Small-angle neutron scattering from microemulsions near the disorder line in water/formamide-octane-CiEj systems

摘要: Small‐angle neutron scattering measurements were performed on symmetric microemulsions containing equal volume fractions of water/formamide, n‐octane, and a sufficient amount n‐alkyl polyglycol ether (CiEj). By changing the surfactant chain length in order C8E3, C6E2, C4E1 pure water, as well for given C8E3 C6E2 by increasing relative formamide water/formamide mixture, amphiphilic strength (the amphiphilicity) is reduced. We observe that characteristic peak becomes weaker its position moves into q=0 showing microstructure disordered. However, q−2 q−4 behavior large q film bulk contrast, respectively, still observed indicating persistence internal interfaces. As further weakened, disorder line passed at which real space correlation function changes from damped oscillatory to monotonically decreasing one. determine this has be...