2. Surface tension:
*The cohesive forces between liquid molecules are responsible
for the phenomenon known as surface tension
2
3. *
*Surfactants are substances that absorb to surfaces or
interfaces, causing a marked decrease in the surface
tension.
OR
*A molecule that contains a polar portion and a non polar
portion is called surface active agent/ surfactant.
3
4. How Does Surfactant works?
*A surfactant can interact with both polar
and non polar molecules.
*A surfactant increases the solubility of the
otherwise insoluble substances.
4
5. *
*In water, surfactant molecules tend to cluster into a
spherical geometry non polar ends on the inside of the
sphere polar ends on the outside .These clusters are
called micelles.
5
6. *
*All surfactants are characterized by having two regions in
their molecular structure:
* A HYDROPHOBIC GROUP: such as a hydrocarbon chain,
that has no affinity for aqueous solvents
* A HYDROPHILLIC GROUP: that has an affinity for
water.
6
7. *A molecular or ion that possesses this type of structure is
termed amphipathic (amphiphilic).
*These molecules preferentially position themselves at the
water-organic interface due to energetic effects – they
are surface active!
7
8. Classification of surfactants
*Dependent on the molecular composition
and the nature of dissociation of their
polar head groups the surfactants are
classified as:
1. Anionic
2. Cationic
3. Non-ionic
4. Zwitter ionic Or Amphoteric
8
9. *
*Probably the most commonly used surfactants in
cleaning chemistry are anionic surfactants.
*Anionic surfactants possess a negative charge on their
hydrophilic end.
*This charge helps the surfactant molecules to interact
with both the fibers and soil particles, lifting and
suspending soils in “bubble-like” arrangements called
micelles.
.
9
10. *Because of negative charge, They foam or
lather best in hard / alkaline water or in
neutral aqueous solutions.
*They make a lot of foam when agitated.
Also, they tend to be flaky or powdery
when dry, not sticky like other surfactants
and have very good cleaning power but they
can also be quite irritating to skin if used
without being combined with other milder
surfactants.
10
11. *However, these detergents tend to not be
as good at emulsifying oily soils as some
other detergent types.
*Anionic surfactants, therefore, are the
most common type of surfactant found in
low moisture carpet cleaners, like
traditional shampoos and encapsulation
products.
11
12. *When reading the ingredients list on your cleaning
products, you can identify anionic surfactants as
those that have the following in their names:
*Sodium
*Ammonium
*Magnesium
*Sulfate
*Sulfonate
*Gluconate
*(For example, sodium laurel sarcosinate, magnesium
laurel sulfate, and sodium gluconate)
12
13. *
*Cationic surfactants are less common in cleaners, and
almost always absent from carpet products.
*Cationics have positively charged ends, which makes
them ideal in antistatic formulas like fabric softeners
and automobile “cheater waxes.”
*Also, cationic surfactants have antimicrobial
characteristics, and they are found in hard-surface
disinfectants and cleaners.
13
14. *However, cationic surfactants have been shown to
damage the mill-applied protectants on carpet, and
are therefore strictly verboten in carpet products
*Although they are produced in much smaller
quantities than the anionics, there are several types,
each used for a specific purpose.
14
15. *Non-Ionic Surfactants:
*Nonionics have no charge on their hydrophilic end,
which helps make them superior oily soil
emulsifiers.
*Some nonionics are high foamers (like anionics),
while others do not generate much foam. Because
of their lower foam profile and strong emulsifying
potential,
15
16. *However, unlike anionic surfactants,
nonionics are thick liquids or syrups that
are sticky or “gooey” to the touch. When
left in the carpet, nonionic surfactants are
the primary contributors to rapid resoiling.
16
18. *
*Amphoteric surfactants are characterized by the fact
that these surfactants can carry a positive charge on a
cationic site and a negative charge on an anionic site. The
use of amphoteric terminology is still restrictive.
*The charge of the molecule must change with pH, showing
a zwitterionic form at an intermediate pH.
18
19. *Probably the least talked about surfactants are the
amphoterics. These unique molecules possess both a
positive and a negative charge on their hydrophilic end,
giving them a net charge of zero.
*Amphoteric surfactants have little utility on their own,
but work extremely well in enhancing the cleaning
effect of both anionic and nonionic surfactants..
19
20. *They can serve as “coupling agents,” which hold the
surfactants, solvents and inorganic salt components of
a formula together.
*Amphoterics are usually named in some way to indicate
that they are amphoterics, as in amphoterge. Other
examples of amphoterics are betaines and amine
oxides. used in cosmetics.
20
23. *
*Paraffin or new cotton cloth barely wetted
by water, but when surfactant is added to
water their surface easily becomes wet
*Surfactant in floor cleaner as a wetting
agent
23
28. *
*Foam consist of gas covered with thin liquid film.
Surfactant molecule absorbed to interface between
gas and liquid
28
29. *They can be used in shampoos & lathering shaving cream so it
can produce stable foam when mixed with air pockets enclosed
with thin film of liquid.
29
31. * ANTI FOAMING AGENTS
*They can be used in fermentation process to prevents the
foams in production .eg , ocotnol , ether, castor oil &
silicones
31
32. *ANTIBACTERIAL ACTIVITY
*These are alter the integrity and lost the
essential elements by leak
*Mainly cationic surfactants show activity
*But non ionic surfactants help in
metabolism of organisms & facilitate their
growth
*Natural surfactants enhances the
absorption of antibiotics
32
33. 33
*Uses In Drugs
*Surface-active agents have been widely shown to
enhance drug dissolution rates.
*This may be due to wetting effects, resulting in
increased surface area, effects on solubility and
effective diffusion coefficient or a combination of
effects.
34. *They are added to the drugs in order to increase the
product characteristics in the design of dosage forms in a
variety of ways like solublising agents, wetting agents
,detergents, suspending ,foaming, emulsifying agents
34
35. *The effect of surfactants on the dissolution of solids is
complex. In addition to effects on the available surface
area, surfactants in concentrations above the CMC can
increase drug solubility and hence the effective
concentration gradient.
35
36. *However they also reduce the effective rate of drug
diffusion as a consequence of drug solubilization within
micelles.
36
37. *Hard Gelatin Capsules
and Tablets
*Wetting agents : Surfactants are used in capsule and
tablet formulations as wetting agents to aid dissolution.
*This wetting effect is found to be operative at
concentrations below the CMC
37
38. 38
*Consequently surfactants have been included in tablet and
capsule formulations to improve wetting and deaggregation
of drug particles and thus increase the surface area of
particles available for dissolution.
* Sodium sulphate is used in the production of hard gelatin
capsules
39. 39
* Common water-insoluble lubricants (which are
surfactants) include magnesium stearate, calcium
stearate, sodium stearate, and stearic acid
*water-soluble lubricants include sodium lauryl sulphate
and magnesium lauryl sulphate
*Magnesium stearate is used extensively as a lubricant in
tablet manufacture
40. 40
*Removal of Ear Wax
*Excessive accumulation of cerumen in the
ear may cause itching, pain, impaired
hearing and is a deterrent to otologic
examination.
*Recently, solutions of synthetic surfactants
have been developed for their
cerumenolytic activity in the removal of
ear wax
41. *Cerumen is a combination of the secretions of sweat and
sebaceous glands of the external auditory canal.
*The secretions, if allowed to dry, form a sticky semisolid
which holds shredded epithelial cells, fallen hair dust and
other foreign bodies that make their way into the ear
canal
41
42. *Surfactants in mouth
washes:
*Mouthwashes are aqueous solutions often in concentrated
form containing one or more active ingredients or
excipients.
*They are used by swirling the liquid in the oral cavity.
*Surfactants are used because they aid in the solubilization
of flavours and in the removal of debris by providing
foaming action.
42
43. *Gemini Surfactant
*SURFACTANTS show interesting interfacial and bulk
properties and have a wide variety of uses, which
are mostly met by conventional representatives.
Changes in the molecular structure and type to
improve upon their properties have attracted the
attention of chemists.
*This has led to the preparation of new generation
surfactants such as geminis (also called dimeric)
surfactants
43
44. * Conventional surfactant has a single hydrophobic tail
connected to an ionic or polar head group, whereas Gemini
surfactants are a group of novel surfactants with more than
one hydrophilic head group and hydrophobic tail group linked by
a spacer at or near the head groups.
44
45. *Unique properties of gemini surfactants, such as low
critical micelle concentration, good water solubility,
unusual micelle structures and aggregation behavior,
high efficiency in reducing oil/water interfacial
tension, and interesting rheological properties have
attracted the attention of academic researchers and
field experts.
45
46. *Properties:
These surfactants usually have better surface-
active properties than corresponding
conventional surfactants of equal chain length.
Geminis are used as promising surfactants in
industrial detergency and have shown efficiency
in skin care, antibacterial property, metal-
encapped porphyrazine and vesicle formation,
construction of high- porosity materials, etc.
46
47. *Geminis have remarkably low CMC values compared to
the corresponding conventional surfactants of
equivalent chain length.
*Geminis are considerably more surface-active than
conventional surfactants.
47
48. In comparison to their corresponding
monomer counterparts, gemini surfactants
are more efficient at reducing surface
tension, have better wetting properties, and
typically have critical micelle concentration
(CMC) values that are one to two orders of
magnitude lower.
48
49. * Gemini surfactants have been shown to
form a rich array of aggregate
morphologies in solution, through alteration
of their chemical structure.
49
50. *The prospective applications of gemini
surfactants are multi-fold. These include
their potential use in cleaning agents and
detergents; cosmetics and personal care
products; preparative chemistry;
pharmaceutical and biological applications;
enhanced oil recovery etc.
50
