Alignment of Shortened Single-Walled Carbon Nanotubes on Chemically Modified Si Wafer Surface
Single-walled carbon nanotubes (SWNTs)를 320 ℃에서 90분 동안 가열하여 비정질 탄소를 제거하고
남아 있는 금속 촉매를 제거하기 위해 염산에 24시간 처리하였다. 정제된 SWNT 표면에 산화반응을 통해 카복실기를 도입하였으며, 가혹한 환경으로 인해 길이가 짧아진 SWNT를 얻었다. 세정된 실리콘 웨이퍼를 3-aminopropyldiisopropylethoxysilane (3-APDIPES)의 톨루엔 용액에 담가 표면에 3-APDIPES의 자기 조립 단층막을 형성시켰다. SWNT의 카복실기와 3-APDIPES의 아미노기 사이의 산-염기 반응을 통해 생성되는 이온 사이의 정전기적 인력을 이용하여 실리콘 웨이퍼 표면에 SWNT를 배열하였다. Atomic Force Microscopy (AFM) 분석을 통해 반응시간과 농도에 따른 효과를 확인하였고, Transmission Electron Microscopy (TEM)을 이용해 산 처리 시간에 따른 효과를 확인하였다.
Single-walled carbon nanotubes (SWNTs) were heated at 320℃ for 90 minutes to remove
amorphous carbons. Then remaining metal particles were removed by HCl treatment for 24 hours. Carboxyl groups were introduced to the surface of purified SWNT through the oxidation process, simultaneously shortened SWNTs were observed because of terrible conditions. Cleaned Si wafer was immersed into the toluene solution of 3-aminopropyldiisopropylethoxysilane (3-APDIPES) to form self-assembled monolayer
(SAM) of 3-APDIPES. SWNTs were aligned to the surface of Si wafer by the electrostatic interaction between carboxyl group of SWNT and amino group of 3-APDIPES. By the investigation of atomic force microscopy (AFM) studies, we identified the effects of reaction time and SWNT concentration. In addition, trasmission electron microscopy (TEM) was also used to identify the effect of acid treatment time for SWNTs.