Just about any well-equipped laboratory, these days should have magnetic stirrers on hand. Magnetic stirrers are easy to use, affordable, and allow for consistent mixing and dispersion. Perhaps best of all, you can set up magnetic stirrers and ensure that substances continue to mix even as you move on to other tasks.
Show magnetic stirrers to a young child, and he or she might think it’s magic. While technology often does seem magical, magnetic stirrers aren’t particularly mystic. These stirrers use rotating magnetic fields to spin a stir bar that’s been placed in your beaker or another container. As the stir bar spins, it’ll mix up the liquids.
If you’re going to use a magnetic stirrer, you’ll typically need a power source. That may include batteries, a simple plug, or whatever else. Electric motors are normally used to rotate the magnet fields (often simply by moving the magnets) thus spinning the stir bar.
Magnetic stirrers generally work best with smaller amounts of liquid (4 liters or less). While magnetic stirrers are very effective and easy to use, there are some limitations. The center of your solution, for example, will often be very well mixed. The top and outside of your solution may not be.
Particularly thick, or viscous, materials also won’t mix well with magnetic stirring. Thin, watery substances, on the other hand, are often very easy to mix with magnetic stirrers.
In some cases, you can use different stir bars to improve mixing. One stir bar may work better with a solution than another. Fortunately, science and chemistry supply companies often sell a variety of stirrers. This way, you can select the one that works best for you.
Magnetic stirring devices often come with hotplates and other features too, making them multi-faceted tools that are useful for a range of applications.