A polymer is defined as a large organic molecule formed by combining many smaller molecules (monomers) in a regular pattern.Polymer applications are found everywhere in our lives today.The cars we drive, the clothes we wear, the containers which keep our food, and the tools we use at work have one thing in common; they are partially comprised of polymers. Micromeritics Analytical Services works with researchers in all industries to determine physical properties such as porosity, BET surface area, density and particle size. Polymer chemists and engineers use this information to change formulations in order to obtain a product with the desired properties. Recently we measured the porosity of microporous polymer membranes used as filters for liquid and air purification systems. The end user wanted to have both macropores and micropores, which they were able to achieve as evidenced by the graph below.