Characterization of the behavior of hydrophobic domain in hydrogel on hydrophobic and hydrophilic interfaces

Biocompatible hydrogels are of central importance for many applications in the field of life science. A central point in all such applications is their adhesion to a solid surface, which is typically achieved by the application of soft pressure. We have developed such a hydrogel that contains cholic acid groups and whose adhesion underwater becomes stronger with increased content of cholic acid. Assumed is here the formation of hydrophobic domains of the cholic acid moieties at the interface that should also depend on the extent of hydrophobicity of the substrate. Neutron reflectometry in D2O shall be done in order to see how the hydrogel structure at the interface changes as a function of applied pressure and the content of cholic acid in the hydrogel. This is essential to understand macroscopic adhesion in terms of mesoscopic structure and thereby rationalize molecular hydrogel design.

生物相容性水凝胶（Biocompatible hydrogels）在生命科学领域的诸多应用中占据核心地位。这类应用的核心要点在于水凝胶与固体表面的黏附性，通常可通过施加轻柔压力实现。我们开发了一种含胆酸基团（cholic acid groups）的水凝胶，其水下黏附性随胆酸含量增加而增强。推测胆酸片段（cholic acid moieties）在界面处会形成疏水结构域，且这一过程同样依赖于基底的疏水性程度。将在重水（D₂O）中进行中子反射法（neutron reflectometry）实验，以探究界面处水凝胶结构如何随施加压力及水凝胶中胆酸含量的变化而改变。这对于从介观结构层面理解宏观黏附性、进而合理化分子水凝胶设计至关重要。