Application Cases

Experiment Name: Application of High-Voltage Amplifier in the Synthesis of Siloxane Smectic Monomers

Research Direction: Crystal Materials

Test Objective:
Bistability includes nematic bistability, smectic A phase bistability, and cholesteric phase bistability. Current research focuses primarily on smectic A phase bistability. Smart glass made from the smectic A phase has no viewing angle issues.

Smectic A phase bistable liquid crystals are mainly composed of smectic liquid crystals and ionic salt clearing agents. When a high-frequency voltage (>1000 Hz) is applied, the ionic salt cannot be driven, and the liquid crystal molecules maintain a uniform orientation under the applied voltage, resulting in a transparent state. However, due to the high viscosity of the smectic liquid crystal, it cannot return to the scattering state when the voltage is removed. When a low-frequency voltage (<100 Hz) is applied to the liquid crystal, the ionic salt is driven. Its random motion disrupts the alignment of the liquid crystal molecules, resulting in a hazy state. Similarly, due to the high viscosity, it cannot return to the original state when the voltage is removed.

Testing Equipment: ATA-2041 high-voltage amplifier, differential scanning calorimeter, nuclear magnetic resonance spectrometer, elemental analyzer, polarizing microscope, Abbe refractometer, haze transmittance tester

Experimental Procedure:

Figure: Synthesis of Smectic Liquid Crystal Monomer Compound 2

In this experiment, 10-bromo-1-decene, 4-hydroxy-4'-cyanobiphenyl, and 1,1,1,3,3,5,5-heptamethyltrisiloxane were used as raw materials. A smectic A phase liquid crystal monomer containing a long-chain siloxane structure was synthesized in high yield through a two-step reaction. The structure was confirmed by nuclear magnetic resonance (NMR) and elemental analysis. The liquid crystal parameters were measured using a polarizing microscope and a differential scanning calorimeter. This smectic A phase liquid crystal monomer containing a long-chain siloxane structure was used to prepare a smectic A phase mixed crystal. Using this mixed crystal material, an optical device with bistable characteristics was fabricated.

Experimental Results:

Figure: DSC Curve of the Smectic Phase Formulation

Experiments show that the smectic phase bistable device made with this smectic phase mixed crystal formulation has a wide smectic phase temperature range (-62°C to 60°C), a low driving voltage (50 V), excellent transparent state parameters (haze = 0.06%, parallel light transmittance = 90.34%), no viewing angle defects, and achieves bistability by requiring power only when switching states.

Aigtek ATA-2041 High-Voltage Amplifier:

Figure: Specifications of the ATA-2041 High-Voltage Amplifier