A novel technique combining photoelectronic microscopy and computer imaging tracing was used to investigate the synthesis of thioether(2-[3-methyl-4-(2,2,2-trifluoro-ethoxy)-pyridine-2-(methylsulfanyl)]-1H-benzoimidazole),which is an intermediate for lansoprazole.Visualization in sub-microcosmic surroundings was realized to study interfacial phenomenon.The reaction kinetics study by a visualization technique was carried out in a mini-reactor,and the concentration-gray scale standard curves for thioether were obtained by analyzing the gray scales of digital images.Based on the concentration-gray scale standard curves,the reactant concentrations at different times were calculated,and the reaction kinetics curve and reaction rate equation were obtained.Also the total mass-transfer resistance from bulk phase to interface of sodium imidazole and bromopyridine was obtained.Liquid-liquid interface of synthesizing thioether was observed and its mass transfer mechanism was discussed.
A visualization system based on microscopy,photoelectric imaging analysis and digital processing was developed to investigate the micrometer-level mass transfer process of polyvinylpyrrolidone(PVP)across the interface of dichloromethane-water.The concentration-gray scale standard curves were obtained by measuring the gray scales of the images of 10 PVP dichloromethane solutions with different concentrations.The concentrations of PVP corresponding to different times were determined by measuring the gray scales of the images of PVP dichloromethane solutions at the corresponding times.The mass transfer kinetics curve of PVP across the interface of dichloromethane-water was then obtained.In addition,the evolution of flow field in the dichloromethane phase near the interface was observed and analyzed via the visualization system.
