A　homologue　of　carboxylate　gemini　surfactants　with　an　azobenzene　spacer　and　different　lengths　of　the　alkyl　tails,　referred　to　as　Cm(azo)Cm,　has　been　synthesized.　All　the　surfactants　formed　wormlike　micelles　at　relatively　low　concentrations　without　addition　of　salt.　The　reason　was　attributed　to　the　long　and　rigid　characteristic　of　the　azobenzene　spacer,　which　yielded　the　pseudo　volume　between　the　two　tails　and　thus　a　columnar-like　molecular　geometry　favorable　for　the　formation　of　wormlike　micelles.　The　results　of　rheology　and　FF-TEM　measurements　showed　that　the　length　of　the　alkyl　tails　strongly　affected　the　viscoelastic　properties　of　the　wormlike　micelle　solution.　With　the　increase　of　the　alkyl　tail　length,　the　solutions　evolved　from　a　typically　viscous　fluid　to　a　strong　viscoelastic　solution　and　then　to　a　gel-like　state.　This　was　attributed　to　the　different　microstates　as　revealed　by　scaling　law.　These　solutions　behave　as　polyelectrolyte　systems　because　of　their　additive-free　nature.　©　2009.