Multifunctional Cellulosic Natural Rubber and Silver Nanoparticle Films with Superior Chemical Resistance and Antibacterial Properties

Abstract

Composite films of natural rubber/cellulose fiber/silver nanoparticle were synthesized in a green route via the latex solution process. Hybrid cellulose filler containing carboxymethyl cellulose and cellulose microfibers was used to facilitate facile and fast preparation and to improve mechanical strength to the composites, respectively. All the composites possessed a high tensile strength of ~120 MPa, a high heat resistance of nearly 300 °C, and more than 20% biodegradability in soil in two weeks. Chemical resistance and antibacterial activity of the composite was enhanced depending on sizes and concentrations of silver nanoparticles (AgNPs). The composites containing 0.033–0.1% w/w AgNPs retarded toluene uptake to less than 12% throughout 8 h, whereas the composite containing 0.067–0.1% w/w AgNPs exhibited excellent antibacterial activities against Escherichia coli and Staphylococcus aureus. In comparison, 50 nm-AgNPs presented higher antibacterial activities than 100 nm-AgNPs. In vitro cytotoxicity test assessed after incubation for 24 h and 48 h revealed that almost all AgNPs-composite films exhibited non/weak and moderate cytotoxicity, respectively, to HaCaT keratinocyte cells.

Effect of Reduction Methods on the Properties of Composite Films of Bacterial Cellulose-Silver Nanoparticles

“…Among the BC-Ag composites, the highest degree of crystallinity was observed in BC-Ag(Ascorbic), while BC-Ag(Chitosan) showed the lowest degree of crystallinity. Except for BC-Ag(Ascorbic), the incorporation of AgNPs resulted in a slight reduction in the crystallinity of the composites, which could be due to silver interfering with hydrogen bonds within the BC matrix [ 43 ], while chitosan-reduced composites exhibited a significant reduction of crystallinity. The interaction of chitosan molecules with cellulose fibrils might play a significant role in this effect.…”

“…Furthermore, the findings suggest that the antimicrobial effect of BC-Ag composites was not significantly influenced by the method of Ag reduction under the conditions in this study. However, it was previously reported that smaller AgNPs tended to exhibit higher antibacterial activity than larger AgNPs [ 43 ], due to the higher total surface area of the nanoparticles [ 52 ]. Silver particles were shown to strongly adhere to BC, preventing the leakage of AgNPs from the film [ 22 , 53 ].…”

An overview on recent approaches on drying of natural rubber materials

“…The addition of silver nanoparticles resulted in a slight reduction in the tensile strength, crystallinity and water absorption capacity of the composite, but the cellulose microfiber reinforcement maintained these properties at a good level. The composites showed heat resistance and biodegradability [59]. These recent studies demonstrate the continued interest in studying the drying behavior of different types of natural rubber and the effects of additives on this process [60].…”

Bacterial Nanocellulose Produced by Cost-Effective and Sustainable Methods and Its Applications: A Review

“…Several findings support the development of BC composites for targeted biomedical applications, particularly as antimicrobial wound dressings. The development of BCbased composites incorporating bactericidal nanoparticles like Se [142], Cu [143], Ag [144], ZnO [145], Au [146], and TiO 2 [138] have been extensively researched. Nevertheless, the potential toxicity of these nanoparticles to healthy mammalian cells, resulting from the production of reactive oxygen species, cannot be overlooked despite their antibacterial properties [147,148].…”