Wu Muqiu, An Rong, Yadav Sudheer Kumar, Jiang Xiaohong
Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology Nanjing 210094 P. R. China
Center for Nanotechnology and Physical Institute, University of Münster 48149 Münster Germany.
RSC Adv. 2019 May 23;9(28):16235-16245. doi: 10.1039/c9ra02008j. eCollection 2019 May 20.
This study reports stable superhydrophobic FeO/graphene hybrid coatings prepared by spin coating of the FeO/graphene/PDMS mixed solution on titanium substrates. By tailoring graphene sheets with FeO nanoparticles, the superhydrophobicity of graphene platelets was largely enhanced with a water contact angle of 164° and sliding angle <2°. FeO nanoparticles interact with FLG sheets Fe-O-C covalent link, to form a graphene micro-sheet pinned strongly by nano-sized FeO. The newly-formed micro/nano-structured sheets interact with each other strong dipole-dipole attractions among FeO nanoparticles, confirmed by the blue shifts of G band observed in Raman spectra. The strongly interactive micro/nano-structured sheets are responsible for the improvement of both the surface hydrophobicity and the durability towards water impacting. The obtained hybrid coatings possess excellent durability in various environments, such as acidic and basic aqueous solutions, simulating ocean water. And also the coatings can retain their stable superhydrophobicity in Cassie-Baxter state even after annealing at 250 °C or refrigerating at -39 °C for 10 h. We employed an AFM to probe nanoscale adhesion forces to examine further the ability of the as-prepared coatings to resist the initial formation of water layers which reflects the ability to prevent the water spreading. The most superhydrophobic and durable hybrid coating with 1.8 g FeO, shows the smallest adhesion force, as expected, indicating this surface possesses the weakest initial water adhesive strength. The resulting low-adhesive superhydrophobic coating shows a good self-cleaning ability. This fabrication of low-adhesive and durable superhydrophobic FeO/FLG hybrid coatings advances a better understanding of the physics of wetting and yield a prospective candidate for various practical applications, such as self-cleaning, microfluidic devices,
本研究报道了通过在钛基底上旋涂FeO/石墨烯/聚二甲基硅氧烷（PDMS）混合溶液制备的稳定超疏水FeO/石墨烯复合涂层。通过用FeO纳米颗粒修饰石墨烯片，石墨烯薄片的超疏水性得到了显著增强，水接触角为164°，滑动角<2°。FeO纳米颗粒通过Fe-O-C共价键与少层石墨烯（FLG）片相互作用，形成由纳米级FeO强烈固定的石墨烯微片。新形成的微/纳米结构片通过FeO纳米颗粒之间强烈的偶极-偶极吸引力相互作用，这在拉曼光谱中观察到的G带蓝移得到证实。强相互作用的微/纳米结构片负责表面疏水性和抗水冲击耐久性的提高。所获得的复合涂层在各种环境中具有优异的耐久性，如酸性和碱性水溶液、模拟海水。并且即使在250°C退火或在-39°C冷藏10小时后，涂层仍能在Cassie-Baxter状态下保持其稳定的超疏水性。我们使用原子力显微镜（AFM）探测纳米级粘附力，以进一步检查所制备涂层抵抗水层初始形成的能力，这反映了防止水扩散的能力。如预期的那样，含有1.8 g FeO的最超疏水且耐用的复合涂层显示出最小的粘附力，表明该表面具有最弱的初始水粘附强度。所得的低粘附超疏水涂层显示出良好的自清洁能力。这种低粘附且耐用的超疏水FeO/FLG复合涂层的制备有助于更好地理解润湿物理，并为各种实际应用，如自清洁、微流控装置等，提供了一个有前景的候选材料。
