Abstract
One of the key characteristics of mesoporous films, making them attractive in many applications, is the surface enhancement gained by the porosity. Today, this attribute is rarely presented for particle-based mesoporous films. This work shows that krypton physisorption can be used to determine the available surface area of particle-based silica films synthesized by the direct growth (DiG) method. The surface area per substrate area of the films was measured to be 50-170 m2/m2 and the surface area per film volume was 310-490 m2/cm3 when the film thickness was varied between 100 and 520 nm. For comparison, a 105 nm thick film synthesized using dip-coating was used, as this technique renders more smooth films. The corresponding values for the dip-coated film was 90 m2/m2 and 880 m2/cm3, showing a higher surface area per film volume for the continuous film. The method is hence suitable for the characterization of mesoporous films synthesized with various techniques and can be used for the optimization of catalysts, drug delivery systems, and sensors.