quaternary ammonium in detail

Breaking Down the Details of Quats

As was noted in What Is A “Quat Cleaner”?  for our purposes, “quat” is a shorthand term for a type of chemical known as a quaternary ammonium salt.  Put in the simplest terms then, a quat is a complex organic salt compound that finds multiple applications in the modern world.  And while this definition meets the basic necessities of answering the question, it doesn’t adequately cover some of the details that were embedded and not explicated in the earlier post.

It was noted that despite the similarity in naming, a quat is NOT and does NOT contain either ammonia or the true ammonium ion, both of which have been written about extensively in other posts which you can review.  The naming convention comes from some chemical structure similarities to these other molecules, but again does not mean that they are actually contained in a quat.

Ammonia is a simple inorganic (non-carbon atom containing compound) that contains 3 hydrogen atoms and one nitrogen atom.  This molecule carries no electric charge and exists as a free substance in the natural world, especially in the outer Solar System.  Ammonium is another simple inorganic molecule that contains 4 hydrogen atoms and one nitrogen atom.  This molecule carries a positive electric charge, meaning it is called a cation.  No cation can exist freely in nature but instead is always found in combination with another negatively charged molecule called an anion.  For example, a sodium cation is not the same as an uncharged sodium atom and it is commonly found combined with a chlorine anion, which likewise is not the same as an uncharged chlorine atom.

Similar Structure with Nitrogen

quats : 1 nitrogen surrounded and permanently charged

quats : 1 nitrogen surrounded and permanently charged

The reason why the term “ammonium” is used in conjunction with quaternary ammonium salt compounds is because of the underlying structure of the molecule.  As we saw, an ammonium cation consists of a nitrogen atom surrounded by 4 hydrogen atoms.  In a similar structure, a quaternary ammonium cation consists of a nitrogen atom surrounded by four other molecules, which while they may contain hydrogen, are far more complex that a simple hydrogen atom.  Most commonly, the hydrogen atoms are substituted for by a more complex type of molecule known as either aryls or alkyls.    The term aryl is an abbreviation for a type of molecule that is derived from a parent ring structure molecule such as benzene.  An alkyl is an abbreviation for a type of molecule that is derived from an alkane, which is a saturated hydrocarbon molecule, the simplest of which is methane, or natural gas.  The detailed chemistry behind these terms is not critical to understand, but what is important to try to understand is that while the central nitrogen atom from an uncharged ammonia molecule or a charged ammonium cation remains present, the hydrogens that surrounded that nitrogen have been exchanged for much more complex and larger molecules, which usually contain several hydrogens as well as one or more carbon atoms.  These exchange molecules can be quite large and the resulting cations may have literally dozens of hydrogen and carbon atoms in them.

There are three other cations that are structurally closely related to the quaternary ammonium cation and those are the primary, secondary, and tertiary ammonium cations.  Respectively, these have one, two, and three of the hydrogens surrounding the primary nitrogen core atom replaced with more complex carbon and hydrogen containing groups.  Depending on the pH of the solution in which they are found, these three cations, as well as the simpler ammonium cation, can lose their charge, but quaternary ammonium cations always retain their positive charge regardless of the pH of the surrounding solution.  This enhances their ability to perform functions such as acting as a detergent.

Salt :  Anti-microbial not culinary

The term salt was also used to describe quaternary ammonium compounds and most people associate this term with the sodium chloride that is commonly added to our foods by commercial processors, cooks and by diners at the table.  This form of “salt” is composed of one sodium cation and one chloride anion, and chemically speaking referring to it as “salt” is completely correct, but it is important to note that chemically speaking there are literally thousands of compounds that are technically salts in the world.

From the chemical perspective a salt is the product of the neutralization reaction between an acid and base (alkali).  For example, when hydrochloric acid (one hydrogen atom and one chlorine atom) is neutralized by the addition of sodium hydroxide, or lye, (one sodium atom, one hydrogen atom, and one oxygen atom) the result is salt sodium chloride and water.  A salt is also commonly known as the combination of one metallic cation and one non-metallic anion.  An organic salt is commonly known as the combination of one organic, carbon containing, cation and an inorganic anion.  In the case of quaternary ammonium salt compounds, a common anion added to the organic cation is chloride, forming quaternary ammonium chloride organic salts.  MoldStat is an example of a cleaning and disinfectant chemical that contains quaternary ammonium chloride salts, specifically four of them.  Other anions may be used of course instead of chloride.  For example, sulfates are commonly found in the types of quaternary ammonium salts that are used in dryer sheets.

Those quaternary ammonium salt compounds that contain substituted long alkyl chains are most effective as antimicrobials.  A commonly found example of this is benzalkonium chloride, a component of the brand name personal disinfectant, Bactine, as well as the brand name household and industrial disinfectant MoldStat (MoldStat must NOT be substituted for Bactine, nor Bactine substituted for MoldStat; the actions and additional components are quite different).  These types of quaternary ammonium salt compounds work by disrupting the cell membrane, thus killing the organism completely instead of just weakening it.  They do not work especially well in the presence of organic material so it is important to first clean the surface to be disinfected with a detergent cleaner to remove dirt, blood, or other organic matter before continuing to disinfect.

Surfactant and Detergent support

Surfactants work to allow the distribution of solid or liquid contaminants into watery liquids by lowering the surface tension between the two substances.  Surface tension is the characteristic of a liquid that resists disruption between the molecules and it is by taking advantage of this characteristic that small insects are capable of walking on water.  Surfactants have four common forms, anionic which the most common as well as cationic, zwitterionic and nonionic.  The names refer to which portion, or portions, of the molecule act to disrupt the surface tension.  Quaternary ammonium surfactants, such as MoldStat, are of the cationic type, meaning that is the cation, or the quaternary ammonium portion of the molecule that acts to disrupt the surface tension.

A detergent is a mixture of surfactants that work in dilute solutions.  They are similar in action to soaps but are differentiated by their origins.  Soaps are the result of the saponification of fats, a chemical reaction in which alkali substances, such as lye, act on fats to produce the salt of fatty acids.  Detergents do not have their origins in fats or other animal products and may be more acceptable to people with an aversion to animal products.  Their action is similar though in that both have an attraction for both water and oils, so they attach to dirt and oils but also remain suspended in water which allows the wastes to be washed away easily even though the dirt and oil might by itself be able to repel the water and thus resist rinsing.  The quaternary ammonium chloride salts in MoldStat Plus, in addition to the added nonionic surfactants, allow MoldStat Plus to function as a detergent

Four Powerful QUATs in MoldStat Plus

The four specific quaternary ammonium chloride salts that are found in MoldStat Plus are:

DIDECYL DIMETHYL AMMONIUM CHLORIDE:

Widely used and EPA registered as a general purpose disinfectant and sanitizer.  Its many known uses include acting as an antimicrobial for hard surfaces, laundry, carpets, agricultural equipment, food handling facilities, medical equipment, water storage and purification equipment, swimming pools, industrial water systems and as a wood preservative.  Agriculturally it is used as a broad-spectrum fungicide, bactericide, and algaecide for horticultural areas and equipment.  In concentrated form it can irritate skin and eyes and if ingested it can be harmful to the liver, but in the limited concentrations found in even undiluted MoldStat Plus it is largely harmless to humans.

ALKYL(C12-C16) DIMETHYL BENZYL AMMONIUM CHLORIDE:

Commonly found in dozens of household cleaners and disinfectants.  It is known by the EPA to specifically be active against norovirus, the virus that has recently been in the news for making hundreds of people ill on a cruise ship.  It is not known to have any negative human health effects and has never been found in human tissues.

 

OCTYL DECYL DIMETHYL AMMONIUM CHLORIDE:

Commonly found in dozens of household cleaners and disinfectants.  It is widely used in nursery applications, including both ornamental and food growing applications, as a fungicide, meaning it kills molds on nursery surfaces and equipment.  It is not known to have any negative human health effects and has never been found in human tissues.

DIOCTYL DIMETHYL AMMONIUM CHLORIDE:

Commonly found in dozens of household cleaners and disinfectants.  It is widely used in nursery applications, including both ornamental and food growing applications, as a fungicide, meaning it kills molds on nursery surfaces and equipment.  It is also used in aquaculture to inhibit and kill algae.  Unfortunately, it can be harmful to humans in concentrated form, especially as a skin and eye irritant, but in the concentrations found in even undiluted MoldStat Plus it is quite dilute and thus the negative health effects are minimized.

 

It is hoped that you have found this more detailed information helpful and informative.  If you need additional information about MoldStat Plus or its components, please do not hesitate to ask.

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