چكيده انگليسي :
The idiom of Active Carbon is attributed to a group of carbonaceous materials that have high porosity and specific surface area. Commercially, these carbonaceous structures would be produced in the forms of powder, granule, fiber, and fabric. According to the IUPAC classification, porosity is classified into three groups depending on the pore size. Porous carbon products with a pore size diameter less than 2nm, between 2-50nm, and bigger than 50nm are defined as Micropores, Mesopores, and Macropores, respectively. To obtain activated carbon, three steps of oxidation, carbonization, and physical or chemical activation must be carried out. CO2 and H2O gases are the two main active agents used during the physical activation, but Zinc chloride, phosphoric acid, sulfuric acid, and other chemicals are applied in chemical activation. It has been proved that activated carbons obtained from fiber and fabric (ACF) have a porosity better than granule and powder forms. ACFs have significant properties. Because of these remarkable properties, ACFs have a wide range of applications. Generally, activated carbons have high surface area and can be used for filtering impurity in liquids and gases, eliminating heavy metal in waste water, decreasing sulfur concentration in crude oil, absorbing toxic exhausted gases from automobiles and factories, faster healing of wounds, drug delivery, stem cells, energy storage, supercapacitors, etc. Between different forms of textile precursors, fibers such as cotton, flax, jute, ramie, PAN are mainly used to produce ACFs.
In this work, weft-knitted cotton fabric precursor was employed to produce ACFs. Physical activation method at 800-1000 °C was applied using H2O and CO2 agents. To investigate the properties of ACFs, FT-IR, Raman, BET, SEM, and XRD analyses were employed. The specific surface area and mean pore diameter of ACFs varied from 512-1436 m2g-1, and 1.904-2.834 nm, respectively. According to the results, the parameters of activation agent, activation time, activation temperature, and kind of gases used during carbonization have critical effects on the final properties of ACFs namely, fiber diameter, weight loss, shrinkage, final texture, etc. It was also found that the effect of H2O agent on the final properties of ACFs was more pronounced than CO2. The increase of lumen diameter after activation was notable. The Final areas of the ACFS (6-44 cm2) were compared with the area of the precursor (60 cm2). Carbonization and activation stages, Activation agents had a remarkable effect on this parameter.
