1 μl 정도의 미량 titanium tetraisopropoxide(TTIP)를 주사기를 사용하여 1 cc 부피의 증발관에 주입하여 기화시킨 후 질소에 의해 직경 4 mm, 길이 35 cm의 관형 에어로졸반응기로 운반하여 열분해 시킴으로써 30-300 nm 크기의 TiO2 나노입자를 제조하였으며, 반응온도 및 TTIP 증기 농도가 생성된 TiO2 입자의 형상, 크기, 결정성 등에 미치는 영향을 조사하였다. 전구체 증기 농도 1 mol％에서 반응온도를 300, 500, 700 ℃로 변화시킨 결과 반응온도가 증가함에 따라 응집체를 구성하고 있는 1차 입자 크기가 감소하였고, 700 ℃에서는 입자 크기분포가 bimodal 형태를 나타내었다. 반응온도를 700 ℃로 유지하고 전구체 증기 농도를 1, 3.5, 7 mol％로 변화시킨 결과 전구체 증기 농도 3.5 mol％ 이상 에서는 1 mol％에서 관찰되었던 bimodal 분포가 사라지고 응집체 내 1차 입자들의 개수가 상대적으로 많이 증가하였다. 반응온도 및 전구체 농도가 입자의 형상, 크기분포에 미치는 이와 같은 영향들을 이전의 연구결과들과 함께 비교 분석하였다.

TiO2 particles, 30-300 nm in diameter, were prepared by thermal decomposition of titanium tetraisopropoxide (TTIP) using an aerosol microreactor, by which about 1 μl of the liquid precursor is injected into an evaporator, 1 cc in volume, and vaporized precursor is then transported by nitrogen as a bolus to a tubular reactor 4 mm in diameter and 35 cm in length. Investigated were the effects of the reactor temperature and the concentration of TTIP vapor on the morphology, particle size distribution and crystalline structure of produced TiO2 particles. With TTIP vapor concentration kept constant at 1 mol％, the reactor temperature was varied from 300 to 500 and 700 ℃. The primary particle size decreased with increasing the temperature, and the size distributions were mono-modal at 300 and 500 ℃, but bi-modal at 700 ℃. The TTIP vapor concentration was increased from 1 to 3.5 and 7 mol％, holding the reactor temperature at 700 ℃. The bi-modal distribution seen at the concentration of 1 mol％ disappeared and the number of particles composing an agglomerate increased at the higher concentrations. These effects of the reactor temperature and the precursor concentration were discussed in comparison with experimental results reported earlier.

Titanium Tetraisopropoxide Microreactor Titania Decomposition

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