Cobalt(iii) acetylacetonate initiated RAFT polymerization of acrylonitrile and its application in removal of methyl orange after electrospinning

Abstract

This study describes reversible addition-fragmentation chain-transfer (RAFT) polymerization initiated by cobalt(III) acetylacetonate (Co(acac) 3 ). With Co(acac) 3 as the initiator, RAFT polymerization of acrylonitrile was achieved at 90 C mediated by 2-cyanoprop-2-yl dithionaphthalenoate. The polymerization exhibited "living"/controlled characteristics with a molar mass distribution as low as 1.25. Homogeneous polyacrylonitrile nanofibers (PAN-nFs) were produced via the electrospinning technique. FTIR, SEM and TGA analyses revealed aminated-PAN-nFs (APAN-nFs) were successfully obtained via ethylenediamine grafting onto the surface of PAN-nFs. The adsorption interaction between methyl orange (MO) dye and APAN-nFs is discussed in detail. The maximum saturation adsorption capacity was 102 mg g À1 . The adsorption kinetics followed a pseudo-second-order model. The Langmuir model was better for interpreting the isothermal process for MO and APAN-nFs. The Dubinin-Radushkevich isothermal model indicated that the adsorption proceeded chemically. Intraparticle diffusion was not the only rate-limiting step. The thermodynamics properties indicated the adsorption process was exothermic and spontaneous in nature. The MO dye adsorbed by APAN-nFs could be reversibly desorbed by an aqueous solution of pH ¼ 1. APAN-nFs could be recycled efficiently.

Preparation and Characterization of AMT/Co(acac)3-Loaded PAN/PS Micro-Nanofibers with Large through-Pores

“…Petrov et al [12] presented a result of laboratory experiments on modeling of heavy oil oxidation processes in an air-oxygen environment using Co(acac) 3 as a catalyst at certain temperature and pressure which was typical thermal production method. Xu et al [13] carried out reversible addition-fragmentation chain-transfer polymerization of acrylonitrile using Co(acac) 3 as an initiator which was achieved at 90 °C and mediated by 2-cyanoprop-2-yl dithionaphthalenoate. In another research [14], iron- and cobalt-incorporated carbon nanofibers (FeCo-CNFs) were prepared as a substitute of Pt-based electrocatalyst via electrospinning of PAN solution containing iron(III) acetylacetonate and cobalt(II) acetylacetonate and subsequent pyrolysis of the blend precursor fibers.…”