Week 6
This past Tuesday, the ratios of polymer to liquid crystal were tested in the Nanoparticles Lab. Each test mixture was around 0.50 g, with the ratio of liquid crystal to polymer varied each time. Four different mixtures were measured, with the amount of liquid crystal added ranging from 25% to 40%. The table below shows the measurements and experimental ratios for each of the four tests.
Polymer | Mass Added | Experimental Ratio |
0.75 | 0.3823 g | 0.7561 |
0.70 | 0.3613 g | 0.7033 |
0.65 | 0.3359 g | 0.6531 |
0.60 | 0.3013 g | 0.6009 |
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Liquid Crystal | Mass Added | Experimental Ratio |
0.25 | 0.1233 g | 0.2439 |
0.30 | 0.1524 g | 0.2967 |
0.35 | 0.1784 g | 0.3469 |
0.40 | 0.2001 g | 0.3391 |
The polymer dispersed liquid crystal mixture was then placed between two thin sheets of conductive substrate in order to create a thin film. A balloon press was used to distribute the PDLC evenly across the substrate. The four test plates had to be cured in order for the polymer dispersed liquid crystal film to harden. Each was then tested with an applied voltage of 2.0 V to find the polymer to liquid crystal ratio which maximized the privacy glass effect.
However, the results of this experiment showed that an even greater ratio of liquid crystal to polymer would be more effective. The substrate with the PDLC mixture containing 40% liquid crystal had only a faint difference in transparency under the applied voltage.
The hardened polymer dispersed liquid crystal thin film should appear as a translucent white material or milky, in order to become transparent under the applied voltage. The only test plate that shows this characteristic is the one with the least amount of polymer.
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Each of the 4 substrates tested with varied ratios of polymer to liquid crystal. |