基于UPy, DeUG, DAN 四重氢键单元的超分子自组装聚合物构筑和材料的表界面行为研究

四重氢键单元在材料表界面的识别行为和规律不清楚，缺少量化分析，严重制约了其在超分子聚合物中的应用。为此，本研究采用分子识别的原理，合成基于UPy, DeUG 和 DAN 四重氢键单元，建立对材料表面进行一步法官能化改性的方法。通过比较三组体系：自互补vs异互补识别, 常规表面自组装单层vs混合表面自组装单层, 三烷氧基vs单烷氧基硅烷体系, 以含互补四重氢键的改性高聚物作为媒介层，通过剪切拉伸力学实验测试，系统的研究四重氢键构筑单元在材料表面的力学行为。通过将溶液相的关键识别参数与剪切拉伸测试的力学数据相结合，发展了新的理论计算方法，揭示超分子四重氢键识别单元在材料表界面的识别规律，获得四重氢键识别单元在材料内部的关键量化参数: 单个四重氢键的瞬间同步拉断力；四重氢键识别单元形成互补配对结构的百分效率；四重氢键在材料界面总黏附功中贡献的百分比。为四重氢键在超分子材料的设计提供关键理论基础。

Clear understanding of the recognition process of quadruple hydrogen bonding modules on material surface and interface is still missing which significantly limits their application in supramolecular polymer. In order to answer this fundamental question, quadruple hydrogen bonding modules include: 2-ureido-4[1H]-pyrimidone (UPy), 7-deazaguanine urea (DeUG). And 2,7-diamido-1,8-naphthyridine (DAN) with designed structure and function are synthesized based on the mechanism of molecular recognition,. One step surface modification of glass microscope slides was achieved by condensation using designed UPy, DeUG and DAN modules. Three sets of systems are designed to compare their adhesion and mechanical behavior, physical and chemical properties of the quadruple hydrogen bonding modules on modified surface. These systems include self-complimentary vs hetero-complimentary quadruple hydrogen bonding complex; self-assembled mono-layer vs mixed mono-layer; functionalized quadruple hydrogen bonding modules with terminal trialkoxysilane groups vs with mono- alkoxysilane groups. Modified polymeric materials including PS-DAN (DAN modified polystyrene), PBMA-DeUG (DeUG modified poly butyl methacrylate) and PBA-UPy (UPy modified poly butyl acrylate) are designed to use as intermediate layer to promote the pairing efficiency of quadruple hydrogen bonding modules. Significant amount of surface and interface adhesion is observed due to the strong quadruple hydrogen bonding modules interactions. Lap-shear experiment is used to investigate the quadruple hydrogen bonding pair interaction at molecular level and evaluate the physical and chemical properties of the resulting material. By combining key parameter measured from solution studies, such as change of Gibbs free energy, enthalpy, entropy and association constant of the quadruple hydrogen bonding modules, new calculation method is developed to extract different types of non-specific interactions from the total surface adhesion. Mechanical lap-shear test are designed to evaluate the fracture resistance of QHB heterocomplexes. With the method proposed and developed, Several most fundamental yet important questions such as: single pair rupture force, pairing efficiency and percent contribution due to specific quadruple hydrogen bonding in total adhesion can be answered.