ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Reduction of silver ions to silver with polyaniline/poly(vinyl alcohol) cryogels and aerogels
Patrycja Bober, Miroslava Trchová, Jana Kovářová, Udit Acharya, Jiřina Hromádková, and Jaroslav Stejskal
Academy of Sciences of the Czech Republic, Prague 6, Czech Republic
Abstract: The macroporous conducting polymer cryogels were prepared by the oxidation of aniline hydrochloride in the frozen aqueous solutions of poly(vinyl alcohol) at − 24 °C. Corresponding polyaniline aerogels supported with poly(vinyl alcohol) have been obtained after thawing of cryogels followed by freeze-drying. Silver was deposited on the composites using the ability of polyaniline to reduce silver ions after the immersion in silver nitrate solutions. Swollen cryogels were coated only on the surface with macroscopic silver particles due to the closed-pore structure in cryogels and limited penetration of silver ions into macropores. The diffusion of silver ions to freeze-dried aerogels was better and further improved by vacuum treatment. Silver microcubes were produced in the pores, the weight fraction of silver in dry composites being typically several per cent, a maximum 13 wt%. The conductivity of the aerogels compressed to pellets depended on the processing and the highest value was 0.27 S cm−1. The aerogels containing silver were characterized in detail with Raman spectroscopy.
Keywords: Conducting polymer ; Polyaniline ; Cryogel ; Aerogel ; Silver ; Silver microcubes
Full paper is available at www.springerlink.com.
Chemical Papers 72 (7) 1619–1628 (2018)