Wang Chenyu, Fuller Trae, Zhang Wei, Wynne Kenneth J
Department of Chemical and Life Science Engineering, Virginia Commonwealth University , 601 West Main Street, Richmond, Virginia 23284, United States.
Langmuir. 2014 Nov 4;30(43):12819-26. doi: 10.1021/la5030444. Epub 2014 Oct 27.
Minimizing adhesion of ice has been the subject of extensive studies because of importance to applications such aircraft wings, spacecraft, and power transmission wires. A growing interest concerns coatings for wind turbine blades and refrigeration. Herein, a new laboratory test was employed to obtain the thickness dependence of ice adhesion for Sylgard 184-a filled polydimethylsiloxane elastomer. A correlation between ice adhesion and coating thickness (t) was found that follows a relationship developed by Kendall over 40 years ago for removal of a rigid object from an elastomer. With a 0.05 mm/s probe speed a nearly linear relationship between peak removal stress (Ps) and 1/t(1/2) was obtained with Ps ∼ 460 kPa for an 18 μm coating, decreasing to ∼120 kPa for 533 μm. Preliminary results suggest that below ∼10 μm Ps departs from the 1/t(1/2) correlation while above ∼500 μm a limiting value for Ps may be reached. We previously reported that probe speed has negligible effect on the glassy polymer PMMA. In contrast, probe speed is identified as an important variable for testing ice release on elastomeric Sylgard 184 coatings. While work of adhesion, which is related to surface free energy, is recognized as an important factor that can affect ice release, the results reported herein show that coating thickness can override this single parameter for elastomeric substrates.
由于在飞机机翼、航天器和输电线路等应用中的重要性，使冰的附着力最小化一直是广泛研究的主题。人们对风力涡轮机叶片和制冷用涂层的兴趣与日俱增。在此，采用了一种新的实验室测试方法来获取Sylgard 184（一种填充聚二甲基硅氧烷弹性体）的冰附着力与涂层厚度的关系。发现冰附着力与涂层厚度（t）之间的相关性遵循肯德尔40多年前提出的从弹性体上移除刚性物体的关系式。在探针速度为0.05 mm/s时，对于18μm的涂层，峰值移除应力（Ps）与1/t(1/2)之间获得了近乎线性的关系，Ps约为460 kPa，对于533μm的涂层则降至约120 kPa。初步结果表明，在约10μm以下，Ps偏离1/t(1/2)的相关性，而在约500μm以上，Ps可能达到极限值。我们之前报道过，探针速度对玻璃态聚合物聚甲基丙烯酸甲酯的影响可忽略不计。相比之下，探针速度被确定为测试弹性体Sylgard 184涂层上冰释放的一个重要变量。虽然与表面自由能相关的粘附功被认为是影响冰释放的一个重要因素，但本文报道的结果表明，对于弹性体基材，涂层厚度可以超越这一单一参数的影响。
