Nanocomposite hydrogels—Controlled synthesis of chiral polyaniline nanofibers and their inclusion in agarose

Chiral polyaniline nanofibers were synthesized by using two different oxidants potassium tetrachloroaurate (PTC) and ammonium persulfate (APS) in sequence to oxidize aniline in the presence of a chiral inducing agent (1S)-(+)-10-camphorsulfonic acid (( S )-(+)-CSA) or ( R )-(−)-CSA. The optical activity of the chiral polyaniline varies as a function of the mass ratio of PTC to APS, with the highest optical activity being observed in the ratio range from 1.0 to 2.5. The resulting chiral polyaniline nanofibers were then included into agarose hydrogels via ‘wet process’ and the chiroptical properties of the polyaniline nanofibers are retained within the composite hydrogels, although the degree of chiral organization of the polyaniline appears to be somewhat modified by the presence of the agarose matrix.