Adding small molecules improves polymer composites

Blends of polymers and nanoparticles that react to different stimuli, like heat and light, can be made by adding small molecules to the mixture. This simple and generally applicable approach is a step towards making such materials functional for use in industrial applications, reports a study published online this week in Nature Materials.

Ting Xu and colleagues used small molecules that are attracted to both the nanoparticles and certain parts of the polymers. This combination of small molecules, nanoparticles, and polymers, creates an ordering of the nanoparticles into complex shapes within the polymer material. The scientists then used small molecules that change either their affinity for the polymers or their own shape in response to heat or light, which means that the nanoparticle ordering within the polymers can be altered on demand.

The approach can be used in a variety of different blends to order the nanoparticles at different length scales with high precision. It also simplifies the material fabrication because the nanoparticles can be used without further chemistry.