English English Nederlands Nederlands Deutsch Deutsch Italiano Italiano Español Español Français Français 简体中文 简体中文 Português Português Русский Русский
    DetailingWiki Newsletter
    Get free and automatic updates on new articles
    We respect your privacy. No data is used for anything other than sending the newsletter!

    Advertisement

What is surface tension

Written by:

Surface tension is the energy a liquid contains that prevents its surface to be deformed by an object with a higher surface tension/energy. The surface energy of water has as a side effect that it can form beads on surfaces with a very low surface energy or high repulsive force.

What is surface tension

All molecules have a certain attraction towards each other. Molecules from water have a higher attraction towards each other then to the molecules of air. This means that water and air don’t easily mix. Because the attraction between the water molecules is higher then the attraction with the air molecules, the water stays together. Without adding any form of energy, the air won’t be able to cut through the water, or mix with it. If an object with a very low surface energy comes into contact with the water, it will push the molecules away, rather then mixing with them. Some insects are able to “walk” on water, which is thanks to the surface tension of the water. Their feet push the water away, but the viscosity of the water creates enough resistance to carry the weight of the insect.

How to change surface tension

A paperclip floating on water thanks to Surface Tension
A paperclip floating on water thanks to Surface Tension

Surfactants are an easy way to change surface tension. For example, if you very carefully put a sewing-needle on top of water, it will float on top of the water. If a surfactant is added to the water, the surface tension will drop, and the needle will sink into the water. This surface tension also prevent water from being very good at mixing/combining with other substances, which also means that is very bad at cleaning (water would have to combine/mix with contaminants and be able to carry them away). Adding a surfactant will make it much easier for the water to combine with the contaminant and carry it away. A lowered surface tension will also allow the formation of foam.

Surface tension is also affected by temperature, the lower the temperature of water, the higher the surface tension. This basically means that colder water will form nicer round beads. Very hot water will create flatter, less round beads. Rinsing your car with warm water will give you a false idea of beading. It might in fact be better then it looks. However, warmer water has better cleaning properties.

Surface tension vs surface energy

Surface tension only applies to liquids, surface energy can also be applied to solids, which makes it a more universal term. The two terms are equivalent.

Surface tension and beading/sheeting

Thanks to surface tension, water can create nice round beads, which is a loved side-effect by detailers. If the roll-off angle is right, it will also aid greatly in the sheeting properties of a product. If the surface tension of water was much lower, the beads would be more flat and the sheeting would be a lot less. This can be seen when you spread a water/shampoo mixture over a surface. It is clear to see that water/shampoo doesn’t create the nice round beads that just water does.
The same happens with snowfoam, if the surface energy is low enough, the snowfoam would suffer from the low roll-off angle and the snowfoam will not clinge very well. A dirty unprotected car will keep its snowfoam blanker, while a clean and well protected car will cause the snowfoam to break open and slide off.

Different related articles

  • The best sprayheads
    Detailing Miscellaneous
    It is often asked on detailing fora and social media: "what is the best sprayhead". Off course there is a difference between certain products and brands, but it is important to know what you are asking. In this guide I will try to explain what the problem is with this question unless it is asked more in-depth....
  • Alchimy7
    Manufacturers
    Alchimy7 is a French manufacturer of detailing products, their main focus lies on synthetic products. The complete range includes products for almost every step in the detailing process....
  • What is a fallout remover
    Decontaminating
    A fallout remover is a special product aimed at decontamination that has the chemical ability to help you to remove iron(III)oxide particles from a surface without having to remove them mechanically. These particles are loosened up via a chemical process, that allows for them to be rinsed off safely. This product is sometimes also called "Iron-X". This is not the name of the liquid, but a productname of Carpro Trading Ltd, which is only one of many fallout removers on the market....
  • Underbody cleaning
    Detailing Miscellaneous
    Underbody cleaning is the act of cleaning the underside of the car to remove any dirt and restore the looks as when the car was new. This is a tedious and labor intensive job, but good cleaning products and tools can help to make it easier....
  • The best polish
    Detailing Miscellaneous
    It is often asked on detailing fora and social media: "what is the best polish". Off course there is a difference between certain products and brands, but it is important to know what you are asking. In this guide I will try to explain what the problem is with this question unless it is asked more in-depth....
  • A guide into wax
    Guides
    Carnauba waxes are the traditional automotive paintwork protection. Carnauba wax is secreted by the leaves of a tree in the rainforests of Brazil in order to protect the leaves from the blistering heat. It is one of natures most durable waxes with excellent protective properties that makes it ideal for protecting paint....

Links to this article

There are no external links to this article. Yet.
Sidebar



Stay up to date with our free newsletter
Always be the first to know about new updates, articles and other informative content.
Don't miss out, opt in!
We respect your privacy. No data is used for anything other than sending the newsletter!