The Influence of Synthesis Parameters on Vertically Aligned CNT Sheets: Empirical Modeling and Process Optimization Using Response Surface Methodology

In the present work, vertically aligned carbon nanotube (VA-CNT) sheets were synthesized via pyrolysis of polybenzimidazole (PBI)–Kapton inside the pores of anodized aluminum oxide (AAO). The synthesized VA-CNT sheets were then evaluated for the desalination of salty water. The results indicated that the VA-CNT sheets were effective for application as an adsorbent for desalination of salty water due to their high adsorption capacity, with no loss of CNTs in the treated water. This study explored the impact of operating time and temperature on liquid adsorption performance through optimization and modeling methods. An empirical model was developed through the evolution of a full factorial design process which considered two significant factors for enhanced antibacterial efficiency and adsorption uptake. The highest antibacterial efficiency was achieved with carbon precursors synthesized at a higher temperature. However, optimal values were obtained for both antibacterial efficiency and adsorption uptake (NaCl) with a combination of CNT membranes. The best conditions for such a membrane were 800 °C and 18 min. Under these conditions, antibacterial efficiency, contact angle, carbon content, adsorption uptake (NaCl = 10,000) and adsorption uptake (NaCl = 20,000) were 90.079, 1.69256, 75.213, 76.2352 and 0.997, respectively.