中文摘要：

采用^1H—NMR和FT-IR表征了在摩尔比1：4条件下，由均苯四甲酸和对羟基吡啶合成的一种凝胶因子（G2）。通过在室温下冷却G2的水溶液，形成了超分子水凝胶，采用扫描电子显微镜（SEM）、示差扫描量热仪（DSC）和流变仪等多种技术研究了冷却速率对凝胶的组装纤维结构及宏观性能的影响。随着冷却速度的降低，纤维尺寸变大而凝胶的稳定性降低。因此，可以通过环境因素来控制凝胶的性能．采用流变仪分析表明凝胶具有高的机械强度，DSC分析结果表明随着凝胶因子浓度的增加，凝胶中可冻结水的含量降低，相对于在摩尔比1：2条件下，由均苯四甲酸和对羟基吡啶合成的凝胶因子G1，在相同浓度下，G2在更高的最低凝胶因子浓度（MGC）使水凝胶，并且得到的凝胶具有更低的凝胶，溶胶破坏温度（Tgel），利用环境扫描电镜（ESEM）直接观测了实际含水状态下凝胶的形貌，结果表明采用常规SEM观测到的纤维状网络与ESEM的结果一致，这说明在干燥过程中形貌并未发生太大变化、组装体结构和性能关系有助于认识凝胶形成机理并使凝胶满足不同的应用。

英文摘要：

A gelator （G2） synthesized from 1,2,4,5-benzene tetracarboxylic acid and 4-hydroxy pyridine at molarratio of 1：4 was characterized by ^1H-NMR and FT-IR. Supramolecular hydrogels were formed via cooling the aqueous solutions of G2 under ambient condition. The influence of cooling speed on the structure of the assembling fibers and the macroscopic properties of the gels was investigated via multiple techniques, including scanning electron microscopy （SEM）,differential scanning calorimetry （DSC） and rheology measurements. As decreasing the cooling speed, the fiber size becomes larger, and the gel stability becomes lower. Therefore it is possible to control the gelperformances via the environmental stimulation. The gel possesses high mechanical properties as indicated by the rheology measurements. The DSC measurement reveals that the freezing water content for the gels becomes lower as increasing the gelator concentration. Compared with G1 synthesized from 1,2,4,5-benzene tetracarboxylic acid and 4-hydroxy pyridine at molar ratio of 1 ： 2, G2 gelled water at higher minimum gelator concentration （MGC） and gave the gel with lower gel-to-sol dissociation temperature （ Tgel ） at the same concentration. Environmental scanningelectron microscopy （ESEM） was applied to study the naturally hydrated state of gels directly,it was also noticed that the fibrous networks observed by conventional SEM are similar to those obtained by ESEM, which means that the morphology does not change significantly under drying. The relationship between the assembled structure and properties is helpful for understanding the gel formation mechanism and makes the gels suitable for different applications.