A Brief Introduction on Colloids

 

 C O L L O I D S 

A brief introduction 

Just what are they?

 - Colloids are substances that are evenly inside another substance. They can be in two different phases or states of matter. 

- One substance is the dispersion medium, such as water and gas. The other is the dispersed medium, sometimes called the 'internal phase'. This is usually tiny solid particles. Otherwise, if the dispersion medium is a gas, then the internal phase can either be tiny particles or tiny droplets of liquid.

- The dispersed-phase particles have a diameter between 5 or 200 nanometers.

Properties of Colloids:

- Colloids appear to be homogenous but is actually heterogeneous.

*Homogenous = These substances are completely mixed together and are indistinguishable from one another.

*Heterogeneous = These substances remain separate and one substance is spread through out the other substance as small particles, droplets or bubbles.

 - The size of particles in a colloid is between 1nm (1 m = 10^9 nm) and 100 nm in diameter.

- The particles of most colloids cannot be seen with a microscope.

 - The particles of a colloid can pass through filter paper. So a colloid cannot be separated through 

- A colloid scatters a beam of light passing through it (because its particles are fairly large). This process is also known as the tyndal effect.

EXAMPLES OF COLLOIDS

 

MILK:

- Milk is an emulsion, which is a colloid in which both parties are liquids.

- Why is milk a colloid? Because it isn't a solution. It's particles can be seen when you put light into it.

*Milk contains a series of lipid globules surrounded by an outer coating in a proteinousstructure called a micelle. This micelle shields the lipids from separation by providing an electronegative and consequently hydrophilic covering around the lipids. The electronegativity also prevents the micelles from sticking together and forming large grains. However, these micelles are still reasonably-large particles which are not dissolved in the surrounding water, so the substance is a colloid.

SHAVING CREAM AND WHIPPED CREAM:

- Colloids of gas and liquid.
- Why are they considered colloids? They have properties of colloids. Simple.

"Agar" comes from the Mala word "Agar-agar" meaning Jelly. Chemically comes from agarose. It is obtained from red algae Gellidium and Gracillaria. It is used to grow bacteria in an microbiology laboratory, and to make some foods thicker, like soup.

GELS:

- Gels such as jelly, agar and even opals colloids of liquids inside solids.

- Why are they considered colloids? They are colloids because it's particles are too large to dissolve completely into a solution. Instead it disperses evenly and is suspended when mixed with a liquid.

  STYROFOAM AND PUMICE:
- They are gas colloids inside solids.

Ohmegash I wub mud! 8D

 MUD:
- Is a colloid of water and clay.



Aero Sprays, one colloid that can release cfc into the atmosphere.




WHAT ARE THE HARMFUL AND BENEFICIAL EFFECTS OF COLLOIDS?

Some colloids cause pollution to the environment. They can release harmful CFCs that contribute to ozone layer depletion. However, the existence of colloids have been relatably useful in other applications, such as the use of milk in strengthening our body's bones. And to this, it also has it side effects, such as mixing a colloid with another substance. This can either cause a harmful or beneficial effect depending on the substance. Too much can also be a bad thing.