灵活的磁热纤维子用于室温能源应用
Vahideh Bayzi Isfahani1,2, Indrani Coondoo2, Igor Bdikin3,4
1Centre of Physics of Minho and Porto Universities (CF-UM-UP), LAPMET, Physics Department, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
ACS applied materials & interfaces
|February 1, 2024
概括
研究人员开发了一种柔性复合材料,使用电活性聚乙烯化物 (PVDF) 纤维和磁热La,Fe,Si) 颗粒. 这种新型材料保留了巨大的磁热性能和增强的压电性,为高效,环保的制冷和传感器件提供了潜力.
科学领域:
- 材料科学 材料科学 材料科学
- 热力学是一种热力学.
- 纳米技术纳米技术
背景情况:
- 磁热制冷为传统系统提供了一个环保的替代方案,但它面临着材料机械性能和加工方面的挑战.
- 多刺激热力学循环和多多制冷剂提高了热的效率.
- 开发多功能材料是克服磁热技术当前局限性的关键.
研究的目的:
- 创建一个灵活,易于塑造的磁热材料,具有用于先进制冷和传感应用的增强性能.
- 将La,Fe,Si) 13粒子的磁热效应与聚乙烯化物 (PVDF) 纤维的压电特性相结合.
- 为了解决传统磁热材料的机械性质挑战.
主要方法:
- 电技术被用来制备电活性 (EA) 聚乙烯化物 (PVDF) 纤维的柔性复合材料地毯,其中嵌入了La,Fe,Si) 颗粒.
- 结构特征涉及X射线衍射 (XRD) 分析和富里埃变换红外光谱学 (FTIR).
- 为了评估压电性质,进行了局部尺度的压电响应测量.
主要成果:
- 该复合材料表现出一个立方NaZn13类型的结构,用于La (Fe,Si) 13阶段和PVDF.的主导极 β-阶段.
- 在PVDF-La(Fe,Si) 13复合物中观察到 -11.01 pm/V的增强纵向压电系数 (有效d33),而仅PVDF的 -9.36 pm/V.
- 在PVDF-La(Fe,Si) 13复合物中成功保留了La(Fe,Si) 13粉末的巨大的磁热效应.
结论:
- 一种新的,灵活的,多功能复合材料通过在PVDF电纤维中嵌入La (Fe,Si) 颗粒成功开发出来.
- 复合材料显示保留了巨大的磁热特性和增强的压电性,使其适用于多热热设备.
- 这种材料为开发下一代节能,环保冷却和传感技术提供了有希望的解决方案.
相关概念视频
01:31Ferromagnetism
2.4K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.4K
01:28Magnetostatic Boundary Conditions
934
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
934
01:24Energy In A Magnetic Field
2.3K
If a magnetic field is sustained, there must be a current in a closed circuit or loop, implying some energy has been spent in creating the field. If this energy is not dissipated via the circuit's resistance, it is stored in the field.
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...
2.3K
01:17Magnetic Damping
458
Eddy currents can produce significant drag on motion, called magnetic damping. For instance, when a metallic pendulum bob swings between the poles of a strong magnet, significant drag acts on the bob as it enters and leaves the field, quickly damping the motion.
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
458
01:22Magnetic Force On Current-Carrying Wires: Example
1.5K
In a magnetic field, moving charges encounter a force. If a wire contains these moving charges, i.e., if the wire is carrying a current, then a force acts on the wire as well. Consider a pair of flexible leads holding a wire that is 40 cm long and 10 g in weight in a horizontal position. The wire is placed in a constant magnetic field of 0.40 T, as shown in Figure 1(a). Determine the magnitude and direction of the current flowing in the wire needed to remove the tension in the supporting leads.
1.5K
01:23Faraday Disk Dynamo
2.2K
A Faraday disk dynamo is a DC generator, producing an emf that is constant in time. It consists of a conducting disk that rotates with a constant angular velocity in the magnetic field, perpendicular to the disk's plane. The rotation of the disk causes a change in magnetic flux, which induces an emf, causing opposite charges to develop on the rim and in the center of the disk. The polarity of the induced emf can be determined by the direction of the magnetic field and the direction of the...
2.2K