防晒剂光稳定性和防晒增效作用的机理研究

丁基甲氧基二苯甲酰甲烷是性价比较高的UVA防晒剂,但其紫外光稳定性较差,特别是和UVB防晒剂甲氧基肉桂酸乙基己酯复配时更是如此。通过使用Visia-CR仪器拍摄丁基甲氧基二苯甲酰甲烷在紫外光照射下,处于一级激发态分子释放光子会发出荧光现象的照片,研究双-乙基己氧苯酚甲氧苯基三嗪对丁基甲氧基二苯甲酰甲烷光稳定作用的机理。结果表明,由于偶极子-偶极子作用,产生荧光共振能量转移,双-乙基己氧苯酚甲氧苯基三嗪可以淬灭单重激发态下的丁基甲氧基二苯甲酰甲烷分子,使其分子光稳定。在紫外照射前后,加入和未加双-乙基己氧苯酚甲氧苯基三嗪的防晒剂溶液吸光度曲线下面积,和防晒霜的SPF值变化同时也验证了上述结论。文中对双-乙基己氧苯酚甲氧苯基三嗪这种防晒增效作用的机理进行了探讨。

Study on the photostabilization and SPF boosting of bemotrizinol in sunscreen

Bemotrizinol （bis-ethylhexylphenol methoxyphenyl triazine, BMT） is a UV filter with broad spectrum absorption. Its photoprotection efficacy to avobenzone and its mixture with oetinoxate have been reported in the references. In this study, VISIA-CR instrument was used to monitor the fluorescence emitted by the excited state molecule under UV irradiation. BMT could quench the excited state of AVB and turn it to ground state. By measuring the luminance （L ＊ value） of the fluorescence spots, the BMT concentration and the strength for quenching sing, let excited state were studied. The results showed both BMT and Oetocrylene （OCT） could stabilize AVB under the UV radiation, but BMT is more effective. By testing the SPF and the area under UVA curve （315 nm - 400 nm） pre and post UV-irradiation, the photostabilization of bemotrizinol to avobenzone and its mixture with octinoxate was studied in emulsion, and the mechanic was explored in the paper.