Emulsions

Emulsions are pretty much everywhere. Some example are milk, mayonnaise, vinaigrettes, creams and lotions. So what exactly is an emulsion? Well, it is a mixture of two immiscible liquids. What are immiscible liquids? They are liquids that do not mix in all proportions. Huh, aren't those conflicting statements? Kind of, but no. Immiscible liquids don't mix on the molecular level, but they become dispersed in each other.Oil and water are the most common set of immiscible liquids, but there are many others. In fact, you can make multiphasic emulsions that are comprised of a set of more than two mutually immiscible liquids. For example, liquid silicone is immiscible with both oil and water. Neat stuff.

A good example of an emulsion is a vinaigrette. If you shake it up you see the little balls of vinegar in the oil. This is what happens in milk too, but the balls of fat are so small that you can't see them with your naked eye. But milk doesn't separate, so how can milk and vinaigrettes both be emulsions? A vinaigrette is an example of an unstable emulsion because it separates over time and milk is an example of a stable emulsion. Milk is not naturally stable, but it has been stabilized through the use of proteins that lie on the fat-water interface. Emulsions can also be stabilized with particles, in which case they are called Pickering emulsions (as are emulsions stabilized with proteins), or they can be stabilized with surfactants (e.g. soap).

Globules of dark matter in space

And now it's time for the crazy talk that will be forgotten to the sands of time, but I actually hope someone says, wow, that's not half bad. So, similar to my musing in my foam post, you could do the whole poppin' possibilities thing with emulsion coalescence (when to oil bubbles merge and form a larger bubble). But reeling it in a bit, but only a little bit, if you think of matter and  dark matter as a set of immiscible liquids...we live in an emulsion! Maybe even a multiphasic one with matter, antimatter and empty space all being immiscible? Above is a picture of a slice of the dark matter in the universe. Just something to think about.  

Sophistication Luxury Tap Water

Everybody wishes they invested in bottled water, but when it first came out, the question on everybody's mind was, "Who on earth would buy bottled water? How silly." Now it pervades our society and even the Coca-Cola Company has its own bottled water brand (Dasani, in case you didn't know). The bottled water industry is extremely wasteful, producing tons and tons of plastic that ends up in a lot of land fills. There is also a large amount of fuel wasted by transporting water around in trucks (water is very heavy, so heavy in fact, if you were to fill an entire tractor trailer car with it, the suspension wouldn't be able to handle it).

Sophistication Luxury Tap Water sets its satirical cross hairs on the bottled water industry by branding good ol' tap water and adds a filter just in case there's anything nasty in your local tap, though that's unlikely because tap water is more regulated than the bottled kind. Visit www.luxurytapwater.com for more info.

Magnetic "Micro-robots"

These magnetic particles are manipulated by magnetic fields to open and close their pincers and pick up a glass bead to move it around. The particles lie at the interface between layers of oil and water. A magnetic field perpendicular to the interface causes the particles to form the clumps/"micro-robots" and a magnetic field parallel to the interface causes them to swim. So the next step is obviously to filter different beads from a mixed bag of them. And then, world domination.

Superhydrophobicity

A hydrophobic material is one that repels water and a hydrophilic material is one that likes water. Pretty obvious. It's not so obvious how to go about testing where a material falls on the hydrophobicity/hydrophilicity scale. This is where something called the contact angle comes into play. It's the angle made at the interface of a water droplet with air at the surface of a solid material. Here's a picture that will clarify.

This test can be done with any two fluids (air and water are the most common) at a solid surface to compare surface tensions of different materials. When the contact angle is less than 90 degrees the surface is considered hydrophilic and if the contact angle is more than 90 degrees it is considered hydrophobic. If the contact angle is greater than 150 degrees then the surface is considered super-hydrophobic. There's not too much work on superhydrophilicity but a contact angle of nearly 0 degrees is the general consensus.
So why are super-hydrophobic surfaces worth writing a blog post about? Well, they can be used to reduce drag anywhere that a surface is pulled against water (hulls of ships, inside of pipes, etc). They can also be used as a self cleaning surface coating, so anytime it rains, dirt will be easily swept away. Imagine cleaning your car (well) by leaving it out in the rain.

Magnetohydrodynamic Drive

Actually, a magnetohydrodynamic (MHD) drive uses some electrohydrodynamics as well. Generally salt water flows though the poles of a magnet while a current is run through the salt water. The interaction of the current and the magnetic field cause a force that pushes the ions. The ions drag the water with them creating a jet and propelling the craft in the opposite direction. Get all that? No? Well you're in luck because there's a picture that explains everything, just replace the plasma with salt water.