Relationship between wet coating thickness and nanoparticle loadings based on the performance of mixed matrix composite membranes

Wet coating thickness and nanoparticle loadings are two important parameters that greatly impact the performance of mixed matrix composite membranes (MMCMs). In this work, two kinds of MMCMs, with Pebax as the continuous phase polymer and MIL-101(Cr) and UiO-66(Zr) as the dispersed phase porous materials respectively, were fabricated to explore the internal relationship between the two parameters. The change of membrane performance via adjusting wet coating thickness and nanoparticle loadings is discussed through pure gas and mixed gas tests and shown by contour data analysis. Generally, the wet coating thickness is significant to keep the membrane densification and nanoparticle loadings to increase the permselectivity to some degree. In addition, the nanoparticle size shows great impact on membrane performance due to the small-size nanoparticles with huge surface energy. At last, this work verifies that reinforcing the interaction between nanoparticles and polymer matrix is beneficial to improve the membrane performance.