Conventional gelation of organic solvents is unable to perform for some solvent with low boiling point due to the fact that gelator should be dissolved at high temperature and self-assemble in the process of cooling. Herein, three kinds of reaction type of gelators, methylbenzene–2, 4–bis (N, N'–alkyl) urea derivatives were synthesized by using high reactivity of isocyanate and alkylamine. These dialkylurea derivatives can make some aromatic and halide solvents into thermal reversible organogels at room temperature. The formation of organogels was greatly influenced by the solvophilic interaction of alkyl groups and the characteristic of solvents. The images of FE–SEM revealed a three-dimensional network consisting of fiber-like aggregates of the dialkylurea derivatives. Moreover, the length of alkyl groups in dialkylurea lead to different morphology of the aggregates. The study of FT–IR and 1H–NMR further indicates that the hydrogen bonding interaction is a main driving force for the self–assembly of dialkylurea derivatives. A possible self-assembly mode was proposed based on the data of XRD and molecular stimulation.

Key words: reaction type, dialkylurea gelator, gelation at room temperature