Effect Of Activation Process On The Stucture And Properties Of PAN Based Activated Carbon Fibers

In the 1970s,activated carbon fibers（ACFs）were developed as new type of highly-potent adsorption materials.Usually,ACFs have high surface area as well as activated carbons（ACs）but a fiber shape.And compared to ACs,ACFs also have higher carbon content and adsorption/desorption speed,narrower distribution of porous;stronger regeneration ability,and could be prepared as cloth,paper,flet and so on.Consequently,ACFs attracted the great interest of scientists and entrepreneurs when they were first discovered,and have been widely used as mediation solution for air and water purification,catalysis,energy storage and so on.However,most of ACFs also have worse mechanical properties apart from smaller pore diameters in current,and these factors limitted their application.Therefore,it is great significance to seek ACFs that with both high specific surface area and excellent mechanical properties.The raw materials used in this topic are 12K polyacrylonitrile based fibers,and the activation equipment is continuous activation furnace,to prepare PAN-ACFs that with high specific surface area and excellent mechanical properties.This topic mainly includes the following content:First of all,preparation of PAN-ACFs by potassium phosphate activation;secondly,effect of nitrogen flow rate on the preparation of PAN-ACFs by KOH+steam co-activation;thirdly,effect of tension on the preparation of PAN-ACFs by KOH+steam co-activation;finally,efficient preparation of PAN-ACFs by KOH+steam co-activation.Additionally,this topic also studied the relationship between micro-structure,adsorption properties and mechanical properties of ACFs by measuring their iodine adsorption value,mechanical properties,BET,XRD,SEM and so on.Finally,we achieve the continuous preparation of high performance activated carbon fibers.The results showed that compared with single physical or chemical activation,the complex performance of ACFs prepared by physical+chemical co-activation is better.For KOH+steam co-activation process,nitrogen flow rate has a certain influence on the properties of ACFs:With the decrease of nitrogen flow rate,the adsorption performance of ACFs increased.At the same time,the existence of tension also had a great effect on the adsorption performance of ACFs:With the increase of tension,the adsorption performance of ACFs increased,and the specific surface area of ACFs was 2445m².g^-1 when tension was 7N.Finally,through the systematic research work,this topic has obtained the high-performance activated carbon fibers that with specific surface area and tensile strength of 2139m.g-1,0.60GPa,when activation time was 5min.And this greatly broaden the application areas of ACFs.