Colloids and interfaces in the environment Flashcards
What are the 3 phases of matter?
Solid (definite shape and volume)
Liquid (take container shape, fixed volume)
Gases (shape and volume of container)
What 2 things can happen to substances when transitioning between phases?
Increased temp- faster particle, pushed apart
Attractive force- stickiness, pull together
What is a colloid?
Mixture of 2 phases of matter
What are some examples of colloids?
Liquid aerosols
Solid aerosols
Liquid foam
Emulsions
SOL (solid liquid)
Solid foam
Gel
Solid sol
What is a SOL? (colloid)
solid particles dispersed in a liquid
What are some examples of SOLs? (colloid)
Paint
Starch
Tea in water
Soapy water
What is a gel or solid emulsion?
continuous network of solid particles dispersed in liquid (e.g., jellies)
How will colloidal solutions appear?
milky
What is the particle diameter range in colloids?
1-1000nm
What does not happen with colloid particles?
don’t settle to bottom of container and cannot be removed by filtering
What is the Tyndall effect?
a way to distinguish a colloid from solution by shining a light through as the large particles in the colloid will scatter light
What other particles are around the size of colloids?
Smaller then bacterium
Larger then protein
Around size of virus
What does PM stand for?
particulate matter
What are the 3 main types of pm size?
10
2.5
0.1
What is the most dangerous type of pm?
0.1 as ultrafine and can make it to alveoli and into bloodstream while 10 only trachea and 2.5 bronchioles
How can soils be colloids?
pore in between soil particles fill with water in sand there is bigger void while clay is more platy
What properties can vary between soils?
swelling
shrinkage
and contribution to aggregate stability
What will tend to organic compounds in soil because of their large surface area?
will usually sorb onto or into soil colloids
In what industries are colloids used?
Effluent treatment (flocculant)
Paint industry
Food
Cosmetics and toiletries
Detergent industry
Pharmaceutical industry
Agriculture
What is a micelle?
Particle of colloidal dimensions that exists in equilibrium with the molecules or ions in solution which it formed
What are micelle polymers like?
Organized self-assembly formed in a liquid
and composed of amphiphilic macromolecules, made of
hydrophilic (like water) and hydrophobic (hate water) blocks
What is the reason why water isnt at gas at current earth temp and atmospheric pressure?
due to H bonds
Why dont water and oil mix?
oil is hydrogen and carbon little unpaired to interact with water
How can oil and water be forced to mix?
by adding energy e.g, stirring
but re-separation will occur
When can be added to oil and water to form a bridge between the 2?
Surface active molecule or surfactant
What does a surfactant do?
sit on the interface of oil and water and stabilises the mixture
What can surfactants be used to remediate?
oil spills by pulling oil down into water
What are the positives of using surfactants for oil spills?
oil broken down into smaller blobs which are more available to micro organisms
What problem can arise from using surfactants?
they are a chemical which alter surface tension and waters H bond
What can affect the effectiveness of using surfactants on oil spills?
Viscosity (thickness) of the oil
Wind speed
Wave height & frequency
Interferes with other methods
