Nickel nanoparticle-stabilized room-temperature blue-phase liquid crystals

Area of Science:

• Materials Science
• Condensed Matter Physics

Background:

• Blue-phase liquid crystals (BPLCs) are promising for optical devices but limited by narrow temperature ranges.
• Stabilization of BPLCs using nanoparticles (NPs) typically focuses on specific phases (BPII, BPI) with limited success in widening temperature ranges.

Purpose of the Study:

• To investigate the effect of nickel nanoparticles (Ni NPs) on the temperature range and stability of blue-phase liquid crystals (BPLCs).
• To explore the potential of Ni NPs for enhancing BPLC applicability in optical devices.

Main Methods:

• Synthesis of nickel nanoparticles (Ni NPs).
• Introduction of varying concentrations of Ni NPs into a BPLC system.
• Investigation of concentration-dependent temperature effects on BPLC phases (BPII and BPI).

Main Results:

• A trace amount of Ni NPs effectively stabilized the BPLC, increasing the temperature ranges for both BPII and BPI phases.
• The BPLC doped with 0.05 wt% Ni NPs exhibited a wider operational range (7.7 °C) compared to undoped BPLC (5.9 °C).
• Ni NPs were observed to stabilize the BPLC lattice by being trapped at disclination line joints due to elastic interactions.

Conclusions:

• Nickel nanoparticles can significantly enhance the thermal stability and broaden the operational temperature range of blue-phase liquid crystals.
• The reproducible phase behavior upon heating and cooling indicates thermodynamic stability, making Ni NP-doped BPLCs suitable for practical optical applications.