The application of thermal energy storage (TES) technology in practical engineering has been limited by liquid leakage and material rigidity during phase change. In this study, we prepared novel ...polyethylene glycol (PEG)/polyurethane acrylate (PUA)-based flexible phase-change films (PCFs) using ultraviolet (UV) curing technology to solve these problems. The PCFs showed a desirable phase-change enthalpy (113.1 J/g), low leakage rate (1.70%), reversible optical performance, excellent shape stability, and superior flexibility. The tensile strength of the PCF was 5.00 MPa, and the elongation at break reached 1342.3%, which was five times higher than that of pure PUA, indicating outstanding flexibility and toughness. The as-prepared PCFs show great potential for future applications, such as incorporation into flexible electronic devices and temperature control systems.
Rubber composites with excellent radiation shielding and flexibility are extremely important to personal protective equipments (PPEs) for protecting workers from radiation hazards, especially for ...mixed radiations. It is, however, challenging to achieve uniform dispersion of fillers and good compatibility of the interfaces in highly‐filled rubber composites that are closely related to their physical properties. In this article, lead borate@polydopamine (PBO@PDA) core–shell particles are chemically bonded with silicone rubber (SR) for co‐shielding of neutron and γ‐rays. Uniform dispersion of the core–shell particles and good compatibility of the interfaces give rise to enhanced flexibility of the rubber composites. Particularly, the SR composite with 40 wt% PBO particles displays increases of 106% in elongation at break and 490% in tensile strength to neat SR. Furthermore, the mass attenuation coefficient of γ‐rays (105 KeV) reaches 2.35 and the thermal neutron absorption rate (0.025 eV) of is 76.9%. This work takes into account the balance between radiation shielding and flexibility of rubber composites, which provides a facile strategy to fabricate excellent integrated properties of flexible materials for shielding mixed neutron and γ‐rays.
Lead borate micro–nano particles chemically bonded with silicone rubber are used to coordinately shield thermal neutrons and gamma rays.
Flexible materials with excellent radiation shielding and flexibility are essential to the personal protective equipments (PPEs) for protecting workers from nuclear radiations. However, it is an ...enormous challenge to obtain the desired materials since high loading filler in polymer nanocomposites usually promotes radiation shielding while restrains its flexibility. Here, a facile “thiol‐ene click” means is applied to chemically bond high loading boron nitride (BN) nanoparticles with silicone rubber (SR) in SR/BN nanocomposites for thermal neutron shielding. Uniform dispersion of BN nanoparticles and good compatibility of interfaces in the nanocomposites with high loading filler lead to increased flexibility instead of decrease. In particular, the nanocomposite with 40 wt% BN displays 911% of elongation at break that is about 50% enhancement to that of neat SR. Furthermore, higher loading BN in the nanocomposites means better thermal neutron shielding. Namely, enhanced thermal neutron shielding and flexibility is achieved at SR/BN nanocomposite with 40 wt% BN. The present work provides a facile strategy towards superior integrated performance of flexible materials for radiation shielding, such as wearable devices.
Chemically bonding BN nanoparticles with silicone rubber contributes to good interfacial compatibility in highly‐filled polymer nanocomposites, leading to enhanced radiation shielding and flexibility.
Hydrophobically associating copolymers using acrylamide (AM), acrylic acid (AA), and Styrene (St) as comonomers were successfully prepared by self‐emulsified microemulsion polymerization, in which ...low‐molecular‐weight AM/AA/St copolymers as surfactant and AM as cosurfactant. The structure and chemical composition of AM/AA/St copolymers were characterized by Fourier transform infrared, nuclear magnetic (NMR), and differential scanning calorimeter. The content of PSt in the copolymers is determined by 1H nuclear magnetic resonance spectra, suggesting that the self‐made polymer surfactant can disperse uniformly the St monomers to improve the copolymerization efficiency. Furthermore, the polymerization mechanism of the self‐emulsified microemulsion method is explored preliminarily. During the synthesis of the copolymers, the purified copolymer solution is obtained in one step without using a small molecular emulsifier such as sodium dodecyl sulfate, in order to avoid the complicated post‐treatment process of the small molecular emulsifier. The copolymers revealed good hydrophobic association properties and low surface tension.
Incorporating ultralow loading of nanoparticles into polymers has realized increases in dielectric constant and breakdown strength for excellent energy storage. However, there are still a series of ...tough issues to be dealt with, such as organic solvent uses, which face enormous challenges in scalable preparation. Here, a new strategy of dual in situ synthesis is proposed, namely polymerization of polyethylene terephthalate (PET) synchronizes with growth of calcium borate nanoparticles, making polyester nanocomposites from monomers directly. Importantly, this route is free of organic solvents and surface modification of nanoparticles, which is readily accessible to scalable synthesis of polyester nanocomposites. Meanwhile, uniform dispersion of as ultralow as 0.1 wt% nanoparticles and intense bonding at interfaces have been observed. Furthermore, the PET-based nanocomposite displays obvious increases in both dielectric constant and breakdown strength as compared to the neat PET. Its maximum discharged energy density reaches 15 J cm
at 690 MV m
and power density attains 218 MW cm
under 150 Ω resistance at 300 MV m
, which is far superior to the current dielectric polymers that can be produced at large scales. This work presents a scalable, safe, low-cost, and environment-friendly route toward polymer nanocomposites with superior capacitive performance.
As important physiological regulators, peptides have been used in many fields including medicine, cosmetics, healthcare products, animal nutrition and health, and plant nutrition and protection. In ...recent years, peptides have become a popular research subject in plant protection as antimicrobial and immune inducers, plant growth regulators, insecticides, and herbicides for their extensive raw material sources, excellent activity, and ideal environmental compatibility. This paper briefly introduces peptide research progress, presents an overview of peptide studies in plant protection, and summarizes the application of the peptides in plant protection and prospects for peptides as green agrochemicals.
•Peptides, as new tools in plant protection, have drawn increasing attention in agriculture worldwide.•We present an overview of peptide research progress and their application in plant protection.•About 315 agricultural active peptides are listed and 18 peptide agrochemicals are introduced in this paper.•New technologies will accelerate the growth of peptides as green agrochemicals in eco-agriculture.
In order to solve the problem of poor thermal conductivity of polymer‐based radiation shielding composite materials, h‐BN@PDA@PbWO4 hybrid powders were prepared by combining h‐BN with high thermal ...conductivity and PbWO4 with γ shielding. With the assistance of polydopamine, PbWO4 particles were synthesized in situ on the h‐BN surface. The effects of h‐BN@PDA@PbWO4 on thermal conductivity, γ‐ray shielding, and mechanical properties of chloroprene rubber were studied. The results showed that the hybrid particles had better dispersibility than the pure mixing of h‐BN and PbWO4 in chloroprene rubber and significantly improved the thermal conductivity gamma‐ray shielding performance and mechanical properties of CR composites. When the filler content of the hybrid powder reaches 40 wt%, the thermal conductivity of the composite is about 3.16 times that of the pure CR. The γ shielding rates at 86.5 KeV and 105.3 KeV photon energies increase by 14.14% and 17.61% compared with the pure CR. Compared with pure CR, the tensile strength of the composites increased by 4.79 MPa, and the elongation at break decreased slightly. These were because h‐BN@PDA@PbWO4 shows had an excellent synergistic effect in CR substrate. The new kind of CR/h‐BN@PDA@PbWO4 composite can be used for thermal management and gamma shielding.
The combination of h‐BN and PbWO4 is used to coordinate thermal conductivity and gamma shielding performance.
