Defoamer
Encyclopedia
A defoamer or an anti-foaming agent is a chemical additive that reduces and hinders the formation of foam
in industrial process
liquids. The terms anti-foam agent and defoamer are often used interchangeably.
A defoamer is normally used in industrial processes to increase speed and reduce other problems. It addresses both problems with surface foam and entrained or entrapped air. A wide variety of chemical formulas are available to promote coalescence
of foam.
and a facility to spread rapidly on foamy surfaces. It has affinity to the air-liquid surface where it destabilizes the foam lamellas. This causes rupture of the air bubbles and breakdown of surface foam. Entrained air bubbles are agglomerated, and the larger bubbles rise to the surface of the bulk liquid more quickly.
, fuel oil
and other light oil products were used to break down foam. Other vegetable oils also found some use. Fatty alcohol
s (C7 - C22) were effective but expensive antifoams. They were added to oil products to boost the efficiency. Milk
and cream
were forbears for modern day emulsion type defoamers.
During the 1950s experiments with silicone
based defoamers started. These were based on polydimethylsiloxane
(silicone oil) dispersed in water or light oil. Silicone oils worked well, but caused surface disturbances in many applications like paint
s and papermaking
. In 1963 the first antifoams with hydrophobic particles (hydrophobic silica
) in light oil
were patented. In the early 1970s, hydrophobic waxes like ethylene bis stearamide
dispersed in oils developed. These types of defoamers were very efficient, but the oil crisis of 1973
made these too expensive and resulted in a push for reduction of the oil content. The solution was adding water
. So water extended (water in oil emulsion) and water based (oil in water emulsion) defoamers appeared.
The development of silicone based defoamers has continued, using different emulsifiers and modified silicone oils. In the early 1990s, silicone emulsion defoamers that caused less surface disturbances were used in the wood pulp
ing industry with great success. These caused better washing, reduced biological oxygen demand (BOD) in effluent
and reduced deposits.
, vegetable oil, white oil
or any other oil that is insoluble in the foaming medium, except silicone oil
. An oil based defoamer also contains a wax
and/or hydrophobic silica
to boost the performance. Typical waxes are ethylene bis stearamide
(EBS), paraffin
ic waxes, ester
waxes and fatty alcohol
waxes. These products might also have surfactants to improve emulsification and spreading in the foaming medium.
These are heavy duty defoamers and are normally best at knocking down surface foam.
, plaster
and detergent
s.
s or vegetable oils and the waxes are long chain fatty alcohol
, fatty acid
soap
s or ester
s. These are normally best as deaerator
s, which means they are best at releasing entrained air.
compound
as the active component. These might be delivered as an oil or a water based emulsion. The silicone compound consists of an hydrophobic silica
dispersed in a silicone oil
. Emulsifiers are added to ensure that the silicone spreads fast and well in the foaming medium. The silicone compound might also contain silicone glycols and other modified silicone
fluids.
These are also heavy duty defoamers and are good at both knocking down surface foam and releasing entrained air.
Silicone based defoamers are also suitable in non-aquaous foaming systems like crude oil and oil refining. For very difficult systems fluorosilicones may be suitable.
and polypropylene glycol
copolymers. They are delivered as oils, water solutions, or water based emulsions. EO/PO copolymers normally have good dispersing properties and are often well suited when deposit problems are an issue.
carrier like petroleum
distillates.
The main classes of air that are of concern to the mechanical systems are
The easiest is looking at the surface foam. All that is needed is a system for generating foam. This might be done with a round pumping system with a nozzle and a cylinder or an air injection system into a cylinder. The cylinder is fitted with a scale to measure the foam height. This equipment may have a heater to control the temperature.
Entrained air can be tested with a similar equipment that have a density
meter that can record changes of the liquor density over time.
Drainage can be tested with a filter
system for measuring the time to drain a liquid through the filter. The filter might be pressurized or have a vacuum
.
s to reduce foaming
that might decrease the action of the detergent. For example dishwasher
detergents have to be low foaming for the dishwasher to work properly.
, antifoaming agents are intended to curb effusion
or effervescence
in preparation or serving. The agents are included in a variety of foods such as chicken nuggets in the form of polydimethylsiloxane
(a type of silicone
).
Silicone oil
is also added to cooking oil
to prevent foaming in deep-frying.
, paper
, paint
, industrial wastewater treatment
, food processing
, oil drilling, machine tool
industry, oils cutting tools, hydraulics
, etc
. A familiar example is the drug Simethicone
, which is the active ingredient in drugs such as Maalox
, Mylanta
, and Gas-X.
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
in industrial process
Industrial process
Industrial processes are procedures involving chemical or mechanical steps to aid in the manufacture of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy industry....
liquids. The terms anti-foam agent and defoamer are often used interchangeably.
A defoamer is normally used in industrial processes to increase speed and reduce other problems. It addresses both problems with surface foam and entrained or entrapped air. A wide variety of chemical formulas are available to promote coalescence
Coalescence (chemistry)
In chemistry, coalescence is a process in which two phase domains of the same composition come together and form a larger phase domain.-References:*...
of foam.
Properties
Generally a defoamer is insoluble in the foaming medium and has surface active properties. An essential feature of a defoamer product is a low viscosityViscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
and a facility to spread rapidly on foamy surfaces. It has affinity to the air-liquid surface where it destabilizes the foam lamellas. This causes rupture of the air bubbles and breakdown of surface foam. Entrained air bubbles are agglomerated, and the larger bubbles rise to the surface of the bulk liquid more quickly.
History
The first defoamers were aimed at breaking down visible foam at the surface. KeroseneKerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
, fuel oil
Fuel oil
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...
and other light oil products were used to break down foam. Other vegetable oils also found some use. Fatty alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s (C7 - C22) were effective but expensive antifoams. They were added to oil products to boost the efficiency. Milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
and cream
Cream
Cream is a dairy product that is composed of the higher-butterfat layer skimmed from the top of milk before homogenization. In un-homogenized milk, over time, the lighter fat rises to the top. In the industrial production of cream this process is accelerated by using centrifuges called "separators"...
were forbears for modern day emulsion type defoamers.
During the 1950s experiments with silicone
Silicone
Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
based defoamers started. These were based on polydimethylsiloxane
Polydimethylsiloxane
Polydimethylsiloxane belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, and is particularly known for its unusual rheological properties. PDMS is optically clear, and, in general, is...
(silicone oil) dispersed in water or light oil. Silicone oils worked well, but caused surface disturbances in many applications like paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
s and papermaking
Papermaking
Papermaking is the process of making paper, a substance which is used universally today for writing and packaging.In papermaking a dilute suspension of fibres in water is drained through a screen, so that a mat of randomly interwoven fibres is laid down. Water is removed from this mat of fibres by...
. In 1963 the first antifoams with hydrophobic particles (hydrophobic silica
Hydrophobic silica
Hydrophobic silica is a silica that has hydrophobic groups chemically bonded to the surface. Hydrophobic silica can be made both from fumed and precipitated silica. The hydrophobic groups are normally alkyl or polydimethylsiloxane chains.-Manufacturing:...
) in light oil
Light oil
Light oil may refer to:*Light fuel oil produced through distillation.*Light crude oil, which is less viscous than intermediate and heavy crude oil....
were patented. In the early 1970s, hydrophobic waxes like ethylene bis stearamide
Ethylene bis stearamide
Ethylene bis stearamide is derived from stearic acid and ethylenediamine. It is a waxy white solid and is also found as powder or beads.-Plastics:...
dispersed in oils developed. These types of defoamers were very efficient, but the oil crisis of 1973
1973 oil crisis
The 1973 oil crisis started in October 1973, when the members of Organization of Arab Petroleum Exporting Countries or the OAPEC proclaimed an oil embargo. This was "in response to the U.S. decision to re-supply the Israeli military" during the Yom Kippur war. It lasted until March 1974. With the...
made these too expensive and resulted in a push for reduction of the oil content. The solution was adding water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
. So water extended (water in oil emulsion) and water based (oil in water emulsion) defoamers appeared.
The development of silicone based defoamers has continued, using different emulsifiers and modified silicone oils. In the early 1990s, silicone emulsion defoamers that caused less surface disturbances were used in the wood pulp
Wood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...
ing industry with great success. These caused better washing, reduced biological oxygen demand (BOD) in effluent
Effluent
Effluent is an outflowing of water or gas from a natural body of water, or from a human-made structure.Effluent is defined by the United States Environmental Protection Agency as “wastewater - treated or untreated - that flows out of a treatment plant, sewer, or industrial outfall. Generally refers...
and reduced deposits.
Oil based defoamers
Oil based defoamers have an oil carrier. The oil might be mineral oilMineral oil
A mineral oil is any of various colorless, odorless, light mixtures of alkanes in the C15 to C40 range from a non-vegetable source, particularly a distillate of petroleum....
, vegetable oil, white oil
White oil
White oil is a home made insecticide spray used for controlling a wide range of insect pests in the garden. The spray works by blocking the breathing pores of insects causing suffocation and death...
or any other oil that is insoluble in the foaming medium, except silicone oil
Silicone oil
A silicone oil is any polymerized siloxanes with organic side chains. They are formed of alternating silicon-oxygen atoms or siloxane, rather than carbon atoms . Other species attach to the tetravalent silicon atoms, not to the divalent oxygen atoms which are fully committed to forming the...
. An oil based defoamer also contains a wax
Wax
thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...
and/or hydrophobic silica
Hydrophobic silica
Hydrophobic silica is a silica that has hydrophobic groups chemically bonded to the surface. Hydrophobic silica can be made both from fumed and precipitated silica. The hydrophobic groups are normally alkyl or polydimethylsiloxane chains.-Manufacturing:...
to boost the performance. Typical waxes are ethylene bis stearamide
Ethylene bis stearamide
Ethylene bis stearamide is derived from stearic acid and ethylenediamine. It is a waxy white solid and is also found as powder or beads.-Plastics:...
(EBS), paraffin
Paraffin
In chemistry, paraffin is a term that can be used synonymously with "alkane", indicating hydrocarbons with the general formula CnH2n+2. Paraffin wax refers to a mixture of alkanes that falls within the 20 ≤ n ≤ 40 range; they are found in the solid state at room temperature and begin to enter the...
ic waxes, ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
waxes and fatty alcohol
Fatty alcohol
Fatty alcohols are aliphatic alcohols consisting of a chain of 8 to 22 carbon atoms. Fatty alcohols usually have even number of carbon atoms and a single alcohol group attached to the terminal carbon. Some are unsaturated and some are branched...
waxes. These products might also have surfactants to improve emulsification and spreading in the foaming medium.
These are heavy duty defoamers and are normally best at knocking down surface foam.
Powder defoamers
Powder defoamers are in principle oil based defoamers on a pariculate carrier like silica. These are added to powdered products like cementCement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...
, plaster
Plaster
Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...
and detergent
Detergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...
s.
Water based defoamers
Water based defoamers are different types of oils and waxes dispersed in a water base. The oils are often white oilWhite oil
White oil is a home made insecticide spray used for controlling a wide range of insect pests in the garden. The spray works by blocking the breathing pores of insects causing suffocation and death...
s or vegetable oils and the waxes are long chain fatty alcohol
Fatty alcohol
Fatty alcohols are aliphatic alcohols consisting of a chain of 8 to 22 carbon atoms. Fatty alcohols usually have even number of carbon atoms and a single alcohol group attached to the terminal carbon. Some are unsaturated and some are branched...
, fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
soap
Soap
In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...
s or ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s. These are normally best as deaerator
Deaerator
A deaerator is a device that is widely used for the removal of oxygen and other dissolved gases from the feedwater to steam-generating boilers. In particular, dissolved oxygen in boiler feedwaters will cause serious corrosion damage in steam systems by attaching to the walls of metal piping and...
s, which means they are best at releasing entrained air.
Silicone based defoamers
Silicone based defoamers have a siliconeSilicone
Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
compound
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
as the active component. These might be delivered as an oil or a water based emulsion. The silicone compound consists of an hydrophobic silica
Hydrophobic silica
Hydrophobic silica is a silica that has hydrophobic groups chemically bonded to the surface. Hydrophobic silica can be made both from fumed and precipitated silica. The hydrophobic groups are normally alkyl or polydimethylsiloxane chains.-Manufacturing:...
dispersed in a silicone oil
Silicone oil
A silicone oil is any polymerized siloxanes with organic side chains. They are formed of alternating silicon-oxygen atoms or siloxane, rather than carbon atoms . Other species attach to the tetravalent silicon atoms, not to the divalent oxygen atoms which are fully committed to forming the...
. Emulsifiers are added to ensure that the silicone spreads fast and well in the foaming medium. The silicone compound might also contain silicone glycols and other modified silicone
Silicone
Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
fluids.
These are also heavy duty defoamers and are good at both knocking down surface foam and releasing entrained air.
Silicone based defoamers are also suitable in non-aquaous foaming systems like crude oil and oil refining. For very difficult systems fluorosilicones may be suitable.
EO/PO based defoamers
EO/PO based defoamers contain polyethylene glycolPolyethylene glycol
Polyethylene glycol is a polyether compound with many applications from industrial manufacturing to medicine. It has also been known as polyethylene oxide or polyoxyethylene , depending on its molecular weight, and under the tradename Carbowax.-Available forms:PEG, PEO, or POE refers to an...
and polypropylene glycol
Polypropylene glycol
Polypropylene glycol or polypropylene oxide is the polymer of propylene glycol. Chemically it is a polyether. The term polypropylene glycol or PPG is reserved for low to medium range molar mass polymer when the nature of the end-group, which is usually a hydroxyl group, still matters...
copolymers. They are delivered as oils, water solutions, or water based emulsions. EO/PO copolymers normally have good dispersing properties and are often well suited when deposit problems are an issue.
Alkyl polyacrylates
Alkyl polyacrylates are suitable for use as defoamers in non-aqueous systems where air release is more important than the breakdown of surface foam. These defoamers are often delivered in a solventSolvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
carrier like petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
distillates.
Industrial problems
The most noticeable form of foam is foam floating on the stock surface. It is easy to monitor and relatively easy to handle. Surface foam may cause problems with liquid levels and give overflow. This might reduce the process speed and availability of process equipment.Mechanical problem factors
Mechanical factors that may generate foam and entrapped air:- Leaky seals on pumps
- High pressure pumps
- Poor system design (tank, pump inlet, outlet and manifoldManifoldIn mathematics , a manifold is a topological space that on a small enough scale resembles the Euclidean space of a specific dimension, called the dimension of the manifold....
design) - PressurePressurePressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
release
The main classes of air that are of concern to the mechanical systems are
- Dissolved air behaves as part of the fluid phase, except that it can come out of solution as small bubbles (entrained air)
- Entrained air consists of bubbles that are small enough to collect on top of a fluid
- BubblesLiquid bubbleA bubble is a globule of one substance in another, usually gas in a liquid.Due to the Marangoni effect, bubbles may remain intact when they reach the surface of the immersive substance.-Common examples:...
that have sufficient buoyancyBuoyancyIn physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
to rise to the surface and are described as foam
Foam in process and coolant liquids
Foam, entrained and dissolved air that are present in coolants and processing liquids, may cause various kinds of problems, including:- Reduction of pumpPumpA pump is a device used to move fluids, such as liquids, gases or slurries.A pump displaces a volume by physical or mechanical action. Pumps fall into three major groups: direct lift, displacement, and gravity pumps...
efficiency (cavitationCavitationCavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...
) - Reduced capacity of pumps and storage tankStorage tankA storage tank is a container, usually for holding liquids, sometimes for compressed gases . The term can be used for reservoirs , and for manufactured containers. The usage of the word tank for reservoirs is common or universal in Indian English, American English and moderately common in British...
s - BacteriaBacteriaBacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
l growth - Dirt flotationFlotation processFlotation process is a method of separation widely used in the wastewater treatment and mineral processing industries.Various flotation processes include the following:* Dissolved air flotation...
/ DepositFoulingFouling refers to the accumulation of unwanted material on solid surfaces, most often in an aquatic environment. The fouling material can consist of either living organisms or a non-living substance...
formation - Reduced effectiveness of the fluid solution(s)
- Eventual downtime to clean tanks
- Drainage problems in sieveSieveA sieve, or sifter, separates wanted elements from unwanted material using a woven screen such as a mesh or net. However, in cooking, especially with flour, a sifter is used to aerate the substance, among other things. A strainer is a type of sieve typically used to separate a solid from a liquid...
s and filterFiltrationFiltration is commonly the mechanical or physical operation which is used for the separation of solids from fluids by interposing a medium through which only the fluid can pass...
s - Formation problems (i.e in a paper millPaper millA paper mill is a factory devoted to making paper from vegetable fibres such as wood pulp, old rags and other ingredients using a Fourdrinier machine or other type of paper machine.- History :...
it may cause the fibers to form an inhomogeneous sheet) - Cost of replenishing the liquid
- Cost of entire material rejection due to imperfections
Test methods
There are several ways to test defoamers.The easiest is looking at the surface foam. All that is needed is a system for generating foam. This might be done with a round pumping system with a nozzle and a cylinder or an air injection system into a cylinder. The cylinder is fitted with a scale to measure the foam height. This equipment may have a heater to control the temperature.
Entrained air can be tested with a similar equipment that have a density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
meter that can record changes of the liquor density over time.
Drainage can be tested with a filter
Filtration
Filtration is commonly the mechanical or physical operation which is used for the separation of solids from fluids by interposing a medium through which only the fluid can pass...
system for measuring the time to drain a liquid through the filter. The filter might be pressurized or have a vacuum
Vacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...
.
Detergents
Anti-foams are added in certain types of detergentDetergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...
s to reduce foaming
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
that might decrease the action of the detergent. For example dishwasher
Dishwasher
A dishwasher is a mechanical device for cleaning dishes and eating utensils. Dishwashers can be found in restaurants and private homes.Unlike manual dishwashing, which relies largely on physical scrubbing to remove soiling, the mechanical dishwasher cleans by spraying hot water, typically between ...
detergents have to be low foaming for the dishwasher to work properly.
Food
When used as an ingredient in foodFood
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
, antifoaming agents are intended to curb effusion
Effusion
In physics, effusion is the process in which individual molecules flow through a hole without collisions between molecules. This occurs if the diameter of the hole is considerably smaller than the mean free path of the molecules...
or effervescence
Effervescence (chemistry)
Effervescence is the escape of gas from an aqueous solution and the foaming or fizzing that results from a release of the gas. The word effervescence is derived from the Latin verb fervere preceded by the adverb ex, which means to boil...
in preparation or serving. The agents are included in a variety of foods such as chicken nuggets in the form of polydimethylsiloxane
Polydimethylsiloxane
Polydimethylsiloxane belongs to a group of polymeric organosilicon compounds that are commonly referred to as silicones. PDMS is the most widely used silicon-based organic polymer, and is particularly known for its unusual rheological properties. PDMS is optically clear, and, in general, is...
(a type of silicone
Silicone
Silicones are inert, synthetic compounds with a variety of forms and uses. Typically heat-resistant and rubber-like, they are used in sealants, adhesives, lubricants, medical applications , cookware, and insulation....
).
Silicone oil
Silicone oil
A silicone oil is any polymerized siloxanes with organic side chains. They are formed of alternating silicon-oxygen atoms or siloxane, rather than carbon atoms . Other species attach to the tetravalent silicon atoms, not to the divalent oxygen atoms which are fully committed to forming the...
is also added to cooking oil
Cooking oil
Cooking oil is purified fat of plant origin, which is usually liquid at room temperature ....
to prevent foaming in deep-frying.
Industrial use
Defoamers are used in many industrial processes and products: wood pulpWood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...
, paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
, paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
, industrial wastewater treatment
Industrial wastewater treatment
Industrial wastewater treatment covers the mechanisms and processes used to treat waters that have been contaminated in some way by anthropogenic industrial or commercial activities prior to its release into the environment or its re-use....
, food processing
Food processing
Food processing is the set of methods and techniques used to transform raw ingredients into food or to transform food into other forms for consumption by humans or animals either in the home or by the food processing industry...
, oil drilling, machine tool
Machine tool
A machine tool is a machine, typically powered other than by human muscle , used to make manufactured parts in various ways that include cutting or certain other kinds of deformation...
industry, oils cutting tools, hydraulics
Hydraulics
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
, etc
Pharmaceuticals
Antifoaming agents are also sold commercially to relieve bloatingBloating
Bloating is any abnormal general swelling, or increase in diameter of the abdominal area. As a symptom, the patient feels a full and tight abdomen, which may cause abdominal pain sometimes accompanied by increased borborygmus or more seriously the total lack of borborygmus.-Symptoms:The most common...
. A familiar example is the drug Simethicone
Simethicone
Simethicone is an oral anti-foaming agent used to reduce bloating, discomfort and pain caused by excess gas in the stomach or intestinal tract. It is a mixture of polydimethylsiloxane and silica gel.-Chemical action and pharmaceutical effects:...
, which is the active ingredient in drugs such as Maalox
Maalox
Maalox is a brand name antacid containing aluminium hydroxide and magnesium hydroxide to neutralize or reduce stomach acid.Maalox helps relieve symptoms of excessive stomach acidity in patients with indigestion, heartburn, gastroesophageal reflux disease, or stomach or duodenal ulcers. In large...
, Mylanta
Mylanta
Mylanta is an over the counter antacid medication used for the treatment of acid reflux, heartburn, and gastroesophageal reflux disease .-Ingredients:...
, and Gas-X.