In the present article, we have studied the effect of copper nano-particles on the thermal, optical and dielectric parameters of a liquid crystalline material 2,3,6,7,10,11-hexabutyloxytriphenylene (in short HAT4) showing wide temperature range (~65°C) hexatic columnar mesophase. A composite has been prepared by dispersing 0.6wt.% of copper nano-particles. UV–vis spectroscopy has been used to record the absorption spectra. It has been observed that the presence of copper nano-particles introduces surface plasmon resonance and reduces the optical band gap of HAT4. Though isotropic to mesophase transition temperature is unaffected but mesophase-crystal transition temperature has decreased and hence range of the mesophase has enhanced due to the presence of copper nano-particles. While dc conductivity has increased by about two orders of magnitudes, dielectric permittivity has also moderately increased. With the enhanced properties, HAT4-copper nano-particle composite is useful for one dimensional conduction and photovoltaic applications.