THERMODYNAMIC MODELING OF HYDROTHERMAL SYNTHESIS OF CERAMIC POWDERS

被引:313
作者
LENCKA, MM [1 ]
RIMAN, RE [1 ]
机构
[1] RUTGERS STATE UNIV,COLL ENGN,DEPT CERAM,POB 909,PISCATAWAY,NJ 08855
关键词
D O I
10.1021/cm00025a014
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A thermodynamic method is proposed for analyzing the hydrothermal synthesis of ceramic materials. The method utilizes standard-state thermodynamic data for solid and aqueous species and a comprehensive activity coefficients model to represent solution nonideality. The method is used to generate phase stability diagrams for the species that predominate in the system. The stability diagrams can be used to predict the optimum suspension synthesis conditions (i.e., feedstock composition, pH and temperature) for hydrothermal synthesis of ceramic materials. The synthesis of barium titanate (BaTiO3(s)) and lead titanate (PbTiO3(s)) are discussed as examples. In the case of the synthesis of BaTiO3(s), which can be obtained at temperatures as low as 363 K, it is important to use solutions of appropriate pH. Practical techniques have been suggested to maintain the required pH by using a correct molar ratio of feedstocks, such as barium hydroxide (Ba(OH)2(s)) to titanium dioxide (TiO2(s)) or use of a mineralizer such as sodium hydroxide (NaOH(s)). It has been shown that contact with atmospheric carbon dioxide (CO2(g)) will always lead to the contamination of the product with barium carbonate (BaCO3(s)). Also, a low-temperature synthesis of PbTiO3(s) has been proposed.
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页码:61 / 70
页数:10
相关论文
共 61 条
  • [1] ADAIR JH, 1988, CERAMIC T CERAMIC 2A, V1, P135
  • [2] ANGER JF, UNPUB
  • [3] [Anonymous], 1987, PROPERTIES GASES LIQ
  • [4] [Anonymous], 1982, J PHYS CHEM REF DATA
  • [5] Baes C.F., 1976, HYDROLYSIS CATIONS
  • [6] THE THERMODYNAMICS OF CATION HYDROLYSIS
    BAES, CF
    MESMER, RE
    [J]. AMERICAN JOURNAL OF SCIENCE, 1981, 281 (07) : 935 - 962
  • [7] BARIN I, 1977, THERMOCHEMICAL PRO S
  • [8] Barin I., 1989, THERMOCHEMICAL DATA, Vthird
  • [9] Barner H.E., 1978, HDB THERMOCHEMICAL D
  • [10] THERMODYNAMIC PROPERTIES OF SEA SALT-SOLUTIONS
    BROMLEY, LA
    SINGH, D
    RAY, P
    SRIDHAR, S
    READ, SM
    [J]. AICHE JOURNAL, 1974, 20 (02) : 326 - 335