通过自由基抑制剂研究聚多巴胺的形成机理

Investigation of Formation Mechanism of Polydopamine by Adding Free Radical Quencher

利用自由基抑制剂二甲基亚砜(DMSO)与依达拉奉(Edaravone)研究了多巴胺(DA)聚合中可能存在的自由基聚合路径,并考察了pH值对聚合过程的影响.利用紫外-可见光谱跟踪了反应过程.研究结果表明,DMSO和Edaravone均可抑制DA的聚合,而且Edaravone的抑制作用更加显著.研究结果表明,自由基聚合路径存在于DA的聚合过程中.实验还发现,DA的聚合速率随着pH值的升高而增大,但不同pH值时溶液的最终外观基本一致.

In this paper,by using dimethyl sulfoxide(DMSO)and edaravone as the free radical quencher,the free radical polymerization pathways of dopamine under different pH conditions were studied.Besides,the absorbance of the dopamine solutions was characterized by means of UV-Vis spectroscopy.It is found that the dopamine polymerization rate decreases with the increase of the DMSO concentration,indicating that DMSO can slow down the polymerization of dopamine.Further experiments show that edaravone can slow down the polymerization of dopamine more significantly.These results indicate that the free radical polymerization is one of the possible pathways of dopamine polymerization.Although DMSO can slow down the polymerization of dopamine,it cannot completely restrain the polymerization,which indicates that the polymerization has other reaction pathways besides the free radical polymerization.These pathways may be the main reason for the structure complexity of polydopamine.Moreover,it is found that the polymerization rate increases with the increase of pH and the final reaction products under different pH conditions are similar.