The use of hot and cold aisle containment systems is a common tactic to ensure that the inefficient mixing of air does not occur in data centers.
The construction and material of containment systems typically vary by region and climate zones due to regulatory and temperature demands. However, steel and aluminum for framing and panels made of metal, plastic, or insulation materials are common.
Read this whitepaper which contains a study on the effect of different panel and framing materials on a cold aisle temperature rise.