News

ambience: soda pouring, fizzing

Anyone who’s ever opened a bottle of soda knows that sound. But why is it that even unopened plastic soda bottles lose their fizz over time? I’m Jim Metzner, and this is the Pulse of the Planet.

“The carbon dioxide that gives soda what people normally associate with as fizz is soluble and will dissolve into the wall of the plastic and be transported through the plastic and escape. In much the same way that air in your tires will eventually escape and the tire pressure goes down with time.”

Benny Freeman is an Associate Professor of chemical engineering at North Carolina State University. He’s been studying the effectiveness of plastic packaging. [Read more…] about Pulse Planet: Barrier Plastics

SCIENCE NEWS ONLINE
Food for Thought
August 24, 1996

If it sits on the shelf long enough, even an unopened 2-liter bottle of Coca-Cola or Diet Sprite will lose its zesty effervescence. What happens is the pent up carbon dioxide slowly leaks through microscopic holes in the molecular structure of the container’s plastic. Fortunately, not all plastics are as permeable as the inexpensive polyethylene terephthalate (PET) used to make large soft-drink bottles. One novel class of more rigid polyesters appears to offer particular promise for bottled drinks. It develops extraordinary barrier properties after it’s been transformed into a liquid crystal, for example, by heating.

Benny D. Freeman of North Carolina State University began working with these experimental materials 5 years ago under a grant issued jointly by the National Science Foundation and Electric Power Research Institute (EPRI). Initially, his mission was one of basic research: to understand how heat alters the structure and barrier properties of these polyesters. [Read more…] about To really hold that fizz

ELIZABETH TENNYSON
Associated Press Writer

Raleigh (AP) – Does your soda go flat? Is the gas tank on your car corroding? Are your wine bottles to heavy?

If so, researchers at North Carolina State University may have the solution to your problems.

Chemical engineers at the school are working on a strain of liquid crystalline polymer plastic that could seal in flavor and carbonation while keeping out air. The plastic could also be used to stop corrosion of fuel tanks and underground power lines.

“The main science behind it is these polymer molecules pack very well,” said Chris McDowell, a doctoral student working on the project. “The molecules are long and stiff like a pen. That allows them pack together so there is no room for small molecules like oxygen to pass through.” [Read more…] about Experimental Plastic Could Keep Soda Fizz From Fizzling

Congratulations to those who won student poster prizes at the North American Membrane Society (NAMS) meeting 2011 in Las Vegas:

1. Norman Horn, First Place, Gas Separations
2. Dan Miller, Second Place, Liquid Separations
3. Wei Xie, Second Place, Membrane Materials and Formation