surfactants are alkanolamides and amine
oxides.
The behavior of amphoteric surfactants is
a result of two different functional groups in
the molecule. The principal amphoteric sur-
factants are alkyl betaine derivatives, imida-
zole derivatives, amine sulfonates, and fatty
amine sulfates.
Surfactants exhibit certain characteristics,
such as:
●solubility in at least one phase of a liq-
uid system
●amphipathic structure with opposing
solubility tendencies; i.e., hydrophilic,
lipophilic, or hydrophobic
●orientation of monolayers at phase
interfaces formed by ions of surfactant
molecules
●equilibrium concentration of a surfac-
tant solute at a phase interface greater
than the concentration in the bulk of
either of the solutions
●micelle formation when the concentra-
tion of the solute in the bulk of the solu-
tion exceeds a limiting value that is a
fundamental characteristic of each
solute-solvent system
●exhibition of one or more functional
properties; i.e., detergency, wetting,
foaming, emulsifying, solubilizing, dis-
persion, demulsifying, and defoaming.Scouring compounds...............................................................................
Scouring compounds, also known as chem-
ical abrasives, are normally manufactured
from inert or mildly alkaline materials. These
abrasives are generally compounded with var-
ious soaps and are provided for scouring with
brushes or metal sponges. Neutral scouring
compounds are frequently compounded with
acid cleaners for removal or alkaline deposits
and encrusted materials. Abrasive cleaning
compounds should be used carefully when
cleaning stainless steel to avoid scratching.
Slightly Alkaline Scouring Compounds
Scouring compounds that are made from
mildly alkaline materials and used for light
deposits of soil are borax and sodium bicar-
bonate. These compounds have limited deter-
gency and emulsifying capabilities.Neutral Scouring Compounds
These compounds are made from earth,
including volcanic ash, seismotites, pumice,
silica flours, and feldspar. They may be
found in cleaning powders or pastes used in
manual scrubbing and scouring operations.Water Quality Considerations
The chemical properties of water should
be considered as this is a cleaning medium
basic to most cleaning compounds. Water
with varying amounts of calcium, magne-
sium, and other alkali metals (hard water)
interferes with the effectiveness of cleaning
compounds (especially bicarbonates), con-
tributing to precipitate formation. Precipi-
tates serve as sites for accumulation of debris
and microorganisms, and make effective san-
itation more difficult. The United States
Geological Survey (USGS) definitions for
water hardness are provided in Table 9–6.
If hard water exists, it may be more eco-
nomical to use a water softener than to
include chelators that mitigate the problem.
With few exceptions, hot water causes less
scale formation than does cold water. How-
ever, where hard water is used, maximum
scale formation occurs at 82ºC.Cleaning compound selection
The type of soil determines which clean-
ing compound can be used most effectively.
As previously emphasized, “like cleans
like.” In general, organic soils are most
effectively removed through alkaline, gen-
eral-purpose cleaning compounds. Heavy