Wednesday, August 01, 2007

Lazy Engadget, Neatorama, Treehugger push bullshit "detergentless" washing machine

The best thing I can say about Engadget, Treehugger and Neatorama and others about their articles on the Haier's detergentless WasH20 washing machine is that they are lazy. I don't understand why these sites just repeat the news of this "detergentless" washer with suspect, crackpot science behind it instead of really investigating whether or not the thing could work. Even applying the most basic science principles might allow one to evaluate the claims. Unfortunately most of us don't seem to know or care to use enough logic and science to make a critical judgement.

At least, I hope it is laziness and not ignorance (or stupidity) that causes them to pass on their responsibility. Engadget is ostensibly a blog that breaks the news on all of the latest cool gadgets. I would expect that the authors have some technical savvy, the post was still only mildly skeptical. Treehugger is supposed to be a forum and guide for living "greener" lives, much of which should require knowledge of some basic science to choose things that are better for the environment. Neatorama is just for fun, so they perhaps get a buy on this one, yet their posts are often laced with interesting science or history so I was hoping for more from them. I guess the pressure to generate posts is enormous.

Regarding the "detergentless" washer: It supposedly electrolyzes water into its components: OH- and H+ ions. The stains of the linen are attracted and retained by ions OH-. The linen is sterilized by the H+ ions. How it does this is not mentioned, though pure water doesn't conduct electricity very well and electrolysis would generate oxygen and hydrogen, not ions.

Good old water, all by its lonesome, has some fraction broken down into hydroxyl (OH-) ions and hydrogen (H+) ions, about 1e-7 molarity for pure water. That is the origin of pH = -log([H+]); pure water is at a pH of 7. Even distilled water in contact with air dissolves some carbon dioxide and the pH drops (to about 5.7) because you have carbonic acid in the water, so pure, in this sense, is impossible to maintain. The OH- attracting the stains and the H+ sterilizing the clothes is just cartoon science at its worst. I could also mention that, in solution, charge neutrality must be maintained so unless you add another ion to the mix, the OH- must equal the H+, and you are using pure water to clean your clothes.

As to stains and detergents: Detergents are surfactants. Surfactants are surface active agents, they lower the surface tension of water and can solubilize oil. Why is that? They contain a hydrophobic oil loving part connected to a hydrophillic water loving part. Stains are usually greasy or oil loving. The detergent helps to remove the grease stain because it is attracted to the hydrophobic part of the detergent which is connected to the water loving part and allows the grease to be soluble in the water. Then it gets washed away in the washer.

Hot water does clean clothes pretty well, so I expect many folks will think they got a good product when they buy this thing. Yet the science and the criticality of the reviews, posts and announcements of the product are extremely lacking. People have used soap to clean clothes for thousands of years because they needed to. For some reason water just didn't get the job done.

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