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Details

Autor(en) / Beteiligte
Titel
Role of dextran in stabilization of polypyrrole nanoparticles for photoacoustic imaging
Ist Teil von
  • European polymer journal, 2021-08, Vol.157, p.110634, Article 110634
Ort / Verlag
Oxford: Elsevier Ltd
Erscheinungsjahr
2021
Link zum Volltext
Quelle
Elsevier ScienceDirect Journals Complete
Beschreibungen/Notizen
  • [Display omitted] •Dextran acts as a good dispersion stabilizer in the polypyrrole particle syntheses.•The stabilizing effect improves significantly with the molecular weight of dextran.•Dextran allows good control of particle size by its concentration.•Dextran interacts with polypyrrole by adsorption, not covalent grafting.•Dextran allows the use of various oxidants to prepare NIR active contrast agents. Polypyrrole with bioinert surface is a prospective contrast agent for photoacoustic imaging. Dextran (Dex) was successfully tested as a steric stabilizer of the dispersion polymerization producing stable polypyrrole nanoparticles (PPy-NPs). Polymerizations were mediated with three different oxidizers: iron (III) chloride, ammonium persulfate and cerium ammonium nitrate. The use of the Dex allowed good control of particle size within the range 60–200 nm through varying concentration of the Dex and polymerization temperature, with the exception of cerium mediated polymerizations, which produced 30 nm particles independently of the reaction conditions. Stabilization effect of the Dex resulted from a reversible adsorption of the Dex on the surface of nanoparticles. Spectral analysis confirmed the complete removal of the Dex from particle surfaces during washing procedure, which indicated no grafting of the Dex to PPy-NPs mediated with a radical process initiated with decay of persulfate or single electron oxidation of the Dex by cerium ammonium nitrate. Photoacoustic measurement proved detectable signals in near infrared regions.

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