Ze Wu,Enjie Zhu,Youqiang Xing,Peng Huang,Bingjue Li,Lei Liu
Electrochemical ionic actuators have garnered significant attention following their discovery due to their potential to supplement or replace conventional rigid actuators, owing to their ability to achieve precise control over bending displacement across a wide range. This paper employs an MXene/CNT@Fe 3 O 4 electrode in electrochemical ionic actuators, which consists of a three-dimensional conductive network comprising a one-dimensional carbon nanotube loaded with ferroferric oxide magnetic particles (CNT@Fe 3 O 4 ) and a two-dimensional Ti 3 C 2 T x MXene. This actuator is characterized by high bending displacement (12.3 mm), a comprehensive response range (0.1–10 Hz), fast response time (≈5 s), and excellent durability (5 h, 93% actuation retention). The exceptional characteristics mentioned above can be attributed to manipulating the CNT@Fe 3 O 4 distribution within the MXene layers using magnetic regulation. This approach enhances dispersion and facilitates the formation of a three-dimensional conductive network structure with MXene, enabling efficient and multi-directional ionic migration. Moreover, the artificial muscles have successfully replicated flytraps' predation and birds' claw grasping. This study presents a new idea for the electrode design of electrochemical ionic actuators, elucidating the significant potential of MXene-based soft actuators in the domains of artificial muscles and bionics.
Owing to the large surface energy and easy agglomeration, ferroferric oxide (Fe 3 O 4 ) nanoparticle usually is difficult to be widely application in microwave absorbing coatings. In this paper, a new synthesis process was used to prepare solvent-free fluid Fe 3 O 4 (S-Fe 3 O 4 ) by surface modification of solid Fe 3 O 4 with a long chain of organic bimolecular layer, which showed excellent dispersion in resin materials. Moreover, S-Fe 3 O 4 was compounded with CNT@Fe 3 O 4 to prepare S-Fe 3 O 4 /CNT@Fe 3 O 4 /EP composites, which realized the multiple loss mechanism of electromagnetic wave (EMW) absorption. The results showed that the minimum reflection loss of composite was −52.57 dB with a matching thickness of 3.3 mm; the maximum effective absorption bandwidth at 1.4 mm thickness was 5.2 GHz (12.08–17.28 GHz). This surface molecular engineering composite based on inorganic particles enhanced the attenuation ability of EMW by improving the dispersion of inorganic particles and providing multiple loss mechanisms, which was a novel medium regulation strategy to provide a new insight for nanoparticles in the field of EMW absorbing coatings.
Li Xiaoyan,Li Ming,Peng Wei,Li Chao,Yi Jialong,Zhao Longqi,Song Wenliang
Next-generation wearable electronics demand lightweight membranes integrated with multiple functionalities. Here, heterogeneous composite membranes of carbon nanotubes (CNTs) from vertical orientation to spreading are developed with a simple method to address this challenge. Magnetite (Fe 3 O 4 ) nanoparticles with polydopamine ligands were uniformly adsorbed on acidified CNTs, resulting in magnetic responsive CNTs. Applying a magnet above the filtration membrane yielded a freestanding CNT/Fe 3 O 4 heterogeneous membrane with an adaptive gradient structure of CNTs transitioning from vertically aligned to horizontally spread. The heterogeneous surfaces of the magnetically aligned CNT/Fe 3 O 4 composite membranes displayed distinct differences in water contact angle, electrical conductivity, and thermal conductivity. Based on the adaptive alignment of CNTs, the fabricated freestanding heterogeneous composite membranes exhibited remarkable Joule heating effect and enhanced electromagnetic shielding effect. Graphical abstract
危险品化学品经营许可证（带存储）