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This study focuses on utilizing montmorillonite (MMT) to induce a multi-micro/nanolayer morphology in PA6/ABS blend polymers by mitigating phase retraction and coalescence. Both untreated and modified MMT were incorporated at weight contents ranging from 1 to 5 wt% to manipulate morphology through selective localization at the interface. The nanocomposites' morphology was analyzed, and the cooperative effects were correlated with their structural, thermal, rheological, and mechanical characteristics. Structural analysis revealed that intercalation resulted in the appearance of novel bands, particularly in CTAB-modified MMT, which adopted a tilted monolayer arrangement. SEM results demonstrated excellent distribution and dispersion of exfoliated modified MMT, effectively suppressing coalescence and promoting a finer multilayer morphology. Compared to nanocomposites based on unmodified MMT, the ones based on CTAB-modified MMT exhibited superior thermal stability. Furthermore, the stiffness of the blend matrix increased with clay content, and the nanocomposites stabilized with modified MMT showed enhanced strain-to-failure properties. [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]

A photoinitiating system has been developed based on a charge transfer complex (CTC) between a cationic sulfonium salt derivative synthesized from thioxanthene-9-one and heterocyclic nitrogen- and sulfur-containing donor compounds of thiazole derivatives. It has been found that the absorption bands of the formed CTCs lie in the blue region of the visible spectrum and the presence of a phenolic ring conjugated with the thiazole moiety leads to a hyperchromic effect in the absorption spectrum of the complexes. The molecular composition of 1 : 1 CTC was confirmed using the isomolar series method. The modified Benesi–Hildebrand equation was used to calculate the complexation constant (Kas (278 K) = 48.1 L/mol). the thermodynamic parameters enthalpy (ΔH = −11.5 kJ/mol), entropy (ΔS° = −9.3 J/(mol K)), and Gibbs energy (ΔG° = −8.95 kJ/mol) have been calculated by means of the van't Hoff equation. According to the negative change in enthalpy, the CTC formation reaction is an exothermic process. The formed complexes have photosensitivity in the spectral region of the charge transfer band (400–500 nm), allowing their use as sensitizers of holographic photopolymer materials for laser hologram recording at λ = 457 nm with a high diffraction efficiency of ~75%. [ABSTRACT FROM AUTHOR]

In this investigation, a novel Fe3O4-enhanced biochar derived from winter melon (Fe3O4@WBC) was synthesised by an innovative ethylene glycol reduction and thermal polymerisation approach for efficiently eliminating U(VI) from contaminated environments. The factors influencing uranium(VI) adsorption by Fe3O4@WBC, including pH, adsorbent dosage, time, temperature, and initial U(VI) concentration were explored. The material's performance was characterised, and the underlying mechanism of U(VI) removal was analysed using various techniques. The results demonstrated that Fe3O4@WBC effectively removed U(VI), achieving a maximum adsorption capacity of 199.84 mg g−1 at a pH of 5.0. These findings provided a theoretical basis for the treatment of wastewater contaminated with U(VI). [ABSTRACT FROM AUTHOR]

The path to minimal life involves a series of stages that can be understood in terms of incremental, stepwise additions of complexity ranging from simple solutions of organic compounds to systems of encapsulated polymers capable of capturing nutrients and energy to grow and reproduce. This brief review will describe the initial stages that lead to populations of protocells capable of undergoing selection and evolution. The stages incorporate knowledge of chemical and physical properties of organic compounds, self-assembly of membranous compartments, non-enzymatic polymerization of amino acids and nucleotides followed by encapsulation of polymers to produce protocell populations. The results are based on laboratory simulations related to cyclic hydrothermal conditions on the prebiotic Earth. The final portion of the review looks ahead to what remains to be discovered about this process in order to understand the evolutionary path to minimal life. [ABSTRACT FROM AUTHOR]

The kinetics of polymerization of epoxy resin ED-20 cured with a polyethylene polyamine hardener modified with silicone rubber, tris(trimethylsiloxy) phenylsilane, octamethyl cyclotetrasiloxane is studied. A more rapid decrease in the amount of epoxy groups in systems modified with silicon-contained additives during polymerization is observed. A differential equation describing the change in changes in the concentration of epoxy groups with the polymerization time is proposed. The found exact solution to the proposed equation describes adequately the experimental data. The modification of epoxy binder reduces the time and temperature of the maximum heat release during the curing. The modification with the addition of tris(trimethylsiloxy) phenylsilane leads to the maximum increase in heat release. A differential equation describing the change in the heat release temperature with the curing time is formulated. The exact solution to the equation formulated is found, which is applied to estimate the curing end time of the compositions. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the influence of different factors on the aggregation effect on hemoglobin (Hb) and enzymes during the preparation of Polyhemoglobin-Superoxide dismutase-Catalase-Carbonic anhydrase (PolyHb-SOD-CAT-CA). Several factors including temperatures, pH values, Glutaraldehyde (GDA) amounts and enzymes amounts were investigated systematically to study their effects on the enzymes recoveries and polymerization rates including the Superoxide dismutase (SOD), Catalase (CAT) and Carbonic anhydrase (CA), as well as their effects on the molecular weight distribution of PolyHb-SOD-CAT-CA. Then the oxygen affinity and methemoglobin (MetHb) contents of obtained PolyHb-SOD-CAT-CA were measured to evaluate the effects of enzyme crosslinking on the properties of Polyhemoglobin (PolyHb) moieties in the molecular structure of obtained PolyHb-SOD-CAT-CA conjugate. The results showed that the enzyme recoveries and polymerization rates could be decreased with the temperatures increasing and could be generally kept stable in the physiological pH conditions, but presented only slight changes among the investigated enzyme amounts ranges. Although the GDA concentration increasing could promote the enzyme polymerization rates, the enzyme recoveries decreased in whole. The polymerization rate and molecular size of PolyHb-SOD-CAT-CA conjugate increased with the elevation of temperature and the concentration of GDA. Lastly, the P50 values, Hill coefficients, and MetHb contents of PolyHb-SOD-CAT-CA conjugate with different enzyme crosslinking degrees exhibited no obvious differences with each other. In conclusion, the polymerization reactions between enzymes and Hb molecules could be remarkably affected by temperatures, pH values, and GDA amounts, and the enzyme crosslinking presented no obvious effects on the Hb properties, especially about the oxygen affinity and oxidation degrees. [ABSTRACT FROM AUTHOR]

A plug flow reactor was constructed to scale the synthesis of metastable, phthalaldehyde-based polymers to achieve production rates of 1–2 kg per day. The flow-induced mixing and in-line polymerization quench and precipitation sequences resulted in improved polymer purity and long-term stability compared to the same materials made from a conventional batch process. Cryogenic rheology was used to probe the complex fluid dynamics encountered during the polymerization of PPA homopolymers. It is envisioned that this continuous flow manufacturing approach could be extended to other low ceiling temperature or aldehyde monomer systems to help implement and support a plastic circular economy. [ABSTRACT FROM AUTHOR]

Conducting polymers have attracted significant interest due to their unique properties, including metal-like conductivity, ionic conductivity, optical transparency, and mechanical flexibility. Poly(3,4-ethylene-dioxythiophene):poly(styrene sulfone) (PEDOT:PSS) is commonly utilized as the hole transport layer (HTL) in optoelectronic devices. However, its high acidity, primarily attributed to the low pH of PSS, poses challenges such as counter electrode etching, detrimental interactions with the photoactive layer, and device instability. To address these issues, researchers are exploring alternative HTL materials and deposition methods. Oxidative chemical vapor deposition (oCVD) has emerged as a promising technique to fabricate high-quality PEDOT thin films without PSS, enhancing device stability. The selection of an appropriate oxidant is crucial in oCVD, as it significantly influences film properties and performance. The utilization of liquid oxidants enables direct integration of conductive polymer thin films into devices through a one-step, dry process, eliminating the need for post-deposition rinsing and ensuring compatibility with solvent-sensitive and temperature-sensitive substrates. Moreover, precise control over liquid oxidant flow rates provides advantages over solid oxidants. This prospective article provides an overview of recent advancements in engineering the texture and nanostructure of conducting polymers to boost electrical conductivity and enhance optoelectronic performance. Additionally, it provides a comprehensive overview of recent progress in oCVD method, focusing on the use of liquid oxidants. Furthermore, the prospective article underscores the significance of oCVD in the efficient fabrication of PEDOT thin films without PSS, thus playing a pivotal role in the development of stable optoelectronic devices. [ABSTRACT FROM AUTHOR]

3D printing has revolutionized the fabrication and rapid prototyping of microfluidic devices. However, it remains challenging to achieve optically transparent microfluidic chips with 3D printing, which limits their applicability in high-resolution imaging applications. We present a paradigm-shifting, low-cost, and generalizable post-processing method to address this challenge. Our method is centered around the implementation of a novel post-processing equipment "Spinning Desicurer" which integrates solvent-free resin removal, surface smoothing, and efficient surface curing. Our method produces microfluidic devices with high optical transparency and can be readily used to image microscopic objects such as cells and microparticles with fine details. [ABSTRACT FROM AUTHOR]

In this research work, a polyaniline-multiwalled carbon nanotube (MWCNT)-based gas sensor is fabricated and tested for CO2 gas at room temperature. Polyaniline-MWCNT (PCT) composites were synthesized through a chemical oxidation process using FeCl3 as an oxidant. The polymerization process was conducted at room temperature. The PCT composites were characterized using XRD, FTIR, UV spectroscopy, scanning electron microscopy (SEM), and impedance spectroscopy. The PCT 15% shows highest sensitivity at room temperature. XRD and FTIR spectroscopy confirm the formation of a PCT composite. SEM image confirmed the change in morphological structure for PCT 15% composite than pure polyaniline. Through impedance spectroscopy, it was found that all the composites show conductive properties as their phase angle is less than 90°. The response and recovery time of PCT (5%, 10%, 15%, and 20%) was found to be (148 s, 121 s), (125 s, 141 s), (110 s, 261 s), and (121 s, 63 s). [ABSTRACT FROM AUTHOR]

With the ever-growing reliance on polymeric materials for numerous applications, new avenues to induce, design and control degradation are clearly important. Here, we describe a previously unreported approach to controlling enzymatic hydrolysis of high molecular weight branched polymers formed from the new free-radical polymer synthesis strategy transfer-dominated branching radical telomerisation (TBRT). Modifying the chemical nature of TBRT polymers may be accomplished through telogen selection and multi-vinyl taxogen (MVT) design, and we show telogen-driven control of enzyme-catalysed hydrolysis and the impact of careful placement of hydrolytically susceptible groups within readily synthesised MVTs. Our results indicate that utilising conventional free-radical chemistries and unsaturated monomers as feedstocks for highly branched polymer architectures has considerable potential for the design of future materials that degrade into very low molecular weight byproducts at variable and controllable rates. With the ever-growing reliance on polymeric materials for numerous applications, new avenues to induce, design and control degradation are clearly important. Here, the authors report an approach to controlling the enzymatic hydrolysis of high molecular weight branched polymers formed from transfer-dominated branching radical telomerisation, through telogen selection and multi-vinyl taxogen design. [ABSTRACT FROM AUTHOR]

An ultrasound-assisted synthesis of a new polymer, poly[N1-({4-[3-(4-aminophenoxy)phenoxy]phenyl}carbamothioyl)-N3-thioformylisophthalamide] by a polycondensation reaction of isophthaloyl diisothiocyanate and 4,4′-(1,3-phenylenedioxy)dianiline was reported. Different techniques were utilized to prove the chemical structure of the synthesized polymer, including FTIR, 1H NMR, TGA, Brunauer–Emmett–Teller (BET), and field emission scanning electron microscopy (FESEM). The capability of the synthesized polymer to adsorb Ni(II) ions from an aqueous solution was analytically evaluated. The change of several parameters including contact time, Ni(II) ions concentration, pH, and temperature on the adsorption process onto the target polymer was extensively investigated. The results indicated that the optimal adsorption pH was about 7 with the removal efficiency of 78.379% and the adsorbed amount of Ni(II) ions increased when the temperature was increased. The adsorption isotherms analysis revealed that the Langmuir model was the most relevant to describe the adsorption process compared with the Freundlich model. The study of adsorption kinetics showed that the adsorption model of Ni(II) ions onto the surface polymer being significantly correlated with pseudo-second-order model. Based on the thermodynamic studies, the calculated ΔG was negative, ΔH was endothermic, and ΔS was positive, verifying that the adsorption process is spontaneous. [ABSTRACT FROM AUTHOR]

In this work, with the aim of increasing the monomer conversion rate in the styrene-graphite in situ polymerization system, graphite modification methods have been investigated. Modification of the graphite in the presence of nitric acid, sodium hydroxide or sodium dodecyl benzene sulfate (SDBS) was investigated with five different methods in order to reduce its adverse effects on the polymerization rate of styrene. The most effective modification approach was determined using quantitative data such as polymerization conversion and graphite dispersion in organic phase. Compared to other modified samples and unmodified graphite, graphite modified in sodium hydroxide solution with SDBS showed the most compatibility with the polymerization system and caused a significant increase in the monomer conversion rate. Monomer conversion increases by 22% and 29% respectively in the presence of 0.5% and 2% of the best modified graphite compared to non-modified graphite. Also, the results showed that this modification method stabilizes the suspension of graphite particles in styrene for a longer period of time than other methods. [ABSTRACT FROM AUTHOR]

Stable and inexpensive catalysts are particularly important in the catalysis industry. This study investigated cheap stable Ce2O3 and CeO2 as catalysts for the ring-opening polymerization of rac-lactide (rac-LA) and ε-caprolactone (ε-CL). Both Ce2O3 and CeO2 effectively catalyzed the polymerization of lactones. The catalytic efficiency of Ce2O3 was significantly higher than that of CeO2. The catalytic polymerization process was carried out under controlled conditions, and narrow molecular-weight distributions of polylactide and polycaprolactone were obtained. A kinetic study of the catalytic polymerization of rac-LA showed that the polymerization conformed to first-order kinetics and was controllable. [ABSTRACT FROM AUTHOR]

Context: This work introduces a method for generating generalized structures of amorphous polymers using simulated polymerization and molecular dynamics equilibration, with a particular focus on amorphous polymers. The techniques and algorithms used in this method are described in the main text, and example input scripts are provided for the GMXPolymer code, which is based on the GROMACS molecular dynamics package. To demonstrate the efficacy of our method, we apply it to different glassy polymers exhibiting varying degrees of functionality, polarity, and rigidity. The reliability of the method is validated by comparing simulation results with experimental data in various structural and thermal properties, both of which show excellent agreement. Methods: This work implements the GMXPolymer simulated polymerization algorithm on the GROMACS program. GMXPolymer code controls the main polymerization loop. The energy minimizations and molecular dynamics simulations use the GROMACS program called by the GMXPolymer code. A new ITP file is generated when a new bond is formed, and the necessary additions to the ITP file are made to include new bonds, angles, and dihedrals. In preparing the ITP file of the monomer, the charge of the reactive atom must be modified before the code runs so that it is a correct value after bonding. [ABSTRACT FROM AUTHOR]

New psychoactive substances, including 2-aminoindane, pose significant health risks due to their availability and structural similarity to amphetamines. Current detection methods are limited by lengthy analysis times and complex sample preparation. To address this, we present the first voltammetric determination of 2-aminoindane in oral fluid using a graphite electrode modified with a methoxyphenylthiophene-based layer. The electrochemically deposited layer was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and both infrared and Raman spectroscopies. After the electropolymerization of methoxyphenylthiophene, the electrode was homogeneously covered with shorter oligomers of the substituted polythiophene. Cyclic and square-wave voltammetry were used to gain insight into the interaction between the modified electrode and 2-aminoindane. The modification of the electrode surface enables to record the oxidation of the primary amino group at 0.85 V, with an additional signal assigned to specific interactions being observed at 1.33 V. Determination of a 1.0 × 10–4 M 2-aminoindane concentration in oral fluids was possible, with a recovery ranging from 98 to 100%. [ABSTRACT FROM AUTHOR]

Decatungstate ((nBu4N)4W10O32, marked as DTs) and PMo12-nVn could be easily synthesized via polymerization in acidic aqueous solution. They can efficiently catalyze the oxidation of cyclohexane to afford cyclohexanone and cyclohexanol under visible light, affording about 30% conversion in the presence of additive HCl. This is the first example to show the influence of HCl on oxidizing capacity for DTs and PMo12-nVn. It was found that PMo12-nVn could induce the generation of chlorine radical in the presence of HCl, playing a significant role to realize the oxidation of cyclohexane. [ABSTRACT FROM AUTHOR]

Decatungstate ((nBu4N)4W10O32, marked as DTs) and PMo12-nVn could be easily synthesized via polymerization in acidic aqueous solution. They can efficiently catalyze the oxidation of cyclohexane to afford cyclohexanone and cyclohexanol under visible light, affording about 30% conversion in the presence of additive HCl. This is the first example to show the influence of HCl on oxidizing capacity for DTs and PMo12-nVn. It was found that PMo12-nVn could induce the generation of chlorine radical in the presence of HCl, playing a significant role to realize the oxidation of cyclohexane. [ABSTRACT FROM AUTHOR]

The fundamental question of how forces are generated in a motile cell, a lamellipodium, and a comet tail is the subject of this note. It is now well established that cellular motility results from the polymerization of actin, the most abundant protein in eukaryotic cells, into an interconnected set of filaments. We portray this process in a continuum mechanics framework, claiming that polymerization promotes a mechanical swelling in a narrow zone around the nucleation loci, which ultimately results in cellular or bacterial motility. To this aim, a new paradigm in continuum multi-physics has been designed, departing from the well-known theory of Larché–Cahn chemo-transport-mechanics. In this note, we set up the theory of network growth and compare the outcomes of numerical simulations with experimental evidence. [ABSTRACT FROM AUTHOR]

Grouting engineering is extensively employed in highway maintenance, tunnel excavation, mining, and other domains. As application scenarios become more complex, the demands for injectivity and toughness of grouting materials escalate. This research presents the fabrication of a dual-network cementitious material through acrylamide (AM) monomers in-situ polymerization and ultra-fine portland cement for grouting. The in-situ polymerization of AM increases the fluidity of cement paste, forms a hydrogel three-dimensional network structure, and significantly reduces the initial setting time from 345 to 35 min at a 5% AM content. The early-stage compressive strength (0–7 days) is inhibited by the in-situ polymerization, the flexural strength is notably increased, with an overall toughness improvement of 174.4% at a 7% AM content. The in-situ polymerization influences the early hydration behavior of ultra-fine portland cement by delaying the hydration induction period and affecting calcium hydroxide content and the bound water in calcium silicate hydrate. The complexation between metal ions (Ca2+, Al3+) in ultra-fine portland cement and carboxyl groups in the polymer enhances organic–inorganic interaction. The three-dimensional network structure of the cement hydration products and the polymer will form a dual-network structure, further enhancing the performance of the ultra-fine portland cement. In this research, the potential application of AM in-situ polymerization in the enhancement of ultra-fine portland cement grouting is proposed. [ABSTRACT FROM AUTHOR]

Purpose: The main aim of the present study was to carry out a scoping review on the differences in degree of conversion of monomers regarding several types resin cements, indirect restorative materials, and light-curing procedures used in dentistry. Method: A bibliographic review was performed on PubMed using the following search items: “degree of conversion” OR “filler” AND “resin cement” OR “inorganic cement” AND “organic” OR “radiopacity” OR “refractive” OR “transmittance” OR “type” AND “resin composite.” The search involved articles published in English language within the last thirteen years. A research question has been formulated following the PICO approach as follow: “How different is the degree of conversion of monomers comparing several types of resin-matrix cements?”. Results: Within the 15 selected studies, 8 studies reported a high degree of conversion (DC) of the organic matrix ranging from 70 up to 90% while 7 studies showed lower DC values. Dual-cured resin-matrix cements revealed the highest mean values of DC, flexural strength, and hardness when compared with light- and self-polymerized ones. DC mean values of resin-matrix cements light-cured through a ceramic veneer with 0.4 mm thickness were higher (~ 83%) than those recorded for resin-matrix cements light-cured through a thicker ceramic layer of 1.5 mm (~ 77%). Conclusions: The highest percentage of degree of conversion of monomers was reported for dual-cured resin-matrix cements and therefore both chemical and light-induced pathways promoted an enhanced polymerization of the material. Similar degree of conversion of the same resin-matrix cement were recorded when the prosthetic structure showed a low thickness. On thick prosthetic structures, translucent materials are required to allow the light transmission achieving the resin-matrix cement. Clinical relevance: The chemical composition of resin-matrix cements and the light-curing mode can affect the polymerization of the organic matrix. Thus, physical properties of the materials can vary leading to early clinical failures at restorative interfaces. Thus, the analysis of the polymerization pathways of resin-matrix cements is significantly beneficial for the clinical performance of the restorative interfaces. [ABSTRACT FROM AUTHOR]

In this study, poly(ɛ-caprolactone-g-2-hydroxy ethyl methacrylate) [P(CL-g-HEMA)] graft copolymer hydrogels were successfully synthesized through multi-step reactions. For this purpose, firstly, hydroxyl-terminated poly(ɛ-caprolactone) (PCL-OH) was obtained by ring-opening polymerization (ROP) method of ɛ-caprolactone using 3-chlor-1,2-propanediol initiator, which is suitable for ring-opening polymerization method. Then, from the reaction of synthesized PCL-OH and 3-bromopropionyl chloride, a new brominated poly(ɛ-caprolactone) (PCL-Br) was synthesized for use as a functionalized atom transfer radical polymerization (ATRP) initiator. Poly(ɛ-caprolactone-g-2-hydroxy ethyl methacrylate) [P(CL-g-HEMA)] graft copolymer hydrogels were synthesized by "grafting from" atom transfer radical polymerization (ATRP) of 2-hydroxy ethyl methacrylate (HEMA) presence the new synthesized functionalized ATRP initiator (PCL-Br) and hydrogel properties were investigated. The synthesized functionalized initiators and graft copolymer hydrogel were characterized by spectroscopic methods such as 1H-NMR, FT-IR, TGA, DSC and SEM. The observation of two different decomposition temperatures, respectively, from the TGA analysis results may support the formation of the biblock graft copolymer. A glass transition temperature (Tg) of the graft copolymer hydrogel was found by DSC, and this value is between the Tg values of the homopolymers forming the graft copolymer hydrogel. Water swelling values of graft copolymer hydrogels were measured and calculated every 24 h in pure water with pH = 7 at from + 4 to 65 °C. Considering the weight of dry graft copolymer hydrogels, it was seen that water was absorbed at most at + 4 °C. As the temperature increased, the water absorption or swelling of the hydrogel decreased. [ABSTRACT FROM AUTHOR]

Designing and synthesizing flawless two-dimensional polymers (2D-Ps) via meticulous molecular preorganization presents an intriguing yet challenging frontier in research. We report here the single-crystal-to-single-crystal (SCSC) synthesis of a 2D-P via thermally induced topochemical azide-alkyne cycloaddition (TAAC) reaction. A designed monomer incorporating two azide and two alkyne units is synthesized. The azide and alkyne groups are preorganized in the monomer crystal in reactive geometries for polymerizations in two orthogonal directions. On heating, the polymerizations proceed in a hierarchical manner; at first, the monomer reacts regiospecifically in a SCSC fashion to form a 1,5-triazolyl-linked 1D polymer (1D-P), which upon further heating undergoes another SCSC polymerization to a 2D-P through a second regiospecific TAAC reaction forming 1,4-triazolyl-linkages. Two different linkages in orthogonal directions make this an architecturally attractive 2D-P, as determined, at atomic resolution, by single-crystal X-ray diffraction. The 2D-P reported here is thermally stable in view of the robust triazole-linkages and can be exfoliated as 2D-sheets. The design and synthesis of two-dimensional polymers (2D-Ps) via molecular preorganization presents an intriguing yet challenging frontier in research. Here, the authors report the single-crystal-to-single-crystal synthesis of a 2D-P via thermally induced topochemical azide-alkyne cycloaddition reaction. [ABSTRACT FROM AUTHOR]

The functionalization of polymeric matrices through graft polymerization offers various advantages by providing new properties, allowing for additional chemical reactions that the matrix alone could not undergo or that would require drastic chemical conditions to occur. In this work, epoxy groups were incorporated through a graft polymer of poly(glycidyl methacrylate), using a prefunctionalization with peroxide groups in the polytetrafluoroethylene matrix through gamma radiation. These peroxide groups were subsequently used as radical chemical initiators in the graft polymerization reaction of glycidyl methacrylate. The graft polymerization reaction was studied based on the absorbed dose, monomer concentration, reaction time, and temperature. [ABSTRACT FROM AUTHOR]

Dopamine (DA) can undergo complex oxidative self-polymerization to modify the surface properties of cotton fabrics; however, the disordered polymerization of dopamine to polydopamine (PDA) results in poor colorfastness and limits the application of DA to textile fibers. To ensure the ordered polymerization of DA and the growth of PDA and to obtain good colorfastness and depth in the PDA-modified cotton, we used the hot pad-batch (HPB) dyeing method for DA and Reactive Red 239 (RR-239), along with the action of the fabrics squeezing each other. We compared the differences in colorfastness caused by the disordered and ordered polymerization of DA and aluminum ions. We studied the effect of sodium carbonate, DA, and RR-239 concentration on the K/S values of the cotton fabric. We also analyzed the dyeing mechanism of PDA/RR-239 for cotton fibers and the effect of the aluminum ions therein via attenuated total reflection–Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) and determined the UV resistance, mechanical properties, and thermal properties of the cotton fabric. HPB dyeing produced better colorfastness than exhaustive dyeing with a co-bath of DA/RR-239 and enabled ordered polymerization of PDA on the fibers. HPB dyeing accelerated the formation of PDA in the presence of a small amount of aluminum salt. Thus, HPB dyeing is suitable for the modification of cotton fabric with DA and reactive dyes because it is a short dyeing process that can improve the washing and rubbing colorfastness to 4 and 3–4, respectively. [ABSTRACT FROM AUTHOR]

Polyaniline is a conducting polymer with a wide variety of applications. In the recent years, exploring the different avenues for the synthesis of polyaniline has gained immense popularity among the researchers. This study focuses on the experimental investigation and subsequent data modeling to determine the kinetics of chemical (oxidative) polymerization of aniline with ammonium persulfate as an oxidant in aqueous hydrochloric acid solutions at 277 K. The concentration of the polyaniline formed was determined using colorimetry. The effect of different initial concentrations of oxidant/monomer from 0.010–0.025 M on the rate of polymerization was observed. The polymerization kinetics at various initial oxidant to monomer mole ratios from 1–2.5 was also investigated. Using a well-established kinetic rate expression, the reaction rate constants were determined that best fitted the experimental data. Further, the polyaniline concentrations were predicted using the kinetic parameters with an absolute average relative deviation ranging from 4 to 17%. [ABSTRACT FROM AUTHOR]

We report here a method to make a branched and partially ethoxylated polyethyleneimine derivative directly from ethanolamine. The polymerization reaction is catalysed by a pincer complex of Earth-abundant metal, manganese, and produces water as the only byproduct. Industrial processes to produce polyethyleneimines involve the transformation of ethanolamine to a highly toxic chemical, aziridine, by an energy-intensive/waste-generating process followed by the ring-opening polymerization of aziridine. The reported method bypasses the need to produce a highly toxic intermediate and presents advantages over the current state-of-the-art. We propose that the polymerization process follows a hydrogen borrowing pathway that involves (a) dehydrogenation of ethanolamine to form 2-aminoacetaldehyde, (b) dehydrative coupling of 2-aminoacetaldehyde with ethanolamine to form an imine derivative, and (c) subsequent hydrogenation of imine derivative to form alkylated amines. The industrial process for the synthesis of branched polyethylenimine (PEI) and polyethylenimine ethoxylated (PEIE) uses highly toxic and mutagenic chemicals. Here the authors report a method to make a branched and partially ethoxylated polyethyleneimine derivative directly from ethanolamine using a pincer complex of Earth-abundant manganese, and producing water as the only byproduct. [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]

Cadmium is a highly toxic metal, and its presence can have adverse effects on both human health and aquatic ecosystems. The efficient removal of cadmium from wastewater is therefore of crucial importance, but traditional methods have proved to be inadequate. Thus, technologies for the treatment of wastewater containing cadmium, including adsorption, have been developed. The aim of this study was the preparation of a polymeric material by the grafting reaction of κ-carrageenan and its use as an adsorbent for cadmium removal. This was performed to study the removal capacity of cadmium ions in synthetic solutions, as well as the effects of pH and ions on adsorption capacity, adsorption kinetics, isotherms, and reusability. Additionally, the disinfectant potential of the solution was evaluated for the inactivation of total coliforms and E. coli in river water. The best adsorption capacity was 75.52 ± 1.325 mg g−1, with the kinetics described by the pseudo-second order model. Maximum adsorption capacity (127.6 ± 1.833 mg g−1) and RL (0.0113) were determined using the Langmuir model, the Freundlich model was the one that best fits the experimental data and indicated cooperative adsorption, and the Dubinin-Radushkevich isotherm was used to obtain the adsorption energy and identify that it is physical. The presence of ions K+, Na+, Mg2+, and Ca2+ in a concentration of 0.5% decreased the adsorption capacity, and that at pH 2.0, the adsorption capacity was drastically reduced. The study indicates that the polymer has potential as an adsorbent for removing cadmium from aqueous solutions and exhibits self-disinfecting properties. [ABSTRACT FROM AUTHOR]

Since the seminal work presented by Olah in 1966 on fluorinated carbocations, several strategies have been presented to introduce fluorinated moieties in polymer backbones via carbocation chemistry. The hexafluoroisopropylidene (6F) group is well known for its ability to enhance thermal properties and processability of polymers. However, its direct electrophilic incorporation into polymers has been largely ignored due to the challenges posed by activating hexafluoroacetone monomer for electrophilic aromatic substitution (EAS). In this article, we review the role of fluorinated carbocations from 1966 up to our recent versatile fluoroalkylation strategy to directly enchain the 6F group in polymers. Via EAS interfacial polymerization we reacted hexafluoroacetone trihydrate (HFAH) with aromatic monomers in triflic anhydride (Tf2O) and 1,2-dichloroethane (DCE) with Aliquat® 336. In addition, the polymerization of dibenzo-1,4-dioxin with HFAH is presented. A semi-fluorinated diol, 4,4′-bis(2-hydroxyhexafluoroisopropyl)diphenyl ether, was synthesized by this method and used to prepare the first reported polycarbonate with hexafluoroisopropoxy groups –C(CF3)2O– incorporated in the main chain via polycondensation. Polysilyl ethers were also prepared from this diol. Additionally, we briefly mention Carraher's legacy in the synthesis of metal-containing polymers via reactions of group IVB metallocene dichloride with dinucleophiles (diamines, diol, dicarboxylic acids, and dithiols) in solution and interfacial conditions in terms of electrophilic vs nucleophilic polycondensation. The new acidic, sterically hindered semi-fluorinated diol and bisphenol AF were reacted with group IVB metallocene dichloride in attempts to form metallocene condensation polymers with improved solubility. [ABSTRACT FROM AUTHOR]

Organosilicon compounds play a crucial role as essential building blocks and valuable organic molecules in various materials. They are extensively utilized as synthetic intermediates in chemical synthesis processes. Recent studies have highlighted the multifaceted role of silicon compounds, showcasing their significance not only as reactive participants or products but also as potent catalysts in various chemical reactions, as reported by researchers. In this comprehensive review, our objective is to provide a summary of recent advancements in synthesizing various organosilicon compounds in formation of silicon–carbon, silicon–oxygen, silicon–nitrogen and explore the applications of siliconic materials as catalysts in polymerization, reduction, and isomerization processes. Emphasizing the significant potential of this methodology, we aspire to inspire further research and applications in this rapidly emerging field. Furthermore, this review covers over 50 years of research on organosilicon chemistry in CCERCI under supervision of Prof. Seyed Mohammad Bolourtchian. [ABSTRACT FROM AUTHOR]

This report highlights a novel approach in utilizing the natural properties of a mechanically strong and graphene-like bond structure membrane present inside the casing of the pea pod, a byproduct of the pea processing industry to create flexible gas sensors through the polymerization of polyaniline (PANI). Pea membranes exhibit a distinctive 2-D honeycomb bond structure (like graphene) which serves as a template for polymerization of PANI creating composite flexible conducting membranes suitable for electronic applications. The effect of various parameters such as polymerization time, pH and different initiators were optimized to obtain polymer layer with ~ 5 µm thickness for the best performance of the composite material. The synthesized polymerized pea membrane was found to act as room temperature chemo-resistive ethanol gas sensor with appreciable sensor responses in the range ~ 2.42 and rise time of 20 s and a fall time of 25 s. For applications where rapid detection is crucial (e.g., real-time breath alcohol checkers), the current composite's fast response time is a significant advantage. This natural template structure gives a fast response time and reproducible results and could be explored for multiple industries opening avenues for further innovation. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the impact of two chain transfer controllers, ethyl 2-(phenylcarbonothiolthio)-2-phenylacetate (EPPA) and 2-(4-methoxyphenylcarbonothiolthio) ethanoic acid (MPEA), from the dithioester family (dithiobenzoates), on the RAFT polymerization of β-myrcene. The initiators employed were azobisisobutyronitrile (AIBN) or dicumylperoxide (DCP), at 65 °C and 90 °C, respectively. The study analyzed the impact of the type of controller, temperature, and initiator/controller ratio on the living nature of β-myrcene polymerization. The results showed that with an increase in the initiator/controller ratio, the rate of polymerization increased, but the obtained molar masses decreased. The MPEA controller showed better performance in controlling the termination and chain transfer reactions, especially when AIBN was used as the initiator. A rise in polymerization temperature led to a loss in the control of polymerization, causing an increase in the degree of polydispersity due to the presence of transfer reactions. The most effective control in the RAFT polymerization of β-myrcene was achieved using MPEA as the controller and AIBN as the initiator, resulting in a poly(β-myrcene) with 87% 1,4-addition according to proton NMR analyses and a polydispersity of 1.27 by gel permeation chromatography (GPC). Finally, the study synthesized a poly(β-myrcene)-b-poly(styrene) block copolymer with low polydispersity (Ð1.1) by sequentially adding styrene to the previously synthesized MPEA-poly(β-myrcene)-based RAFT macrocontroller. [ABSTRACT FROM AUTHOR]

Elevating the heat resistance of the highly transparent cyclic block copolymer (CBC) is of great significance for the synthesis of high-performance polymers. In this study, a novel bimetallic NixPd/NCNT@MFN catalyst was prepared and applied in the hydrogenation of α-methylstyrene-butadiene-styrene (α-SBS) ternary block copolymer. Ni2Pd/NCNT@MFN exhibited excellent catalytic performance, and after 8 h of reaction, a new fully hydrogenated polymer, α-CBC, was obtained. The hydrogenation of the butadiene segment in α-SBS became more difficult as the length of the segment increased. The presence of α-methyl resulted in the highest adsorption-activation energy for the α-methylstyrene monomer unit, leading to a longer hydrogenation time with increasing length of this segment. Furthermore, the introduction of α-methylstyrene not only increased the glass transition temperature of the styrene and α-methylstyrene (S) segments in α-SBS, but also increased the glass transition temperature of α-CBC even more after hydrogenation. This conclusion provides valuable theoretical guidance for the synthesis of high-heat-resistant α-CBC polymers. [ABSTRACT FROM AUTHOR]

Conjugate electrospinning, with two oppositely placed and charged spinning nozzles, is a modified electrospinning technique to prepare continuous nanofibers with the aligned structure. In the present work, conjugate electrospinning is used to prepare highly aligned polyvinyl pyrrolidone (PVP) nanofibers. The influences of an unheeded parameter, the intersection angle between the oppositely charged spinning nozzles, on the morphology and alignment of the polymer nanofibers are investigated. It is found that the alignment degree of the nanofibers increases first and decreases then when the intersection angle increases from 60 to 240°, reaching the best alignment at the angle of 120°. The main reason is that the swing fibers on the same side entangle together when the intersection angles are small, and those mutually attracted ones from the opposite side also entangle at high intersection angles. Raising the collecting rate can improve the alignment degree of the PVP nanofibers. The critical collecting rate (beyond which the collecting fibers will fracture) increases at higher intersection angle. Though the fibers prepared at 240° are collected at a higher rate, their alignment degree is still worse that of the fibers spun at 120°. In summary, to acquire well-aligned nanofibers by conjugate electrospinning, an appropriate intersection angle between the oppositely charged spinning nozzles should not be neglected. [ABSTRACT FROM AUTHOR]

The impact of aluminum trialkyl (AlR3) and esters/silane-external electron donor (EED) on the activity and reaction kinetics of ZN catalyst (TiC14//MgCl2—ethyl benzoate/diisobutyl phthalate) in propylene polymerization was studied. The polymerization kinetic was studied for different types of catalysts with various types of EEDs. To correlate the kinetic behavior of propylene polymerization and various reactions taking place during the polymerization, we have studied in situ interactions of EEDs with co-catalyst by FT-NMR. The used EEDs are (1) p-isopropoxy methyl benzoate (PIPMB), (2) diphenyldimethoxy silane (DPDMS) and (3) mixture of isopropyl myristate (IPM) and (DPDMS) were interacted with triethyl aluminum (TEAl) at defined molar ratios. In the diester type of catalyst, two types of kinetic profile were observed with two different types of EED systems. Initially very fast polymerization kinetic was observed when only silane type of EED was used during polymerization which became steady with mixed EED (Silane + Aliphatic Ester). This EED system shows steady-state and controllable kinetic characteristics due to mixing of IPM with silane. The study by FT-NMR spectroscopy indicated the formation of the new compounds that are inhibiting the rate of polymerization reaction. The compounds, such as ketones and alcohols, are responsible for controlling the rate of polymerization reaction. The contribution of each of these product formations during processes depends on the catalyst composition and on the polymerization conditions. [ABSTRACT FROM AUTHOR]

Covalent organic framework (COF) monolayers, with atomically thin, ordered networks, and rich functionality, are widely studied due to their unusual structure/property relationships. However, synthesizing COF monolayer has remained an unmet challenge due to the difficulty of controlling reactions at the monolayer limit with large-scale uniformity. The identification and development of new reactions and polymerization conditions are critical for the further advancement of COF monolayer materials. Moreover, as one-molecule-thick a freestanding films, COF monolayer offers an ideal material system. Many advanced applications of COF monolayer have been explored in recent literature. This review provides an overview of the current state of precise synthetic strategies for COF monolayer, highlighting the advantages and limitations of different synthetic approaches and key challenges related to enhancing quality, and emphasizing the unique benefits of COF monolayer as both an ideal model system and for advanced applications. [ABSTRACT FROM AUTHOR]

In a deep, curved cavity, polymerization of a bulk fill composite can be challenging. The aim of this study was to investigate the solubility, water absorption, and conversion rate of bulk-fill composite samples prepared using molds with various slope angles. Bulk-fill composite resin (Filtek One Bulk Fill) was placed into cylindrical Teflon molds with a depth of 4 mm, angled at varying degrees (90°, 75°, 60°, 45°). Two different LED light-curing units (VALO Cordless, iLed Curing Light) were used to cure the samples. Polymerizations were performed at three different distances (0 mm, 2 mm, and 4 mm). Five samples per group were used, resulting in a total of 24 groups. The Fourier Transform Infrared Spectrometer was utilized to evaluate the conversion levels of the samples. Water sorption and solubility values were determined by storing the composites in distilled water at 37 °C for 21 days. The VALO light-curing unit applied closest to samples inserted in a 90° angulation mold had the highest mean degree of conversion (41.55%), while iLED light-curing unit group that applied from 4 mm to the samples inserted in a 45° angulation mold had the lowest mean conversion (8.97%). The angle of the cavity and the distance at which the light-curing unit is applied significantly affected bulk-fill composite resin conversion. In addition, the choice of light-curing unit impacted the conversion levels. However, with the tested conditions, the water sorption and solubility values of polymerized composite resin samples remain unaffected by these factors. [ABSTRACT FROM AUTHOR]

Coupling the Si-based anodes with nickel-rich LiNixMnyCo1−x−yO2 cathodes (x ≥ 0.8) in the energy-dense cell prototype suffers from the mechanical instability of the Li-Si alloys, cathode collapse upon the high-voltage cycling, as well as the severe leakage current at elevated temperatures. More seriously, the cathode-to-anode cross-talk effect of transitional metal aggravates the depletion of the active Li reservoir. To reconcile the cation utilization degree, stress dissipation, and extreme temperature tolerance of the Si-based anode||NMC prototype, we propose a gel polymer electrolyte to reinforce the mechanical integrity of Si anode and chelate with the transitional cations towards the stabilized interfacial property. As coupling the conformal gel polymer electrolyte encapsulation with the spatial arranged Si anode and NMC811 cathode, the 2.7 Ah pouch-format cell could achieve the high energy density of 325.9 Wh kg−1 (based on the whole pouch cell), 88.7% capacity retention for 2000 cycles, self-extinguish property as well as a wide temperature tolerance. Therefore, this proposed polymerization strategy provides a leap toward the secured Li batteries. The cycling performance of Li-ion batteries based on silicon and Ni-rich oxide electrodes is limited by undesired phenomena including Si pulverization, cross talk, and interfacial instability. Here, the authors report in-situ polymerization to improve the stability of gel polymer Li-ion batteries. [ABSTRACT FROM AUTHOR]

While the elucidation of regulatory mechanisms of folded proteins is facilitated due to their amenability to high-resolution structural characterization, investigation of these mechanisms in disordered proteins is more challenging due to their structural heterogeneity, which can be captured by a variety of biophysical approaches. Here, we used the transcriptional master corepressor CtBP, which binds the putative metastasis suppressor RAI2 through repetitive SLiMs, as a model system. Using cryo-electron microscopy embedded in an integrative structural biology approach, we show that RAI2 unexpectedly induces CtBP polymerization through filaments of stacked tetrameric CtBP layers. These filaments lead to RAI2-mediated CtBP nuclear foci and relieve its corepressor function in RAI2-expressing cancer cells. The impact of RAI2-mediated CtBP loss-of-function is illustrated by the analysis of a diverse cohort of prostate cancer patients, which reveals a substantial decrease in RAI2 in advanced treatment-resistant cancer subtypes. As RAI2-like SLiM motifs are found in a wide range of organisms, including pathogenic viruses, our findings serve as a paradigm for diverse functional effects through multivalent interaction-mediated polymerization by disordered proteins in healthy and diseased conditions. CtBP is a transcriptional master co-repressor with oncogenic activity. Here, the authors use structural and biophysical methods to show that CtBP interacts with RAI2 through SLiMs that induce CtBP polymerization and inactivation. [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]

The tuning of the viscosity of polyurethane (PU) during its polymerization enables its use in different applications including the liquid composite molding (LCM). In this work, the rheological behavior during polymerization of PU from castor oil (CO), polyether (PE), and a mixture of both polyols (COPE, 50/50 wt%) was investigated using oscillatory rheometry at different isotherms (40, 50, 60, 70, and 80 °C). Approaches based on artificial neural networks (ANNs) and response surface methodology (RSM) were used for data analysis and to obtain prediction tools related to the PU polymerization. This approach can contribute to experimentally estimate new formulations to obtain information that kinetic models based on conversion rates are unable to provide. The polymerized PU(CO), PU(COPE), and PU(PE) compositions showed flexible phase Tg of 15, − 13, and − 30 °C, respectively. Due to the greater reactivity of the PU(CO), its viscosity increased faster than that of PU(PE). The balance of properties obtained with the mixtures of polyols resulted in viscosity values of 300, 500, and 1000 mPa s, which are suitable for the LCM. This approach shows the combination of ANN and RSM can be advantageous to complement the kinetics analysis of PU resins with tunable properties for the LCM. Highlights: Rheokinetics of PUs analyzed using oscillatory rheometry. Experimental data examined with neural networks and response surface methodology. Successful utilization of ANN and RSM for predicting PU polymerization. Combined ANN and RSM enhance kinetics analysis of PU resins. This approach reveals viscosity values suitable for composite liquid molding. [ABSTRACT FROM AUTHOR]

To emulate the ordered arrangement of monomer units found in natural macromolecules, single-unit monomer insertion (SUMI) have emerged as a potent technique for synthesizing sequence-controlled vinyl polymers. Specifically, numerous applications necessitate vinyl polymers encompassing both radically and cationically polymerizable monomers, posing a formidable challenge due to the distinct thiocarbonylthio end-groups required for efficient control over radical and cationic SUMIs. Herein, we present a breakthrough in the form of interconvertible radical and cationic SUMIs achieved through the manipulation of thiocarbonylthio end-groups. The transition from a trithiocarbonate (for radical SUMI) to a dithiocarbamate (for cationic SUMI) is successfully accomplished via a radical-promoted reaction with bis(thiocarbonyl) disulfide. Conversely, the reverse transformation utilizes the reaction between dithiocarbamate and bistrithiocarbonate disulfide under a cationic mechanism. Employing this strategy, we demonstrate a series of synthetic examples featuring discrete oligomers containing acrylate, maleimide, vinyl ether, and styrene, compositions unattainable through the SUMI of a single mechanism alone. To emulate the ordered arrangement of radically and cationically polymerizable monomers using single-unit monomer insertion (SUMI) remians challenging. Here the authors demonstrate sequence-defined vinyl polymers via SUMI by manipulating thiocarbonylthio end-groups. [ABSTRACT FROM AUTHOR]

Regulation of phase structure has been recognized as one of the most effective ways to fabricate self-healing polymers with high mechanical strength. The mechanical properties of the resultant polymers are certainly affected by the size of separated phase domain. However, the study on this aspect is absence, because it can hardly exclude the influence of variation in monomer proportion required for tuning the separated phase size. Here, we report the first study on tuning the phase size through reversible addition-fragmentation chain transfer (RAFT) polymerization without changing the proportion of monomers. As expected, the size of separated phase has been successfully mediated from 15 nm to 9 nm by tuning the molecular weight of the chain transfer agent. It is found that the mechanical strength and the self-healing efficiency of the resultant polymers increase simultaneously with the decrease of phase size. The study on the formation kinetics of hydrogen bonds reveals that the decrease of phase size can facilitate the re-bonding rate of hydrogen bonds, even if the migration of polymer chains is restricted. [ABSTRACT FROM AUTHOR]

The tacticity of vinyl polymers is a key factor affecting the properties of materials. Recently, organic Brønsted acids have been demonstrated as effective catalysts for the development of highly stereoselective cationic reversible addition-fragmentation chain transfer (RAFT) polymerizations of vinyl ethers, in which the use of RAFT agents could allow the control the molecular weight and tacticity of polymer products simultaneously. However, the effect of RAFT agents on the tacticity-regulation remains elusive and lacks of investigation. In this study, we synthesized four types of RAFT agents and evaluated their influence in the stereoselective cationic polymerization of isobutyl vinyl ether in the presence of PADI as a Brønsted acid catalyst, which unveils that the Z group of RAFT agents could not only affect the polydispersity of the products, but also exert a profound effect on the stereoselectivity. After extensive screening of the RAFT agents, high stereoregularity (isotacticity, 90% m) was obtained when using dithiocarbonate ester-type RAFT agents with a benzyloxy Z group. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the fabrication of polymersomes, protein-blended polymersomes, and polymeric microcapsules using droplet microfluidics. Polymersomes with uniform, single bilayers and controlled diameters are assembled from water-in-oil-in-water double-emulsion droplets. This technique relies on adjusting the interfacial energies of the droplet to completely separate the polymer-stabilized inner core from the oil shell. Protein-blended polymersomes are prepared by dissolving protein in the inner and outer phases of polymer-stabilized droplets. Cell-sized polymeric microcapsules are assembled by size reduction in the inner core through osmosis followed by evaporation of the middle phase. All methods are developed and validated using the same glass-capillary microfluidic apparatus. This integrative approach not only demonstrates the versatility of our setup, but also holds significant promise for standardizing and customizing the production of polymer-based artificial cells. [ABSTRACT FROM AUTHOR]

The uncertainty of the structure of melamine-formaldehye polymer is one of the important factors limiting its widespread application. The chemical reactions of melamine are almost always reversible, so controlling the microstructure is difficult. For the synthesis of polymer particles in water, it is unclear how the type of catalyst affects the microstructure of melamine-formaldehye polymers. Therefore, we conducted a detailed study to understand how different catalyst types(including 10% NaOH, trimethylamine, and a Na2CO3-NaHCO3 buffersolution)affect the hydroxymethylation reaction, structure and the thermal properties of the melamine-formaldehye polymer). The results showed that with the same molar ratio and pH conditions, the use of triethylamine as catalyst in the melamine-formaldehye polymer increased the possibility of side reactions in the hydroxymethylation reaction. However, the occurrence of side reactions has a favorable effect on the thermal properties of melamine-formaldehyepolymers. Specifically, melamine formaldehyde polymers synthesized using triethylamine as a catalyst exhibit higher thermal decomposition characteristic temperatures, lower kinetic values, and higher reactivity. These results provide insights into the effect of catalyst type on the reaction mechanism, microstructure and thermal properties of melamine-formaldehye polymers, which may prove useful for their improved and controlled synthesis. [ABSTRACT FROM AUTHOR]

This work finds suitable enzyme activity protectants to improve the recovery rate of enzyme activity in the preparation of human polymerized hemoglobin-superoxide dismutase-catalase-carbonic anhydrase (PolyHb-SOD-CAT-CA), including trehalose, sucrose, glucose, hydroxypropyl-β-cyclodextrin, and mannitol.Different types and concentrations of enzyme activity protective agents were added during polymerization to compare their protective ability to enzyme activity and the effect on the properties of hemoglobin. The study found that compared with trehalose, the protective effect of sucrose on CA enzyme activity is non-significant to that on hemoglobin, the recovery rate of SOD, and CAT enzyme activity has significant increased. Glucose, hydroxypropyl-β-cyclodextrin, and mannitol are unsuitable for the added enzyme activity protective agent of PolyHb-SOD-CAT-CA.The protective effect of sucrose on CA was non-significant with trehalose. The protective effect of sucrose on SOD and CAT enzyme activity was higher than trehalose, and the protective effect reached the maximum when the concentration reached 1.5%. [ABSTRACT FROM AUTHOR]

Crystal structures of mononuclear cyclopentadienyl-anthracenide complexes [(1,3-Ph2C5H3)Lu(C14H10)(THF)2]•THF (1a), [(1,2,4-Ph3C5H2)Lu(C14H10)(THF)2]•0.17hexane•1.53THF (2a), [(1,2,4-Ph3C5H2)Lu(C14H10)(THF)2]•3C6D6 (2b), [(1,2,4-Ph3C5H2)Y(C14H10)(THF)2] •0.23hexane•1.37THF (3a), and [(1,2,4-Ph3C5H2)Lu(2,6-tBu2C14H8)(THF)2]•0.5THF (4a) have been studied. Complexes exhibit a structural rigidity of the (η5-C5)Ln(η2-C14)(O)2 crystallographic node. Electronic and steric effects are discussed. The cyclopentadienyl-anthracenide complexes are able to activate C = C bonds without a co-catalyst, using ethylene polymerization as an example. [ABSTRACT FROM AUTHOR]