A valuable reference for the high-value utilization of lignin in the cosmetics industry
Researchers develop a novel lignin sub-microsphere loaded with TiO2 for enhanced sunscreen capabilities
image: Researchers develop a novel lignin sub-microsphere loaded with TiO2 for enhanced sunscreen capabilities
Credit: College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
An international research team led by the College of Light Industry and Food Engineering at Guangxi University has achieved a significant breakthrough in the cosmetics industry. Researchers have developed a new type of sunscreen that utilizes lignin, a naturally abundant polymer, along with titanium dioxide (TiO2). The study, conducted under the leadership of Yarong Li and Zhiguang Tang, was published in the Journal of Bioresources and Bioproducts. It provides detailed insights into the innovative application of dual-modified lignin sub-microspheres to enhance sun protection factor (SPF) while improving the color properties of sunscreens.Lignin, a byproduct of the pulp industry, is known for its UV-absorbing properties and antioxidant capabilities. However, its application in commercial sunscreens has been constrained due to its low SPF and dark coloration. To address these challenges, the researchers conducted a dual modification of lignin's chemical structure and physical form. They grafted methylene bis-benzotriazolyl tetramethylbutylphenol (MBBT) onto alkali lignin (AL) to create a polymer, AL-g-MBBT. And this polymer was then transformed into sub-micron spheres with and without TiO2 loading.
The results were remarkable. Sunscreens prepared with 10% AL-g-MBBT3 demonstrated an SPF of 42.93, a significant increase from the 4.74 SPF of unmodified AL. Moreover, the color of the modified lignin-based sunscreen was considerably lighter, with a color difference value (ΔE) of 45.6, compared to the 49.5 ΔE of unmodified AL, making it more appealing for cosmetic use.
The researchers further enhanced the performance of the sunscreen by creating TiO2-loaded sub-micron spheres. These AL-g-MBBT3/TiO2@C sunscreens achieved a remarkable SPF of 66.20, surpassing both the unmodified AL and the sub-micron spheres without TiO2 loading. Additionally, the color of these sunscreens was also improved significantly, with a ΔE value of 36.3.
The study also assessed the photostability and biocompatibility of the lignin-based sunscreen. The findings demonstrated that the sunscreen preserved its sun protection efficacy and color even after three hours of UV exposure. Furthermore, the biocompatibility tests revealed that the modified lignin-containing sunscreen was non-toxic to human keratinocytes, indicating its safety for application on human skin.
This research presents a significant advancement in the utilization of lignin, providing a sustainable and high-performing alternative to conventional sunscreen ingredients. The findings have the potential to pave the way for a new generation of eco-friendly and effective sunscreen products.
See the article:
DOI
https://doi.org/10.1016/j.jobab.2024.09.003
Original Source URL
https://www.sciencedirect.com/science/article/pii/S2369969824000574
Journal