Study of Liquid Crystals
(Chemistry Experiment Course in Meiwa High School)

1. Microscopic Observation of Displays

Microscope	Photomicrograph of Display	Red-Green-Blue

 Let's take a look under a microscope.

2. Experiment with The 3-Primary Colors of Light

Create your favorite color with the LED.

 How do white LEDs make white light? 

3. LCD(Liquid Crystal Display) of Calculator

front and back	90°rotation

    How to disassemble ? → LINK(Japanese)

Let's move the polarizer.

4. Experiment with Polarizer
Try to sandwich various things between two polarizers.     

	Scotch Tape	CD Case

5. Polarization
  (1) Description of Textbook

	■Suken Shuppan	■Keirinkan

  (2) Explanation with Animation

    LINK→  https://www.geogebra.org/m/E6jZ52vK

  (3) Make A Polarizer

			How to make a polarizer ?    → LINK(Japanese)
	Stretch in One Direction	Stretch The Vinylon Film

 Let's look at various things through a polarizer.

 Are there other effective combinations like iodine and PVA?

Reflected Light

At what angle of reflected light can the polarizer block most effectively?
   → Let's explore “Brewster's angle”.
 There is a good web page about polarization.  → Industrial polarized camera by SONY

6. Change from Solid to Liquid

Normal Materials		→
	Solid	→	Liquid
Liquid Crystal Materials
	Solid	Liquid Crystal (nematic)	Liquid

 Let's measure two melting points of liquid crystal. 

While heating up the liquid crystals,    we can see melting point twice.

7. Molecular Shape by MolView     LINK → MolView

(1) 4-Cyano-4'-pentylbiphenyl (5CB)
   

(2) N-(4-Methoxybenzylidene)-4-butylaniline (MBBA)
   

Let's move these molecules on the screen above.
 Look at other liquid crystal substances. →  LINK
 What are the characteristics of liquid crystal molecules?

8. Let's try to make your own LC Display !

  (1) How It Works ?

	■ Layer Structure	■ Conductive Part

   What is Rubbing ? (Twist the LC molecules) → LINK(Japanese)

 ITO glass → Geomatec Co.,Ltd (external page)

  (2) What Is A Spacer ? 

	MICROPEARL (5μm)	Sandwich the spacer with glass

   (3) Masking and Etching Process  → LINK(Japanese)
    

 Design Sheet → LINK(Japanese)

【Etching Process】  �@ Place the masked ITO glass in the tray.  �A Put the zinc powder on the ITO glass.  �B Pour 1mol/L HCl over the zinc.  �C Check if the unmasked part is melted.  �D Remove the ink with ethanol (or acetone).

   (4) Set Up The LCD

【Set Up Process】  �@ Place the ITO glass.  �A Put spacer on the ITO glass.  �B Add a few drops of 5CB and mix with spacer.  �C Put another ITO glass on it.

 How much 5CB is needed for this LCD ?  → LINK(Japanese)

  Is your LCD working well ?

	Use the battery snap like a switch.	The "M" disappeared for my mistake.

 During the LCD works, how much electric current is flowing?

●Application example

I tried to make a 7-segment number display. In places where the wiring is narrow, the molecules of liquid crystal are not align well, so the screen looks dirty.

9. Review
　Post-Course Learning, Q&A → LINK(Japanese)


10. Icons List　　　　   
■ACTIVITY
Let's take a look under a microscope.
 Create your favorite color with the LED.
 Let's move the polarizer.
 Try to sandwich various things between two polarizers.
 Let's look at various things through a polarizer.
 Let's measure two melting points of liquid crystal.
 Let's move these molecules on the screen above.
 Design Sheet → LINK(Japanese)
 Is your LCD working well ?

■RESEARCH
How do white LEDs make white light?
LINK(Explanation with Animation)
　　→ https://www.geogebra.org/m/E6jZ52vK"
Are there other effective combinations like iodine and PVA?
At what angle of reflected light can the polarizer block most effectively?
　　→ Let's explore “Brewster's angle”
There is a good web page about polarization.
　　→ LINK：Industrial polarized camera by SONY
Look at other liquid crystal substances.→ LINK
What are the characteristics of liquid crystal molecules?
What is Rubbing ? → LINK(Japanese)
How much 5CB is needed for this LCD ? → LINK(Japanese)
During the LCD works, how much electric current is flowing?
Post-Course Learning, Q&A → LINK(Japanese)

■OTHERS
  How to disassemble ? → LINK(Japanese)
ITO glass → LINK:Geomatec Co.,Ltd (external page)