How to Make Polymeric Nanoparticles

A new method of producing micro- and nanoparticles made of polymers has been presented by a team of researchers, who claim they can obtain a wide variety of shapes and sizes just by using readily available laboratory chemical and equipment.

This new technique was presented by a team of scientists at the College of Engineering at University of California Santa Barbara, led by Samir Mitragotri, a professor of chemical engineering. They used spherical polystyrene beads as a starting point that were liquefied with solvents or heat and then stretched.

A second method embedded the beads in a polyvinyl alcohol film and the film was stretched to create voids around the beads that were then filled by, again, liquefying the beads, using the same processes. The team successfully created more than 20 different shapes, from simple eggs and nanorods to complex lenses, diamonds and even nanoscale tacos and ravioli.

Polymers are repeating structural units, or monomers, connected by covalent chemical bonds, present in many natural and artificial materials, from plastics to DNA. By controlling the shape and size of these polymer nano- and microparticles, scientists hope to develop new applications in many industrial fields.

Plastics are made of semisynthetic polymerization products composed of organic condensation or addition polymers and may contain other substances to improve performance or economics and are now widespread in many materials and devices, used in microbiology, drug delivery, rheology (the study of the deformation and flow of matter under the influence of an applied stress) and many more.

A special category of fibers is reinforcing composite materials based on metals, ceramics and polymers for high performance and light weight, with uses in automotive, space, athletic equipment and medical prosthetic markets.

Today there are primarily six polymers in use, namely polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene and polycarbonate that make up nearly 98% of all polymers and plastics encountered in daily life.