The Chemistry of Encapsulation
In the 1976 made-for-television movie, “The Boy in the Plastic Bubble,” John Travolta played a teenager who was born without immunities to disease and therefore forced to live in incubator-like conditions. Whenever he traveled outside, he had to do so encased in a large plastic bubble.
Encapsulation performs basically the same function for cleaning chemicals as the bubble did for Travolta’s character. Encapsulation is the process by which a material is surrounded and protected from extraneous conditions that would otherwise break it down. Just as the plastic bubble protected the character from germs, chemical encapsulation allows cleaning formulas to experience longer staying power.
Encapsulation is found in a variety of products, some of which might surprise you. Chewing gum, for example, makes good use of the process. The act of chewing causes the release of flavor, but not all at once; the flavor buds are encapsulated so as to make the flavor last longer (sound familiar?). The process may sound simple, but extensive R&D work was done to determine when that release should occur. Saliva wet-down, pH values, teeth grind, jaw force and mental acceptance are just some of the factors taken into account to determine the correct method to deliver this seemingly simple pleasure.
Where is the encapsulation process found in cleaners? One segment where it is used is in the enzyme powder cleaners. Not only is the enzyme itself protected, the process prevents it from being released into the air as a raw material. Without that protection, a serious problem might occur; inhalation of such substances can easily harm the lungs. The encapsulation process not only influences health concerns, it is very important to the cleaning cycle itself, wherein encapsulated enzymes are released, at the right time, to work on the more difficult proteinaceous stains.
Encapsulation is also used in the area of fragrance. Powdered cleaners are incorporated with encapsulated fragrances that produce greater “fresh and clean” results. At the time of cleaning, this fragrance encapsulation can create a sense of cleanliness that might not be found in a standard cleaner. For improved customer impact, a cleaning agent must exhibit a pleasing fragrance that will make the customer ask what type of cleaner is being used. There have been successful deodorizers and cleaners that incorporate flavors such as apple, peach and coconut. The delicate nature of the flavor is not broken down in its encapsulated form.
A process similar to encapsulation is emulsion. Emulsions are a mixture of partially solubilized liquids, one of which is dispensed into the other as finely divided globules. The old clich¿hat “water and oil don’t mix” holds true because of the difference in weight, structure and ionic characteristics. But add a little soap in the blend and, lo and behold, the two intertwine as an emulsion.
The part, or phase, of an emulsion that is mixed/locked into the other is called the dispersed phase. The surrounding liquid is called the continuous phase, and carries the principal physical characteristic of the liquid into the dispersed phase. These phases are not necessarily permanent, and may be changed by adding more of either constituent.
Emulsions are stabilized by emulsifying agents such as soaps or surfactants; without these agents the emulsion would separate immediately. Encapsulated products, when compared with emulsions, can be considered to have a more permanent lock between the carrier and the inner, separated chemical. Only upon physical or lightweight intrusion, such as by water, will the encapsulated protector break down and release the active material.
A tremendous advance in the carpet cleaning industry would be the introduction of an encapsulated peroxide cleaner. What an impact it would have; a product that would enhance stain removal while working in sync with a cleaning agent. It would also be a more realistic approach to dealing with stain problems than are the peroxide powders currently in vogue. Some of these products have been found to create problems on carpet, and should not be used to remove carpet stains. A cleaner with encapsulated peroxides, on the other hand, would be regulated so as not to offset the carpet’s characteristics.