Effects of Graphite Flakes on the Material and Mechanical Properties of Polystyrene Membranes

The use of polymer composite membranes has been widely increased to improve the mechanical and material properties. In this research, graphite flakes are used as nanofiller in polystyrene (PS) membrane to improve hydrophobicity, moisture blocking capacity, thermal stability, tensile strength, and gas separation ability. The membranes are prepared by a solution casting technique and are characterized by fourier transformation infrared spectroscopy, X-ray diffractometry, scanning electron microscope, thermal gravimetric analysis, water contact angle (WCA), moisture transmission rate (MTR), and mechanical testing. The prepared membranes are also tested to determine the O2 and N2 permeability and O2/N2 selectivity. The quantity of graphite flakes is varied from 0-1.0 wt% of PS. 0.7 wt% graphite-filled PS has shown the best results among all the prepared samples. The WCA of the PS membrane is increased from 97.3 to 114.803 degrees, which shows that graphite flakes are well-suited to increase the hydrophobicity of the PS membrane. The MTR of 0.7 wt% graphite-filled PS shows that the membrane is well suited for moisture blocking and also showed better thermal stability. Graphite flakes are also found suitable for increasing the tensile strength of the membrane. Also, the highest O2/N2 selectivity is achieved for 0.7 wt% graphite-filled membranes, which makes them suitable for gas separation operation. Furthermore, the potential application of graphite-filled PS membranes is also presented.