Dynamic covalent gels assembled from small molecules: from discrete gelators to dynamic covalent polymers

Dynamic covalent chemistry has emerged recently to be a powerful tool to construct functional materials. This article reviews the progress in the research and development of dynamic covalent chemistry in gels assembled from small molecules. First dynamic covalent reactions used in gels are reviewed to understand the dynamic covalent bonding. Afterwards the catalogues of dynamic covalent gels are reviewed according to the nature of gelators and the interactions between gelators. Dynamic covalent bonding can be involved to form low molecular weight gelators. Low molecular weight molecules with multiple functional groups react to form dynamic covalent cross-linked polymers and act as gelators. Two catalogues of gels show different properties arising from their different structures. This review aims to illustrate the structure-property relationships of these dynamic covalent gels.