| 초록 |
The simple method for fabrication of mesoporous polypyrrole (PPy) using template synthesis is described. Colloidal silica (Ludox SM-30: average particle size 7nm) was used as templates to obtain mesoporous PPy. In order to obtain uniform pore size and to polymerize pyrrole, silica particles were surface-modified with CDVS. Then pyrrole was polymerized on the exterior of stabilized silica particles. After silica particles were removed by HF or NaOH solutions, mesoporous PPy was accomplished. Different amounts of silica sol solution was used to optimize the BET surface area of mesoporous PPy. TGA data show these different loading amounts of silica on PPy/silica nanocomposites. The change of BET surface area of mesoporous PPy indicates the maximum of BET surface area of mesoporous PPy and the critical amounts of silica for the highest BET surface area. Nitrogen adsorption-desorption isotherms prove the presence of nanosized pore in PPy. The pore size distribution of the mesoporous PPy also show that the pore sizes of PPy are identical to those of silica particles used as template. TEM images of the mesoporous PPy reveal that the pore sizes of mesoporous PPy are correspond to those of silica template. It is evident that the mesoporous PPy can be synthesized by this template synthesis. As a selective adsorbent, mesoporous PPy was investigated their extracting capacities of heavy metal ions. Mesoporous PPy had a higher complexation affinity for the soft metal ions (Hg2+, Ag2+ and Pb2+), rather than hard metal ions (Cu2+, Ni2+, Cd2+ and Cr3+). These results might be interpreted by the nitrogen functional group upon a base-acid treatment. |
