Copper Nanospike Fillers with High Aspect Ratios for Enhancing the Separation Performance of Mixed Matrix Membranes

Copper nanospikes (Cu) were introduced as fillers to Pebax MH 1657 (Pebax) matrix to enhance the CO2 separation performance in mixed matrix membranes (MMMs). The polymer chains were wound on copper nanospikes with high aspect ratios, further increasing the mechanical strength of the MMMs. Pebax-Cu MMMs exhibit higher tensile strength and Young's modulus compared to pure Pebax membranes. The Young's modulus of PebaxCu MMMs filled with 5 wt % (Pebax-Cu-5 MMMs) was 145 MPa in the tensile test, an increase of 170.5% over the pure Pebax membrane. The addition of copper nanospike to MMMs improves the membrane's affinity for CO2. Furthermore, the copper nanospikes with a high aspect ratio in the membrane matrix tend to align horizontally, enhancing the diffusion route of gas molecules and improving membrane selectivity. As a result, the Pebax-Cu-5 MMMs had the best gas separation performance, with a CO2 permeability of 487 Barrer and CO2/CH4 separation factor of 41.