“超浓盐酸”介质中钯微乳萃取行为

An Ultra-concentrated Hydrochloric Acid Model and Palladium Microemulsion Extraction Behavior

采用多种分子谱学的表征手段,研究了萃钯有机相中由于酸的共萃导致溶液微观聚集态结构的变化.研究结果表明,与高酸度盐酸水溶液平衡后的TBP载钯有机相微乳水团中形成了浓度远大于常规饱和浓盐酸的'超浓盐酸';微乳水团内H+和Cl-的大量聚集增浓对Pd离子的络合配位状态产生影响,H+参与了Pd离子配位状态的转变;有机相'超浓盐酸'形成后,使得微乳水团中大量存在的H+有可能参与调控水团中各种HmPdClnz+络合离子配位状态的相对含量.被H+活化的TBP表面活性剂与钯离子的各种配位状态的匹配程度最终决定了钯的萃取行为.

Evolution of the microscopic aggregating structure phases, with the increase of hydrochloric acid extracted into, in the palladium loaded TBP extractive organic was characterized by various spectroscopic tech-niques. It is indicated that, （ 1 ） within the nano-water pools of W/O reversed micelles/microemulsions from TBP equilibrated with higher concentration aqueous HCI solutions, the concentration of acid were far higher than that of saturated concentrated hydrochloric acid. It means an ultra-concentrated hydrochloric acid formed in the nano-water pool; （2） the nanometer-sized confinement brings aggregation of a large amount of H^＋ and CI^- ions within the micro-droplets, the coordination states of palladium complex ions were changed. It is pos- sible that the hydrated H^＋ ions participate in the formation of complexes, HmpdCIn^z＋ ; （3） with respect to various HmpdCIn^z＋ coordination compounds, such as pdCI4^2-, HpdCI4^- and H2PdCI4, their content ratios were different corresponding to the H^＋ ion concentrations in confined nano-water pools. The acidified TBP molecules have a higher surface activity. The association ability of the acidified TBP molecules with various HmPdCIn^z＋ complexes plays an important role by influencing the palladium extraction behavior.