A multifunctional microwave absorber with high thermal conductivity for 5G base station packaging comprising silylated GO/FeSiAl epoxy composites were fabricated by a simple solvent-handling method, ...and its microwave absorption properties and thermal conductivity were presented. It could act as an applicable microwave absorber for highly integrated 5G base station packaging with 5G antennas within a range of operating frequency of 2.575-2.645 GHz at a small thickness (2 mm), as evident from reflection loss with a maximum of -48.28 dB and an effective range of 3.6 GHz. Such a prominent microwave absorbing performance results from interfacial polarization resonance attributed to a nicely formed GO/FeSiAl interface through silylation. It also exhibits a significant enhanced thermal conductivity of 1.6 W/(mK) by constructing successive thermal channels.
Hybrid copolymerization of structurally different, reactivity and mechanism distinct monomers (e.g., cyclic and vinyl type monomers) is of great interest and challenge for both academic research and ...practical application. Herein, ethylene oxide-co-tert-butyl methacrylate-co-poly(ethylene glycol) benzyl methacrylate (EO-co-BMA-co-bPEO), a statistical copolymer was synthesized via hybrid copolymerization of EO and BMA using an uncharged, non-nucleophilic organobase t-BuP4 as the catalyst. Detailed characterizations indicate that hybrid copolymerization of ethylene oxide and vinyl monomer forms a statistical copolymer concurrently with the transesterification of tert-butyl group and oligomer PEO anions. The application of the copolymer as all solid lithium-ion battery polymer electrolyte was investigated by detecting the ionic conductivity (σ) with electrical impedance spectrum measurement.
Multicomponent polymerization (MCP) is a fascinating synthetic method for the construction of polymers with diverse structures and multifunctionalities. As a rapidly developing field, MCP begins to ...show great impact in polymer chemistry and polymer materials, which attract scientists’ attention by their high convenience and efficiency, great structure diversity, high atom economy, and environmental benefit. In this work, a facile one-pot three-component polymerization of diynes, disulfonyl azides, and iminophosphorane is developed to construct N, O, S, and P-containing heteroatom-rich poly(phosphorus amidine)s with advanced functionalities. The optimized MCP proceeds at room temperature in THF under the catalysis of CuI, generating polymers with high molecular weights (up to 85 600 g/mol) in excellent yields (up to 92%). The MCP enjoys general applicability of various monomers including aromatic and aliphatic alkynes, and the only byproduct generated from the polymerization is nitrogen gas, demonstrating high atom economy and environmental benefit. Interestingly, the phosphorus amidine model compounds were found to possess both aggregation-induced emission behavior and thermally activated delayed fluorescence, indicating unique feature of the corresponding polymer materials. The polymers generally enjoy good solubility in polar organic solvents, good film-forming ability, satisfactory thermal stability, and high refractivity. They can also function as fluorescent chemosensors for Pd2+ ions detection with high sensitivity (K q up to 207 600 M–1) and selectivity. This MCP provides an efficient approach for the synthesis of heteroatom-rich multifunctional polymer materials, which directly construct the luminescent phosphorus amidine moiety in situ, demonstrating high synthetic efficiency and the potential application in material science.
Ionogels have gained increasing attentions as a flexible conductive material. However, it remains a big challenge to integrate multiple functions into one gel that can be widely applied in various ...complex scenes. Herein, a kind of multifunctional ionogels with a combination of desirable properties, including transparency, high stretchability, solvent and temperature resistance, recyclability, high conductivity, underwater self‐healing ability, and underwater adhesiveness is reported. The ionogels are prepared via one‐step photoinitiated polymerization of 2,2,2‐trifluoroethyl acrylate and acrylamide in a hydrophobic ionic liquid. The abundant noncovalent interactions including hydrogen bonding and ion–dipole interactions endow the ionogels with excellent mechanical strength, resilience, and rapid self‐healing capability at room temperature, while the fluorine‐rich polymeric matrix brings in high tolerance against water and various organic solvents, as well as tough underwater adhesion on different substrates. Wearable strain sensors based on the ionogels can sensitively detect and differentiate large body motions, such as bending of limbs, walking and jumping, as well as subtle muscle movements, such as pronunciation and pulse. It is believed that the designed ionogels will show great promises in wearable devices and ionotronics.
A physically crosslinked multifunctional ionogel is designed and prepared via a simple one‐step photoinitiated polymerization of a fluorinated monomer and a hydrogen bond enabling comonomer in a hydrophobic ionic liquid. The ionogels possess excellent comprehensive performance, including high transparency, robust mechanical properties, self‐healing and self‐adhesion in air/underwater, easy recyclability, solvent tolerance, and sensitive and reliable strain sensing.
Active ingredients from Traditional Chinese Medicines (TCMs) have been a cornerstone of healthcare for millennia, offering a rich source of bioactive compounds with therapeutic potential. However, ...the clinical application of TCMs is often limited by challenges such as poor solubility, low bioavailability, and variable pharmacokinetics. To address these issues, the development of advanced polymer nanocarriers has emerged as a promising strategy for the delivery of TCMs. This review focuses on the introduction of common active ingredients from TCMs and the recent advancements in the design and application of polymer nanocarriers for enhancing the efficacy and safety of TCMs. We begin by discussing the unique properties of TCMs and the inherent challenges associated with their delivery. We then delve into the types of polymeric nanocarriers, including polymer micelles, polymer vesicles, polymer hydrogels, and polymer drug conjugates, highlighting their application in the delivery of active ingredients from TCMs. The main body of the review presents a comprehensive analysis of the state-of-the-art nanocarrier systems and introduces the impact of these nanocarriers on the solubility, stability, and bioavailability of TCM components. On the basis of this, we provide an outlook on the future directions of polymer nanocarriers in TCM delivery. This review underscores the transformative potential of polymer nanocarriers in revolutionizing TCM delivery, offering a pathway to harness the full therapeutic potential of TCMs while ensuring safety and efficacy in a modern medical context.
Nitrogen-containing polymers are a group of fascinating materials, which are usually prepared from nitrogen-containing organic monomers produced from NH3 gas or aqueous solution of ammonia. The ...direct utilization of safe, clean, convenient, and inexpensive inorganic NH4Cl salt as a nitrogen source for the construction of functional polymers is highly desired but challenging. Multicomponent polymerizations, with their strong designability, structural diversity, high efficiency, simple procedure, and environmental benefit, have been proven to be powerful tools to efficiently convert simple monomers to complex polymer materials. In this work, Cu(I)-catalyzed multicomponent polymerizations of alkynes, sulfonyl azides, and NH4Cl are developed, utilizing simple inorganic NH4Cl salt to serve as a monomer for the preparation of functional poly(sulfonyl amidine)s. The heterogeneous polymerization goes smoothly at room temperature in CH2Cl2/tetrahydrofuran, which is also applicable to a range of different monomer structures, affording seven poly(sulfonyl amidine)s with high yields (up to 96%) and high molecular weights (up to 47,100 g/mol). Unique functionalities such as photophysical properties and metal ion detection can be introduced to the poly(sulfonyl amidine)s either from monomer structures or the in situ generated product structures, rendering them as selective and sensitive fluorescence sensors for Ru3+. This multicomponent polymerization showed high synthetic efficiency with environmental and economic benefit, which has opened up a feasible synthetic method of using inorganic NH4Cl salt instead of organic amines, isocyanates, isocyanides, or nitriles to construct nitrogen-containing polymers, demonstrating a promising synthetic approach for the synthesis of advanced functional polymer materials.
► The room temperature ferromagnetism was suppressed by Cu doping in ZnO. ► Enhance room temperature ferromagnetism was observed in Zn0.98Cu0.02O after annealing in H2. ► The ferromagnetism ...originates from the neighboring Cu ions mediated by the interstitial H ions.
Abstract
Zn0.98Cu0.02O powders have been synthesized by microemulsion method. The room temperature ferromagnetism was significantly suppressed, compared with the ZnO powders prepared by the same method. Enhanced room temperature ferromagnetism has been obtained after annealing in H2 atmosphere at 500°C for 2h. The structural characterizations have confirmed the incorporation of the interstitial H and the suppression of the O vacancies. The possibility of the O vacancy mediated room temperature ferromagnetism has been excluded. Our results clearly demonstrated that the observed ferromagnetism originates from the neighboring Cu ions mediated by the interstitial H ions.
Pure ZnO films were prepared by pulsed laser deposition on oxidized Si substrates under different oxygen pressure and substrate temperature. Clear room temperature ferromagnetism has been observed in ...the ZnO film prepared under high vacuum and room temperature. The observation of anomalous Hall effect confirms the intrinsic nature of the ferromagnetism. The photoluminescence and X-ray photoelectron spectroscopy spectra show the high concentration of oxygen vacancies in the ferromagnetic ZnO film. Our results clearly demonstrate the ferromagnetic contribution of the oxygen vacancies mediated by the spin polarized electrons hopping between discrete states in pure ZnO.
Objective Increasing evidence has proved the functions of microRNAs (miRNAs) in human diseases, our research was designed to explore the effects of miR-133b on the progression of depression with the ...involvement of connective tissue growth factor (CTGF). Methods Depression rat models were established by chronic unpredictable mild stress, then the ethology of rats in each group was observed, and the morphological changes as well as the apoptosis of hippocampal neurons was measured. Subsequently, the expression of miR-133b, CTGF, glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF), Bax, Bcl-2, interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α) and neurotransmitters was determined. The target relation between miR-133b and CTGF was assessed. Results We have found in this study that miR-133b was poorly expressed, and CTGF was highly expressed in hippocampal tissues of depression rats. Additionally, elevated miR-133b and inhibited CTGF could restrain apoptosis of hippocampal neurons, repress inflammatory reaction, and increase the expression of GFAP, BDNF and neurotransmitters in hippocampal tissues of depression rats, resulting in a protective impact on neural injury in depression rats. Conclusion This study demonstrates that elevated miR-133b could suppress the expression of CTGF to protect the hippocampal neurons from apoptosis and inflammatory injury in depression rats.
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