs at room temperature through separable and manipulable polymerization and carbonization process. [Display omitted] Polymerization and carbonization are believed as two basic processes for the bottom-up synthesis of carbon dots (CDs). Since these two processes usually occur simultaneously due to the high reaction temperature and fast reaction rate, it is still a challenge to separate and control these two processes. In the present work, we reported a new room temperature method, which achieved the separated and controlled polymerization and carbonization processes. The polymerization process is realized by dissolving o-phenylenediamine (OPD) in ethanol at room temperature, and finally obtained polymer dots (PDs) without any lattice with a sphere size of 29.6 nm. The carbonization process begins in a manual way by adding concentrated sulfuric acid. After carbonization, CDs (noted as CPDs in this work) with a size of 3.6 nm and a clear lattice can be obtained. Importantly, the separated polymerization and carbonization make us possible to adjust the composition or interactions of intermediate products during the synthesis process. As a prototype, we added acetic acid (AA) additives into OPD precursors during the polymerization stage. Due to the crosslink enhanced emission (CEE) effect via hydrogen bonds which are produced by the amide groups from AA reaction products with H in the –NH 3 + or aromatic ring, the resulted CPDs show improved PLQY from an initial 6.87% (without AA) to 16.47%. The current work realized the separated and controllable polymerization and carbonization processes, opening up the door for tuning the composition and interactions of intermediate products before carbonization. [ABSTRACT FROM AUTHOR]

With their distinct star architecture, star polymers show some desirable materials properties and have received extensive research interest. To date, the advancements in living anionic and controlled radical polymerization techniques have empowered the versatile synthesis of a variety of star polymers from several groups of monomers that are amenable to these polymerization techniques. Despite the fact that polyethylene is the largest produced commodity polymer worldwide, the synthesis of star polyethylenes as a unique polyethylene grade has somehow lagged due to the limited availability of powerful transition metal catalysts that can effectively facilitate 'living' ethylene polymerization for the construction of star architectures. Nevertheless, some progress had been made over the past two decades. In this review, we attempt to summarize the developments in the area, with an emphasis on synthesis strategies. [ABSTRACT FROM AUTHOR]

Polymerization in living systems has become an effective strategy to regulate cell functions and behavior. However, the requirement of high concentrations of monomers, the existence of complicated intracorporal interferences, and the demand for extra external stimulations hinder their further biological applications. Herein, a nanocompartment-confined strategy that provides a confined and secluded environment for monomer enrichment and isolation is developed to achieve high polymerization efficiency, reduce the interference from external environment, and realize broad-spectrum polymerizations in living systems. For exogenous photopolymerization, the light-mediated free-radical polymerization of sodium 4-styrenesulfonate induces a 2.7-fold increase in the reaction rate with the protection of a confined environment. For endogenous hydrogen peroxide-responsive polymerization, p‑aminodiphenylamine hydrochloride embedded in a nanocompartment not only performs a 6.4-fold higher reaction rate than that of free monomers, but also activates an effective second near-infrared photoacoustic imaging-guided photothermal immunotherapy at tumor sites. This nanocompartment-confined strategy breaks the shackles of conventional polymerization, providing a universal platform for in vivo synthesis of polymers with diverse structures and functions. Polymerizations in living systems can effectively regulate cell functions and behaviors, but their uses have been hindered by the existence of complicated intracorporal interferences, the needs of high concentration of monomers and extra stimulates. Here, the authors address these issues by developing a nanocompartment-confined strategy to achieve broad-spectrum polymerizations in living systems. [ABSTRACT FROM AUTHOR]

The cellular environment offers some unique features to carry out polymerizations under controlled conditions. Polymerization of monomers in cellular compartments and on the surface of living organisms holds much promise in the engineering of biofunctional synthetic polymers for sensing and probing cell behavior and of late has received significant interest. This effort lies at the interface of synthetic biology and polymer chemistry and can pave the way for innovative solutions to many existing challenges in healthcare, environment, energy, and the study of the "origin of life". Herein, recent advances in controlled polymerization strategies for intracellular and surface of living cells are presented with a particular emphasis on nanobiomedicines. Furthermore, polymerization strategies, cytocompatible monomer structures, compatible cell lines and microorganisms, nature of stimulus, catalysts, along with specific polymerization conditions to produce non-natural biofunctional polymers that can undergo polymerization-induced self-assembly within and onto the living cells are presented in detail. Furthermore, the review offers a window into the future of such novel emerging synthetic bionano systems in biomedical sciences. [ABSTRACT FROM AUTHOR]

Polymer micelles represent one of the most attractive drug delivery systems due to their design flexibility based on a variety of macromolecular synthetic methods. The environmentally safe chemistry in which the use or generation of hazardous materials is minimized has an increasing impact on polymer-based drug delivery nanosystems. In this work, a solvent-free green synthetic procedure was applied for the preparation of an amphiphilic diblock copolymer consisting of biodegradable hydrophobic poly(acetylene-functional carbonate) and biocompatible hydrophilic polyethylene glycol (PEG) blocks. The cyclic functional carbonate monomer 5-methyl-5-propargyloxycarbonyl-1,3-dioxane-2-one (MPC) was polymerized in bulk using methoxy PEG-5K as a macroinitiator by applying the metal-free organocatalyzed controlled ring-opening polymerization at a relatively low temperature of 60 °C. The functional amphiphilic block copolymer self-associated in aqueous media into stable micelles with an average diameter of 44 nm. The copolymer micelles were physico-chemically characterized and loaded with the plant-derived anticancer drug curcumin. Preliminary in vitro evaluations indicate that the functional copolymer micelles are non-toxic and promising candidates for further investigation as nanocarriers for biomedical applications. [ABSTRACT FROM AUTHOR]

The thermochemical method is one of the most potential ways to treat waste plastics. In order to reduce the energy consumption of pyrolysis, this study selected spent fluid catalytic cracking (FCC) catalyst as a catalyst for pyrolysis of waste plastics to explore the pyrolysis process of mixed waste plastics (polypropylene (PP)/polyethylene (PE)/polystyrene (PS)). The kinetic calculations show that there was a positive synergistic effect in the co‐pyrolysis of mixed plastics, which was beneficial to the reduction of activation energy. However, the participation of spent FCC catalysts can further reduce the pyrolysis temperature and activation energy of plastics, and increase the thermal degradation rate. Compared with non‐catalytic pyrolysis, the pyrolysis temperature corresponding to the maximum weight loss rate during catalytic pyrolysis was about 12 K earlier, the maximum degradation rate was about 41% higher, and the average activation energy decreased by about 22 kJ/mol. In order to further improve the catalytic efficiency of spent FCC catalysts, the spent FCC catalysts were modified by ball milling or ultrasonic method and then used for plastic pyrolysis. It was found that the modification effect of ball milling method was better than that of the ultrasonic method. Through thermodynamic analysis, it was found that the endothermic reaction occurred in the process of plastic pyrolysis and could not proceed spontaneously. The formed pyrolysis products reduced the disorder of a microscopic system. Combined with the experimental results of this paper, it can provide theoretical support for the catalytic pyrolysis of spent FCC catalysts for mixed waste plastics. [ABSTRACT FROM AUTHOR]

Towards intracellular engineering of living organisms, the development of new biocompatible polymerization system applicable for an intrinsically non-natural macromolecules synthesis for modulating living organism function/behavior is a key step. Herein, we find that the tyrosine residues in the cofactor-free proteins can be employed to mediate controlled radical polymerization under 405 nm light. A proton-coupled electron transfer (PCET) mechanism between the excited-state TyrOH* residue in proteins and the monomer or the chain transfer agent is confirmed. By using Tyr-containing proteins, a wide range of well-defined polymers are successfully generated. Especially, the developed photopolymerization system shows good biocompatibility, which can achieve in-situ extracellular polymerization from the surface of yeast cells for agglutination/anti-agglutination functional manipulation or intracellular polymerization inside yeast cells, respectively. Besides providing a universal aqueous photopolymerization system, this study should contribute a new way to generate various non-natural polymers in vitro or in vivo to engineer living organism functions and behaviours. Developing a biocompatible polymerization system applicable for the synthesis of intrinsically non-natural polymers is a key step towards intracellular engineering of living organism. Here the authors report tyrosine residues-mediated radical photopolymerizations for intracellular synthesis of non-natural macromolecules [ABSTRACT FROM AUTHOR]

Recently, biotin (vitamin H) has been described as a ligand for active targeting and it has been found that many cancer cells overexpress the biotin receptor. In this study a biotin‐conjugated block copolymer, biotin‐poly(2‐ethyl‐2‐oxazoline)‐block‐poly{N '‐[N‐(2‐aminoethyl)‐2‐aminoethyl]aspartamide} (biotin‐pEtOx‐b‐pASP(DEA) is synthesized by a living cationic polymerization of the pEtOx‐block followed by the nucleophilic ringopening polymerization of the pASP‐block. The biotin moiety is coupled to the pEtOx‐b‐pASP precursor by a Cu(I) mediated azide‐alkyne click chemistry and finally, the diethylamine (DEA) side chain is introduced by a polymer analogous reaction. The final polymer P1 formed polyplexes in the presence of plasmid DNA that are characterized with respect to N/P ratio, size, zeta potential, and shape compared to a control polymer P2 without biotin. In addition, HEK293 cells are transfected with these polyplexes and the number of fluorescent HEK293 cells is evaluated to assess the influence of polymer nature on the activity of the micelles. Flow cytometric analysis revealed a significantly higher uptake of the biotin‐PEtOx‐PASP(DEA)/pDNA micelle than the PEtOx‐PASP(DEA)/pDNA micelle against HEK293 cells at a low N/P ratio of 20, consistent with the transfection results whereas at higher N/P ratio no difference can be observed anymore between the two polymers. [ABSTRACT FROM AUTHOR]

Styrene-based thermoplastic elastomers (TPEs) demonstrate excellent overall performance and account for the largest industrial output. The traditional methods of preparation styrene-based thermoplastic elastomers mainly focused on anionic polymerization, and strict equipment conditions were required. In recent years, controlled/living radical polymerization (CRP) has developed rapidly, enabling the synthesis of polymers with various complex topologies while controlling their molecular weight. Herein, a series of core crosslinked star-shaped poly(styrene-b-isoprene-b-styrene)s (SISs) was synthesized for the first time via reversible addition–fragmentation chain transfer (RAFT) polymerization. Meanwhile, linear triblock SISs with a similar molecular weight were synthesized as a control. We achieved not only the controlled/living radical polymerization of isoprene but also investigated the factors influencing the star-forming process. By testing the mechanical and thermal properties and characterizing the microscopic fractional phase structure, we found that both the linear and star-shaped SISs possessed good tensile properties and a certain phase separation structure, demonstrating the characteristics of thermoplastic elastomers. [ABSTRACT FROM AUTHOR]

In this work, a commercial SBS was functionalized with the 2,2,6,6-tetramethylpiperidin-N-oxyl stable radical (TEMPO) via free-radical activation initiated with benzoyl peroxide (BPO). The obtained macroinitiator was used to graft both vinylbenzyl chloride (VBC) and styrene/VBC random copolymer chains from SBS to create g-VBC-x and g-VBC-x-co-Sty-z graft copolymers, respectively. The controlled nature of the polymerization as well as the use of a solvent allowed us to reduce the extent of the formation of the unwanted, non-grafted (co)polymer, thereby facilitating the graft copolymer's purification. The obtained graft copolymers were used to prepare films via solution casting using chloroform. The –CH2Cl functional groups of the VBC grafts were then quantitatively converted to –CH2(CH3)3N+ quaternary ammonium groups via reaction with trimethylamine directly on the films, and the films, therefore, were investigated as anion exchange membranes (AEMs) for potential application in a water electrolyzer (WE). The membranes were extensively characterized to assess their thermal, mechanical, and ex situ electrochemical properties. They generally presented ionic conductivity comparable to or higher than that of a commercial benchmark as well as higher water uptake and hydrogen permeability. Interestingly, the styrene/VBC-grafted copolymer was found to be more mechanically resistant than the corresponding graft copolymer not containing the styrene component. For this reason, the copolymer g-VBC-5-co-Sty-16-Q with the best balance of mechanical, water uptake, and electrochemical properties was selected for a single-cell test in an AEM-WE. [ABSTRACT FROM AUTHOR]

The isoselective ring-opening polymerization of rac-LA is a challenging goal. In this work, a series of potassium amidate complexes (K1–K10) were easily prepared and characterized using the 1H/13C NMR spectrum. The molecular structures of potassium complexes K2 and K10 were determined by X-ray diffraction, which showed that both were two-dimensional coordination polymers due to the adjacent π interactions of the aryl. In the presence of benzyl alcohol (BnOH), all of the potassium complexes exhibited a high catalytic activity toward the ring-opening polymerization of L-lactide and rac-LA, yielding linear polylactides capped with BnO or CH3O end groups. A significant solvent effect on the ROP of the L-LA was observed, with a superior efficiency in toluene than in THF and CH2Cl2. These complexes are iso-selective and act as active catalysts for the controlled ring-opening polymerization of rac-lactide, with a Pm from 0.54 to 0.76. This is a rare example of simple alkali metal complexes for the isoselective ROP of rac-lactide. The substituent greatly affected the monomer conversion and isoselectivities. [ABSTRACT FROM AUTHOR]

As a powerful protocol for the preparation of common polymers, such as polyolefins, polyesters, and polycarbonates, late-transition-metal-catalyzed polymerization can be carried out by controlling the reaction conditions or developing dynamic catalytic systems that use external stimuli to influence the performance of the active sites, resulting in well-defined polymeric materials. In particularly, under the latter conditions, 'one catalyst' can provide more than one kind of polymer with a controlled sequence from the monomer mixture, making full use of the prepared catalyst. In this review, tunable modes, including reaction conditions, redox, light or electrochemical properties, Lewis acids, and alkali metal cations, of late-transition-metal-complex (especially iron, cobalt, and nickel)-catalyzed polymerization were collected and thoroughly discussed. [ABSTRACT FROM AUTHOR]

Rapid RAFT polymerization can significantly improve production efficiency of PAM with designed molecular structure. This study shows that ideal Reversible Addition–Fragmentation Chain Transfer (RAFT) polymerization of acrylamide is achieved in dimethyl sulfoxide (DMSO) solution at 70 °C. The key to success is the appropriate choice of both a suitable RAFT chain transfer agent (CTA) and initiating species. It is illustrated that dodecyl trithiodimethyl propionic acid (DMPA) is a suitable trithiocarbonate RAFT CTA and is synthesized more easily than other CTAs. Compared to other RAFT processes of polymers, the reaction system shortens reaction time, enhances conversion, and bears all the characteristics of a controlled radical polymerization. The calculation result shows that high concentrations can reduce high conversions, accelerate the reaction rate, and widen molecular weight distributions slightly. This work proposes an excellent approach for rapid synthesis of PAMs with a restricted molecular weight distribution. [ABSTRACT FROM AUTHOR]

Atom transfer radical polymerization (ATRP), reversible addition/fragmentation chain transfer polymerization (RAFT), and nitroxide-mediated polymerization (NMP) are common examples of controlled polymerization processes. On the contrary, the Zn complex efficiently catalyzed random I L i -LA/ CL copolymerization; the presence of mono-lactate subunits in the copolymer clearly verified the transesterification mechanism of copolymer formation, and the Al complex was less active. An amazing variety of polymerization mechanisms enables the creation of polymers with given microstructures and comonomer sequences. [Extracted from the article]

Polyethylene-b-polypeptide copolymers are biologically interesting, but studies of their synthesis and properties are very few. This paper reports synthesis and characterization of well-defined amphiphilic polyethylene-block-poly(L-lysine) (PE-b-PLL) block copolymers by combining nickel-catalyzed living ethylene polymerization with controlled ring-opening polymerization (ROP) of ε-benzyloxycarbonyl-L-lysine-N-carboxyanhydride (Z-Lys-NCA) and sequential post-functionalization. Amphiphilic PE-b-PLL block copolymers self-assembled into spherical micelles with a hydrophobic PE core in aqueous solution. The pH and ionic responsivities of PE-b-PLL polymeric micelles were investigated by means of fluorescence spectroscopy, dynamic light scattering, UV-circular dichroism, and transmission electron microscopy. The variation of pH values led to the conformational alteration of PLL from α-helix to coil, thereby changing the micelle dimensions. [ABSTRACT FROM AUTHOR]

Aliphatic polycarbonate (APC) compounds are an important class of biodegradable materials with excellent biocompatibility, good biodegradability, and low toxicity, and the study of these compounds and their modification products aims to obtain biodegradable materials with better performance. In this context, the ring-opening polymerization (ROP) of trimethylene carbonate (TMC) from a low nucleophilic organic superbase of phosphazene (t-BuP4) as a catalyst and benzyl alcohol (BnOH) as an initiator at room temperature was carefully studied to prepare poly(trimethylene carbonate) (PTMC) which is one of the most studied APC. 1H NMR and SEC measurements clearly demonstrate the presence of a benzyloxy group at the α-terminus of the obtained PTMC homopolymers while investigation of the polymerization kinetics confirms the controlled/living nature of t-BuP4-catalyzed ROP of TMC. On the basis of this, the block copolymerization of TMC and δ-valerolactone (VL)/ε-caprolactone (CL) was successfully carried out to give PTMC-b-PCL and PTMC-b-PVL copolymers. Furthermore, PTMC with terminal functionality was also prepared with the organocatalytic ROP of TMC through functional initiators. We believe that the present ROP system is a robust, highly efficient, and practical strategy for producing excellent biocompatible and biodegradable PTMC-based materials. [ABSTRACT FROM AUTHOR]

Atom Transfer Radical Polymerization (ATRP) is an effective catalytic process leading to well-defined polymers with desired properties. This process based on reversible deactivation of propagating chains has a lower rate in comparison with conventional radical polymerization, especially in the case of obtaining polymers with high molecular weights. Thus, the increase of the rate of this process with preserving control over molecular weight distribution is a challenging task. In this work, novel catalytic systems for Activators Generated by Electron Transfer (AGET) ATRP of acrylonitrile based on copper (II) bromide complexes were proposed. It was found that Rochelle salt (potassium sodium tartrate tetrahydrate) may be used as a reducing agent for regeneration of copper-based catalysts to increase the rate of the process. The provided UV-vis spectroscopy experiments have confirmed the reducing ability of tartaric anion. It was found that the use tandem catalytic system based on two copper complexes with different ligands also increases the polymerization rate. The performed experiments allowed us to develop a catalytic system for rapidly obtaining polyacrylonitrile polymers with desired molecular weights exceeding 100 kDa. [ABSTRACT FROM AUTHOR]

Cationic photo-initiated and polymerized epoxies are characterized by good adhesion, high modulus, zero volatiles, low shrinkage and living polymerization characteristics. Radiation—cured acrylate resins are characterized by rapid initial curing with increased initial strength. The combination of radiation-cured acrylates and epoxies may present advantageous attributes. Thus, the system investigated is a hybrid epoxy/methyl acrylate and three different initiators for cationic polymerization of epoxies, the radical reaction of acrylates and the thermal initiator. When incorporating additives like opaque WS2 nanoparticles (NPs), absorption of the photo radiation takes place, which may lead to low photo activity. Curing kinetics measurements revealed that the absorbing/masking effect of WS2 was insignificant, and surprisingly, the level of curing was enhanced when the WS2 NPs were incorporated. FTIR results demonstrated that covalent bonds were formed between the inorganic fullerenes (IF-WS2) and the crosslinked matrix. Viscosity measurements showed a surprising reduction of five to ten times in the low-shear viscosity upon NPs incorporation compared to neat resins. It was concluded that the decrease of viscosity by the inorganic NPs, in addition to the enhanced level of conversion, has profound advantages for structural adhesives and 3D printing resins. To the best of our knowledge, this investigation is the first to report on a radiation-induced curing system containing opaque WS2 NPs that leads to an enhanced degree of curing and reduced shear viscosity. [ABSTRACT FROM AUTHOR]

Graft modifications of PVDF fluoropolymers have been identified as the efficient route to improve the properties and expand the applications. Taking advantage of C-F and C-Cl bonds in the repeat units, atom transfer radical polymerizations (ATRP) were widely used for graft modification. Recently, photoinduced ATRP has shown good spatial and temporal control over the polymerization process in contrast to thermal activation mode. This minireview highlights the progress in PVDF-based fluoropolymer modifications by using photoinduced Cu(II)-mediated ATRP and organocatalyzed ATRP. The challenges and opportunities are proposed with the aim at advancing the development of synthesis and applications of fluoropolymer. [ABSTRACT FROM AUTHOR]

In the current work, atom transfer radical polymerization-induced self-assembly (ATRP PISA) phase diagrams were obtained by the means of dissipative particle dynamics simulations. A fast algorithm for determining the equilibrium morphology of block copolymer aggregates was developed. Our goal was to assess how the chemical nature of ATRP affects the self-assembly of diblock copolymers in the course of PISA. We discovered that the chain growth termination via recombination played a key role in determining the ATRP PISA phase diagrams. In particular, ATRP with turned off recombination yielded a PISA phase diagram very similar to that obtained for a simple ideal living polymerization process. However, an increase in the recombination probability led to a significant change of the phase diagram: the transition between cylindrical micelles and vesicles was strongly shifted, and a dependence of the aggregate morphology on the concentration was observed. We speculate that this effect occurred due to the simultaneous action of two factors: the triblock copolymer architecture of the terminated chains and the dispersity of the solvophobic blocks. We showed that these two factors affected the phase diagram weakly if they acted separately; however, their combination, which naturally occurs during ATRP, affected the ATRP PISA phase diagram strongly. We suggest that the recombination reaction is a key factor leading to the complexity of experimental PISA phase diagrams. [ABSTRACT FROM AUTHOR]

Scientific research based on the self-assembly behavior of block copolymers (BCs) comprising charged-neutral segments has emerged as a novel strategy mainly looking for the optimization of efficiency in the generation and storage of electrical energy. The sulfonation reaction re- presents one of the most commonly employed methodologies by scientific investigations to reach the desired amphiphilic character, leading to enough ion concentration to modify and control the entire self-assembly behavior of the BCs. Recently, several works have studied and exploited these changes, inducing improvement on the mechanical properties, ionic conduction capabilities, colloidal solubility, interface activity, and stabilization of dispersed particles, among others. This review aims to present a description of recent works focused on obtaining amphiphilic block copolymers, specifically those that were synthesized by a living/controlled polymerization method and that have introduced the amphiphilic character by the sulfonation of one of the segments. Additionally, relevant works that have evidenced morphological and/or structural changes regarding the pristine BC as a result of the chemical modification are discussed. Finally, several emerging practical applications are analyzed to highlight the main drawbacks and challenges that should be addressed to overcome the development and understanding of these complex systems. [ABSTRACT FROM AUTHOR]

The equilibrium of copper-catalyzed atom transfer radical polymerization was investigated in silico with the aim of finding an explanation for the experimentally observed solvent effect. Various combinations of alkyl halide initiators and copper complexes in acetonitrile (MeCN) and dimethyl sulfoxide (DMSO) were taken into consideration. A continuum model for solvation, which does not account for the explicit interactions between the solvent and metal complex, is not adequate and does not allow the reproduction of the experimental trend. However, when the solvent molecules are included in the coordination sphere of the copper(I,II) species and the continuum description of the medium is still used, a solvent dependence of process thermodynamics emerges, in fair agreement with experimental trends. [ABSTRACT FROM AUTHOR]

Recent years have witnessed an enormous development in photoinduced systems, opening up possibilities for advancements in industry and academia in terms of green chemistry providing environmentally friendly conditions and spatiotemporal control over the reaction medium. A vast number of research have been conducted on photoinduced systems focusing on the development of new polymerization methods, although scarcely investigated, depolymerization of the synthesized polymers by photochemical means is also possible. Herein, we provide a comprehensive study of visible light induced dimanganese decacarbonyl (Mn2(CO)10) assisted depolymerization system for poly(methyl methacrylate) with chlorine chain end prepared by Atom Transfer Radical Polymerization. Contrary to the conventional procedures demanding high temperatures, the approach offers ambient temperature for the photodepolymerization process. This novel light-controlled concept is easily adaptable to macroscales and expected to promote further research in the fields matching with the environmental concerns. [ABSTRACT FROM AUTHOR]

[Display omitted] • PP-based olefin block copolymers (OBCs) with up to five alternating hard/soft blocks. • OBCs combine high strength, high elongation, and high elastic recovery. • OBCs promote PE/PP mixed recycling, transforming brittle blends into tough materials. Polyethylene (PE) and isotactic polypropylene (i PP) are two of the most widely used polymer materials, whose huge consumptions urge people to tackle their recycling problem. The incompatibility of PEs and PPs has resulted in their waste streams being recycled into low-value products with poor mechanical properties. Herein, a series of i PP-based olefin block copolymers (OBC) with up to five alternating hard/soft blocks were prepared via coordinative chain transfer polymerization. The facile synthetic strategy of multiblock OBCs not only overcame the inefficiency and diseconomy of living coordination polymerization, but also avoided the critical requirements of complex dual-catalyst systems for chain shuttling polymerization, making it suitable for low-cost and large-scale production of OBCs. These well-designed OBCs provided excellent elastomeric properties combining high strength, high elongation, and high elastic recovery. More importantly, they also demonstrated a strong ability in the upcycling of PE/PP mixtures, transforming brittle blends into tough materials. The PE/PP blends compatibilized with OBCs exhibited greatly improved interfacial adhesion and mechanical properties, with up to 25 times higher elongation at break compared to uncompatibilized blends. It was further demonstrated by the extruding-blow-molded bottles prepared using post-consumer PE/PP products, where recycled bottles containing OBCs exhibited much better mechanical properties than those without OBC. The synthetic strategy of OBCs and the upcycling route of PE/PP blends in this work are not only of great academic value, but also of substantial economic and environmental significance, providing insights into the sustainable development of plastics. [ABSTRACT FROM AUTHOR]

Electrochemically mediated atom transfer radical polymerization (eATRP) is developed in dispersion conditions to assist the preparation of cellulose-based films. Self-degassing conditions are achieved by the addition of sodium pyruvate (SP) as a ROS scavenger, while an aluminum counter electrode provides a simplified and more cost-effective electrochemical setup. Different polyacrylamides were grown on a model cellulose substrate which was previously esterified with 2-bromoisobutyrate (-BriB), serving as initiator groups. Small-scale polymerizations (15 mL) provided optimized conditions to pursue the scale-up up to 1000 mL (scale-up factor ~67). Cellulose-poly(N-isopropylacrylamide) was then chosen to prepare the tunable, thermoresponsive, solvent-free, and flexible films through a dissolution/regeneration method. The produced films were characterized by Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), dynamic scanning calorimetry (DSC), and thermogravimetric analysis (TGA). [ABSTRACT FROM AUTHOR]

In this study, we describe an atmospheric pressure plasma jet (APPJ) device made of four-bore tubing operable in inhospitable humid environments and introduce two potential applications of liquid material processing: decomposition of aqueous phosphorus compounds and solution-plasma polymerization. A four-bore tube was used as the plasma transfer conduit and two diagonal bores contained metal wires. In the proposed APPJ device, the metal wires serving as electrodes are completely enclosed inside the holes of the multi-bore glass tube. This feature allows the APPJ device to operate both safely and reliably in humid environments or even underwater. Thus, we demonstrate that the proposed electrode-embedded APPJ device can effectively decompose aqueous phosphorus compounds into their phosphate form by directly processing the solution sample. As another application of the proposed APPJ device, we also present the successful synthesis of polypyrrole nanoparticles by solution plasma polymerization in liquid pyrrole. [ABSTRACT FROM AUTHOR]

Diazoacetate polymerization has attracted considerable research attention because it is an effective approach for fabricating carbon–carbon (C–C) main chain polymers. However, diazoacetate polymerization based on inexpensive catalysts has been a long-standing challenge. Herein, we report a Ni(II) catalyst that can promote the living polymerization of various diazoacetates, yielding well-defined C–C main chain polymers, polycarbenes, with a predictable molecular weight (Mn) and low dispersity (Mw/Mn). Moreover, the Ni(II)-catalyzed sequential living polymerization of thiophene and diazoacetate monomers affords interesting π-conjugated poly(3-hexylthiophene)-block-polycarbene copolymers in high yields with a controlled Mn, variable compositions, and low Mw/Mn, although the structure and polymerization mechanism of the two monomers differ. Using this strategy, amphiphilic block copolymers comprising hydrophobic poly(3-hexylthiophene) and hydrophilic polycarbene blocks are facilely prepared, which were self-assembled into well-defined supramolecular architectures with tunable photoluminescence. Diazoacetate polymerizations using inexpensive catalysts has been a long-standing challenge to achieve. Here the authors report a Ni(II) catalyst that can promote living polymerization of various diazoacetates, yielding well-defined carbon–carbon main chain polymers, polycarbenes. [ABSTRACT FROM AUTHOR]

Mono-substituted imidazolinX-2-iminato hafnium(IV) complexes (X = iPr, tBu, Mesityl, Dipp) were synthesized and fully characterized, including solid-state X-ray diffraction analysis. When the X group is small (iPr), a dimeric structure is obtained. In all the monomeric complexes, the Hf-N bond can be regarded as a double bond with similar electronic properties. The main difference among the monomeric complexes is the cone angle of the ligand, which induces varying steric hindrances around the metal center. When the monomeric complex of mono(bis(diisopropylphenyl)imidazolin-2-iminato) hafnium tribenzyl was reacted with three equivalents (equiv) of iPrOH, the benzyl groups were easily replaced, forming the corresponding tri-isopropoxide complex. However, when BnOH was used, dimeric complexes were obtained. When five equivalents of the corresponding alcohols (BnOH, iPrOH) were reacted with the monomeric complex, different dimeric complexes were obtained. Regardless of the high oxophilicity of the hafnium complexes, all complexes were active catalysts for the ring-opening polymerization (ROP) of ε-caprolactone. Dimeric complexes 5 and 6 were found to be the most active catalysts, enabling polymerization to occur in a living, immortal fashion, as well as the copolymerization of ε-caprolactone with rac-lactide, producing block copolymer PCL-b-LAC. The introduction of imidazolin-2-iminato ligands enables the tailoring of the oxophilicity of the complexes, allowing them to be active in catalytic processes with oxygen-containing substrates. [ABSTRACT FROM AUTHOR]

The tridentate PNP ligand-supported rare-earth metal complexes, i.e., bis[o-diphenylphosphinophenyl]amido-Re-bis[o-dimethylaminobenzyl], [(Ph2P-o-C6H4)2N]Re[(CH2-o-Me2N(C6H4))2]: (Re = Y, 1; Nd, 2; Gd, 3) were applied to isoprene polymerization. When activated with borate activator ([PhMe2NH][B(C6F5)4] (NH-BARF), catalysts 1 and 3 exhibited excellent catalytic efficiency in aromatic media, produced very-high to ultrahigh molecular weight (Mw over 130 × 104 g/moL) polyisoprene rubber (PIR), and the obtained PIR contained over 98% cis-1,4 head-to-tail repeating unites. In most cases, the borate-activated polymerization reaction proceeded in a quasi-living pattern (PDI = 1.2–1.5) under controlled monomer conversion; whereas, activated with the commercially available modified methylaluminoxane (MMAO3A) in aliphatic hydrocarbon media, complexes 1, 2 and 3 all showed high catalytic efficiency, produced high molecular weight PIR with narrow molecular weight distribution (PDI ≤ 2.0) and high cis-1,4 head-to tail repeating unites in the range of 91–95%. Thus, the catalyst systems that consisted of 1, 2 and 3/MMAO3A, are closely relevant to the current industrial polybutadiene rubber (PBR) and PIR production processes. [ABSTRACT FROM AUTHOR]