Nitrate-citrate 혼합 전구체로부터 ZnO 입자 합성을 위한 자체진행 반응(Self-propagating reaction)의 특성을 고찰하였다. 질화물과 Citrate 그룹간의 자체진행 반응을 위해 탄소/질소 성분의 비는 0.7~0.8 수준으로 유지하였으며, 출발물질의 시료를 TGA방법에 의해 열분해하였다. 반응의 후반부인 반응 전환율이 0.5 이상에서 자체진행 반응의 특성을 나타내었으며 시료는 매우 짧은 시간에 많은 열을 방출하며 분해되었다. 반응의 전반부(X<0.5)가 전체반응의 율속단계로 나타났으며, 이 율속단계에서 반응의 특성을 Friedman, Ozawa-Flynn-Wall 그리고 Vyazovkin의 방법들을 사용하여 해석하였다. 율속단계에서 활성화 에너지는 46~130 (kJ/mol)의 범위로 반응 전환율이 증가함에 따라 증가하였으며, 반응차수는 2.9~0.9, 그리고 반응속도의 빈도인자(Frequency factor)는 85~287 (min-1)의 범위에서 승온속도가 증가함에 따라 각각 전자는 감소하고 후자는 증가하였다.

Characteristics of self-propagating reaction for the preparation of ZnO powder from precursors composed of nitrate and citrate compounds were examined. The ratio of C/N was maintained in range of 0.7~0.8 to initiate the selfpropagating reaction between the reducing citrate and oxidizing nitrate groups. The samples were decomposed thermally by using TGA. The sudden decomposition occurred in the range of X > 0.5 in a very short time with a very sharp decrease of mass, indicating that the self-propagating reaction would occur. Friedman, Ozawa-Flynn-Wall and Vyazovkin methods were employed to predict the activation energy, reaction order and frequency factor of the reaction rate in the rate determining step of X < 0.5 range. The activation energy increased with increasing fractional conversion in the range of 46~130 (kJ/min). The reaction order decreased in the range of 2.9~0.9, while the frequency factor increased in the range of 85~278 (min-1), respectively, with increasing the rate of temperature increase.

Self-propagating reaction Activation energy Reaction order Frequency factor ZnO powder Nitrate-Citrate precursor

Roy TK, Sanyal D, Bhowmick D, Chakrabarti A, Mater. Sci. Semicond. Process, 16, 332 (2013)
Lee SH, Yang SW, Lim DH, Yoo DJ, Lee CK, Kang GM, Kang Y, Korean Chem. Eng. Res., 53(5), 597 (2015)
Liu SZ, Zhang YC, Wang TX, Yang FX, Mater. Lett., 71, 154 (2012)
Zeng Y, Qiao L, Bing Y, Wen M, Zou B, Zheng W, Zhang T, Zou G, Sens. Actuators B-Chem., 173, 897 (2012)
Chaudhari SP, Bodade AB, Chaudhari GN, Korean J. Chem. Eng., 30(11), 2001 (2013)
Thongrom B, Amornpitoksuk P, Suwanboon S, Baltrusaitis J, Korean J. Chem. Eng., 31(4), 587 (2014)
Yu HF, Chou HY, Powder Technol., 233, 201 (2013)
Lu CH, Lai YC, Kale RB, J. Alloy. Compd., 477, 523 (2009)
Chakraborty A, Devi PS, Maiti HS, Mater. Lett., 20, 63 (1994)
Chakraborty A, Devi PS, Roy S, Maiti HS, J. Mater. Res., 9, 986 (1994)
Chakraborty A, Devi PS, Maiti HS, J. Mater. Res., 10, 918 (1995)
Bell RJ, Millar GJ, Drennan J, Solid State Ion., 131(3-4), 211 (2000)
Blank DHA, Kruidhof H, Flokstra J, J. Phys. D-Appl. Phys., 21, 226 (1988)
Mancic L, Milosevic O, Marinkovic B, Lopez S, Rizzo F, Physica C.-Superconductivity, 341-348, 503 (2000)
Friedman HL, J. Polym. Sci. Part C, 6, 183 (1964)
Kim SJ, Lee CG, Song PS, Yun JS, Kang Y, Kim JS, Choi MJ, J. Korean Ind. Eng. Chem., 14(5), 634 (2003)
Pielichowski K, Solid State Ion., 104(1-2), 123 (1997)
Music S, Dragcevic S, Ivanda M, Eur. Polym. J., 43, 980 (2007)
Kim UY, Son SM, Kang SH, Kang Y, Kim SD, Jung H, Korean Chem. Eng. Res., 45(6), 604 (2007)
Vyazovkin S, Wight CA, Int’l. Rev. Phy. Chem., 17, 407 (1998)
Vyazovkin S, Wight CA, Thermochim. Acta, 340-341, 53 (1999)
Park SW, Jang CH, Waste Manage., 27, 422 (2010)