Functional characteristics, wettability properties and cytotoxic effect of starch film incorporated with multi-walled and hydroxylated multi-walled carbon nanotubes

• Published in: International journal of biological macromolecules 2017-11, Vol.104 (Pt A), p.597-605
• Main Authors: Shahbazi, Mahdiyar, Rajabzadeh, Ghadir, Sotoodeh, Shahnaz
• Format: Article
• Language: English
• Subjects: Animals; Cell Line; Cytotoxicity test; Cytotoxins - chemistry; Cytotoxins - toxicity; Food Packaging; Hydroxylation; Mechanical Phenomena; Mice; Nanocomposite film; Nanocomposites - chemistry; Nanotubes, Carbon - chemistry; Permeability; Starch - chemistry; Steam; Surface free energy; Thermodynamics; Wettability
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2017.06.031

[Display omitted] •Functional properties of starch/CNT and starch/CNT-OH film were compared.•CMC used to improve interfacial compatibility between nano-fillers and starch.•CNT-OH was more increased hydrophobic character of starch film compared to CNT.•Lowered polar and dispersive components obtained by incorporation of CNT and CNT-OH.•Both nanocomposite films showed cytotoxic activity against L-929 cells. Two types of multi-walled carbon nanotubes (CNT and CNT-OH) at different levels (0.1–0.9wt%) were introduced into starch matrix in order to modify its functional properties. The optimum concentration of each nanotube was selected based on the results of water solubility, water permeability and mechanical experiments. The physico-mechanical data showed that CNT up to 0.7wt% led to a notable increase in water resistance, water barrier property and tensile strength, whilst regarding CNT-OH, these improvements found at 0.9wt%. Therefore, effects of optimized level of each nanotube on the starch film were evaluated by XRD, surface hydrophobicity, wettability and surface energy tests. XRD revealed that the position of starch characteristic peak shifted to higher degree after nanotubes introducing. The hydrophobic character of the film was greatly increased with incorporation of nanoparticles, as evidenced by increased contact angle with greatest value regarding CNT-OH. Moreover, CNT-OH notably decreased the surface free energy of the starch film. Finally, the conformity of both nanocomposites with actual food regulations on biodegradable materials was tested by cytotoxicity assay to evaluate the possibility of application in food packaging sector. Both nanocomposite films had potential of cytotoxic effects, since they could increase cytoplasmic lactate dehydrogenase release from L-929 fibroblast cells in contact with their surface.