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Influence of pH on the specific surface area of polyaniline matrices
Author(s) -
Chowdhury AlNakib,
Saleh Farhana Sultana,
Rahman Mohammad Rezaur,
Rahim Abdur
Publication year - 2008
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.28227
Subject(s) - polyaniline , aqueous solution , adsorption , aniline , polymerization , materials science , specific surface area , distilled water , hydrochloric acid , nuclear chemistry , chemical engineering , polymer chemistry , chemistry , inorganic chemistry , organic chemistry , polymer , composite material , catalysis , chromatography , engineering
We report the successful measurement of the specific surface area of chemically synthesized and treated polyaniline (PANI) and its composite PANI/silica (SiO 2 ). PANI was synthesized chemically from an aqueous solution of aniline and hydrochloric acid (HCl) in the presence of an oxidant, ammonium peroxydisulfate [(NH 4 ) 2 S 2 O 8 ]. In the synthesis of PANI/SiO 2 , SiO 2 was incorporated from its colloidal solution contained in the solution for the polymerization of PANI. PANI and PANI/SiO 2 thus synthesized were pretreated with double‐distilled water (pH = 6.95), aqueous HCl (pH = 1.09), and aqueous ammonia (pH = 10.15) solutions to control their pH levels. Surface morphologies of the treated PANI and PANI/SiO 2 matrices were investigated with scanning electron microscopy. The successful incorporation of SiO 2 into the PANI/SiO 2 composite was confirmed by the characteristic infrared absorption band at 1096 cm −1 . The adsorption of methylene blue, which was found to follow the Langmuir isotherm, onto the prepared materials was probed to estimate the real surface area. The base‐treated PANI matrix showed a higher surface area than the acidic and neutral ones. The incorporation of SiO 2 into the PANI matrix yielded a larger surface area. However, the treated PANI/SiO 2 showed the same trend as the treated PANI matrices. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008