可持续的设计和合成高性能素基防晒成分的设计和合成
1School of Chemistry and Materials, Taiyuan Normal University, 319 University Street, Yuci District, Jinzhong 030619, China.
International journal of biological macromolecules
|September 14, 2024
概括
研究人员开发了以素为基础的纳米囊 (DLNCs) 作为一种新型防晒剂. 这些DLNC提供高阳光保护因子 (SPF) 和扩展的紫外线保护,可能取代传统的防晒成分.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
- 摄影化学的使用.
背景情况:
- 防晒通常使用芳香化合物来吸收紫外线.
- 宁是一种丰富的可再生芳香聚合物,可以成为吸收紫外线的化学物质的来源.
- 开发可持续和有效的防晒成分是一个关键的研究领域.
研究的目的:
- 为了研究宁模型化合物 (LMCs) 的紫外线吸收.
- 开发用于防晒应用的基于素的纳米囊 (DLNC).
- 评估DLNC作为防晒活性成分的性能.
主要方法:
- 研究了香草素,酸和5-5二次体的紫外线吸收性.
- 准备LMC杂交分散物并用超声波化在去甲基化红素 (DL) 中封装它们,以形成DLNC.
- 使用DLNC作为唯一活性成分配制的防晒,并测试了其防晒因子 (SPF) 和稳定性.
主要成果:
- 瓦尼林和酸显示强烈的UVB吸收;5-5二分体在UVA范围内有效吸收.
- DLNCs在10 wt%的度下达到高达55的SPF.
- 基于DLNC的防晒保持了SPF>8小时,这是由于素的抗光解性质,并显示出出色的抗透性,抗氧化能力和生物相容性.
结论:
- 素衍生化合物是防晒配方中有效的紫外线吸收剂.
- DLNCs代表了石油基防晒剂的有希望,生物相容和可持续的替代品.
- 素的抗光解作用增强了防晒的寿命和有效性.
相关概念视频
Accelerators
Accelerators in concrete serve as admixtures to speed up the hardening process, enabling the concrete to achieve early strength faster. Although accelerators do not necessarily impact the time it takes concrete to set, they reduce this time in practice. A common accelerator is calcium chloride, which is particularly useful for hastening early strength development in cold weather or for rapid repair jobs that require quick heat generation after mixing.
The effectiveness of calcium chloride can...
The effectiveness of calcium chloride can...
Retarders
Retarders are chemical admixtures designed to extend the setting time, which is especially useful when there is a delay in sequential concrete pours to prevent cold joints and to achieve a cohesive structure. Retarders, when used in appropriate amounts, can also enhance the architectural appearance of exposed aggregate finishes.
The function of retarders is to delay the setting of concrete, and this effect can be measured using a penetration test. The retardation process involves adding...
The function of retarders is to delay the setting of concrete, and this effect can be measured using a penetration test. The retardation process involves adding...
Waterproofing and Anti-Bacterial Admixtures in Concrete
Concrete's susceptibility to water absorption is due to the capillary action within the pores of its hydrated cement paste. This action draws water in, creating the need for waterproofing admixtures to prevent such penetration. The efficacy of these admixtures is contingent upon the water pressure, with variations arising from different conditions such as rain, capillary rise, or hydrostatic pressure in structures intended to hold water.
Waterproofing admixtures render concrete hydrophobic,...
Waterproofing admixtures render concrete hydrophobic,...
Design Example: Sustainability in Concrete Building
As the construction industry moves towards more eco-friendly practices, concrete's adaptability and its ability to incorporate sustainable features make it a key material in the drive towards greener building solutions.
There are multiple approaches to achieve sustainability in a commercial concrete building. For instance, construct a concrete parking area under the building, utilizing pervious concrete paver blocks in open areas to facilitate rainwater collection through an underground cistern.
There are multiple approaches to achieve sustainability in a commercial concrete building. For instance, construct a concrete parking area under the building, utilizing pervious concrete paver blocks in open areas to facilitate rainwater collection through an underground cistern.
Frost Resistant Concrete
Concrete's susceptibility to frost damage during freeze-thaw cycles demands strategic measures to enhance its frost resistance. Employing techniques like air entrainment, adjusting the water-cement ratio, proper curing, and selecting appropriate aggregates are essential.
Introducing microscopic air bubbles into the concrete mix through air entrainment creates small voids that accommodate ice expansion, thereby reducing internal pressures and preventing cracking. The optimal amount of entrained...
Introducing microscopic air bubbles into the concrete mix through air entrainment creates small voids that accommodate ice expansion, thereby reducing internal pressures and preventing cracking. The optimal amount of entrained...
Design Example: Managing Concrete Workability
This example deals with managing the workability of concrete for a raft foundation project under hot weather conditions. Workability is crucial for ensuring the concrete is easy to place, compact, and finish. In this scenario, a slump test — a common method to measure the workability of fresh concrete — initially indicated low workability. This was attributed to the rapid water loss from the concrete mix, exacerbated by the high temperatures causing the course aggregates to heat up.
To address...
To address...


