Macromolecular Rapid Communications最新文献

Wearable strain transducers are poised to transform the field of healthcare owing to the promise of personalized devices capable of real-time collection of human physiological health indicators. For instance, monitoring patients' progress following injury and/or surgery during physiotherapy is crucial but rarely performed outside clinics. Herein, multifunctional liquid-free ionic elastomers are designed through the volume effect and the formation of dynamic hydrogen bond networks between polyvinyl alcohol (PVA) and weak acids (phosphoric acid, phytic acid, formic acid, citric acid). An ultra-stretchable (4600% strain), highly conducting (10 mS cm^-1), self-repairable (77% of initial strain), and adhesive ionic elastomer is obtained at high loadings of phytic acid (4:1 weight to PVA). Moreover, the elastomer displayed durable performances, with intact mechanical properties after a year of storage. The elastomer is used as a transducer to monitor human motions in a device comprising an ESP32-based development board. The device detected walking and/or running biomechanics and communicated motion-sensing data (i.e., amplitude, frequency) wirelessly. The reported technology can also be applied to other body parts to monitor recovery after injury and/or surgery and inform practitioners of motion biomechanics remotely and in real time to increase convalescence effectiveness, reduce clinic appointments, and prevent injuries.

Fluorosilicone rubber is essential for sealing in extreme temperatures and non-polar environments due to its exceptional adaptability. However, achieving a high yield of fluorosilicone polymers with medium and high fluorine content remains a challenge. Herein, a facile gradient strategy is developed that involves modifying the method of cyclic monomer addition based on the rate of ring-opening polymerization (ROP), to improve yield and adjust fluorine content precisely. The polymerization process is designed and tailored based on the reaction rates of anionic ring-opening polymerization (AROP) and cationic ring-opening polymerization (CROP) via an efficient gradient strategy. The effects of the polymerization process on the viscosity and yield of vinyl fluorosilicone polymers and hydrofluorosilicone polymers are investigated and optimized. Notably, the as-prepared vinyl-terminated fluoromethylsilane with 60% fluorine content (FMS-Vi-60F) has a high yield (86.6%) and high viscosity (150 000 mPa·s) in a short reaction time, which is superior to previous methods. Clearly, the gradient ring-opening method developed in this work provides a facile and efficient synthesis for fabricating fluorosilicone polymers with a high yield and tunable fluorine content.

Covalent Organic Frameworks (COFs) exhibit a range of exceptional attributes, including notable porosity, outstanding stability, and a precisely tuned π-conjugated network, rendering them highly promising candidates for fluorescence sensors applications. In this study, the synthesis of two emissive hydrazone-linked COFs designed for hydrazine detection is presented. The partially conjugated structure of the hydrazone linkage effectively weakens the fluorescence quenching processes induced by aggregation. Additionally, the incorporation of flexible structural components further reduces conjugation, thereby enhancing luminescent efficiency. Remarkably, these COFs possess a significant abundance of heteroatoms, enabling distinctive interactions with hydrazine molecules, which in turn results in exceptional selectivity and sensitivity for hydrazine detection. The detection limit of these COFs reaches the nanomolar range, surpassing all previously reported COFs, thereby underscoring their superior performance in chemical sensing applications.

Benefiting from the advantages of high conductivity and good electrochemical stability, the conjugated conducting polymer poly (3, 4-ethylenedioxythiophene) is a promising energy storage material in zinc-ion batteries. Zinc-ion batteries have the advantages of high safety, environmental friendliness, and low cost, but suffer from unstable cathode material structure, poor electrical conductivity, and uncontrollable dendritic growth of zinc anodes. PEDOT, with its fast electrochemical response and wide potential window, is expected to make up for the shortcomings and enhance capacity and cycle life of zinc-ion batteries. Herein, in this review different polymerization methods of poly (3, 4-ethylenedioxythiophene) as well as their structure and properties are summarized; the progress in doping strategies related to the increasing conductivity and dispersivity of poly (3, 4-ethylenedioxythiophene) materials is discussed; specific applications of poly (3, 4-ethylenedioxythiophene)-based materials in anode, cathode, electrolyte, and binder of zinc-ion batteries are explored; and the representative advancements for improving the electrochemical performance of poly (3, 4-ethylenedioxythiophene) in zinc-ion batteries are emphasized. Finally, the current challenges of poly (3, 4-ethylenedioxythiophene) as promising materials in zinc-ion batteries and an insight into their future research directions are pointed out.

Heterogeneous cobalt-based catalysts are highly effective in activing peroxymonosulfate (PMS) and produce free radicals to deal with recalcitrant organic pollutants in water. However, unfeasible recyclability and gradual performance degradation remain challenging due to the easy agglomeration and leaching of active cobalt species. Herein, a strategy is proposed to construct stably anchored and highly dispersed Co²⁺ sites on dual functional sulfonated covalent organic frameworks (COF-Co). The sulfonic acid groups are able to realize the targeted binding with cobalt ions through a two-step cation-exchange method, leading to strong combination with active Co²⁺ sites and utmost utilization efficiencies. Moreover, the super-hydrophility of sulfonic acid groups favors the rapid accessibility of organic molecules to the catalyst and accelerates the degradation. Remarkably, COF-Co exhibits high activity in PMS activation, effective oxidation for tetracycline degradation (92% within 30 min at 30 mg L^-1) and other coloring contaminants, and excellent recycle stability. This work can guide the rational design of efficient and environmentally friendly PMS-activated catalyst with great potential for application in wastewater treatment.

𝜋-Conjugated polymers, including those based on acetylenic repeating units, are an exciting class of materials that offer narrow optical band gaps and tunable frontier orbital energies that lead to their use in organic electronics. This work expands the knowledge of structure-property relationships of acetylenic polymers through the synthesis and characterization of a series of Glaser-Hay-coupled model compounds and random copolymers comprised of BF₂ formazanate, fluorene, and/or bis(alkoxy)benzene units. The model compounds and copolymers synthesized exhibit redox activity associated with the reversible reduction of the BF₂ formazanate units and the irreversible reduction of the fluorene and bis(alkoxy)benzene units. The copolymers exhibit absorption profiles characteristic or intermediate of their respective models and homopolymers, leading to broad absorption of UV-vis light. The alkyne linkages of the model compounds and copolymers are reacted with [Co₂(CO)₈] to convert the alkyne functional groups into cobalt carbonyl clusters. This transformation leads to blue-shifted absorption profiles due to a decrease in π-conjugation, demonstrating the ability to tune the properties of these materials through post-polymerization functionalization. The redox activity and broad absorption bands of the polymers reported make them excellent candidates for use in photovoltaics and other light-harvesting applications.

This work presented an overview of greener technologies for realizing everyday fabrics with enhanced antibacterial activity, flame retardancy, water repellency, and UV protection. Traditional methods for improving these qualities in textiles involved dangerous chemicals, energy and water-intensive procedures, harmful emissions. New strategies are presented in response to the current emphasis on process and product sustainability. Nanoparticles (NPs) are suggested as a potential alternative for hazardous components in textile finishing. NPs are found to efficiently decrease virus transmission, limit combustion events, protect against UV radiation, and prevent water from entering, through a variety of mechanisms. Some attempts are made to increase NPs efficiency and promote long-term adherence to textile surfaces. Traditional wet finishing methods are implemented through a combination of advanced green technologies (plasma pre-treatment, ultrasound irradiations, sol-gel, and layer-by-layer self-assembly methods). The fibrous surface is activated by adding functional groups that facilitate NPs grafting on the textile substrate by basic interactions (chemical, physical, or electrostatic), also indirectly via crosslinkers, ligands, or coupling agents. Finally, other green options explore the use of NPs synthesized from bio-based materials or hybrid combinations, as well as inorganic NPs from green synthesis to realize ecofriendly finishing able to provide durable and protective fabrics.

Potential applications of colloidal polymer nanoparticles in the preparation of smart inks are investigated by physical incorporation of the oxazolidine molecules. Precise adjusting the polymer chain flexibility and polarity is achieved by controlling the ratio of methyl methacrylate and butyl acrylate monomers in the polymerization reaction. In addition, nanofibrous indicators of acid-base vapors are prepared from the latex nanoparticles. This can be beneficial for creating materials that sense and respond to environmental changes, such as humidity or moisture and acidity. Thermochromic inks are prepared by microencapsulating crystal violet lactone dye (CVL) in polymer matrices to prevent their release into the aqueous media. Combining two distinct systems with varying triggers, such as light and temperature, provides an effective strategy for double-encryption anticounterfeiting and crack and scratch detection and indication applications. Preparing labels impregnated with double-responsive inks, a novel approach is developed for food spoilage detection and preservation indication. Labels are manufactured using polymer nanoparticles, which contain photoluminescent oxazolidine molecules, as well as a trinary mixture of CVL within core-shell latex particles as the thermochromic dye. The combination of these two responsive elements transforms traditional packaging into a dynamic and interactive sentinel for the food it holds.

To resist the plastic deformation of polymer particles during hot press molding, high molecular weights, and moduli are required for composites with segregated structures, thus the prepared composites exhibit poor flexibility. Also, larger particle sizes can bring lower percolation thresholds while the ensuing greater deformation destroys the conductive network. Moreover, segregated composites still face preparation complexities. Herein, a facile method for developing flexible composites with large-size segregated structures is proposed. First, silver-coated polydopamine-modified reduced graphene oxide (Ag@PrGO), as conductive fillers, is prepared by electroless plating. Next, polydimethylsiloxane (PDMS)-coated polyolefin elastomer (POE) beads are put into a bag containing the fillers. After a simple shaking, the fillers are adhered to the POE surface as the cohesive property of cured PDMS. Finally, flexible composites with large-size segregated structures are obtained via hot pressing. Benefiting from the 2D structure of the Ag@PrGO and the ability to slip, the conductive networks possess adaptable deformability. The prepared composites exhibit excellent electrical conductivity (203.55 S cm^-1) at filler volume fractions of 3.4 vol%. The EMI shielding effectiveness can reach 70 dB in the X-band at a thickness of 1.9 mm and remains stable after bending and rubbing damage. This work paves the way for constructing large-size segregated structures.

In this study, reversible addition-fragmentation chain- transfer (RAFT) polymerization combined with the polymerization-induced self-assembly (PISA) technique is used to synthesize polyisoprene (PI)-based block and random copolymers with polystyrene (PS), aiming for high molecular weight and monomer conversion. The focus is to optimize the polymerization conditions to overcome the existing challenge of cross-linking and Diels-Alder reactions during the polymerization of isoprene, which typically constrain the reaction conversion and molecular weight of the final polymers. Using a poly(methacrylic acid) (PMAA) macroRAFT agent synthesized in ethanol at 80 °C, random and block copolymers of PS-PI with a target molecular weight of 50 000 g mole^-1 and a high monomer conversion of ≈80% are achieved under optimized conditions in water-emulsion at 35 °C. ¹H nuclear magnetic resonance (NMR) verified the successful synthesis as well as the high content of 1,4 microstructure in polyisoprene. The thermal analysis via differential scanning calorimetry indicated distinct glass transitions for the microphase-separated PI-PS block copolymer, while a single transition for PI-PS random copolymer, indicating no microphase separation. Furthermore, dynamic light scattering analysis together with transmission electron microscopy provided further insight into the self-assembled emulsion nanoparticles of the polymers indicating a particle size in the range 70 to 130 nm.