Abstract
The formation of polyaniline in the layered metal phosphates, α-Ti(HOPO3)2•H2O, α-Zr(HOPO3)2•H2O, and HUO2PO4•4H2O is reported. Aniline and A-phenyl-1,4-phenylenediamine (PPDA) are intercalated in the layered phosphates to form the precursors for polymerization. X-ray diffraction patterns show interlayer expansions with titanium phosphate and zirconium phosphate, consistent with a bilayer of these molecules in the gallery. In contrast, only a monolayer is intercalated in uranyl phosphate. After thermal treatment at 130 °C in air, the intercalated aniline and PPDA are slowly polymerized by ambient oxygen. The formation of polyaniline was confirmed by FT-IR, UV/vis and EPR spectroscopies as well as magnetic susceptibility measurements. Following polymerization, the interlayer spacing slightly increases from 10.46 to 11.8 Å for anilinium/uranyl phosphate but dramatically decreases from 28.3 to 20.5 Å for PPDA/Zr(HOPO3)2 and from 18.87 to 13.25 Å for anilinium/Ti(HOPO3)2, suggesting a monolayer of polyaniline inside the uranyl phosphate and titanium phosphate structures but a bilayer in Zr(HOPO3)2. Gel permeation chromatography was used to determine the MW of the intercalated polyaniline. Prolonged heating in air results in cross-linked polymer in the galleries. All compounds are insulators.
Original language | English (US) |
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Pages (from-to) | 1525-1533 |
Number of pages | 9 |
Journal | Chemistry of Materials |
Volume | 7 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1995 |
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Materials Chemistry