Surfaces: The invisible universe we look upon every day but never really see

This issue of the SURFACE SCIENCE CORNER blog begins a series of essays dealing with the general topic of the hidden aspects of surfaces that, though generally invisible to us, have an important influence not only on our day to day activities but also on our ability to manufacture common objects of everyday use.

A common example is the polymer materials we use to encapsulate all manner of foodstuffs to protect them from moisture, oxidation and other unwanted atmospheric influences. A typical packaging resin may be quite effective at protecting against unwanted atmospheric invaders but also impossible to label or decorate with commonly available inks. The ability of a given surface to be written on by a given ink is controlled by the surface energy of the polymer and the surface energy of any given material is just one among a host of invisible surface properties.

Thus the underlying thread in all of the discussion will be the fact that although most properties of surfaces may be invisible to us they nonetheless have a rather profound influence on not only our ability to manufacture items of common commerce but our everyday experience as well.

The following is an outline of the topics to be explored in more detail in subsequent issues of the blog:

1. OPTICAL PROPERTIES: What we see is only an infinitesimal fraction of the radiation emitted by surfaces.

2. SURFACE ENERGY: A world that can only be explored through the lens of thermodynamics.

3. SURFACE ANALYSIS METHODS: ESCA, AUGER, TOFF SIMS, EELS, … the alphabet soup of surface analysis techniques that allow us examine surfaces at the atomic level.

4. CONTACT ANGLE: A poor man’s surface analysis tool you can implement in your kitchen and curiously enough turns out to be superior to the high power methods in an interesting way.

5. SURFACE FORCES: Ever wonder why insects and the gecko lizard can walk upside down on your ceiling or nearly any other surface? The surface van der Waals forces are of exceedingly short range but their influence extends to surprisingly large distances.

6. ADHESION: Mostly you find that when two objects come into contact they do not adhere very well. Some materials, however, seem to stick to nearly everything. These behaviors can only be sorted out through an understanding of surface forces and interactions.

7. CONTAMINATION: Surfaces are an invisible refuge for all manner of foreign species and these invaders can alter the surface’s properties in ways both benign and malign. The oil layer on the cylinder walls of your car’s engine is absolutely critical to it’s life and function. That same oil can also prevent you from painting over a bare spot on the fender.

8. TRIBOLOGY AND FRICTION: An invisible property that determines whether things stick or slip or whether your tires will keep you on the road or send you to the gutter.

9. SURFACE MODIFICATION: Getting surfaces to behave the way we want.

10. LIFE ON SURFACES: Microbes are another invisible inhabitant in the world of surfaces and have many important consequences including biofouling of pipes and marine surfaces and also the common infections that can lay us low.

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