Mensah Ebenezer Ekow, Abbas Zulkifly, Azis Raba'ah Syahidah, Ibrahim Nor Azowa, Khamis Ahmad Mamoun, Abdalhadi Daw Mohammad
Faculty of Science Education, University of Education, Winneba, P. O. Box 40, Mampong, Ashanti, Ghana.
Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
Heliyon. 2020 Dec 3;6(12):e05595. doi: 10.1016/j.heliyon.2020.e05595. eCollection 2020 Dec.
The development of microwave absorbing materials based on recycled hematite (α-FeO) nanoparticles and polycaprolactone (PCL) was the main focus of this study. α-FeO was recycled from mill scale and reduced to nanoparticles through high energy ball milling in order to improve its complex permittivity properties. Different compositions (5% wt., 10% wt., 15% wt. and 20% wt.) of the recycled α-FeO nanoparticles were melt-blended with PCL using a twin screw extruder to fabricate recycled α-FeO/PCL nanocomposites. The samples were characterized for their microstructural properties through X - ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The complex permittivity and microwave absorption properties were respectively measured using the open ended coaxial (OEC) probe and a microstrip in connection with a vector network analyzer in the 1-4 GHz frequency range. An average α-FeO nanoparticle size of 16.2 nm was obtained with a maximum imaginary (ε) part of permittivity value of 0.54 at 4 GHz. The complex permittivity and power loss values of the nanocomposites increased with recycled α-FeO nanofiller content. At 2.4 GHz, the power loss (dB) values obtained for all the nanocomposites were between 13.3 dB and 14.4 dB and at 3.4 GHz, a maximum value of 16.37 dB was achieved for the 20 % wt. nanocomposite. The recycled α-FeO/PCL nanocomposites have the potential for use in noise reduction applications in the 1-4 GHz range.
基于回收赤铁矿（α-Fe₂O₃）纳米颗粒和聚己内酯（PCL）的吸波材料的开发是本研究的主要重点。α-Fe₂O₃从氧化皮中回收，并通过高能球磨还原为纳米颗粒，以改善其复介电常数特性。使用双螺杆挤出机将不同组成（5%重量、10%重量、15%重量和20%重量）的回收α-Fe₂O₃纳米颗粒与PCL熔融共混，以制备回收α-Fe₂O₃/PCL纳米复合材料。通过X射线衍射（XRD）和高分辨率透射电子显微镜（HRTEM）对样品的微观结构特性进行了表征。在1-4GHz频率范围内，分别使用开放式同轴（OEC）探头和与矢量网络分析仪相连的微带测量复介电常数和微波吸收特性。获得的α-Fe₂O₃纳米颗粒平均尺寸为16.2nm，在4GHz时介电常数的最大虚部（ε）值为0.54。纳米复合材料的复介电常数和功率损耗值随着回收α-Fe₂O₃纳米填料含量的增加而增加。在2.4GHz时，所有纳米复合材料获得的功率损耗（dB）值在13.3dB和14.4dB之间，在3.4GHz时，20%重量的纳米复合材料达到最大值16.37dB。回收α-Fe₂O₃/PCL纳米复合材料具有在1-4GHz范围内用于降噪应用的潜力。
