Reduction of silver ions to silver with polyaniline/poly(vinyl alcohol) cryogels and aerogels

• Published in: Chemical papers Vol. 72; no. 7; pp. 1619 - 1628
• Main Authors: Bober, Patrycja, Trchová, Miroslava, Kovářová, Jana, Acharya, Udit, Hromádková, Jiřina, Stejskal, Jaroslav
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-07-2018
• Subjects: Biochemistry; Biotechnology; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Industrial Chemistry/Chemical Engineering; Materials Science; Medicinal Chemistry; Original Paper; Silver; Conducting polymer; Polyaniline; Aerogel; Silver microcubes; Cryogel
• ISSN: 2585-7290; 1336-9075
• DOI: 10.1007/s11696-017-0374-6

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.