New insights on the crystalline forms in binary systems of n-alkanes: Characterization of the solid ordered phases in the phase diagram tricosane plus pentacosane

X-ray diffraction analyses of the pure components n-tricosane and n-pentaco sane and of their binary mixed samples have enabled us to characterize the crystalline phases observed at "low temperature." Contrary to what was anno unced in literature on the structural behavior of mixed samples in odd-odd binary systems with Delta n = 2, the three domains are not all orthorhombic , This work has enabled us to show that two of the domains are, in fact, mo noclinic (Aa, Z = 4), and the other one is orthorhombic (P-ca21, Z = 4) The conclusions drawn in this work can easily be transposed to other binary sy stems of n-alkanes.