Nanotechnology and packaging

Nanotechnology is used in a number of areas, including the car industry, the aero industry, paints, cosmetics, electronics and packaging. Our goal at Nofima Mat is to exploit the potential of nanotechnology in order to optimise the properties of packaging and the packing of food products.

The effect of using nanotechnology in packaging

Much of the initial research (research into nanocomposites started in Japan in the 1980s) was into nanocomposites, using clay materials.
Composites are two or more materials mixed together to give the desired properties. Thus a polymer nanocomposite is a composite, where one of the components (additives) is of nano size.

A number of the properties of packaging materials may be altered by using nanocomposites. Often we can change several properties simultaneously - unlike with "normal" additives, where we often use one additive to alter one property and a different additive to alter another. Properties that can be modified with the use of nanoparticles are: mechanical properties, tensile strength, heat stability, chemical resistance, electrical conductivity, optical qualities, transparency, UV resistance, permeability and barrier properties. For food packaging the barrier properties are the most important area. With clay composites and plastic materials, for example, the aim is to separate the clay layers and mix them with the polymer, so that the polymer chain comes in between the clay layers. The effect achieved is that the clay layers block or extend the route through the material for, e.g., oxygen molecules, thus improving the barrier properties.

Nanoparticles can also be coated (distributed) over the surface of materials to alter their properties. This may be in the form of active packaging that is designed to affect or react with the food. Examples are reduced oxygen level in the pack, anti-microbial effects (additives or conserving agents) or as intelligent packaging. An intelligent package could be an oxygen indicator or a package that tells us how fresh the product is by the particles changing colour if oxidation of the product has occurred.

Current work in this area

The development of innovative barrier materials for packaging fresh foods is being done in collaboration with SINTEF, manufacturers of polymer packaging and the food industry.

What is nanotechnology?

• a technology involving materials/particles of nano size (Nano = 10-9)
• it may involve either building up larger particles from nanoparticles or breaking larger particles down into nanoparticles
• one is working at atomic level (the size of atoms is about 0.1 nm)
• it is a multi-disciplinary area: i.e. it involves many fields, such as chemistry, biology, physics etc.