超疏水涂层可以有效地阻碍含水腐蚀介质对表面的侵入、附着、凝结行为。然而，传统超疏水涂层差的机械和化学稳定性极大地限制了其在复杂苛刻环境中的应用。为此，采用氧化石墨烯(GO)和纳米二氧化硅(SiO2)复合聚二甲基硅氧烷(PDMS)与环氧树脂(EP)混合基体，结合喷涂技术在Q345钢片表面形成PDMS-EP@SiO2-GO超疏水涂层，并对涂层的超疏水、自清洁、防污、耐机械磨损、耐化学侵蚀和防腐性能进行研究。结果表明，PDMS-EP@SiO2-GO水接触角高达166.57°,滚动角小于3°。由于GO的强化增强作用，涂层能对水温为20～100℃的液体保持155°以上的接触角，对酸碱溶液保持160°以上的接触角，且滚动角均小于4°;在经过砂纸摩擦(40 m总摩擦长度)和30次循环胶带粘脱后，涂层依旧拥有超疏水能力，接触角维持在152°以上。此外，PDMS-EP@SiO2-GO优异的拒水性使得它具有良好的防污和自清洁性能。在腐蚀防护方面，PDMS-EP@SiO2-GO的最低频阻抗值提升了1个数量级，电荷转移电阻提升了2个数量级，表现出了优异的耐腐蚀性能。PDMS-EP@SiO2-GO解决了传统超疏水涂层较弱的机械/化学稳定性的问题，可以实现对金属基体的持久性保护，增强了实用性，助力了机械装备在全寿命周期内的安全可靠服役。
张鹏, 白光亚, 倪向萍, 李雨桓, 陈静远, 彭正, 杨承刚, 刘钪, 张林, 严涵, 林修洲
. 机械/化学稳定性超疏水涂层的构筑及其防腐性能研究[J]. 材料保护, 2024
, 57(6)
: 20
-28
.
DOI: 10.16577/j.issn.1001-1560.2024.0122
The superhydrophobic coating can effectively prevent the intrusion, adhesion and condensation of water-containing corrosive media on the surface. However, the poor mechanical and chemical stability of traditional superhydrophobic coatings significantly limits their application in complex and harsh environments. In this study, a superhydrophobic PDMS-EP@SiO2-GO coating was formed on the surface of Q345 steel sheets by using a composite substrate of graphene oxide(GO) and nano silicon dioxide(SiO2) with polydimethylsiloxane(PDMS) and epoxy resin(EP), combined with spraying technology. The superhydrophobic, self-cleaning, anti-fouling, mechanical wear resistance, chemical corrosion resistance and anti-corrosion properties of the coating were studied. Results showed that the water contact angle of PDMS-EP@SiO2-GO was 166.57°, and the sliding angle was less than 3°. Due to the strengthening effect of GO on the coating substrate, the coating maintained a contact angle of more than 155° for liquids with water temperatures ranging from 20 ℃ to 100 ℃ and a contact angle of more than 160° for acidic/alkaline solutions. The sliding angle was less than 4° under the above conditions. After sandpaper friction(total friction length of 40 m) and 30 cycles of tape-peeling tests, the coating still exhibited good superhydrophobic ability, with the contact angle remaining above 152°. In addition, PDMS-EP@SiO2-GO, with excellent water resistance, demonstrated good anti-fouling and self-cleaning properties. In terms of corrosion protection, the lowest frequency impedance of PDMS-EP@SiO2-GO increased by an order of magnitude, and the charge transfer resistance increased by two orders of magnitude, showing excellent corrosion resistance. PDMS-EP@SiO2-GO addressed the problem of weak mechanical and chemical stability in traditional superhydrophobic coatings and enabled the persistent protection of the metal substrate. The as-prepared superhydrophobic coating, with good practicability, contributes to the safe and reliable service of mechanical equipment throughout its life cycle.
