Long-lasting soap bubbles
The water in soap bubbles evaporates over time making the soap film thinner and thinner. Gravity is pulling most of the water downwards to the bottom of the bubble, and therefore the soap film becomes even thinner in the top part of the bubble. When the top film has become really thin, further evaporation of water will finally break the soap film.
The bubbles will generally have a shorter lifetime in dry air, because the evaporation is higher in dry air than in air with a high humidity. It is therefore a good idea to find a place with high humidity to make soap bubbles. The bathroom is a perfect place right after a shower.
To decrease the evaporation of water from the bubbles, one can use the trick of adding some glycerin to the soap-water mixture. You can read more about what glycerin does to the mixture here: Glycerin in soap bubble mixtures.
If you want to make soap bubbles that can last for hours or even days, you will have to further decrease the evaporation. This can be done by storing the bubble in a closed room with very high humidity. An easy way is to put the bubble in a jar on a ring made of wire. Fill some soap bubble mixture in the bottom of the jar, and make sure to wet the wire and the sides of the jar before making the bubble. When the bubble is made, the jar should be firmly closed. Water from every surface in the jar will now evaporate, and the humidity will quickly increase until the air is saturated with vapor. After saturation the evaporation will almost stop, and the bubble will be able to have a long life in the jar. Using our soap bubble mixtures we have had bubbles lasting for a week in an ordinary jar, but others have had bubbles lasting for much longer. It is said that the soap bubble enthusiast Eiffel Plasterer succeeded in having a bubble lasting for more than a year! To make the bubbles last that long a special recipe is needed, but Eiffel Plasterer’s bubble mixture for long-lasting bubbles was unfortunately kept a secret.
A flat soap film will not break as easily as a curved one. The famous physicist James Dewar kept a soap film disk with a diameter of 19 cm for over three years! The recipe Dewar used can be found in: Dewar, Lady (ed.) (1927) Collected papers of Sir James Dewar, Cambridge, 2. Volume.
Eiffel Plasterer made a number of soap bubble experiments. His most famous experiment is probably his long-lasting bubbles. It is said that he had a soap bubble in a jar for more than a year!
In the end even the strongest bubble will break, and when it does, it will be torn apart. The breakage will start at one point from where the soap film will retract until all the remaining film meets at a point on the opposite side of the bubble. From here, the soap water will be thrown further away from the breaking point. The process of breaking a soap bubble can be seen in slow motion, if recorded with a fast frame camera. Se such a movie here: YouTube
A frozen soap bubble
Alternatively, long-lasting soap bubbles can be made by lowering the temperature of the bubbles. High temperatures will make the water in the soap bubbles evaporate faster. Therefore the bubbles will generally have a shorter lifetime at higher temperatures. Many people think of making soap bubbles as a summer activity, but a hot summer day can be a problem for the life span of the bubbles. The dependence of the bubble life span on temperature becomes obvious, if one tries to put a soap bubble into a preheated oven.
As a soap film is mostly composed of water it can of course be frozen. This can be used as a strategy for making long-lasting bubbles. It is very interesting to make soap bubbles in extremely cold weather, because the bubbles can freeze, while they are falling through the air. If you are lucky, the bubbles will land on the ground without breaking. See it for yourself in this movie: http://www.muft.tv/watch/Video,Item,701061698.html (Sorry that you are forced to watch a commercial when watching the movie clip)
It is still possible to freeze a soap bubble even if you do not live north of the polar circle. Make a small holder for your bubble from a wire and dip it into a bubble mixture. Now blow a bubble on the holder, and place it carefully in a freezer. After a minute the bubble will be frozen. A frozen bubble can last for a long time. When it is kept below 0 degrees Celsius, the evaporation from the bubble will almost be stopped and it will not break. But if you remove it from the freezer it will melt quickly, and in this process it will almost certainly break.
You can make a hole in the frozen bubbles with your finger without breaking the whole bubble. You can also grab the frozen bubble with your hands and experience when it immediately melts.
Frozen soap bubble.