Preparation Of Polyaniline And Nanocomposites By Ball Milling And Solid-State Doping

Polyaniline (PANI) base powers which were doped with camphorsulfonic acid (CSA) and multi-wall carbon nanometer tubes (CNTs) in the solid state by high-energy ball milling.The effect of the milling time, miliing speed, charge ratio(ball and grinding compound mass ratio ), PANI and CSA mole tatio, percentage of CNTs on the conductivity and doping level were investigated. The right technological parameters which powders could get the best conductivity were also worked out. The morphology and structure of the as-made PANI-CSA salt were characterized by SEM, XRD and FT-IR spectroscopy. The main results were summerized as follows:1. At room temperature, the best parameter for highest conductivity was charge ratio50:1, mole ratio 2.5:1, rotational speed 700r/min. The solid-state doping occurred with a fast rate, both the conductivity and the doping level increased in the early stage of ball milling and then dropped down. A maximum of conductivity was reached at 2.5h. The conductivity and doping level reduce, when ball milling time is excessively long. The XRD, FT-IR analysis indicated that ball grinding could realize the high delocalizaton, the high energy ball grinding induces the PANI member chain orientation to arrange and to form the PANI laminar, urgeing CSA to form the high orientation between the PANI-CSA-PANI slice along the PANI chain direction.2 .At low temperature, ball milling could simultaneously promote the solid phase doping response and the physical modified process. The experimental result indicated that the conductivity and doping rate reduced along with the ball grinding temperature decreased, therefore polyaniline had high doping level and high conductivity. After ball grinding 2.5 h at -150℃, PANI-CSA conductivity reached as high as 6.21 S/cm and its doping ratewas 0.32.3 . Accession of 0.3%Wt CNTs could raise the conductivity effectively. After ball grinding 2.5 hour conductivity could achieve 12.8S/cm, corresponding doping rate was 0.32. The SEM observation indicated that CNTs in the PANI-CSA substrate uniform distribution. Accession of carbon nanometer tube caused PANI to wrap the growth taking a carbon nanometer tube as the core. When the MWCNTs content increased, MWCNTs distributed non-uniformly, which affected the conductivity enhancement.