Composites of liquid crystalline nickel phthalocyanine with gold nanoparticles: Liquid crystalline behaviour and optical properties

• Composites of discotic nickel phthalocyanine and gold nanoparticles were obtained.
• Nature of the mesophase is not altered in the composites.
• Composites exhibit enhanced electrical conductivity and distinctive optical properties.

In this work, the composites of discotic tetra-substituted nickel phthalocyanine with hexadecylamine coated gold nanoparticles and uncapped gold nanoparticles deposited by metal organic chemical vapour deposition were obtained and studied for the first time. The influences of the incorporation of gold nanoparticles into the ordered matrix of hexagonal columnar mesophase of the substituted phthalocyanine on the liquid crystalline behaviour, optical and electrical properties were investigated by different physical methods. It was demonstrated that on one hand, the nature of the mesophase is not altered in these composites. On the other hand, the films of gold nanoparticles and phthalocyanine composites exhibit both enhanced electrical conductivity and distinctive surface plasmon properties. It was shown that the type of AuNPs is crucial for the properties of the composites.