Polymerization Method Research Articles

Preparation of Anisotropic Trimeric Poly(Ionic Liquid) Microspheres via Microwave-Assisted Dual-Crosslinked Seed Emulsion Polymerization.

A microwave-assisted dual-crosslinked seed emulsion polymerization method is reported to prepare anisotropic trimeric poly(ionic liquid) (PIL) microspheres. First, ethylene glycol dimethacrylate (EGDMA)-crosslinked PIL (CPIL) seed microspheres are prepared. Then, the CPIL microspheres are swollen with ionic liquid (IL) emulsion containing divinylbenzene (DVB) and polymerized to form dual-crosslinked PIL (D-CPIL) microspheres under microwave irradiation. Finally, the D-CPIL microspheres are swollen with IL monomer emulsion to form trimeric morphology and polymerized to obtain trimeric PIL microspheres under microwave irradiation. The formation process of trimeric PIL microspheres is tracked using an optical microscope and their morphology is observed using scanning electron microscopy. Different from the repeat-swelling seed emulsion polymerization that needs dumbbell-like seed microspheres having gradient crosslinking or gradient surface wettability, this method depends on multiple local contraction forces in D-CPIL microspheres containing lowly crosslinked core and highlycrosslinked shell during swelling to form trimeric PIL microspheres. It is found that microwave polymerization is important because it can well retain trimeric morphology compared to conventional heating polymerization in oil or water baths. The morphology of trimeric PIL microspheres can be adjusted by changing the type and amount of crosslinkers, monomer/seed microsphere ratio, initiator dosage, temperature, etc.

Characterization of thermo-responsive shape memory bio-based thermoplastic polyurethane (SMTPU) for 3D/4D printing applications

In recent years, significant advancements have been made in smart and multifunctional materials through the integration of 4D printing and shape memory polymers (SMPs). This article highlights key SMP fabrication technologies for 4D printing, focusing on the functionality of stimuli-responsive polymers. Bio-based thermoplastic polyurethanes are produced through the prepolymer polymerization method, with 100% bio-based polyester polyols, polypropylene succinate, and 1,3-propanediol by corn sugar. The resulting SMTPU, which contains bio-polyol in the soft segment, along with a chain extender and isocyanate (4,4-methylene diphenyl diisocyanate, MDI), demonstrates excellent shape recoverability even after significant deformation. Atomic force microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were employed to analyze hydrogen bonding, microphase separation, and crystallinity, providing insights into the interactions between hard segments (HSs) and soft segments (SSs), an extent of phase separation, and a proportion of hydrogen-bonded urethane groups. The tensile strength of 15–21 MPa, elongation between 534 and 585%, and a hardness of 82–85 Shore A were shown. This study further explores the sustainability and unique properties of SMTPU, making it well-suited for shape memory applications at different temperatures with varying hard segment content. The findings are expected to contribute to future innovations and advancements in the field of 4D printing.Graphical

Effect of functional monomers on the binding properties of molecularly imprinted polymers (MIPs) for selective recognition of dexamethasone

AbstractThis study examined the feasibility of removing dexamethasone (DEX) from aqueous solutions using molecularly imprinted polymers (MIPs). The binding energy, used to evaluate the affinity between imprinted molecule and functional monomer, was calculated for DEX using molecular simulation via the density functional theory method. From this approach, three different functional monomers were tested: methacrylic acid, N‐(Hydroxymethyl) acrylamide, and 2‐hydroxyethyl methacrylate designated as MIP‐DEX1, MIP‐DEX2, MIP‐DEX3, respectively. All of them were prepared by the precipitation polymerization method, with trimethylolpropane trimethacrylate used as the crosslinker. Moreover, the kinetics of adsorption and adsorption isotherms were evaluated using different models to assess the adsorption mechanisms of DEX on polymers. The results showed that equilibrium between the polymer and DEX is reached at 180 min, with a maximum adsorption capacity of 117.27 mg g−1 for sample MIP‐DEX3. The kinetic studies indicated that the adsorption of DEX on the polymers fits very well with the pseudo‐second‐order kinetic model. Equilibrium data were best described by the Freundlich model, suggesting that the sorption process occurs on a heterogeneous surface of the polymer cavities. The thermodynamic study confirms the role of selectivity cavities, exhibited in the sample MIP‐DEX3. Reusability tests and application on real samples suggest that the synthesized polymers are promising adsorbents.Highlights The functional monomer was chosen using a semiempirical computational simulation. Three monomers were tested to study their influence on dexamethasone recognition. The molecularly imprinted polymers (MIPs) prepared from 2‐hydroxyethyl methacrylate achieved the maximum analyte adsorption. Our MIP exhibited a selectivity constant of 41.11 in the presence of cortisone. The prepared MIP was successfully reused and tested for dexamethasone in real water samples.

High-performance PEI-based nanofiltration membrane by Mxene-regulated interfacial polymerization reaction: Design, Fabrication and Testing

Development of cost-effective materials and technologies for lithium extraction in salt-lake brines is of great importance to meeting rising lithium demands. Nanofiltration (NF) process is a feasible solution, however, it has commonly had operational problems such as low permeability. In this study, an MXene-regulated interfacial polymerization (MRIP) method was developed for fabrication of high-performance polyethyleneimine (PEI)-based polyamide (PA) NF membrane. The MXene nanosheets tiled at the water-oil interface, by which a spatio-temporal confinement effect was created; such structure could nicely regulate diffusion of monomers and precisely control PA nanofilm. The MXene-regulated membrane (PA@M) had thinner thickness, larger pore size, and better hydrophilicity. As a result, the permeance of PA@M membrane was significantly increased by more than 300%. Moreover, the membrane had outstanding cation selectivity with >98% rejection for Mg2+ and <20% rejection for Li+. Meanwhile, the selectivity factor of Li+/Mg2+ reached 31.5. Furthermore, a two-stage nanofiltration process by the membrane could reduce the Mg2+/Li+ ratio from 40 to 0.45, suggesting greater suitability of membrane for lithium extraction. The MRIP method offers a promising strategy and method for development of high-performance PA-NF membranes for resource recovery and water purification applications.

Revolutionizing photocatalysis: Synthesis of innovative poly(N-tertiary-butylacrylamide)-graft-hydroxypropyl cellulose polymers for thermo-responsive applications via metal-free organic photoredox catalysis.

In this study, we present a groundbreaking approach utilizing metal-free, visible light-mediated organic photoredox catalyzed atom transfer radical polymerization (O-ATRP) to synthesize cellulose-based stimuli-responsive polymers. Our method resulted in the successful synthesis of innovative metal-free poly(N-tertiary-butylacrylamide)-graft-hydroxypropyl cellulose (PNTBAM-g-HPC) polymers with exceptional control over molecular weight and narrow dispersity index (Đ) and explored their applications in organo-photocatalytic reactions. This approach addresses the limitations of traditional atom transfer radical polymerization method, which suffer from metal contamination and toxicity related problems. O-ATRP and organic photoredox catalysts have been sought to address these difficult challenges. In this study, we synthesized organic compound; 2,4,5,6-tetrakis(diphenylamino)isophthalonitrile (4DPIPN), which served as an organic photoredox catalyst, enabling the synthesis and application study of PNTBAM-g-HPC polymers via organic photoredox catalysis. Furthermore, by employing 4DPIPN, three different types of PNTBAM-g-HPC polymers were synthesized. Through thorough characterization techniques including FTIR, NMR, UV/Visible spectroscopy, TGA, and GPC analysis, we confirmed the successful synthesis of photocatalyst and three different types of PNTBAM-g-HPC polymers under O-ATRP conditions. By adjusting the molar ratios of PNTBAM side chains, we fine-tuned the LCST of HTA-20 polymers to 37.3°C, demonstrating their thermoresponsive behavior. This synthetic approach shows great potential for applications in biosensors, pharmaceuticals, biomedical engineering, and drug delivery systems.

PH-responsive poly(acrylic acid) coated mesoporous silica nanoparticles for controlled abamectin release: Synthesis, characterization, and agricultural application

BackgroundSmart pesticides, capable of responding to environmental stimuli, hold promise for achieving precise and on-demand release of pesticides, thereby reducing environmental risks and optimizing pesticide utilization. MethodsHerein, we prepared a novel composite nanoparticle with a core-shell structure of poly(acrylic acid)-coated mesoporous silica by distillation precipitation polymerization method, which is simple and efficient. Then, abamectin was successfully loaded by impregnation adsorption, and a novel pH-responsive controlled-release pesticide formulation, Abamectin-MSN@PAA, was prepared. SignificantFindings In this work, Abamectin-MSN@PAA exhibited a loading content of 23.79 % and an average particle size of approximately 272.1 nm. Notably, the formulation demonstrated acid-responsive release kinetics, with cumulative release percentages of 85.91 %, 69.03 %, and 53.44 % observed at pH values of 5, 7, and 9, respectively, after 96 h. Moreover, Abamectin-MSN@PAA effectively preserved abamectin from degradation under UV light exposure. In comparison with abamectin suspension, Abamectin-MSN@PAA exhibited superior adhesion to radish leaves and demonstrated increased aphid mortality in bioassay experiments. Following 7 days of drug spraying, the aphid survival rate was 26.67 % for Abamectin (40 mg L−1) and only 18.3 % for Abamectin-MSN@PAA (40 mg L−1). These findings underscore the potential of pH-responsive poly(acrylic acid)-coated mesoporous silica nanoparticles as a versatile platform for controlled pesticide delivery, thereby enhancing pesticide bioavailability and efficacy in agriculture.

Enhanced specific surface area in 2D graphitic carbon nitride nanosheets via two-step calcination temperature-induced structural transformation

Graphitic carbon nitride (GCN) has been vigorously investigated as a unique type of two-dimensional (2D) soft material in various areas such as catalyst, energy storage and photoelectronics. The GCN was commonly synthesized by involving a facile one-step calcination process. However, this method produced the GCN with low surface area properties (<30 m2/g). Modifying the structure of GCN is an efficient method for enhancing its surface area properties. A facile two-step calcination method was been thoroughly investigated for its efficacy in attaining an enhanced surface area of GCN. Herein, we investigated a simple two-step thermal polymerization method to achieve exfoliated structures of GCN with higher surface area by using melamine and ammonium chloride as precursor and gas templates. In this study, the GCN was synthesized at elevated temperatures (400, 450, 500, 550, and 600°C) and characterized using BET, FTIR, XRD, FESEM, Raman, and TGA analyses. The evolution of morphological characteristics contributed to achieving the highest GCN surface area at a temperature of 550°C. By using a two-step calcination method, which ultimately leads to the formation of exfoliated structures, the GCN surface area has the potential to be increased to a maximum of 122.5 m2/g. The XRD and FTIR findings also revealed that the production and complete formation of GCN was only attainable at temperatures over 450°C. The as-synthesized GCN with the highest surface area may become a potential material for future usage in diverse applications especially in electrochemical and catalysis purposes. These advancements are closely aligned with the United Nations Sustainable Development Goals (SDGs), involving SDG 7 (Affordable and Clean Energy), SDG 9 (Industry, Innovation, and Infrastructure), and SDG 13 (Climate Action). The advancement of high-surface-area GCN supports cleaner energy solutions, promotes industrial innovation, and promotes sustainable environmental practices, thus encouraging a greener future.

Tough and Fast Thermoresponsive Hydrogel Soft Actuators

AbstractThermoresponsive hydrogels hold significant potential for soft actuators due to their ability to undergo reversible shape deformation in response to temperature changes. However, the mechanical brittleness along with slow actuation responsiveness of such hydrogels limit their usage in high‐stress environments. Herein, the design and fabrication of tough and fast‐responding thermoresponsive double‐network (DN) hydrogels, specifically developed for use in soft actuators, are introduced. Using a one‐pot free‐radical polymerization method, DN hydrogels composed of a poly(N‐isopropylacrylamide) (PNIPAm) thermoresponsive first network and an ether‐based polyurethane (EPU) second network, providing both mechanical strength and fast response to temperature variation are synthesized. The fabricated hydrogels exhibit excellent mechanical properties, with an ultimate compressive stress of ≈8 MPa, and demonstrate rapid actuation, achieving ≈30% linear contraction and ≈28% radial contraction within 2 min under hydrothermal conditions at 50 °C. Furthermore, tubular soft actuators fabricated from these hydrogels demonstrate the ability to act as fluidic temperature sensors, automatically switching fluid flow direction in response to temperature change. These DN hydrogels combine toughness, rapid actuation, and temperature sensing, offering substantial advancements for soft robotics and adaptive systems.

Sequential sorption of crystal violet and emulsified oil onto poly(lauryl methacrylate-acrylamide) hybrid hydrogel

Abstract The operational industries continuously contribute significant volumes of synthetic dyes along with other pollutants into the aquatic environment. The global issue of dye induced water contamination was addressed through facile synthesis of hydrophobically associated poly(lauryl methacrylate-acrylamide) [p(LMA-AAm)] hydrogel by free radical polymerization method. The SEM (Scanning Electron Microscope) micrographs depicted suitability of the hybrid sorbent for crystal violet (CV) uptake owing to porous, rough and spongy texture. The fabricated sorbent was utilized for CV sorption by performing different tests like contact time, pH, and initial concentration effect on the CV sorption. The obtained kinetic and isothermal data fitted well into the non-linear versions of pseudo second order and Langmuir models respectively. The thermodynamics tests signified the sorption process of spontaneous and endothermic nature. After sorption, the resultant [CV/p(LMA-AAm)] waste was applied for toluene (oil probe) separation from water which performed excellent separation in the range of 83–74 % during the first three tests. Thus, the desirable sorption properties, facile fabrication and promising oil separation power may recommend the composite sorbent for applications in the relevant fields like water treatment, separation and sorption.

Enhanced photocatalytic degradation of Rhodamine B using polyaniline-coated XTiO3(X = Co, Ni) nanocomposites

In this study, novel polyaniline-coated perovskite nanocomposites (PANI@CoTiO3 and PANI@NiTiO3) were synthesized using an in situ oxidative polymerization method and evaluated for the photocatalytic degradation of Rhodamine B (RhB) a persistent organic pollutant. The nanocomposites displayed significantly enhanced photocatalytic efficiency compared to pure perovskites. The 1%wt PANI@NiTiO3 achieved an impressive 94% degradation of RhB under visible light after 180 min, while 1wt.% PANI@CoTiO3 reached 87% degradation under UV light in the same duration. X-ray diffraction (XRD) confirmed that the crystalline structures of CoTiO3 and NiTiO3 remained intact post-polymerization. At the same time, Fourier transform infrared spectroscopy (FTIR) verified the successful deposition of PANI through characteristic functional group vibrations. Diffuse reflectance spectroscopy (DRS) revealed reduced band gaps of 2.63 eV for 1wt.% PANI@NiTiO3 and 2.46 eV for 1wt.% PANI@CoTiO3, enhancing light absorption across UV and visible ranges. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis demonstrated the uniform distribution of PANI, ensuring consistent surface activity and efficient charge transfer. The photocatalytic test confirmed a pseudo-first-order degradation mechanism. The study elucidates the degradation mechanism through intermediate identification via HPLC-MS analysis, highlighting N-de-ethylation, aromatic ring cleavage and eventual mineralization into CO2 and H2O as critical pathways. Furthermore, the 1wt.%PANI@NiTiO3 nanocomposite demonstrated excellent stability and recyclability, maintaining its degradation efficiency over four consecutive cycles with minimal change. These findings highlight the potential of PANI@XTiO3 nanocomposites for sustainable and efficient wastewater treatment, addressing diverse environmental challenges by tailoring photocatalysts to specific light sources.

Crystalline Covalent Triazine Frameworks and 2D Triazine Polymers: Synthesis and Applications.

ConspectusCovalent triazine frameworks (CTFs) are a novel class of nitrogen-rich conjugated porous organic materials constructed by robust and functional triazine linkages, which possess unique structures and excellent physicochemical properties. They have demonstrated broad application prospects in gas/molecular adsorption and separation, catalysis, energy conversion and storage, etc. In particular, crystalline CTFs with well-defined periodic molecular network structures and regular pore channels can maximize the utilization of the features of CTFs and promote a deep understanding of the structure-property relationship. However, due to the poor reversibility of the basic reaction for constructing the triazine unit and the traditional harsh synthesis conditions, it remains a considerable challenge to synthesize crystalline CTFs with diverse molecular structures, and there is still a significant lack of understanding of their polymerization mechanism, which limits their precise structural design, large-scale preparation, and practical applications. As the basic building block of bulk crystalline CTFs, two-dimensional triazine polymers (2D-TPs) which ideally have single-atom thickness have also aroused intensive interest due to their ultrathin 2D sheet morphology with structural flexibility, a fully exposed molecular plane and active sites, and excellent dispersibility and processability. However, the efficient and scalable production of high-quality 2D-TPs and the investigation of their unique properties and functions remain largely unexplored.In this Account, we summarize our recent contributions to the synthesis and application exploration of crystalline CTFs and 2D-TPs. We first introduce the design, synthesis, and polymerization mechanism of the crystalline CTFs. In order to synthesize high-quality CTFs, we have successively used a series of new synthetic methods including a solution polymerization strategy, microwave-assisted superacid-catalyzed polymerization strategy, polyphosphoric acid-catalyzed polymerization strategy, and solvent-free FeCl3-catalyzed polymerization strategy, achieving the production of highly crystalline layered CTFs from the gram level to the hundred-gram level and then to the kilogram level and realizing new CTF molecular structures. We also reveal a direct ordered 2D polymerization mechanism that provided meaningful guidance for the controllable preparation of functional CTFs. Next, we introduce the design, synthesis, and formation mechanism of 2D-TPs. We have developed effective bottom-up and top-down strategies to prepare 2D-TPs for different needs. On one hand, we have established the dynamic interface polymerization method, the monomer-dependent method, and the solvent-free salt-catalyzed polymerization strategy for the direct synthesis of ultrathin 2D-TPs with thickness down to the single-layer limit and provided important insights into the 2D polymerization mechanism. On the other hand, we have opened up the physical and chemical exfoliation of crystalline layered CTFs such as liquid sonication and ball milling exfoliation and covalent and noncovalent modification exfoliation for the large-scale production of 2D-TPs. Then, we present the application progress of crystalline CTFs and 2D-TPs in various batteries, photo/electrocatalysis, and adsorbents with an emphasis on their unique and outstanding performance and structure-property relationship. Lastly, the main challenges faced by crystalline CTFs and 2D-TPs in practical applications and future research directions are discussed in detail. We hope that this Account will provide valuable insights and practical strategies for promoting the development of functional organic framework materials and 2D polymer materials.

Adsorption of Cu(II) from aqueous solution by modified magnetic starch st/Fe3O4-g-pAA

The composite particles (St/Fe3O4) were prepared using the co-precipitation method, whereby FeSO4 and FeCl3 were precipitated under alkaline conditions. The particles were composed of a starch matrix and Fe3O4. Subsequently, AA was grafted and cross-linked onto the composite particles (St/Fe3O4) via a one-step traditional free radical polymerization method, resulting in the formation of polymer-modified composite particles (St/Fe3O4-g-pAA). The initiator used in this process was 2,2’-Azobis(2-methylpropionitrile). The structures of St/Fe3O4 and St/Fe3O4-g-pAA were characterized by FTIR, thermogravimetric analysis and hysteresis loop. The impact of varying parameters, including the dosage of the St/Fe3O4 and St/Fe3O4-g-pAA adsorbents, the initial pH value of the Cu(II) solution, the initial Cu(II) concentration, the absorption time, and the temperature, on the adsorption behavior of Cu(II) was investigated. The results demonstrated that St/Fe3O4-g-pAA exhibited excellent adsorption performance for Cu(II), with a unit adsorption capacity of 123.92 mg/g and a maximum removal rate of 85% when the original concentration of the Cu(II) solution was 10. The experiment was conducted with 24 mg/L of Cu(II) at a pH of 7 at room temperature, with a mass of 1.5 mg of St/Fe3O4-g-pAA and an adsorption time of 3 h. The adsorption process followed the Langmuir model and the pseudo-second-order kinetic model, which was dominated by chemical adsorption and belonged to single-layer adsorption. The results of the renewable performance studies demonstrated that following eight cycles of adsorption, 92% of the initial adsorption effect was retained. It can therefore be concluded that the St/Fe3O4-g-pAA adsorbent material prepared in this work is an effective means of improving the adsorption rate of Cu(II).

Facile Synthesis of Bioactive Silver Nanocomposite Hydrogels with Electro-Conductive and Wound-Healing Properties

Bioactive metal and metal oxide-based nanocomposite hydrogels exhibit significant antibacterial properties by interacting with microbial DNA and preventing bacterial replication. They offer potential applications as coating materials for human or animal skin injuries to prevent microbial growth and promote healing. In this study, silver nanoparticles (AgNPs) were synthesized using a chemical reduction method and incorporated into a polymer network to fabricate silver nanocomposite hydrogels (AgNCHGs) through a simple free radical polymerization method. N-isopropylacrylamide (NIPA), which has lower critical solution temperature (LCST) at about body temperature, or acrylamide (AAm) was used as the main monomer, while one or more ionic co-monomers, such as acrylic acid (AAc) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS), were incorporated to obtain AgNCHGs. AgNPs were introduced into the hydrogel network via three different approaches. In the first method, the synthesized hydrogel was immersed in a silver nitrate (AgNO3) solution and reduced in situ using sodium borohydride (NaBH4) as a reducing agent. The second method involved mixing AgNO3 with gel precursors before reduction with NaBH4 to form AgNPs within the hydrogel. The final approach synthesized the AgNCHGs directly in a dispersion of pre-fabricated AgNPs. The incorporation of AgNPs in different AgNCHGs was confirmed through various characterization techniques. Varying temperature and pH conditions can trigger the release of bioactive AgNPs from the hydrogels. Furthermore, the antimicrobial and wound-healing properties of the AgNCHGs were evaluated against bacteria and fungi, demonstrating their potential in biomedical applications. In addition, AgNCHGs exhibit excellent electrical conductivity. The electrical conductivity of the hydrogels can be finely tuned by adjusting the concentration of AgNPs, making these materials promising candidates for energy, sensor, and stretchable electronics applications. This study presents facile synthesis methods of AgNCHGs, which integrate bioactivity, wound healing, and electrical conductivity in the same matrix, addressing a significant challenge in designing multifunctional hydrogels for next-generation technologies.

Research on Multi-Time Scale Flexible Resource Aggregation and Evaluation for New Power Systems

The strong uncertainty of the high proportion of new energy and the gradual decrease in the proportion of thermoelectric units have led to a shortage of system flexibility resources. System-level energy storage can efficiently alleviate the pressure of peak shaving and frequency regulation. Effective aggregation of flexibility resources is a key technical foundation for enhancing economic operation and advanced user-side response strategies of new power systems. However, the decentralization and heterogeneity of flexibility resources across generation, grid, load, and storage sides pose dual challenges of aggregation speed and accuracy. In view of this, this paper proposes a large-scale multi-dimensional flexibility polymerization method based on different response time scales. First, the flexibility resource definitions and response characteristics of generation, grid, load, and storage sides were analyzed and categorized according to their response time scales. Second, flexibility regulation models for resources on each side were established. On this basis, an improved Minkowski aggregation algorithm is proposed to precisely quantify the regulation capabilities of multi-dimensional flexibility resources at different time scales, enabling efficient resource aggregation. Finally, the results of the case analysis show that the proposed method can accurately aggregate the flexibility resource adjustment capabilities at different time scales to respond to the multi-time scale flexibility requirements of the system.

Graft-to/Graft-From Synthesis of Janus Graft Copolymers for Bottlebrush Polymer Electrolytes.

Janus graft copolymers, which combine the characteristics of block and graft copolymers, have been used in the fields of reaction catalysis, surface modification, and drug delivery, but their applications in lithium batteries have rarely been reported. Herein, Janus graft copolymers with polyethylene glycol (PEG) and polystyrene (PS) side chains are synthesized by combining reversible addition-fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP) methods and doped with lithium salts to fabricate Janus bottlebrush polymer electrolytes (PEG-J-PS). The PEG side chains of the brush polymers impart good ion-conducting properties to the electrolytes, while the PS side chains improve the mechanical strength and thermal and chemical stability of the electrolytes. Notably, the PEG-J-PS can effectively improve the motility of the polymer chain segments compared to the conventional block copolymer electrolytes (PEG-b-PS). The prepared PEG-J-PS exhibits a considerable ionic conductivity of 2.06 × 10-5 S cm-1 at 30°C and high tensile stress (2.39MPa) and tensile strain (143%) of the PEG45-J-PS20 owing to its Janus graft structure.

Kinetically Controlled Seeded Living Supramolecular Polymerization of Tb(III) Complex

ABSTRACTWe describe the synthesis of metallosupramolecular polymers using a Tb3+ complex as a primary building block. This synthesis is facilitated through the strategic manipulation of non‐equilibrium self‐assemblies, employing a living supramolecular polymerization method. Our extensive investigation into the metallosupramolecular polymerizations, which are both thermodynamically and kinetically regulated and centered around the Tb3+ complex with bisterpyridine‐modified ligand (R‐L1) incorporating R‐alanine units, revealed noteworthy properties. These complexes initially form kinetically metastable aggregates, characterized by a coordination number of nine. This structure involves one Tb3+ cation and three NO3− anions at one terpyridine moiety, while the opposite terpyridine moiety remains unoccupied. Intriguingly, these aggregates can transition into a thermodynamically more stable state, also characterized by a nine‐coordination number. In this state, each of the two terpyridine units is coordinated with one Tb3+ cation and three NO3− anions, respectively. This transformative process is expedited by seed‐induced living polymerization. Therefore, we have successfully executed the seeded living supramolecular polymerization of the monomeric building unit under kinetically controlled conditions. This process yielded a metallosupramolecular polymer with a precisely regulated length and minimal polydispersity, demonstrating the potential of this approach in the design of advanced functional materials.

Three-Dimensional SERS-Active Hydrogel Microbeads Enable Highly Sensitive Homogeneous Phase Detection of Alkaline Phosphatase in Biosystems.

Alkaline phosphatase (ALP) is a biomarker for many diseases, and monitoring its activity level is important for disease diagnosis and treatment. In this study, we used the microdroplet technology combined with an in situ laser-induced polymerization method to prepare the Ag nanoparticle (AgNP) doped hydrogel microbeads (HMBs) with adjustable pore sizes that allow small molecules to enter while blocking large molecules. The AgNPs embedded in the hydrogel microspheres can provide SERS activity, improving the SERS signal of small molecules that diffuse to the AgNPs. A specific hydrolysis reaction of ALP on 5-bromo-4-chloro-3-indolylphosphate (BCIP) was introduced and itsproduct 5,5'-dibromo-4,4'-dichloro-1H,1H-[2,2']bisindolyl-3,3'-dione (BCI) was employed to assess ALP activity due to its highly resonance Raman activity. The sensing platform was applied to model ALP activity in serum and evaluate ALP inhibitors. The SERS assay showed higher sensitivity than UV-vis absorption spectroscopy, with the lowest detectable ALP concentration of 1.0 × 10-20 M. In addition, the ALP activity in HepG2 cells was evaluated using this sensing platform, showing lower ALP-expressing activity than that of controls in response to hypoxia and iron metastasis. This SERS-activated HMB shows great potential in detecting ALP and is expected to help analyze complex clinical samples.

Toward Sustainable Polydienes.

The sustainable management of polydiene waste represents a formidable challenge in the realm of polymer chemistry, given the extensive industrial utilization of polydienes due to their superior elastomeric properties. This comprehensive Perspective addresses the multifaceted obstacles hindering efficient recycling of polydienes, encompassing environmental concerns, technical limitations, and economic disincentives. We systematically dissect the influence of polydienes' chemical structures on their recyclability, tracing the evolution of polydiene utilization and disposal practices while assessing the current landscape of waste management strategies. Our investigation reveals the primary technical challenges associated with polydiene recycling, notably the energy-intensive nature of modification processes and the environmental detriments of prevailing disposal techniques. Furthermore, we critically evaluate existing recycling methodologies─including mechanical recycling, energy recovery, and chemical recycling─highlighting their respective merits, constraints, and environmental implications. Pioneering advancements in recycling technology, such as topochemical polymerization and computational prediction models, are spotlighted for their potential to revolutionize polydiene recycling. Looking forward, we delineate an optimistic trajectory for polydiene waste management, advocating for innovative polymerization methods, the exploration of milder recycling conditions, and the adoption of interdisciplinary approaches to bolster recycling efficiency. The Perspective culminates in a discussion on the pivotal role of policy frameworks, life cycle assessments, and economic analyses in shaping the future of polydiene recycling. Through this scholarly examination, we aim to catalyze further research and development efforts aimed at mitigating the environmental impact of polydiene waste, thereby contributing to the broader objective of sustainable chemistry.

Synthesis of P(AM/AA/SSS/DMAAC-16) and Studying Its Performance as a Fracturing Thickener in Oilfields.

In order to solve the problems of long dissolution and preparation time, cumbersome preparation, and easy moisture absorption and deterioration during storage or transportation, acrylamide (AM), acrylic acid (AA), sodium p-styrene sulfonate (SSS), and cetyl dimethylallyl ammonium chloride (DMAAC-16) were selected as raw materials, and the emulsion thickener P(AM/AA/SSS), which can be instantly dissolved in water and rapidly thickened, was prepared by the reversed-phase emulsion polymerization method. DMAAC-16, the influence of emulsifier dosage, oil-water ratio, monomer molar ratio, monomer dosage, aqueous pH, initiator dosage, reaction temperature, reaction time, and other factors on the experiment was explored by a single-factor experiment, and the optimal process was determined as follows: the oil-water volume ratio was 0.4, the emulsifier dosage was 7% of the oil phase mass, the initiator dosage was 0.03% of the total mass of the reaction system, the reaction time was 4 h, the reaction temperature was 50 °C, the aqueous pH was 6.5, and the monomer dosage was 30% of the total mass of the reaction system (monomeric molar ratio n(AM):n(AA):n(SSS):n(DMAAC-16) = 79.2:20:0.5:0.3). X-ray diffraction analysis (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy analysis were carried out on the polymerization products. At the same time, a series of performance test experiments such as thickening performance, temperature and shear resistance, salt resistance, sand suspension performance, core damage performance, and fracturing fluid flowback fluid reuse were carried out to evaluate the comprehensive effect and efficiency of the synthetic products, and the results show that the P(AM/AA/SSS/DMAAC-16) polymer had excellent solubility and excellent properties such as temperature and shear resistance.

ROMP of Macromonomers Prepared by ROMP: Expanding Access to Complex, Functional Bottlebrush Polymers.

Graft-through ring-opening metathesis polymerization (ROMP) of norbornene-terminated macromonomers (MMs) prepared using various polymerization methods has been extensively used for the synthesis of bottlebrush (co)polymers, yet the potential of ROMP for the synthesis of MMs that can subsequently be polymerized by graft-through ROMP to produce new bottlebrush compositions remains untapped. Here, we report an efficient "ROMP-of-ROMP" method that involves the synthesis of norbornene-terminated poly(norbornene imide) (PNI)-based MMs that, following ROMP, provide new families of bottlebrush (co)polymers and "brush-on-brush" hierarchical architectures. In the bulk state, the organization of the PNI pendants drives bottlebrush backbone extension to enable rapid assembly of asymmetric lamellar morphologies with large asymmetry factors. Overall, this work expands the scope of complex macromolecular architectures and provides insights into the interplay of backbone rigidity and self-assembly that will guide future nanolithography applications.