Transcript Chemistry
Chemistry
You will learn
about:
•Matter
•pH Scale
•Chemistry of
Cosmetics
Why Chemistry?
The professional cosmetologist needs to
understand the chemicals he/she works
with in order to:
- safely perform chemical services
requested by clients,
- teach clients how to care for their hair
following chemical services,
- and, sell products to their clients.
Elements
that make up hair
#
Element
6
Carbon
8
Oxygen
1 Hydrogen
7 Nitrogen
16 Sulfur
Symbol
C
O
H
N
S
Form
Solid
Gas
Gas
Gas
Solid
Chemical Bonds
• Atoms combine
chemically to create
compounds that
eventually create
protein of hair.
Amino Acids
• Compounds of
C,O,H,N
• 22 Common
amino acids
• Join together in
chains to make
proteins
Protein
• Hair is made up of protein
called keratin
• Hair is 97% keratin and 3%
trace minerals
• Hair contains 19 of 22
common amino acids.
Hydrogen Bond
• Unlike charges attract.
• Makes up about 35% of
hairs strength.
• Individually very weak and
can easily be broken by
heat or water to create
physical (temporary)
changes in the hair.
How it Works:
• The hydrogen atom in one
molecule is attracted to an
atom of another molecule
that has many negative
electrons.
Salt Bonds
• This bond is a result of the
attraction of unlike charges.
• Also broken by water to
create physical (temporary)
changes in the hair.
How it Works:
• Negative charge in one amino
acid grouping attracts the
positive charge in another
amino acid grouping.
How Hydrogen and Salt Bonds are
Broken by Water
Water molecules can easily break
hydrogen and salt bonds when the
water molecules move in between the
bonds. When the water molecules are
not present the hydrogen and bonds
come back together.
H
H2O
H
H2O
H
H2O
H
H2O
H
Hydrogen Bonds broken by water molecules
H2O
H
Disulfide Bonds
• Sulfur containing side bond - Most
important to a Cosmetologist.
• A chemical bond that forms between
protein structures; sulfur-type side chains
join with other sulfur-type side chains to
form disulfide bonds.
• Much stronger than hydrogen or salt
bonds.
• Not broken by heat or water. Only a
chemical change.
– Example – permanent wave
End Bonds
(Peptide Bonds)
• Backbone of all protein molecules
• Links the amino acid protein chains
together end to end.
• Do not disturb the end bond, this could
destroy the protein structure.
– If broken, protein chains separate into small
fragments, or revert to groups of amino acids
that no longer have the characteristics of hair.
• RESULT – VERY DAMAGED HAIR!
Side Bonds
• Link the long spiraling
protein chains together.
• Made up of hydrogen, salt
and disulfide and Van der
Waal’s forces.
Label the Bonds
Van der Waal’s
Hair Shaft
Cuticle Layer
Close Look at the Cuticle Layer
The pH Scale
In this section you will learn what the pH
scale is and it’s values associated with
water, acids and alkalines.
Conditioners & Shampoo
Soap
Hair
Hair
relaxers
Potential Hydrogen
• Abbreviation – pH
• Measures whether substance is acidic,
neutral or alkaline
Water-Based Solutions
• pH measures amount
of acid or alkali only in
a water based solution.
• Only solutions
containing water or
solutions that can be
dissolved in water can
be acid or alkaline in
value.
• Most products used in
salon have water listed
as main ingredient.
Acid
More positive
hydrogen ions
than negative
hydroxide ions
Acid
• 0 – 6.99 on pH scale
• Skin and hair acid-balanced
at 4.5 – 5.5
Ex. Lemons and Conditioners
Neutral
Equal number of
hydrogen and
hydroxide ions.
7.0
Ex. Water
Alkaline
• More negative
hydroxide ions
than hydrogen
ions.
Alkaline
• 7.01 – 14 on pH scale
Ex. Amonia and Hair
Relaxer
pH Scale
• Unit of measurement – determines if
substance is acid, neutral or alkaline.
• Ranges from 0 – 14
• 7 is Neutral
0 – 6.99
• Acid range (orange)
• More positive hydrogen ions
7.01 - 14
• Alkaline range (purple)
• More negative hydroxide ions
Acid Balanced
• pH is in the same range
as skin and hair
• 4.5 – 5.5
Ex. Acid Balanced
Shampoo
Emulsions
• 2 or more non-mixable substances united
by a binder (gum).
– Example: oil in water (perms)
– Example: water in oil (cold cream)
Soaps
Mixtures of fat and oil
converted to fatty acids
by heat and then
purified.
Shampoo
• Cleans the scalp
and hair
• Removes all
foreign debris
without adversely
affecting scalp
and hair.
How Shampoo Works
• A push pull action is caused by a
surface active agent causing the oil to
“roll up” into droplets that are lifted and
rinsed away.
Surfactant
•Surface active agent
•Has water loving and
oil loving ends.
Surfactant Molecule
Oil Loving
Water Loving
The tail of the shampoo molecule is
attracted to oil and dirt
Shampoo causes oil to roll up into
small globules
During rinsing, the heads of the
shampoo molecules attach to water
molecules and cause debris to roll off.
Thorough rinsing washes away
debris & excess shampoo.
The Role of Water
• Universal solvent
• Neutral pH
• Hard water = minerals
–Hard to lather
• Soft water preferred (allows
lather)
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CHALLENGE
Types of
Shampoos
All Purpose
• Low Alkaline
• Low surfactants
• Mild, does not strip color
–Example: Redken Clear
Moisture
Plain
•
•
•
•
Usually strong
High alkaline
Not for chemically treated hair
Follow with acid rinse
– Ex: Baby shampoo
• Doesn’t burn eyes because it’s high
in alkaline and so are eyes.
Soapless Shampoo
• Able to lather
without harsh
alkaline ingredient
• Works in soft and
hard water
Acid - Balanced
• Made to have same
pH as the skin and
hair
• Will not strip color
Medicated
• Often must have
prescription
• Designed to treat
scalp and hair
problems
Clarifying
• Removes
residue
–Such as
product
build-up.
Anti-Dandruff
• Control dandruff
• Massage scalp
vigorously and rinse
thoroughly
Liquid Dry
• Used when client
can’t receive normal
shampoo
• Works with wigs
• Evaporates from hair
• Very drying
Powder Dry
• For bedridden
clients
• Orris root powder
absorbs oil and dirt
as product is
brushed through
the hair.
• Don’t use prior to
chemical service.
Conditioning
• Contain animal,
vegetable or mineral
additives that enter
cortex or coat cuticle.
• Improve strength and
porosity.
Color
• Contain temporary
color molecules that
stick to outer cuticle
of hair.
For Thinning Hair
• Gentle
• Lighter molecular
weight
• Provides healthy
environment for
hair growth.
Rinses and Conditioners
Appearance
Rinses and
Conditioners give
hair the appearance
of Shine and Luster
Porosity
Porosity - Amount of moisture in the
hair.
Hair Porosity is the
ability of the hair to
retain & absorb
moisture,
determined by how
raised or compact
the cuticle layers
are.
Porosity Test
Manageability
How easily a
comb passes
through the
hair.
Elasticity
The hairs ability to stretch and return to its
natural shape without breaking.
Types of
Rinses
Vinegar and Lemon Rinse
• Acid rinses
• Remove
soap scum
• Counteract
alkalinity.
Cream Rinse
• Soften
• Add luster
• Only slightly
acidic
Medicated Rinse
Control dandruff and minor scalp
conditions.
Conditioners
Instant Conditioner
• Coat the hair shaft
• Restore moisture
and oils
• Do NOT penetrate
into the cortex
• Not for fine limp
hair
Normalizing
• Contain
vegetable
protein
• Acidic pH
causes cuticle
to close after
chemical
services.
Body-Building
• Required for
fine, limp hair
• Deposits
protein
• Can use prior to
chemical
services
Moisturizing
• Humectants bind
and hold moisture in
the hair.
• Avoid use for
several days
following perm (may
go limp)
Customized
• Formulated to
meet special
needs
• Ex. Moisture
and color
Shampoo Web
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