The Inflation Of Balloons Deflate Over Time
Why Balloons Deflate Over Time
Balloons are perhaps one of the main choices for party decorations. They come in different forms and sizes, and are made of varying materials. Balloons however do not stay inflated for a long period of time even if they are tightly knotted. Some stay inflated for weeks, some for days, and some even for only a few hours. Have you ever wondered how the air inside the balloon escapes?
There are several factors that cause the deflation of a perfectly inflated balloon. The first one is that the knot being tied to keep the air from escaping is not that secure. One may think that the knot is already very tight, but in reality, there are still holes for air to escape. The second factor is the material of the balloon. Balloons are not really perfectly air-tight. Air molecules slowly diffuse through the surface of the balloon. …show more content…
There are two materials that are commonly used in making balloons – one is the rubbery material made of a substance called latex and the other one is the foil material made of Mylar.
Both latex and Mylar balloons contain microscopic holes that allow air molecules to escape. The holes in the latex balloons are slightly bigger that those in the Mylar balloons, which is why Mylar balloons tend to stay inflated for a couple of weeks compared to latex balloons which can stay inflated for only a couple of days. On the other hand, the process of air molecules escaping through tiny holes in their container without colliding with one another is called effusion. This can only happen if the diameter of the hole is relatively smaller than the mean free path of the molecules. According to Graham 's law, the rate at which gases effuse is dependent on their molecular weight; gases with a lower molecular weight effuse more quickly than gases with a higher molecular weight. For two gases at the same temperature, and thus having the same kinetic energy, the root mean square molecular speed, Vrms, of each gas can be found using the
equation
where kB is the Boltzmann constant. Thus, lighter molecules have a higher speed. This results in more molecules passing through the hole per unit time. This is why a balloon filled with low molecular weight hydrogen deflates faster than an equivalent balloon full of higher molecular weight oxygen. The time a balloon deflates also depend on the kind of gas being inflated. Balloons that are inflated with helium tend to deflate faster than balloons inflated with air. This is because helium has smaller particles compared to air, which allows them to escape from the balloon holes faster.
References:
Carpenter, K. (n.d.). How Long Do Balloons Stay Inflated? Retrieved Feb. 13, 2013, from eHow: http://www.ehow.com/about_5349092_long-do-balloons-stay-inflated.html
Effusion. (n.d.). Retrieved Feb. 13, 2013, from Wikipedia: http://en.wikipedia.org/wiki/Effusion
White, C. (2012, Oct. 12). Why do balloons deflate? Retrieved Feb. 13, 2013, from Stack Exchange: http://physics.stackexchange.com/questions/39006/why-do-balloons-deflate
Why do Balloons deflate? (n.d.). Retrieved February 13, 2013, from KnowsWhy.com: http://www.knowswhy.com/why-do-balloons-deflate/
Balloons are perhaps one of the main choices for party decorations. They come in different forms and sizes, and are made of varying materials. Balloons however do not stay inflated for a long period of time even if they are tightly knotted. Some stay inflated for weeks, some for days, and some even for only a few hours. Have you ever wondered how the air inside the balloon escapes?
There are several factors that cause the deflation of a perfectly inflated balloon. The first one is that the knot being tied to keep the air from escaping is not that secure. One may think that the knot is already very tight, but in reality, there are still holes for air to escape. The second factor is the material of the balloon. Balloons are not really perfectly air-tight. Air molecules slowly diffuse through the surface of the balloon. …show more content…
There are two materials that are commonly used in making balloons – one is the rubbery material made of a substance called latex and the other one is the foil material made of Mylar.
Both latex and Mylar balloons contain microscopic holes that allow air molecules to escape. The holes in the latex balloons are slightly bigger that those in the Mylar balloons, which is why Mylar balloons tend to stay inflated for a couple of weeks compared to latex balloons which can stay inflated for only a couple of days. On the other hand, the process of air molecules escaping through tiny holes in their container without colliding with one another is called effusion. This can only happen if the diameter of the hole is relatively smaller than the mean free path of the molecules. According to Graham 's law, the rate at which gases effuse is dependent on their molecular weight; gases with a lower molecular weight effuse more quickly than gases with a higher molecular weight. For two gases at the same temperature, and thus having the same kinetic energy, the root mean square molecular speed, Vrms, of each gas can be found using the
equation
where kB is the Boltzmann constant. Thus, lighter molecules have a higher speed. This results in more molecules passing through the hole per unit time. This is why a balloon filled with low molecular weight hydrogen deflates faster than an equivalent balloon full of higher molecular weight oxygen. The time a balloon deflates also depend on the kind of gas being inflated. Balloons that are inflated with helium tend to deflate faster than balloons inflated with air. This is because helium has smaller particles compared to air, which allows them to escape from the balloon holes faster.
References:
Carpenter, K. (n.d.). How Long Do Balloons Stay Inflated? Retrieved Feb. 13, 2013, from eHow: http://www.ehow.com/about_5349092_long-do-balloons-stay-inflated.html
Effusion. (n.d.). Retrieved Feb. 13, 2013, from Wikipedia: http://en.wikipedia.org/wiki/Effusion
White, C. (2012, Oct. 12). Why do balloons deflate? Retrieved Feb. 13, 2013, from Stack Exchange: http://physics.stackexchange.com/questions/39006/why-do-balloons-deflate
Why do Balloons deflate? (n.d.). Retrieved February 13, 2013, from KnowsWhy.com: http://www.knowswhy.com/why-do-balloons-deflate/