A study on activated carbon nanofibrous adsorbents prepared by technology for electrospun composite yarn

Abstract

In this study, an electrospinning process was used to fabricate nanofibrous PAN composite yarn. During the process, PAN spun yarn was used as the core of the composite yarn to increase the tensile strength of the nanofibrous yarn, PAN nanofibers were spun and coated onto the core surface to form a sheath of the composite yarn, so that it could be smoothly knitted and so that oxidation and carbonization/activation processes could be performed. Fabric knitted from the yarn was used as precursor for a activated carbon nanofibrous adsorbent. It was subjected to continuous heat treatment to carry out oxidation and carbonization/activation processes to examine the characteristics of the oxidized knitted fabric and of the adsorbents. The results suggest that the fiber diameter and the tensile strength of the yarn decreased after the oxidation and carbonization/activation processes. The limited-oxygen index of the oxidized fabric reached >40, indicating that it had become non-combustible. The tensile strength of the oxidized knitted fabric decreased by about 71 % relative to that of the unoxidized knitted fabric. During the carbonization/activation process, the yield of the activated carbon nanofibrous adsorbent was ∼17 %, and the ∼90 % decrease in tensile strength did not affect the processing. The BET specific surface area of the adsorbent reached ∼1100 m²/g, and the diameters of the activated carbon nanofibers were about 100–150 nm.