Macromolecular Rapid Communications最新文献

To develop a binder system suitable for photocurable additive manufacturing of solid propellants, this study utilizes ethylene oxide-tetrahydrofuran copolyether (PET), a commonly employed binder in solid propellants, as foundational material. By modifying terminal groups, two photocurable binders are synthesized: allyl-terminated polyether (AUPET) and acrylate-terminated polyether (PUA). The exothermic behavior of photopolymerization and the mechanical properties of these binders are comprehensively investigated. PUA exhibits a significantly faster photopolymerization rate than AUPET, enabling rapid photocuring and molding. Both binders demonstrate photocuring capability in the presence of thiols. Mechanical property testing indicates PUA forms brittle films under self-curing conditions, with a tensile strength of 1.18 MPa and an elongation at break of 81.07%, whereas AUPET, upon curing in the presence of thiol, exhibits enhanced flexibility, showing a tensile strength of 0.37 MPa and an elongation at break of 587.49%. Additionally, incorporating a triazine ring structure significantly enhances the tensile strength of PUA and AUPET films, the presence of thiols improves their elongation at break.

Poly(thioctic acid) materials exhibit excellent room-temperature self-healing properties due to their dynamic disulfide-bonded supramolecular network and have been widely used in applications such as wearable devices, adhesives, and wound patches. However, the limited mechanical properties of poly(thioctic acid) materials with dynamic supramolecular networks limit their practical applications. Therefore, there is an urgent need for a low-energy-consuming and facile method to enhance their mechanical strength and maintain their room-temperature self-healing properties. Here, a novel approach is developed by introducing Eu³⁺-coordination into the copolymerization of thioctic acid (TA) and sodium thioctate (ST), forming hierarchical dynamic supramolecular networks. Copolymerization of TA and ST under mild conditions (60 °C in ethanol/water solvent) introduces stable hydrogen-bonding interactions without additional chemical cross-linkers. Further Eu³⁺-coordination increases the mechanical modulus of the films by more than 100-fold while significantly improving toughness and strength. This is attributed to the large ionic radius and high coordination number of Eu ions with carboxylates which significantly enhanced the strength of the crosslinked network. This strategy offers a novel pathway for developing supramolecular materials with an optimal balance of mechanical strength and self-repairing capabilities, advancing their potential in various applications.

Ionogels filled with non-volatile ionic liquids effectively mitigate issues such as solvent volatilization, making them suitable for flexible sensors. However, it remains challenging to fabricate recyclable ionogels with outstanding mechanical properties, high transparency, and recyclable capabilities. In this study, a transparent ionogel with dynamic networks is prepared by in situ polymerization of thioctic acid (TA) with polyvinyl pyrrolidone (PVP) in a halometallate ionic liquid. Due to the abundant dynamic crosslinks formed between the halometallate ionic liquid and PTA along with the rigidity of PVP, the ionogels exhibited excellent mechanical strength (≈6.14 MPa), satisfying stretchability (≈1000%), and high toughness (≈20.08 MJ m^-3). Meanwhile, the ionogel displayed high transparency, UV shielding capability, recyclability, and reprocessability. Enabled by the electrochemical properties, the ionogel can be used for flexible sensors, demonstrating good sensitivity and stability for repeatable use. This work provides a straightforward approach for synthesizing high-performance ionogels for flexible sensing applications.

Herein, the photopolymerization of metal-salt/amide-based deep eutectic monomers (DEMs) derived from lithium, sodium, and potassium bis(trifluoromethanesulfonyl) imide (LiTFSI, NaTFSI, and KTFSI, respectively) is described. Three series of DEMs consisting of N-isopropyl acrylamide (NIPAM) and three different metal salts (LiTFSI, NaTFSI, and KTFSI) are tested at various molar ratios to identify suitable combinations. NIPAM/LiTFSI (1/0.2, 1/0.3, 1/0.4, and 1/0.5) and NIPAM/NaTFSI (1/0.2 and 1/0.3) are obtained as liquid DEMs by simple mixing under ambient conditions (≈25 °C in air), while NIPAM/KTFSI (1/0.1, 1/0.2, and 1/0.3) is obtained as a liquid DEM at 50 °C. The nature of the metal species and NIPAM/metal salt ratio affected the characteristic features of the DEMs and specific interactions. Ultrafast photopolymerization of NIPAM/metal salt DEMs is achieved using LED-UV light, with nearly complete monomer conversion attained within 10 s. The mechanical and thermal properties of the polymerized DEMs (PDEMs) depended substantially on the metal species and NIPAM/metal salt ratio. P(NIPAM/0.2LiTFSI) with 20 wt.% succinonitrile (SN) serving as a plastic crystal exhibited the highest ionic conductivity (1.05 × 10^-4 S cm^-1 at 55 °C), and P(NIPAM/0.2NaTFSI) and P(NIPAM/0.2KTFSI) also exhibited improved ionic conductivities of 4.19 × 10^-5 and 6.64 × 10^-5 S cm^-1, respectively, at 55 °C with 20 wt.% SN.

The synthesis of an amphiphilic three-arm block copolymer (AB)₃-BCP, which consists of poly(methyl methacrylate) (PMMA) and poly(butyl methacrylate) (PBMA) in the hydrophobic inner block, is reported. The hydrophilic block segment is based on poly(2-hydroxyethyl methacrylate) (PHEMA) originating from 2-(trimethylsiloxyl)ethyl methacrylate (HEMA-TMS). The preparation is carried out in two steps using a core-first approach. Using atom transfer radical polymerization (ATRP) as a controlled polymerization technique, three (AB)₃-BPCs with HEMA contents of 15 to 38 mol^-1 % are prepared, applying different reaction conditions. Porous structures are generated from these BCPs by applying a self-assembly and nonsolvent-induced phase separation (SNIPS) protocol. Complex surface structures are observed using scanning electron microscopy (SEM). Bulk morphologies are investigated for a better understanding of the underlying self-assembly. For PHEMA-rich (AB)₃-BCPs, non-regular lamellar microphases are observed in transmission electron microscopy (TEM) and confirmed by small-angle X-ray scattering (SAXS). The porous structures and their expected swelling characteristics are analyzed using atomic force microscopy (AFM) in air and water. Time-resolved measurements in water indicate a rapid swelling after immersion into the water bath. The present study paves the way for exciting porous materials based on the herein synthesized amphiphilic three-arm block copolymers useful for applications as absorber materials and coatings.

Developing high-performance, low-resistance, and recyclable air filtration materials remains a formidable challenge. Herein, silica nanoparticles (SiO₂ NPs) and supramolecular complexes consisting of melamine (MA) and trimesic acid (TMA) are constructed as SiO₂@MA·TMA supramolecular nanofibrous composite membrane via a thermally induced precursor process (TIPC) for efficient particulate matter (PM) removal. Hydrophilic SiO₂ NPs as additional nucleation mediators can not only promote the growth of MA·TMA nanocrystalline fibers by shortening the interfacial free energy and thus reducing the nucleation barrier, but also increase fiber surface roughness thus constructing hierarchical structure of membrane. Under the synergy of MA·TMA nanocrystalline fibers and SiO₂ NPs, the membranes possess high filtration efficiency of 99.82% for PM₁, 99.96% for PM_2.5, and 99.98% for PM₁₀ with low air resistance (153 Pa, <0.15% of standard atmospheric pressure). Taking advantage of the thermally reversible property of supramolecular complexes, the closed-loop recycling of MA·TMA nanocrystalline fibers and SiO₂ NPs are realized. Only green solvents (water and ethanol) are involved in the TIPC process, making this strategy environmentally-friendly and cost-effective. This work not only provides an innovative strategy for the preparation of supramolecular nanofibrous composite materials, but opens an avenue for the development of recyclable high-performance air filters.

The supramolecular polymerization of diketopyrrolopyrrole (DPP) derivatives has emerged as a promising strategy for advancing electronic and photonic materials. Gaining a comprehensive understanding of how the structural design of DPP monomers influences their supramolecular polymerization behavior is crucial for the rational design of materials with tailored properties. In this study, a series of DPP derivatives sharing a common molecular framework but differing in core structures, terminal groups, and spacers is synthesized and investigated. The comparative analysis reveals that these structural variations significantly impact the kinetics and mechanisms of the supramolecular polymerization, as well as the aggregate morphologies of the resulting supramolecular polymers. These findings offer valuable information for the strategic design and precise assembly of dye-based supramolecular polymers with complex architectures.

Radioactive pertechnetate (TcO₄ ^-) from the nuclear fuel cycle presents a severe risk to the environment due to its large solubility in water and non-complexing nature. By utilizing the chaotropic properties of TcO₄ ^- and its nonradioactive surrogate perrhenate (ReO₄ ^-) and the principle of chaotropic interactions, a series of quaternary ammonium-containing polyelectrolyte brush-grafted silica particles are designed and applied to remove ReO₄ ^- from water. These cationic hairy particles (HPs) are synthesized by surface-initiated atom transfer radical polymerization of 2-(N,N-dimethylamino)ethyl methacrylate and subsequent quaternization with various halogen compounds. Dynamic light scattering (DLS) studies showed that the HPs with sufficiently long N-alkyl and N-benzyl substituents underwent sharp size reduction transitions in water when titrated with a KReO₄ solution, indicating strong chaotropic interactions between the brushes and ReO₄ ^-. All the HPs exhibited fast adsorption kinetics; the HPs with longer N-alkyl and N-benzyl substituents showed higher capabilities of removing ReO₄ ^- than those with shorter N-alkyls. Moreover, the brush particles with longer N-substituents displayed a significantly stronger ability in selective adsorption of ReO₄ ^- than the particles with shorter N-substituents in the presence of competing anions, such as F^-, Cl^-, NO₃ ^-, and SO₄ ^2-. This work opens a new avenue to design high-performance adsorbent materials for TcO₄ ^- and ReO₄ ^-.

The development of multifunctional nanotheranostic platforms with stimuli-responsive capabilities holds significant potential for enhancing cancer diagnosis and treatment. Herein, a glutathione (GSH)-responsive semiconducting polymer (SP) nanotheranostic system, SP/DOX-SS-PEG nanoparticles (NPs), is presented, designed for combined near-infrared II (NIR-II) fluorescence imaging (FI) and chemo-photothermal therapy. The amphiphilic SP (SP-SS-PEG) is synthesized through a multi-step reaction sequence, including Suzuki coupling, amidation, and thiol-disulfide exchange reactions, and subsequently encapsulates the anticancer drug doxorubicin (DOX) through self-assembly, resulting in the formation of GSH-responsive SP/DOX-SS-PEG NPs. These SP/DOX-SS-PEG NPs exhibit high photothermal stability and significant GSH-triggered DOX release. In vitro studies demonstrate that SP/DOX-SS-PEG NPs display enhanced cellular uptake and robust cytotoxicity against 4T1 cancer cells under 808 nm laser irradiation. Upon intravenous injection in tumor-bearing mice, NIR-II FI reveals efficient tumor accumulation and prolonged retention of the NPs. In vivo anti-tumor efficacy studies indicate that SP/DOX-SS-PEG NPs combined with 808 nm laser irradiation achieve the most significant inhibition of tumor growth, with minimal systemic toxicity. Taken together, these findings highlight the promising potential of SP/DOX-SS-PEG NPs as a multifunctional platform for precision cancer theranostics, integrating efficient NIR-II imaging, GSH-triggered drug release, and dual chemo-photothermal therapy.

The conversion and utilization of greenhouse gases and other polluting gases in a green way represents a crucial strategy for developing C₁ chemistry and mitigating the dual crises of energy scarcity and the greenhouse effect. As a class of polyatomic molecules with a relatively simple structure, gas molecules are directly involved in the assembled process as the building blocks, converting them into polymer assemblies under mild and low energy consumption, and constructing recyclable functional assembled materials, which is of great significance to enrich the building block of assembly and promote the sustainable value-added of gas. The dynamic gas bridge is a new way of combining gas with other molecules, it provides the possibility for gas conversion and dynamic assembly. This perspective systematically introduces the formation mechanism and unique physicochemical properties of the dynamic gas bridge, and discusses the latest research progress of dynamic gas-bridged chemistry with a particular focus on three key aspects: gas-regulated assembled system, gas-constructed assembled materials, and green and efficient catalysis. Finally, a perspective on critical challenges and future directions of assembled materials based on dynamic gas bridge chemistry are also highlighted.