Chapter 17 Household Chemicals

1
Chapter 17Household Chemicals

• Range from garden chemicals to cosmetics
• Present numerous uses and risks
• Risks minimized by reading the label
• Very few people do read them

2
Cleaners

• Used in some form since ancient times
• Varied from adding plants to wood ash to soap
• Large-scale usage of cleaners started only with
  discovery of disease-causing organisms

3
Soap Production

• Made from lye, NaOH, and fats
• Produces fatty acids
• Historically, left unreacted NaOH behind
• Soap is salt of long-chain fatty acid
• Modern soapmaking removes leftover NaOH
• Addition of perfumes, dyes, oils, and creams

4
How Soap Works

• Hydrophobic end nonpolar
• Dissolves nonpolar material
• Hydrophilic end polar
• Dissolves in water

5
(No Transcript)
6
Problems with Soap

• Does not work in hard water
• Contains calcium, magnesium, and iron ions
• Bind to hydrophilic end
• Leave soap scum
• Soap cannot work with stains
• Fewer suds form

7
Water Softeners

• Remove unwanted ions
• Sodium carbonate and trisodium phosphate
• Makes water basic and precipitates out calcium
  and magnesium ions
• Use water softening by ion exchange
• Replace unwanted ions with sodium ions

8
Synthetic Detergents

• ABS detergents alkylbenzenesulfonate
• Nonbiodegradable get foam production on rivers
• Have been banned
• LAS detergents linear alkylsulfonates
• Biodegradable
• Work better in both hard water and acidic
  solutions

9
Laundry Detergents

• Contain several different ingredients
• Main component is surfactant
• Enable cleaning solution to wet surface
• Loosen and remove soil
• Classified by ionic charge
• Also contain builders, brighteners, fabric
  softeners, and other substances

10
Surfactants

• Anionic surfactants negative charge
• Nonionic surfactants no charge
• Cationic surfactants positive charge
• Amphoteric surfactants both positive and
  negative charge

11
(No Transcript)
12
Builders

• Any substance added to surfactant to increase its
  detergency
• Reduce water hardness
• Historically used complex phosphates
• Contribute to eutrophication of lakes
• Modern ones use ion exchange substances

13
Brighteners

• Absorb invisible ultraviolet light and reemit it
  as visible light

14
Liquid Laundry Detergents

• More convenient, but may not clean as well
• Still contain builders and LAS surfactants
• Will contain same things as solid soaps
• Builders, fragrances, fabric softeners,
• Dish detergents made along similar lines
• Contain fewer builders
• Automatic dish detergent made from strongly
  alkaline material

15
Laundry Bleaches

• Oxidizing agents
• Chlorine-releasing bleaches
• Contain 5 NaOCl
• Oxygen-releasing bleaches
• Contain either Na2CO3 or NaBO2 with H2O2
• Less active than chlorine-releasing bleaches
• All work by acting on light-absorbing chemical
  groups

16
All-Purpose Cleaning Products

• Ammonia cleans well
• Should not be used with asphalt tile, wood
  surfaces, or aluminum may pit or stain surfaces
• Baking soda mild abrasive cleanser
• Absorb food odor
• Vinegar cuts film grease
• Will slowly dissolve marble surfaces

17
Special-Purpose Cleaners

• Toilet bowl cleaners tend to be strongly acidic
• Scouring powder contain abrasive and usually a
  surfactant
• Glass cleaners isopropyl alcohol in water
• Ammonia or vinegar may be added
• Drain cleaners and oven cleaners both contain
  sodium hydroxide
• just have different formulation

18
Organic Solvents

• Are good solvents for paint, varnish, adhesives,
  waxes, and other materials
• Most used around home are flammable
• Keep away from open flame
• Pose inhalation hazard
• May get high
• Poses long-term health risk

19
Paints

• Contain pigment, binder, and a solvent
• Most common pigment is TiO2
• Formerly used PbO2
• Add small amount of color pigments to change base
  color
• Binder holds paint to surface
• Solvent keeps paint fluid until applied to surface

20
Waxes

• An ester containing a long-chain fatty acid with
  a long-chain alcohol
• Used by many plants and animals as a protective
  coating
• Some made from hydrocarbon sources
• Paraffin wax

21
Cosmetics

• Substances that can be applied to the body for
  cleansing, beautifying, or altering appearance
• Exceptions soap and anything that affects body
  structure or function
• Typically, drugs are required to be proven safe
  and effective
• Spend billions annually
• 89 billion in 2001

22
Skin
23
Lotions and Creams

• Lotion emulsion of tiny oil droplets dispersed
  in water
• Cream tiny droplets of water dispersed in oil
• Form protective layer over skin to keep moisture
  inside

24
Sunscreen Lotions

• Block shorter wavelength UV (UV-B) and allow
  longer wavelength UV (UV-A)
• Substances that block UV in a lotion provide skin
  protection factor (SPF)
• SPF varies from 2 to 35 or more
• Allows exposure to sun that much longer than with
  unprotected skin

25
Lipstick

• Lipsticks and lip balms have higher proportion of
  wax than oil
• Prevent lips from drying out
• Perfumes and flavorings hide flavor of fatty
  acids
• May also include colorings

26
Deodorants and Antiperspirants

• Deodorants have perfume to mask odor and
  germicide to kill odor-causing bacteria
• Antiperspirants everything in deodorants and
  also retard perspiration
• Astringents constrict openings of sweat glands
• Typically aluminum and zirconium chlorides

27
Toothpaste

• Essential components are detergent and abrasive

28
Perfumes, Colognes, and Aftershaves

• Used by ancients
• Extracted from natural sources
• Synthetic perfumes produced but may not include
  all ingredients in natural ones
• Good perfume has gt100 constituents
• Components divided into categories called notes

29
Notes

• Top note responsible for odor when perfume first
  applied
• Middle note lingering aroma after most top notes
  have vaporized

30
Notes

• End note has low volatility
• Often with musky odors
• Aroma will vary with concentration of all notes

31
Hair Chemistry

• Made of the protein keratin
• Only root is alive, rest is dead
• Hydrogen bonds, salt bridges, and disulfide
  linkages play important roles
• Wash hair disrupt hydrogen bonds and salt
  bridges
• Remove oil and dirt adhering to hair

32
Hair Care Products

• Use different types of surfactants to clean hair
• Shampoo pH between 58
• Flavors and fragrances have no effect on hair
• May attract insects that like floral smell
• Smell sells

33
Hair Color

• Two pigments in natural hair color
• Melanin brownish black pigment
• Phaeomelanin red-brown pigment
• Hair color determined by amount of each pigment
• Dyes may be either water soluble or penetrate the
  hair

34
Permanent Waving

• Break and remake disulfide linkages
• Make or remove curls depending on what customer
  wants

35
Other Hair Care Products

• Hair sprays resins, form sticky film on hair
• Hold hair in place
• Hair removers Use strongly basic mixtures to
  destroy peptide bonds
• Can also remove skin made from peptides
• Hair restorers typically helps hair grow better
• Do not work for everyone