Nanoparticles are commonly used to avoid the opaque white color of TiO2 based sunscreen. However, a dispersing agent is typically required because of the tendency of the nanoparticles (NPs) to agglomerate. Stearic acid is one kind of dispersing agent often used for sunscreen products. However, according to the MSDS data sheet on stearic acid, stearic acid is highly hazardous to aquatic life and causes irritation on human skin. To avoid this problem, in this study a safer organic dispersing agent extracted from Korean seaweed has been studied to disperse TiO2 nanoparticles, and further use as an active agent in sunscreen products. The presence of phytochemicals in seaweed extract, especially alginate, can disperse TiO2 nanoparticles and improve TiO2 dispersion properties. Results show that seaweed extract can improve the dispersion properties of TiO2 nanoparticles and sunscreen products. Reducing the agglomeration of TiO2 nanoparticles improves sunscreen properties, by making it less opaque white in color, and increasing UV protection value. It was also confirmed that adding seaweed extract into sunscreen products had no irritating effects on the human skin, making it more desirable for cosmetics application.

신규 자외선차단제로 개발된 methoxycinnamidopropyl polysilsesquioxane은 유기-무기 혼성 구조의 고분자 입자로, 본 연구진은 이미 신규 자외선차단제에 대한 제조방법, 물리적 특성 및 자외선차단 효과에 대해 보고한 바 있다. 본 연구에서는 기존의 대표적인 유기 자외선차단제인 ethylhexyl methoxycinnamate (EHMC)와 동일한 기능기를 갖는 methoxycinnamidopropyl polysilsesquioxane의 광화학적 특성과 자외선에 대한 광안정성을 평가하였다. 또한, 자외선 흡광도와 형광의 상관관계를 이용하여, 광안정성을 향상시킬 수 있는 광안정화제에 대하여 연구하였다. Methoxycinnamidopropyl polysilsesquioxane은 광화학적으로 EHMC와 유사한 특성을 보였으며, octocrylene, ethylhexyl methoxycrylene 및 bis-ethylhexyloxyphenol methoxyphenyl triazine이 우수한 광안정화제로 확인되었다.