今日更新:Composites Science and Technology 2 篇
Electrostatically self-assembled three-dimensional conductive network for highly sensitive and reliable skin-like strain sensor
Shengkai Li, Jian Tang, Yudong Liu, Jing Hua, Jinhui Liu
doi:10.1016/j.compscitech.2024.110493
静电自组装三维导电网络,用于制造高灵敏度、高可靠性的类肤应变传感器
In recent years, flexible strain sensors have garnered significant attention in industrial manufacturing and daily life. Sensitivity and reliability are two crucial characteristics of flexible strain sensors in practical applications, and they depend on the development of the sensor's internal conductive network. However, the aggregation phenomenon of conductive fillers in the elastic matrix has a serious impact on the construction of a developed conductive network. In this work, we have designed electropositive amino-functionalized carbon nanotubes (CNTs-p) based on the electrostatic self-assembly of electronegative MXene in the aqueous phase. Compared to the use of surfactants, the electrical modulation of carbon nanotubes through chemical bonding modification is more robust and the electrostatic self-assembly with MXene is more stable. CNTs-p and MXene were self-assembled by electrostatic attraction in butyl latex and uniformly dispersed in the latex. Following demulsification, the polymer composite film (MXene&CNTs-p/IIR) with a three-dimensional conductive network was obtained. The skin-like strain sensor, which utilizes the conductive composite film, demonstrates high sensitivity (gauge factor (GF) = 35137 that is among the highest values for the reported strain sensor), remarkable reliability (The signal monitoring capability remains after 15000 cycles), and excellent responsiveness (62 ms). Additionally, the skin-like strain sensor boasts a wide detection range (0–431%) and unprecedented stability, enabling strain sensing functionality in a wide temperature range of -10—100 °C, as well as strong acid (pH = 1) and strong alkali (pH = 11) environment. The preparation of MXene&CNTs-p/IIR provides a safe, environmentally friendly and effective method for improving the sensitivity and reliability of flexible sensors in wearable intelligent electronics and health detection.
近年来,柔性应变传感器在工业制造和日常生活中备受关注。灵敏度和可靠性是柔性应变传感器在实际应用中的两个关键特性,而这两个特性取决于传感器内部导电网络的发展。然而,导电填料在弹性基体中的聚集现象严重影响了导电网络的构建。在这项工作中,我们基于电负性 MXene 在水相中的静电自组装,设计出了电正性氨基功能化碳纳米管(CNTs-p)。与使用表面活性剂相比,通过化学键修饰对碳纳米管进行电学调制的效果更强,与 MXene 的静电自组装也更稳定。CNTs-p 和 MXene 通过静电吸引在丁基胶乳中自组装,并均匀地分散在胶乳中。破乳后,得到了具有三维导电网络的聚合物复合薄膜(MXene&CNTs-p/IIR)。利用该导电复合薄膜制成的类肤应变传感器具有高灵敏度(测量系数 (GF) = 35137,是目前已报道的应变传感器中最高值之一)、卓越的可靠性(15000 次循环后仍能保持信号监测能力)和出色的响应速度(62 毫秒)。此外,这种类似皮肤的应变传感器还具有很宽的检测范围(0-431%)和前所未有的稳定性,可在 -10-100 °C 的宽温度范围以及强酸(pH = 1)和强碱(pH = 11)环境中实现应变传感功能。MXene&CNTs-p/IIR 的制备为提高可穿戴智能电子产品和健康检测领域柔性传感器的灵敏度和可靠性提供了一种安全、环保和有效的方法。
Construction of micro-nano hybrid structure based on carbon nanotube whisker and alumina for thermally conductive yet electrically insulating silicone rubber composites
Xiaowang Ji, Zhaoyu Lu, Junyan Wang, Neng Ye, Huan Zhang, Letian Zhou, Jingchao Li, Yonglai Lu
doi:10.1016/j.compscitech.2024.110495
构建基于碳纳米管晶须和氧化铝的微纳混合结构,用于导热和绝缘硅橡胶复合材料
High-performance electronics urgently need more effective thermally conductive rubber composites to solve interfacial heat transfer problems in the thermal management systems. Tiny amounts nanocarbon materials (NCM) can significantly improve the thermal conductivity of conventional ceramic-filled rubber composites, but the volume exclusion effect of micrometer ceramic fillers makes NCM highly susceptible to the formation of the conductive pathways, which inevitably leads to the substantial decrease in the volume resistivity of the materials, posing a safety hazard, such as short circuits, to electronic devices. Here, we report an electrostatic self-assembly method to prepare CNW@n-Al2O3 hybrids by loading nano-alumina (n-Al2O3) onto carbon nanotube whiskers (CNW) and co-filling them with micrometer alumina (m-Al2O3) to silicone rubber, constructing a micro-nano-multi-level hybrid network structure, which can fully utilize the high thermal conductivity while shielding the electrical conductivity of CNW. The resulting composite filled with 2 phr of CNW@n-Al2O3 exhibits a significantly enhanced thermal conductivity of 1.137 W/(m·K) and a high volume resistance of 1.323 × 109 Ω cm, and is proved to be used as an excellent thermal interface material to assist the heat dissipation of the microelectronic chip. This study provides a facile and effective strategy for the design of thermally conductive yet electrically insulating rubber composites filled with CNW, which shows a bright application prospect in the thermal management of high-performance electronic devices.
高性能电子产品迫切需要更有效的导热橡胶复合材料来解决热管理系统中的界面传热问题。微量纳米碳材料(NCM)可显著提高传统陶瓷填充橡胶复合材料的导热性能,但微米级陶瓷填料的体积排斥效应使 NCM 极易形成导电通路,从而不可避免地导致材料的体积电阻率大幅下降,给电子设备带来短路等安全隐患。在此,我们报告了一种制备 CNW@n-Al2O3 混合材料的静电自组装方法,即在碳纳米管晶须(CNW)上负载纳米氧化铝(n-Al2O3),并在硅橡胶中共同填充微米氧化铝(m-Al2O3),构建微纳多层次混合网络结构,从而在屏蔽 CNW 导电性的同时充分利用其高热传导性。填充了 2 phr 的 CNW@n-Al2O3 的复合材料的热导率显著提高,达到 1.137 W/(m-K),体积电阻高达 1.323 × 109 Ω cm,可用作优良的热界面材料,帮助微电子芯片散热。该研究为设计填充了氯化萘的导热绝缘橡胶复合材料提供了一种简便有效的策略,在高性能电子设备的热管理方面具有广阔的应用前景。