Abstract: With the increasing shortage of freshwater resources, using seawater desalination to produce freshwater is a broaden incremental technology for achieving water resource utilization. The current main methods of seawater desalination include reverse osmosis membrane method and distillation method. Compared with traditional seawater desalination technology, solar-driven water evaporation is less costly and more environmentally friendly. In recent years, low-cost solar thermal desalination has been favored by many researchers.
According to the different placement methods of solar absorbers, they can be divided into two types: suspended solar absorbers and surface solar absorbers. The photothermal materials and principles of the two evaporators are not significantly different. They both absorb specific wavelengths of light and cause electromagnetic field changes through plasma resonance or electron transitions. The interaction between electromagnetic waves and substances at the water interface heats up nanoparticles. The suspended solar absorber heats the bulk water, while the surface solar absorber heats the water soaked in the evaporator. Compared with suspended solar absorbers, surface solar absorbers have more advantages.
The loose porous structure of fabrics can provide efficient water transportation, and the flexibility and elasticity of the fabric structure can provide better compatibility with surface solar absorbers. It can also modify the fabric's properties to better combine with photothermal materials. In current research on solar-driven water evaporation, cotton, linen, nylon, aramid, acrylic, and nonwovens are mainly used as substrate materials, and metal nanoparticles, metal oxides, and carbon-based materials as photothermal materials.
Improving the salt resistance of the evaporator can effectively maintain its evaporation rate and extend its service life. There are two ways to improve the salt resistance: increasing the hydrophilicity or hydrophobicity of the evaporator. In improving evaporation performance, it is necessary to balance heat loss, water supply, and salt crystallization. Excessive water can lead to more heat loss, and rapid water evaporation can cause salt to crystallize on the surface of the evaporator, thereby affecting photothermal performance. In order to achieve a balance between heat loss and water supply, there have been two main types of surface solar absorbers in recent years: hydrophilic bilayer structure and structure with dedicated water transport channels. The hydrophilic bilayer structure loses more heat due to wetting during use, and the water absorption rate of the water transport channels structure is higher than the evaporation rate, which does not limit evaporation and can effectively reduce heat loss.
At present, the solar-driven water evaporation with the highest evaporation rate is the surface solar absorber with a bridge structure composed of Janus hydrogel and cotton fabric. The evaporation efficiency of solar-driven water evaporation is relatively low, making it impractical to provide water for households. However, a solar evaporator with a solar thermal area of 1 square meter can meet the drinking water needs of households. With the continuous improvement of solar desalination technology, it will definitely be more widely used in remote and underdeveloped areas in the future.

Key words: fabric, solar evaporator, desalination of seawater, photothermal

摘要： 随着淡水资源短缺的问题日益加剧，太阳能热脱盐技术受到越来越多研究者的关注。太阳能水热蒸发相比其他海水淡化方式具有成本低、污染小等特点，获得高效光热蒸发效率的关键在于如何更好地将收集的太阳能转换为热能并减少热量损失。此外，若要维持蒸发器的蒸发速率并延长使用寿命，需要其具备优异的耐盐性能。织物具有的疏松多孔结构可以实现高效的水运输，优异的柔韧性和弹性能与蒸发器更好地兼容。文章综述了织物基太阳能蒸发器的优势，光热原理，不同光热材料的光热效果以及提高耐盐性和蒸发速率的方法。最后对太阳能蒸发器的未来发展和应用方向进行了展望。

关键词: 织物, 太阳能蒸发器, 海水淡化, 光热