Jio Jeong's List: stuff

• How Does Sunscreen Work?
• Sunscreen combines organic and inorganic chemicals to filter the light from the sun so that less of it reaches the deeper layers of your skin
• Like a screen door, some light penetrates, but not as much as if the door wasn't present.
• Sunblock, on the other hand, reflects or scatters the light away so that it doesn't reach the skin at all.
• The reflective particles in sunblocks usually consist of zinc oxide or titanium oxide.
• The organic molecules in sunscreen absorb the ultraviolet radiation and release it as heat.     
     
  • PABA (para-aminobenzoic acid) absorbs UVB
     
  • Cinnamates absorb UVB
     
  • Benzophenones absorb UVA
     
  • Anthranilates absorb UVA and UVB
     
  • Ecamsules absorb UVA

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• Soap is formed by molecules with a "head" which likes water (hydrophilic) and a long chain that hates it (hydrophobic).

• Then when soap is added to the water, the long hydrophobic chains of its molecules join the oil particles, while the hydrophilic heads go into the water. An emulsion of oil in water is then formed, this means that the oil particles become suspended in the water and are liberated from the cloth. With the rinsing, the emulsion is taken away.

   
• In summary, soap cleans by acting as an emulsifier. It allows oil and water to mix so that oily grime can be removed during rinsing.

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