Polyvinyl alcohol/multi‐walled carbon nanotubes nanocomposites with ordered macroporous structures prepared by ice‐templating

• Published in: Journal of applied polymer science 2021-02, Vol.138 (7), p.n/a
• Main Authors: Guimarães, Raul, Lapér, Miguel L., Castro, Vinícius G., Silva, Glaura G., Xavier, Ludmila G. O., Matencio, Tulio, Houmard, Manuel, Nunes, Eduardo H. M.
• Format: Article
• Language: English
• Subjects: composites; Electrical properties; Electrical resistivity; electrochemistry; Freezing; fullerenes; graphene; Materials science; mechanical properties; Multi wall carbon nanotubes; Nanocomposites; nanotubes; Polymers; Polyvinyl alcohol; Porosity; porous materials; Scaffolds
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.49837

We demonstrate in this study that it is possible to prepare three‐dimensionally ordered macroporous polymer structures by ice‐templating. Polyvinyl alcohol (PVA) was used as a model system in this study, but the processing route proposed here can be applied to other polymer systems. Multi‐walled carbon nanotubes (MWCNTs) were incorporated into the PVA matrix at concentrations up to 12 wt% to investigate the influence of this addition on the mechanical and electrical properties of the obtained scaffolds. Different freezing routes were used, namely unidirectional, radial, and bidirectional freezing. The addition of MWCNTs had a strengthening effect on the scaffolds, especially when added at loadings around 2 wt%. Samples prepared by unidirectional freezing displayed larger mechanical stability, but materials derived from radial and bidirectional freezing showed a higher electrical conductivity. The obtained materials exhibited apparent porosity above 85%, which can be of great interest in many applications. This work deals with the preparation of three‐dimensionally ordered macroporous polymer structures by ice‐templating. Polyvinyl alcohol was used as a model polymer system and multi‐walled carbon nanotubes (MWCNTs) were incorporated into it. Different freezing routes were used, which led to materials with apparent porosity above 85 %. The addition of MWCNTs had a strengthening effect on the scaffolds. Samples prepared by unidirectional freezing displayed larger mechanical stability, but materials derived from radial and bidirectional freezing showed a higher electrical conduction capacity.