新型聚多巴胺纳米颗粒光热蒸发性能评价

聚多巴胺具有与黑色素相似的吸光性能，是一种被广泛关注的高分子近红外吸收材料，在光热转化方面有良好前景。但由于其本身聚合机理多样，内部结构复杂，目前对聚多巴胺功能性设计的研究较少。本文通过设计Fe³⁺和硅烷偶联剂与多巴胺反应，提高了聚多巴胺的吸光特性和亲水性；通过X射线光电子能谱(XPS)、傅里叶变换红外光谱(FTIR)等表征证明，成功合成了高吸光度亲水聚多巴胺纳米颗粒，吸光度达到90%。同时将合成的纳米颗粒真空抽滤，堆叠构建亲水输运通道。实验表明：在太阳光蒸发环境，一个太阳光强下，使用本文设计的光热膜进行纯水蒸发实验，纯水蒸发速率可以达到1.1 kg/(m²·h),光热转化效率为80%,比普通聚多巴胺提高15%,证明该材料有很好的光热转化性能，在海水淡化领域有着良好的应用前景。

Evaluation of photothermal evaporation performance of novel polydopamine nanoparticles

Polydopamine is a popular near-infrared absorbing polymer material, which has light-absorbing properties similar to melanin and a good prospect in photothermal conversion. However, due to its diverse polymerization mechanism and complex internal structure, there are few reports on the functional design of polydopamine. In this work, Fe³⁺ and silane coupling agent were designed to react with dopamine, so as to improve the light absorption properties and hydrophilicity of polydopamine. According to X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), high absorbance hydrophilic polydopamine nanoparticles were successfully synthesized, and the absorbance reached 90%. Moreover, the synthesized nanoparticles were vacuum-filtered and stacked to construct hydrophilic transport channels. Pure water experiment was performed on the proposed photothermal film at one sunlight intensity under sunlight evaporation environment. Results showed that the evaporation rate of pure water reached 1.1 kg/(m²·h) and the photothermal conversion efficiency was 80%, which was 15% higher than that of ordinary polydopamine, proving that the new material developed in this study has good photothermal conversion performance and has a good application prospect in the field of seawater desalination.