Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials

Abstract

New bio-based packaging materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Waterstable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a low density (33-66 kg/m 3 ) and can inhibit microbial growth; two highly valuable features for insulating packaging materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foamforming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli, a common model bacteria and Aspergillus brasiliensis, a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting low-density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.

Foam forming of fiber products: a review

“…[16,17] Novel applications such as complex 3D forms [19] and growth media [146] can also be produced with foam forming. Moreover, it is also possible to get tailored properties such as antibacterial properties [147] in medical or hygienic applications, [148,149] designed microstructures, [21] or conductive cellulose-based structures. [150] Possible other high-tech applications include soft composites, [151] sensors, [152] chromatography and other diagnostics, substrates for biocatalytic and chemical conversion, and fiber materials with imbedded optics and electronics.…”

“…Filtratation for purifying (drinking) water would need a structure that is water-stable or water-resistant and has high wet-strength properties. There have been a few attempts by Heydarifard et al, [16,17] Jain et al, [159] and Ottenhall et al [147] to improve the wet strength and antimicrobial activity of foam-formed structures to capture and deactivate micro-organisms. Heydarifard et al [17] improved wet strength by using high molecular weight, cationically modified poly(acryla-mide) (C-PAM).…”

“…Ottenhall et al [147] showed that structures with cationic chitosan had good water-stability as well as good antibacterial (against to E. coli) and antifungal (against to Aspergillus brasiliensis) properties.…”

Characterization and structural properties of bamboo fibre solid foams

“…Cellulose is the most abundant organic polymer sourced from plant cell walls (Sfiligoj et al 2013); this characteristic and its compatibility with other materials has led to its fast-growing application as a precursor in foam-making, commonly termed as cellulose-based foams. Examples include fibre foams, where cellulose fibres are suspended in a binder of a secondary phase (Svagan et al 2011;Ottenhall et al 2018;Saz-Orozco et al 2013), which is subsequently blown with a foaming agent, and dried using freeze or critical point drying. In such architectures, the fibres are dispersed in cell walls, and connected at the cell wall or nodal junctions (Alimadadi et al 2018).…”

Computational Investigations on Soundproof Applications of Foam-Formed Cellulose Materials

“…Sound absorbing materials with low density (e.g., polystyrene foam) are often used for protection and insulation applications. However, bio-based alternatives for low-density insulation materials are needed to replace the fossil-based ones [1]. The development of biomaterials based on highly recyclable and biodegradable lignocellulosic fibers have attracted great interest in the composite material science community as a viable alternative to petroleum-based materials [2,3].…”