직경이 0.03 m이고 높이가 1.5 m인 마이크로 액적/기포 유동반응기에서 ZnO 입자의 연속제조 특성을 검토하였다. 마이크로 액적을 운반하는 기체의 속도는 6.0 L/min, 전구체 중 Zn이온의 농도는 0.4 mol/L로 유지하였다. ZnO 입자의 합성을 위한 반응의 온도(973 K~1,273 K)와 마이크로 기포의 유속 (0~0.4 L/min)이 합성된 ZnO 입자의 기공 특성에 미치는 영향을 고찰하였다. 본 연구의 실험범위에서 ZnO 입자의 합성온도는 1,073 K가 합성된 ZnO 입자의 기공을 극대화하는데 최적이었다. 또한, 반응기에서 연속 제조되는 ZnO 입자의 평균크기는 반응온도가 증가함에 따라 감소하였으며 입자의 표면은 점점 매끄럽게 단순화되었다. 반응기 내부에 마이크로 기포를 유입함으로써 유입하지 않는 경우와 비교하여 합성된 ZnO 입자 내부에 기공을 효과적으로 형성시킬 수 있었으며, 평균 BET면적을 58%까지 증가시킬 수 있었다. 마이크로 액적/기포 유동반응기를 사용하여 연속 합성한 ZnO 입자의 평균입도는 반응온도에 따라 1.25~1.75 μm이었다.

Characteristics of continuous preparation of ZnO powder were investigated in a micro drop/bubble fluidized reactor of which diameter and height were 0.03 m and 1.5 m, respectively. The flow rate of carrier gas for transportation of precursors to the reactor was 6.0 L/min and the concentration of Zn ion in the precursor solutions was 0.4 mol/L, respectively. Effects of reaction temperature (973 K~1,273 K) and flow rate of micro bubbles (0~0.4 L/min) on the pore characteristics of prepared ZnO powder were examined. The optimum reaction temperature for the maximum porosity in the ZnO powder was 1,073 K within this experimental condition. The mean size of ZnO powder prepared continuously in the reactor decreased but the surface of the powder became smooth, with increasing reaction temperature. The injection of micro bubbles into the reactor could enhance the formation of pores in the powder effectively, and thus the mean BET surface area could be increased by up to 58%. The mean size of prepared ZnO powder was in the range of 1.25~1.75 μm depending on the reaction temperature.

Micro drop Fluidized reactor ZnO BET Particle Size Pore Size

Sobana N, Swaminathan M, Sep. Purif. Technol., 56(1), 101 (2007)
Morkoc H, Ozgur U, Zinc Oxide: Fundamentals, Materials and Device Technology, Wiley, Germany(2009).
Xu T, Wu G, Zhang G, Hao Y, Sens. Actuators A-Phys., 104, 61 (2003)
Shibata T, Unno K, Makino E, Ito Y, Shimada S, Sens. Actuators A-Phys., 102, 113 (2002)
Gomey H, Olvera ML, Mater. Sci. Eng. B-Solid State Mater. Adv. Technol., 134, 20 (2006)
Li D, Haneda H, Chemosphere, 51, 129 (2003)
Heo JH, You MS, Im SH, Korean Chem. Eng. Res., 51(6), 774 (2013)
Zhang SC, Li XG, Colloids Surf. A: Physicochem. Eng. Asp., 226, 35 (2003)
Wang YJ, Zhang CL, Bi SW, Luo GS, Powder Technol., 202(1-3), 130 (2010)
Lu CH, Yeh CH, Ceram. Int., 26, 351 (2000)
Music S, Dragcevic S, Ivanda M, Mater. Lett., 59, 2388 (2005)
Colon G, Hidalgo MC, Navio JA, Melian EP, Diaz OG, Rodriguez JMD, Appl. Catal. B: Environ., 83(1-2), 30 (2008)
Lu CH, Lai YC, Kale RB, J. Alloy. Compd., 477, 523 (2009)
Lai YL, Meng M, Yu YF, Wang XT, Ding T, Appl. Catal. B: Environ., 105(3-4), 335 (2011)
Yu JG, Yu XX, Environ. Sci. Technol., 42, 4902 (2008)
Thongrom B, Amornpitoksuk P, Suwanboon S, Baltrusaitis J, Korean J. Chem. Eng., 31(4), 587 (2014)
Chaudhari SP, Bodade AB, Chaudhari GN, Korean J. Chem. Eng., 30(11), 2001 (2013)
Yang J, Lin Y, Meng Y, Korean J. Chem. Eng., 30(11), 2026 (2013)
Kang HW, Lim SN, Park SB, J. Hydrol. Eng., 37, 10539 (2012)
Jung DS, Park SB, Kang YC, Korean J. Chem. Eng., 27(6), 1621 (2010)
Li D, Haneda H, J. Photochem. Photobiol. A-Chem., 155, 171 (2003)
El Hichou A, Addou M, Ebothe J, Troyon M, J. Lumines., 113, 183 (2005)
Milosevic O, Uskokovic D, Karanovic LJ, Tomasevic-canovic M, Tronterj M, J. Mater. Sci., 28, 5211 (1993)
Cullity BD, Element of X-ray Diffraction, Addison-Wesley Pub. Co. Reading, MA(1978).
Rouquerol F, Rouquerol J, Sing K, Adsorption by Powders and Porous Solid: Principles, Methodology and Applications, AP, San Diego(1999).
Onsuratoom S, Puangpetch T, Chavadej S, Chem. Eng. J., 173(2), 667 (2011)
Yu HF, Chou HY, Powder Technol., 233, 201 (2013)
Kunii D, Levenspiel O, Fluidization Engineering, Butterwerth-Henemann, Stonehorn, MA(1991).
Serpone N, Maruthamuthu P, Pichat P, Pelizzetti E, Hidaka H, J. Photochem. Photobiol. A-Chem., 85, 247 (1995)