Reinforcement of biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with cellulose nanocrystal/silver nanohybrids as bifunctional nanofillers

Abstract

Green nanocomposites containing biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and cellulose nanocrystals/silver (CNC-Ag) nanohybrids were synthesized and their properties were investigated. It was found that homogeneously dispersed CNC-Ag could act as bifunctional reinforcements to improve the thermal, mechanical and antibacterial properties of PHBV. Compared to pristine PHBV, the tensile strength and the maximum decomposition temperature (T max ) of the nanocomposite with 10 wt% CNC-Ag were enhanced by 140% and 24.2 C, respectively. The nanocomposites displayed reduced water uptake and water vapor permeability along with lower migration level in both non-polar and polar simulants compared to the neat biopolymer, which can be related to the increased crystallinity and improved interfacial adhesion. Moreover, the nanocomposites showed strong antibacterial activity against both Gram-negative E. coli and Gram-positive S. aureus. The results of the study indicate that the high performance nanocomposites show great potential applications in the fields of food, beverage packaging and disposable overwrap films.

Spherical and rod-like dialdehyde cellulose nanocrystals by sodium periodate oxidation: Optimization with double response surface model and templates for silver nanoparticles

“…Particle size of aqueous CN suspension was tested by the Nano ZS Malvern Zetasizer. E. coli as the model Gram-negative bacteria and S. aureus as the model Gram-positive bacteria were chosen to investigate the antimicrobial activities of CN-M-Ag-0.85, SDACN-Ag-0.85 and RDACN-Ag-0.85 nanohybrids as reported in previous literatures [1,2,20].…”

“…The synthesized procedures of CN-Ag nanohybrids were according to the previously described method [1,2]. In general, the aqueous solution of silver ammonia (silver ammonia aqueous solution was prepared by adding 1 mL of 25% ammonia to 100 mL AgNO 3 (0.85 g) solution.…”

“…In general, the aqueous solution of silver ammonia (silver ammonia aqueous solution was prepared by adding 1 mL of 25% ammonia to 100 mL AgNO 3 (0.85 g) solution. The final stage of ammonia addition was performed dropwise to give a clear solution [1,2,22]) was mixed with the CNs suspensions (approx. 1.0 g dry sample), and then heated to 90°C for about 20 min.…”

“…Theoretically, the NaIO 4 oxidation can selectively convert hydroxyl groups on the cellulose into aldehyde groups and form CNs by oxidative cleavage between at C 2 and C 3 bonds of the glucose repeat units [17,18]. The aldehyde groups on the DACN surfaces can be used as the binding site for the fluorescent bioimaging [19] and nanohybrid templates [1,2,20]. Yang et al [16] obtained the rodlike DACN with length of 100-200 nm and diameter of 5 nm by NaIO 4 oxidation of sheet from kraft softwood pulp after soaking in the water for 2 days, but the oxidation process needed long reaction time of 96 h with stirring speed of 105 rpm.…”

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Recently, cellulose nanocrystals (CNs) with various morphologies (rod-like or spherical) isolated from the most abundant cellulosic materials have gained increasing attention in some fields such as antimicrobial packagings [1,2], template for metallic nanoparticles [3], aerogels for wastewater treatment [4], drug delivery [5], and protein immobilization [6] due to their excellent properties, including easily modified functional groups, high specific area, aspect ratios, and outstanding stiffness. As the nanofillers, the requirement of CNs surface group varies with the different applications.

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