Enhanced liquid crystal performance through alkoxybenzoic acid doping

This study investigates the impact of doping agents, 4-octyloxybenzoic acid (8OBA) and 4-octyloxy-3-fluoro benzoic acid (8OBAF), on the thermodynamic and electro-optical properties of the nematic liquid crystal 5CB. The differential scanning calorimetry, dielectric, and polarising optical microscopic measurements revealed intriguing properties. The doped liquid crystal samples exhibit higher phase transition temperatures, increasing birefringence, and order parameters. Dielectric measurements disclose reduced free ion concentration with 8OBA and increased concentration with 8OBAF in the liquid crystal matrix. The threshold voltage, switching time, and rotational viscosity were also diminished in the 5CB + 8OBA mixture, whereas these parameters were increased in the 5CB + 8OBAF mixture due to the strong intermolecular interaction with liquid crystals. The results presented here demonstrate that 8OBA dopant can be used to achieve high thermal stability of the nematic liquid crystal phase with fast response times and low threshold.