松香基超分子水凝胶的构筑与形成机制研究

Supramolecular hydrogels, which are formed by the self-assembly of small molecular hydrogelators, are important soft materials and have wide applications in life science fields. On the other hand, rosin is one of featured forestry products in our country. The synthesis of novel small molecular hydrogelators derived from rosin therefore accords well with the philosophy of green chemistry and is significant for human society in harmony with nature during development. In this project, the research on the fundamental problems in constructing hydrogels is linked to the utilization of the rosin. A novel principal, combination of rigidity and softness, is proposed in designing the hydrophobic groups of the small molecular hydrogelators. A series of small molecular hydrogelators with such hydrophobic groups will be derived from rosin-based raw materials, which are then used for constructing supramolecular hydrogels via self-assembly. The properties and microstructures of the hydrogels formed will be investigated by DSC, rheology, EM and NMR methods. In addition, the effects of additives on the formation and properties of hydrogels will also be concerned. The results obtained by this study will reveal the unique self-assembly rules of rosin-based small molecular hydrogelators, and will also be beneficial to the applications of rosin in new technology fields.

超分子水凝胶是由小分子水凝胶剂自组装形成的重要软物质材料，在生命科学领域有着广泛的用途。松香是我国特色的林业资源，开发以松香为原料的新型超分子水凝胶符合绿色化学的要求，对于实现人与自然的和谐发展有着重要意义。本项目将天然产物松香的利用与超分子水凝胶构筑过程中的基本科学问题相结合，针对小分子水凝胶剂的疏水基团，提出“刚柔结合”的设计理念，合成系列松香基小分子水凝胶剂，构筑应用性能良好的超分子水凝胶体系。用DSC、流变、电镜、核磁共振等方法研究超分子水凝胶的性质与微观结构，关注添加剂对超分子水凝胶形成与性质的影响。研究结果将揭示松香基小分子水凝胶剂独特的自组装规律，为松香在新技术领域的应用奠定理论基础。

松香是我国的特色林业资源，开发以松香为原料的超分子水凝胶符合绿色化学的要求，对于实现人与自然的和谐发展有着重要意义。本项目依据“刚柔结合”的分子结构设计原则，以松香衍生物为原料，获得了系列结构新颖的松香基两亲分子，通过调节体系温度以及添加剂种类等，首次构建出了８种松香基超分子水凝胶。其中，一种氧化胺型的松香基小分子凝胶剂可以形成超级水凝胶，其临界胶凝浓度仅为4mM。以这种分子作为稳定剂，用量仅为连续相的0.2wt%时即可以形成稳定的凝胶乳液，分散相的体积分数可以在2%和95%之间任意调整，打破了传统凝胶乳液的内相体积必须大于74%的定论；以这种分子作为稳定剂，还可以获得一种含水量高达45%的凝胶泡沫。这种泡沫显示了超高的稳定性，半衰期可达12800 min。对水凝胶的微观结构的研究表明，松香基两亲分子形成了手性纳米纤维、蠕虫状胶束、双层膜等不对称聚集结构。随着松香基两亲分子内柔性链段比例的增加，得到的聚集体也存在着由刚性纤维向柔性蠕虫胶束转变的倾向。本项目的研究结果揭示了松香基两亲分子独特的自组装规律，探索了松香基两亲分子的介观聚集结构对体系性能的影响，为天然产物松香在新技术领域的应用奠定了理论基础。