Synergistic effect of bacterial cellulose and halloysite nanotubes on the properties of the sodium caseinate-based nanobiocomposites: Fid-Bau Portal

Synergistic effect of bacterial cellulose and halloysite nanotubes on the properties of the sodium caseinate-based nanobiocomposites

Aghajani-Memar, Shahabeddin / Mohammadkazemi, Fatemeh / Kermanian, Hossein / Hamedi, Sepideh

Abstract

Abstract In this study, nanobiocomposites based on sodium caseinate (SC) protein have been developed and characterized. Different levels of bacterial cellulose (BC; 1 and 2 wt%) and halloysite nanotubes (Hal; 1 and 3 wt%) as reinforcements were incorporated into SC films. Based on FE-SEM results, the pores on the surface of SC film were filled by reinforcements and nanocomposites containing both BC and Hal exhibited a uniform and homogenous surface. FTIR spectra verified the successful incorporation of BC/or Hal into the polymer matrix. XRD patterns of nanocomposites showed a wide reflection at 2θ angle of 20° belonging to sodium caseinate along with two main reflections at 21° and 29° which approved the intercalation of BC/or Hal into matrix. Both bacterial cellulose and halloysite promoted the crystallinity of the control film, but Hal was more efficient. As indicated in TG and DTG thermograms, the interaction of SC matrix with Hal improved the thermal stability of the nanocomposites in comparison with pure SC film. Simultaneous application of BC (2%) and Hal (3%) displayed a synergistic effect on the mechanical strength (11.62 MPa) of the nanobiocomposites. The moisture absorption capability of BC/or Hal-reinforced composites decreased by increasing the amount of fillers. As compared to pure SC film, water vapor permeation (WVP) of the nanocellulose/or Hal-reinforced nanocomposites decreased by increasing their reinforcement content. MTT assay result indicated the biocompatibility of the prepared nanocomposites. The improved mechanical, thermal and barrier properties of the sodium caseinate-based nanocomposite can be promised for food packaging.

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Highlights • Green nanocomposite has been developed based on sodium caseinate (SC) protein. • Bacterial cellulose and halloysite nanotubes were used as the safe reinforcements. • Incorporation of BC and HNTs promoted the mechanical behavior of the nanocomposite. • WVP of the nanocomposites decreased by incorporation of BC/or HNTs. • Thermal resistance of nanocomposites improved in comparison with SC film.