Harvard Researchers Grow Microscopic Flower Structures With Chemical Reactions

Posted on May 19, 2013

Harvard researchers grew microscopic flower structures by perfecting chemical reactions in the lab. Wim L. Noorduin, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS), discoverd that he could control the growth of crystals by manipulating chemical gradients in a beaker of fluid.

Noorduin said in a statement, "For at least 200 years, people have been intrigued by how complex shapes could have evolved in nature. This work helps to demonstrate what's possible just through environmental, chemical changes."

The researchers used barium chloride and sodium silicate to create the micro flowers.

To create the flower structures, Noorduin and his colleagues dissolve barium chloride (a salt) and sodium silicate (also known as waterglass) into a beaker of water. Carbon dioxide from air naturally dissolves in the water, setting off a reaction which precipitates barium carbonate crystals. As a byproduct, it also lowers the pH of the solution immediately surrounding the crystals, which then triggers a reaction with the dissolved waterglass. This second reaction adds a layer of silica to the growing structures, uses up the acid from the solution, and allows the formation of barium carbonate crystals to continue.

The researchers were able to manipulate the chemical reactions to create the flower-like structures. For example, increasing the concentration of carbon dioxide helps to create broad-leafed structures.

The research was published here in Science.

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