The　self-assembly　of　polypentadeca-　and　polyeicosa-oxyethylene　mono　n-hexadecylethers　(C16E15　and　C16E20)　in　cyclohexane　has　been　studied　using　small-angle　X-ray　scattering　(SAXS),　rheology　measurements　and　polarised-microscopy　(POM)　observations.　Both　surfactants　can　dissolve　in　cyclohexane,　which　benefited　from　their　low　cohesive　energy.　A　trace　amount　of　water　was　used　to　help　the　formation　of　reverse　aggregates.　The　SAXS　measurements　and　POM　observations　all　evinced　the　formation　of　reverse　vesicles　in　the　solutions.　The　solution　viscosity　showed　the　dependence　on　both　water　content,　represented　as　the　mole　ratio　of　water　to　surfactant　W0,　and　surfactant　concentration　Cs.　The　samples　at　Cs = 200 mmol L−1　and　W0 = 15–20　had　a　visco-elastic　response　with　elastic　behaviour　at　high　frequencies　(G′　dominating　over　G″)　and　slightly　viscous　behaviour　at　low　frequencies　(G″　exceeding　G′)　which　resulted　in　a　crossover　of　G′　and　G″　at　below　0.1 rad s−1.　The　elastic　plateau　modulus　G′P　increased　with　increasing　W0　or　Cs.　The　effect　of　temperature　on　the　rheological　properties　was　examined.　The　value　of　flow　activation　energy,　Ea,　of　C16E20　was　lower　than　that　of　C16E15,　which　suggested　that　the　former　may　be　more　likely　to　form　reverse　vesicles　than　the　latter.　The　elastic　plateau　modulus　G′P　showed　temperature　dependence,　which　was　explained　in　terms　of　the　hydrogen　bonding　interactions　between　the　water　and　the　POE.　[Figure　not　available:　see　fulltext.]　©　2016,　Springer-Verlag　Berlin　Heidelberg.