Nanoscale Technique Welds Polymer Materials with Light

(NASA.gov)

Physicists and materials scientists at North Carolina State University in Raleigh developed a technique to attach portions of polymers by melting aligned nanoparticles with light waves. The researchers describe their process in a recent online issue of the journal Particle & Particle Systems Characterization (paid subscription required).

The team led by physicists Jason Bochinski and Laura Clarke, and materials scientist Joe Tracy, inserted gold nanorods within solid pieces of polymer materials. Gold nanorods can absorb light at different wave lengths, depending upon the size and orientation of the nanorod, which the nanonrods then convert to heat.

The researchers designed the gold nanorods to respond to light at a wave length of 520 nanometers when in horizontal alignment, and 808 nanometers when in vertical alignment. At wave lengths of 520 nanometers, light is visible to humans as a green color. At 808 nanometers, however, light is in the near-infrared spectrum and invisible to human eyes.

The NC State team tested the technique with different wave lengths of light, and found the light waves melted the selected nanofibers along the designed directions, while leaving surrounding fibers largely intact. In materials with cross-hatched nanofibers, for example, nanofibers with gold nanorods were placed in a parallel vertical alignment. When subjected to waves at 808 nanometers, the light heated and melted the vertical fibers, leaving the horizontal fibers as is.

Physicist Bochinski believes this technique can be valuable for customizing materials that have already been produced. “We can use heat at the nanoscale to change mechanical characteristics of objects postproduction without affecting their physical properties,” says Bochinski, “which means more efficiency and less waste.”

Read more:

• Nanotech Coating Provides Liquid-Repellent Surface
• Nanotech Fibers Remove Sulfur from Petroleum Fuels
• Membrane Technology to be Studied for Industrial Processes
• High-Strength Muscle-Emulating Nanotech Yarn Developed
• Lab Developing Fabric that Repels Chemical, Bio Agents

*     *     *