BPA-NaOH-H_2O体系电离及沉淀溶解平衡的建模及应用

Modeling and application of ionization and precipitation dissolution equilibrium of the BPA-NaOH-H_2O system

研究了BPA-NaOH-H_2O体系中电离及沉淀溶解平衡,首先按照是否有Na_2BPA·6H_2O(s)沉淀生成,将其分为Ⅰ、Ⅱ、Ⅲ和Ⅳ区,并据此建立了该体系的平衡模型,利用所建立的模型模拟了体系中各组分随加入NaOH量的变化分布情况,为研究该体系中各组分浓度的分布规律提供了理论依据。其次以特定BPA初始浓度(1.5mol/L)的BPA-NaOH-H_2O体系进行模型验证,表明pH值在Ⅲ区随NaOH加入量的增大基本不变,且BPA溶解度最大,即该区为缓冲区。最后模拟计算了BPA在不同浓度NaOH溶液中的溶解度,并与实验值进行了比较,结果表明在NaOH稀溶液中,该模型可靠、有实用性。

The ionization and precipitation dissolution equilibrium of the BPA-NaOH-H_2O system is studied,which is firstly classified into four zones（Ⅰ,Ⅱ,ⅢandⅣ） according to the precipitation of Na_2BPA·6H_2O（s）,and a model of which is established,the distribution of each component can be simulated from the established model,which could provide a reference to the theoretical investigation of the concentration of each component in the BPA-NaOH-H_2O system.A certain content of BPA（1.5 mol/l） of BPA-NaOH-H_2O system is taken secondly as an example to verify the model, the results show pH of zone III seldom changed with the addition of NaOH,and solubility of BPA is maximum,that is,the zone is equal to a buffer. At last,the variable solubility of BPA in the sodium hydroxide solution are calculated based on the model,and the calculated results is compared with experimental data,which show the model is accurate and practical.