Abstract

Due to its dual gas- and liquid-like properties, supercritical carbon dioxide (scCO₂) is considered an excellent solvent for dissolving precursors and penetrating nanoscale pores. After subsequent calcination, uniformly dispersed metal or metal oxide nanoparticles or nanowires can be obtained. Organometallic salts are commonly used precursors in this method because they usually have high solubility in scCO₂. Therefore, solubility data are essential for the controllable synthesis of such nanocomposites. This work establishes a facile and accessible method for measuring the solubility of organic solids in scCO₂. The solubilities of copper acetylacetonate and cobalt acetylacetonate were obtained at temperatures of 313–333 K and pressures of 11–24 MPa. And the solubilities were within 2.3 × 10⁻² to 14.1 × 10⁻² g/L for Cu(acac)₂ and 6.9 × 10⁻² to 13.4 × 10⁻² g/L for Co(acac)₂. The experimental data were fitted to the semi-empirical model with the AARD values of 4.58% and 2.14% for Cu(acac)₂ and Co(acac)₂, respectively, and the obtained equations could be used to predict solubility of the same systems in the experimental range.

摘要

超临界二氧化碳 (scCO ₂ ) 由于其类气类和类液双重特性，被认为是溶解前体和穿透纳米级孔隙的优良溶剂。后续煅烧后，可得到均匀分散的金属或金属氧化物纳米粒子或纳米线。有机金属盐是该方法中常用的前体，因为它们通常在 scCO ₂中具有高溶解度。因此，溶解度数据对于此类纳米复合材料的可控合成至关重要。这项工作建立了一种简便易行的方法来测量有机固体在 scCO _{2中的溶解度}. 乙酰丙酮铜和乙酰丙酮钴的​​溶解度是在 313–333 K 的温度和 11–24 MPa 的压力下获得的。并且Cu(acac) ₂的溶解度在2.3×10 ^-2至14.1×10 ^{-2 g/L之间，Co(acac)} ₂的溶解度在6.9×10 ^-2至13.4×10 ^-2 g/L之间。_{将实验数据拟合到Cu(acac) 2}和Co(acac) ₂的AARD值分别为4.58%和2.14%的半经验模型，得到的方程可用于预测相同体系的溶解度在实验范围内。