title: Synthesis and heavy-metal-ion sorption of pure sulfophenylenediamine copolymer nanoparticles with intrinsic conductivity and stability.
abstract: Novel copolymer nanoparticles were easily synthesized with a polymerization yield of 59.3 % by an oxidative precipitation polymerization of aniline (AN) and m-sulfophenylenediamine (SP) in HCl without any external stabilizer. The polymerization yield, size, morphology, electroconductivity, solubility, solvatochromism, lead and mercury ion adsorbability of the HCl-doped copolymer salt particles were studied by changing the AN/SP ratio. The AN/SP (80:20) copolymer particles are found to have the minimal number-average diameter(84.4 nm), minimal size polydispersity index (1.149), high stability, good long-term stability, powerful redispersibility in water, high purity, and clean surface because of a complete elimination of the contamination from external stabilizer. The copolymer salts possess a remarkably enhanced solubility, interesting solvatochromism, and widely adjustable electroconductivity moving across nine orders of magnitudes from 10(-9) to 10(0) S cm(-1). The AN/SP (70:30) copolymer particles have the highest Hg2+ adsorbance and adsorptivity of 497.7 mg g(-1) and 98.8 %, respectively, which are much higher values than those of other materials. The sorption mechanism of lead and mercury ions on the particles is proposed. The copolymer bases with 5-10 mol % SP unit show excellent film formability, flexibility, and smooth appearance. The copolymer should be very useful in the fabrication of cost-effective conductive nanocomposite with low percolation threshold and in removal of toxic metallic ions from waste water.
authors.affiliation: Institute of Materials Chemistry, Key Laboratory of Advanced Civil Engineering Materials, College of Materials Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Qiu-Feng
authors.initials: QF
authors.lastname: Lü
authors.forename: Mei-Rong
authors.initials: MR
authors.lastname: Huang
authors.forename: Xin-Gui
authors.initials: XG
authors.lastname: Li