The word surfactant is relatively new because it’s a conjunction of three words: surface active agents. Meaning, chemical compounds that affect the surface tension of water. It’s hard to believe that water has tension but at one time or another, I’m sure we’ve all seen water bugs walking on top of water. Another example would be large cruise ships that tread the ocean’s surface. As heavy as they appear, weight displacement ratios and surface tension moves them onto their destinies. Let’s move on to surfactants and their role of lowering the surface tension in your cleaning chemicals.
Surfactants not only penetrate dirt quickly, but act as agents to prevent reattachment of dirt particles to the fiber. This is an important function in wand cleaning, especially where speed is so crucial to carpet cleaners. It’s hard to imagine, but when that wand is gliding across the carpet at a pressure of 400 lbs. per square inch, quite a bit of physics takes place.
Firstly, you have temperature, and of course, you have the idea that the performance is based on heat. Secondly, pressure plays an important role. Of course, you know that you’ll get into hot water if you increase pressure to the max, such as browning, fiber disruption, and possible latex breakdown. Finally, the vacuum process comes into play. I know you’ve understood these mechanics, but there’s a reason for their discussion and that is, this whole involved process would be in jeopardy without surfactants. Another viewpoint is you can clean a carpet with straight water, but would you want to spend a lot of time cleaning it? This shows the importance of what a proper cleaning product will do for you.
Did you know that foam is a byproduct of lower surface tension? It’s a fact that the reason those big bubbles you blow through the ring are attributed to low surface tension. This is a phenomenon that you don’t want to deal with when you clean a carpet. Many novices have found out about this to their disappointment when they used an off-the-shelf retail product. Not only were they poor in their judgment, they were also left with tremendous amounts of foam residue. I’ve heard stories where carpet cleaners had to clean with straight water on these overloaded carpets and were experiencing waste tanks filled with foam.
Surfactants are necessary in the formulation, but pity the poor chemist who has to do a balancing act on incorporating the right surfactant that delivers good soil penetration, correct surface tension, along with minimal foam properties. There are only a few surfactants that can fit this bill and they have to be evaluated among the thousands that are available for use in formulations. It’s obvious that to purchase a cleaning product, you must do so from a reputable source because you know the homework has been done.
I firmly believe that future surfactant formulations will be researched on more unique types of molecular makeup. To have a better handle as to where we may go, allow me to project some thoughts in this area.
First of all, new surfactants may be based on what we call dual hydrophilic head groups. This approach would improve solubilization at high, as well as lower temperatures. Just think of the fuel saved if you can lower your temperature for equal, if not better, carpet cleaning. This modified surfactant would also rinse out of the fiber faster producing a cleaner carpet. Of course, this would be a chemist’s fantasy because this dream surfactant would help solubilize the other ingredients in the formula and reduce the need for extra builders along with improved hard water toleration. Could you imagine not having to be concerned about hard water because of having improved water-softening capabilities incorporated into the formula? Now that’s what we call surfing the surf!
We’ve mentioned foam as being a bad actor when it comes to carpet cleaning, and yet its importance is recognized when low surface tension is required for efficient cleaning. Foam is a visual presentation of surface tension by allowing water to transform itself from its liquid phase. Gravity and its internal attraction charge are not enough to contain the liquid in its natural form. Essentially, as rainwater falls, it tends to form a spherical “ball” appearance due to its internal attraction. However, if the surface tension were low enough, that raindrop would be coming down as sheets of water. Surface tension is expressed as dynes per centimeter with water being at 76. Formulation studies have shown that anywhere between 30 and 50 would show improvement in wetting performance.
Chemical formulators are always attempting to reduce the cost of their raw materials but not at the expense of performance quality. One approach is to investigate the coupling of surfactants that would achieve synergism. Of course, this would mean the exploration of countless surfactants to produce that dynamite duo effect. Keep in mind that in order for this to work, the two surfactants must be lower in cost then the original. It becomes a long and tireless thing, which is one more of those factors that assure job security in the chemical world.