Han Zhiwu, Feng Xiaoming, Jiao Zhibin, Wang Ze, Zhang Junqiu, Zhao Jie, Niu Shichao, Ren Luquan
Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University Changchun 130022 China
Department of Mechanical Engineering, Columbia University New York 10027 USA.
RSC Adv. 2018 Jul 25;8(47):26497-26505. doi: 10.1039/c8ra04699a. eCollection 2018 Jul 24.
In this work, inspired by some typical creatures from nature with superhydrophobic surfaces, a bio-inspired antifogging PDMS is designed and fabricated successfully using UV lithography and a template method. First, we fabricated an SU-8 layer with a bio-inspired micro-pillared array (MPA) using traditional UV lithography. Then, it was used as a template to fabricate a PDMS film (PF). After that, it was chemically modified with SiO coatings. It was found that the PF coupled with sprayed SiO coatings and a MPA have a higher water contact angle (CA) of 158° and a lower contact angle hysteresis (CAH) of less than 2°. Water drops can be separated from this bio-inspired PDMS surface within 86.8 ms. More importantly, this film's antifogging property is superior, with a recovery time of less than 13 s, which is significantly superior to that of the flat PF and the PF with the MPA. Afterwards, FTIR was applied to analyse the surface chemistry features and suggested that the bio-inspired PF has extremely low surface tension. So, it can be confirmed that an excellent superhydrophobic antifogging property has been achieved on the surface of the PF. Meanwhile, the microscopic and macroscopic dynamic movement behaviour of the fog drops was further observed. Then, the underlying antifogging mechanism was also revealed. These properties mainly benefit from the coupling effect of intermolecular attraction of droplets, chemical compositions (nanometre roughness SiO) and the physical structures (MPA). The investigations offer a promising way to handily design and fabricate multiscale hierarchical structures on polymers and other materials. More importantly, these findings suggest great potential value for specific antifogging applications in display devices, transport, agricultural greenhouses, food packaging and solar products, especially in continuous harsh fogging conditions.
在这项工作中，受自然界中一些具有超疏水表面的典型生物启发，采用紫外光刻和模板法成功设计并制备了一种仿生防雾聚二甲基硅氧烷（PDMS）。首先，我们使用传统紫外光刻技术制备了具有仿生微柱阵列（MPA）的SU-8层。然后，将其用作模板来制备PDMS薄膜（PF）。之后，用SiO涂层对其进行化学改性。结果发现，结合喷涂SiO涂层和MPA的PF具有158°的较高水接触角（CA）和小于2°的较低接触角滞后（CAH）。水滴可在86.8毫秒内从这种仿生PDMS表面分离。更重要的是，该薄膜的防雾性能优异，恢复时间小于13秒，明显优于平整的PF和具有MPA的PF。随后，应用傅里叶变换红外光谱（FTIR）分析表面化学特征，结果表明仿生PF具有极低的表面张力。因此，可以确认在PF表面实现了优异的超疏水防雾性能。同时，进一步观察了雾滴的微观和宏观动态运动行为。然后，还揭示了潜在的防雾机制。这些性能主要得益于液滴分子间吸引力、化学成分（纳米粗糙度SiO）和物理结构（MPA）的耦合效应。这些研究为在聚合物和其他材料上方便地设计和制造多尺度分级结构提供了一条有前景的途径。更重要的是，这些发现表明在显示设备、交通运输、农业温室、食品包装和太阳能产品等特定防雾应用中具有巨大的潜在价值，尤其是在持续恶劣的起雾条件下。
