Crystalline structures and mesomorphic properties of gemini diammonium surfactants with a pendant hydroxyl group

摘要: Abstract A series of homologous crystals gemini diammonium surfactants (GDAS) containing one hydroxyl substituted methylene spacer are prepared. The crystal structures these compounds, namely [CnH2n+1–N+ (CH3)2–CH2CH(OH)CH2–N+(CH3)2–CnH2n+1], determined by single-crystal X-ray diffraction techniques, in order to have a better understanding the structure relation between solid and mesophase. groups enhance hydrogen bonding interaction neighboring therefore packing GDAS state is arranged form herringbone-like mode. To best our knowledge, this first with structure. Their mesomorphic properties investigated differential scanning calorimetry, polarizing optical microscopy, powder diffraction, rheological measurement. These compounds relatively low melting points thermotropic mesophases over broad temperature range, as compared those without at spacer. behavior smectic phases clearly reveals that bonds exert significant effect on high values moduli viscosity. Moreover, point parameters increase, conforming length alkyl chains.