Hussein Mousa I, Jehangir Syed S, Rajmohan I J, Haik Y, Abdulrehman Tahir, Clément Q, Vukadinovic N
United Arab Emirates University (UAEU), Al Ain, 15551, UAE.
Texas A & M University-Kingsville, Kingsville, TX, 78363, USA.
Sci Rep. 2020 Sep 29;10(1):16013. doi: 10.1038/s41598-020-72928-1.
In this study, we report on the electrical properties of multi-wall carbon nanotubes (MWCNT) composites functionalized with metal or metal alloy oxides and embedded in a polyurethane matrix to develop a lightweight material for microwave absorption and shielding. The CNT nanoparticles are functionalized with metallic oxides such as Cobalt oxide, Iron oxide, and Cobalt Iron oxide, at three different concentrations. Metallic oxides are used at 5%, 10%, and 20% concentration of the total CNT percentage weight. The resulting functionalized CNT is mixed with polyurethane polymer at 5% wt of the total composite weight. Three sets of cylindrical samples are developed, and each set contains three different metal oxide concentrations. The dielectric properties of the nine developed samples are obtained by measuring their permittivity spectra using an open-ended coaxial probe technique in the spectral range 5-50 GHz. The absorption efficiency of the composites is then obtained by calculating the reflection loss at normal incidence. The results show that the spectral range of absorption can be tuned by changing the CNT concentration, and the material thickness. Functionalized CNT with different alloyed metal oxides enhanced the absorption efficiency of the polyurethane/CNT composites. Such functionalized composites can be used to replace the common heavyweight materials used for microwave applications.
在本研究中，我们报告了用金属或金属合金氧化物功能化并嵌入聚氨酯基体中的多壁碳纳米管（MWCNT）复合材料的电学性能，以开发一种用于微波吸收和屏蔽的轻质材料。碳纳米管纳米颗粒用金属氧化物如氧化钴、氧化铁和钴铁氧化物进行功能化，浓度为三种不同值。金属氧化物的使用浓度为碳纳米管总重量百分比的5%、10%和20%。所得功能化碳纳米管与聚氨酯聚合物按总复合材料重量的5%重量比混合。制备了三组圆柱形样品，每组包含三种不同的金属氧化物浓度。通过使用开放式同轴探头技术在5 - 50 GHz光谱范围内测量其介电常数光谱，获得九个制备样品的介电性能。然后通过计算垂直入射时的反射损耗来获得复合材料的吸收效率。结果表明，吸收光谱范围可通过改变碳纳米管浓度和材料厚度来调节。用不同合金化金属氧化物功能化的碳纳米管提高了聚氨酯/碳纳米管复合材料的吸收效率。这种功能化复合材料可用于替代用于微波应用的常见重质材料。
