Mao Dangxin, Wang Xian, Wu Yuanyan, Gu Zonglin, Wang Chunlei, Tu Yusong
College of Physics Science and Technology, Yangzhou University, Jiangsu 225009, China.
Zhangjiang Lab, Interdisplinary Research Center, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.
Nanoscale. 2021 Dec 2;13(46):19604-19609. doi: 10.1039/d1nr05048f.
Current major approaches to access surface hydrophobicity include directly introducing hydrophobic nonpolar groups/molecules onto the surface or elaborately fabricating surface roughness. Here, for the first time, molecular dynamics simulations show an unexpected hydrophobicity with a contact angle of 82° on a flexible self-assembled monolayer terminated only with two hydrophilic OH groups ((OH)-SAM). This hydrophobicity, verified by a water slip phenomenon characterizing the friction on the (OH)-SAM surface, is attributed to the formation of a hexagonal-ice-like H-bonding structure in the OH matrix of (OH)-SAM, which sharply reduces the hydrogen bonds between the surface and the water molecules above. The unique simple interface presented here offers a significant molecular-level platform for examining the bio-interfacial interactions ranging from biomolecule binding to cell adhesion.
当前用于获取表面疏水性的主要方法包括直接在表面引入疏水非极性基团/分子或精心制造表面粗糙度。在此，分子动力学模拟首次显示，在仅由两个亲水性OH基团终止的柔性自组装单分子层（(OH)-SAM）上出现了意想不到的疏水性，接触角为82°。这种疏水性通过表征(OH)-SAM表面摩擦力的水滑现象得到验证，它归因于(OH)-SAM的OH基质中形成了六方冰状氢键结构，这大幅减少了表面与上方水分子之间的氢键。此处呈现的独特简单界面为研究从生物分子结合到细胞粘附等生物界面相互作用提供了一个重要的分子水平平台。
