臺灣大學: 機械工程學研究所張所鋐簡建軒Chien, Chien-HsuanChien-HsuanChien2013-04-012018-06-282013-04-012018-06-282010http://ntur.lib.ntu.edu.tw//handle/246246/256171利用鐵與錫二元素組成的催化劑使用三段式高溫爐一次大量成長奈米碳螺旋線圈叢所組成的結構，達到實驗室可以量化的目的，再將奈米碳螺旋線圈從試片中移下來，利用超音波震盪的方式混入聚二甲基矽氧烷(polydimethyl siloxane, PDMS)製作成薄片，或者以三明治的包覆方式將所成長出的奈米碳螺旋線圈叢用聚二甲基矽氧烷(polydimethyl siloxane, PDMS)包覆於其中製作成薄片，進行不同重量比的奈米螺旋線圈觀察對於電磁波吸收率之影響，其測量的電磁波範圍在18GHz~26GHz和50GHz~75GHz，成功的製作出以超音波震盪方式的電磁波吸收試片在10wt%下吸收率達到-20dB(吸收率超過99%)的頻率可達56GHz~75GHz範圍內，另外以夾層方式的電磁波吸收試片在10wt%下吸收率達到-20dB(吸收率超過99%)的頻率可達18~26GHz,63~75GHz範圍內，兩者製作方式皆具有寬頻效果，並且利用SEM觀察其碳螺旋線圈的外徑、線徑跟螺距討論吸收性質。Carbon nanocoils(CNCs) had been synthesized in large-scale by pyrolysis of acetylene at 700 ℃ over Fe-Sn nanoparticles derived from chemical vapor deposition. The electromagnetic (EM) wave absorption properties in the gigahertz region (12–110 GHz) of CNCs with a three-dimensional-helical/spiral chiral structure (600~1200 nm coil diameter and 300~500 nm fiber diameter and 500~1500 nm coil pitch) were examined using the open space method. We used two different methods to make EM(Electromagnetic microwave) absorber. It was found that the target value of reflection loss over -20 dB (above 99% absorptivity) necessitated for commercial applications. We obtain the EM absorption composite of 10 wt% addition of CNCs in polydimethyl siloxane (PDMS) for the 18~26,63~75GHz bands by sandwich and 10 wt% addition of CNCs in PDMS for the 56~75GHz bands by ultrasonic vibrating. The thickness of EM absorber are only about 1~1.5mm, and Both have the wideband , high EM absorptivity. The absorption mechanism of the EM wave by CNCs is discussed.8336397 bytesapplication/pdfen-US奈米碳螺旋線圈大量成長電磁波吸收高吸收率寬頻carbon nanocoilselectromagnetic wave absorptionhigh absorptivitywidebandthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/256171/1/ntu-99-R97522623-1.pdf