Ice/Solid Adhesion Analysis Using Low-Temperature Raman Microprobe Shear Apparatus
Ice/Solid Adhesion Analysis Using Low-Temperature Raman Microprobe Shear Apparatus
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DOI：
10.1366/0003702934334606
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发表时间：
1993-10
影响因子：
3.5
通讯作者：
N. Sonwalkar;S. Sunder;S. Sharma
中科院分区：
文献类型：
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作者：
N. Sonwalkar;S. Sunder;S. Sharma
为了研究双材料界面键合过程中的分子力学行为，设计并制作了一台拉曼微探针剪切仪。该装置被制造为在受控温度、湿度和蒸气流速环境下在冷金属基底上气相沉积冰薄膜所产生的双材料界面上进行纯剪切实验。用扫描电镜观察了四种金属（钛、铜、铝、不锈钢）和一种聚合物表面的织构。剪切实验在180°和135°散射几何条件下与拉曼微探针光耦合。的拉曼光谱提供有关的分子结构和振动模式在双材料界面的剪切事件之前和之后的原位信息。结果表明，冰格中的氧原子与固体表面原子的相互作用是形成粘结键的主要原因。显示出与冰良好晶格匹配的固体显示出良好的粘合强度。发现粘附强度与机械互锁的程度成正比，与水滴的接触角成反比。粘接强度的活化能分析表明，冰/金属键的失效是速率敏感的，而冰/聚合物键是相对不敏感的应变速率。冰/金属粘结的失效是内聚的，而冰/聚合物粘结的失效是界面的。金属上的冰层结构是多晶的，这是轻微的基板的晶体结构的影响，并显示出增加的振动模式的顺序。剪切后的冰具有大量的缺陷，这反映在拉曼峰的半功率带宽的增加。
In order to understand the molecular mechanics involved in the adhesion of a bimaterial interface bond, a Raman microprobe shear apparatus has been designed and fabricated. The apparatus is fabricated to perform a pure shear experiment on a bimaterial interface produced by the vapor deposition of a thin film of ice on a cold metallic substrate under a controlled temperature, humidity, and vapor-flow rate environment. The textures of four metal surfaces (titanium, copper, aluminum, stainless steel) and one polymer surface have been investigated with the use of the scanning electron micrograph. The shear experiment is optically coupled to a Raman microprobe at the 180° and 135° scattering geometry. The Raman spectra provide in situ information regarding the molecular structure and vibrational modes at the bimaterial interface before and after the shearing event. The results indicate that the adhesive bonds are formed primarily by the interaction of oxygen atoms in the ice lattice with the atoms of the solid surface. A solid, which displays good lattice matching with ice, shows good adhesive strength. The adhesive strength is found to be proportional to the extent of mechanical interlocking and inversely proportional to the contact angle of the water droplet. An activation energy analysis of the adhesive strength shows that the failure of the ice/metal bond is rate sensitive while the ice/polymer bond is relatively insensitive to the strain rate. The failure of the ice/metal bond is cohesive while the failure of the ice/polymer bond is interfacial. The structure of the ice layers on metals is polycrystalline, which is marginally influenced by the crystalline structure of the substrate and shows increased ordering in vibrational modes. The sheared ice has a larger number of defects as reflected by the increase in the half-power bandwidth of the Raman peaks.