## Nanomaterial-Based Membrane
### Polymer Nanocomposites Membranes for Gas Separation  
Over the past two decades, the emission of carbon dioxide has triggered many environmental complications. For the purpose of alleviating the concentration of carbon dioxide in the air, numerous approaches have been employed, and among them is the utilization of polymer nanocomposite membranes to successfully capture carbon dioxide [69]. Membrane separation process efficiently uses energy and it is a cost-effective tool in gas separation utilizations [70]. Presently, polymeric membranes are leading materials for gas separation processes, such as the recovery of landfill gas, sweetening of natural gas, flue gas and air separations, recovery of hydrogen, and purification. These materials possess the preferred mechanical characteristic and the tractability to be transformed into diverse modules [41]. Figure 3 depicts a straightforward representation of porous membrane gas separation, which uses Knudsen's diffusion. The feed from the raw gas mixture is partitioned and moves into the permeate stream and retentate stream; however, this is contingent on the application. In preference, the membrane permits a constituent from the feed stream to move across the membrane in view of the selective interactivity of the gas molecules with the pores and sorption together with higher diffusivity of the same constituent due to variances in molecular size. Nonetheless, the advancement in technology of polymeric membrane separation has been restricted on the account of a performance called upper bound trade-off curve amid gas penetrability and selectivity [71]. Owing to the performance of molecular sieve membranes such as zeolite, it is much above the upper bound trade-off curve, and scientists and scholars have pointed out that these materials are not easy to process and the cost of fabrication is high [72]. For the purpose of overcoming these restrictions, the interest in mixed matrix membranes has grown to materialization as a substituted method in membrane technology [73]. With regard to this method, superior gas separation features of molecular sieve materials with necessary mechanical characteristics and cost-effective processing capability of polymers are used [74]. A well-dispersed phase of inorganic materials in mixed matrix membranes possesses exceptional assembly and high mechanical strength. When these materials are integrated into the polymer matrix, there is an anticipation of the subsequent membrane characteristics having improved properties than the usual polymeric membranes [73]. Furthermore, the improvement in gas penetrability and selectivity by means of merging the fabrication of high-levels of performance membrane materials with present-day state-of-the-art membrane preparation technology is very essential for enlarging the industrial applications of polymeric membranes [75]. Scientists and scholars have investigated the fabrication of TiO\({}_{2}\) nano-inorganic mixed matrix membranes in order to offer a solution to the polymeric membranes' trade-off problem in gas separation [76; 77]. [PERSON] et al. presented a report on the fabrication of amine functionalized TiO\({}_{2}\) with TiO\({}_{2}\) nanoparticles pretreated with ethicaldiamine for gas separation [78]. The impacts of amin-functionalized TiO\({}_{2}\) loading on the gas penetration of the mixed matrix membranes were examined through the variation of the amin- different functionalized TiO\({}_{2}\) loading in the polysulfone matrix. Gas permeation measurements revealed that mixed matrix membranes implanted with a diverse quantity of amin-functionalized TiO\({}_{2}\) revealed diverse separation performances. Owing to the enhanced interactivity of amine groups on functionalized-nano TiO\({}_{2}\) with polar gases, amin-functionalized TiO\({}_{2}\) offered excellent performances concerning penetrability and selectivity when likened to pure TiO\({}_{2}\). Their study showed that the functionalization of TiO\({}_{2}\) has boosted the gas penetrability of synthesized membranes [78]. [PERSON] et al.