Influence of preparation techniques of cellulose II nanocrystals as reinforcement for tannery solid waste–based gelatin composite films

Abstract

Tannery waste–based gelatin composite film reinforced with cellulose II nanocrystal (CNC II) extracted from wet wipes using three different hydrolysis techniques is explored for its functional properties and possible utilization as a biodegradable packaging material. CNC II isolated using hydrogen peroxide (PCNC), citric acid (CCNC), and hydrochloric acid (HCNC) differed in morphological and crystalline character as investigated using DLS, FE-SEM, FTIR, and XRD analysis. The crystallinity of PCNC, CCNC, and HCNC was found to be 81.1%, 75.4%, and 86.1%, respectively. The highly crystalline CNC II (PCNC) incorporation improved mechanical stiffness of rawhide trimming waste–based gelatin films by 50% compared to control gelatin film. Maximum thermal decomposition with T max of 329 °C was obtained for gelatin films with PCNC nano-reinforcement. Films with CNC II were structurally stable and sufficiently antibacterial against Gram-positive S. aureus microbial strain. Strong interfacial non-covalent and hydrogen bonding interactions between gelatin and cellulose II nanocrystal have likely enhanced the properties of the composite films. Incorporation of CNC II reduced the surface wettability of the films and nanocomposites absorbed UV radiation as evidenced by transmittance value T 280 of 0.19%. Nanocomposite films degraded up to 79.9% of initial mass within 7 days of soil burial. Furthermore, based on the optimized system, single-use packaging application of eggplant seeds has been demonstrated. Graphical abstract

Potential of Pinhão husk (Araucaria angustifolia) as a structural reinforcement agent in the properties of edible films of Pinhão flour and gelatin

“…Faced with this problem, the potential of developing biodegradable polymers, such as films, and edible and biodegradable packaging for application in foods, has been considered an alternative 2,3,7–10 . Research on the use of biodegradable materials based on biopolymers has been carried out as one of the strategies to reduce plastic pollution of fossil origin, with biopolymers based on proteins and polysaccharides being the most common alternatives to plastics 11 . The films obtained from these matrices have good oxygen barrier properties due to the ability of these components to form neatly compacted structures through bonds, mainly hydrogen bonds 12 …”

“…Among the studies incorporating nanoparticles or nanomaterials, nanofibers are more recurrent. In contrast, studies using cellulose nanofibers/nanocrystals reported improvements in the permeability to water vapor, tensile strength, and elasticity of films 11,21,31,33‐39 . Some studies have been using nanomaterials from less explored sources, such as ramie nanofibers 40 .…”

“…2,3,[7][8][9][10] Research on the use of biodegradable materials based on biopolymers has been carried out as one of the strategies to reduce plastic pollution of fossil origin, with biopolymers based on proteins and polysaccharides being the most common alternatives to plastics. 11 The films obtained from these matrices have good oxygen barrier properties due to the ability of these components to form neatly compacted structures through bonds, mainly hydrogen bonds. 12 One of the main proteins used in film production is gelatin due to its abundance, low price, accessibility, non-toxicity, resistance to gases and oils, biodegradability, and good film-forming properties with low environmental impact.…”

“…In contrast, studies using cellulose nanofibers/ nanocrystals reported improvements in the permeability to water vapor, tensile strength, and elasticity of films. 11,21,31,[33][34][35][36][37][38][39] Some studies have been using nanomaterials from less explored sources, such as ramie nanofibers. 40 Other studies point to using materials with superior granulometry prepared by milling, among which we mention grape stalks, 10 cassava bagasse 20 and Pinhão husk.…”