Airtight containers are not always so airtight. As any child will discover the day after a birthday party, even a tightly tied helium balloon will leak its gas out over the course of many hours. Now scientists have come up with a supremely efficient barrier that lets nothing in or out.

Full Story: http://feeds.sciencedaily.com/~r/sciencedaily/~3/l0vRGjSAW7A/081125135938.htm