Sustainable multifunctional halochromic nanocomposite films (“smart films”) were prepared using a casting method. Natural pigments (saffron or red barberry anthocyanins) and TiO2 nanoparticles were ...included in these films as pH-responsive color indicators and for light blocking, respectively, as well as for their other functional attributes. The film matrix was constructed from a network of crosslinked biopolymers consisting of gelatin and κ-carrageenan. The mechanical, morphological, spectroscopic, colorimetric, thermal, barrier, ammonia-sensitivity, antimicrobial, antioxidant, and biodegradable characteristics of the films were investigated. Moreover, the efficacy of the films was demonstrated by using them to monitor changes in the freshness of packaged fish during storage. Incorporation of TiO2 nanoparticles and natural anthocyanins significantly improved the mechanical and moisture resistance of the films. Spectroscopic analysis (ATR-FTIR and XRD) indicated the nanoparticles and pigments were dispersed throughout the biopolymer matrix, and identified the important molecular interactions involved (such as hydrogen and electrostatic bonding). The films changed color in response to alterations in the freshness of the fish samples, which was correlated to ammonia production during fish degradation. The presence of the anthocyanins and TiO2 nanoparticles increased the bacteriostatic properties of the smart films, as well as inhibiting oxidative reactions. The smart films were shown to be biodegradable, decomposing within ∼30 days under simulated environmental conditions. In conclusion, these biodegradable smart/active films may be suitable replacements for plastic packaging materials. Moreover, they are able to detect food deterioration and prolong shelf life, thereby improving quality and reducing waste.
Display omitted
•Smart films had appreciable UV–visible light and water barrier properties.•Smart films decomposed faster than synthetic ones under model environmental conditions.•The smart films changed color in response to pH changes.•The smart films exhibited both antimicrobial and antioxidant activities.•The smart films were able to monitor changes in fish freshness during storage.
Abstract Purpose: Following the banning of expanded polystyrene packaging material, the fast food restaurant industry was serendipitously plunged into green sourcing initiatives for its packaging ...materials leading to heightened efforts on evaluating the suitability of various suppliers of green packaging material. This study therefore sought to assess the performance of selected suppliers on supplier performance metrics of total cost of ownership, quality of sourced material and delivery performance, in Zimbabwe’s restaurant industry. Methodology: Data was collected from senior procurement officers of 30 officially registered fast food restaurants in Zimbabwe. Each restaurant randomly selected 5 suppliers from their supplier lists. Each unit was asked to rate their 5 major suppliers of packaging material leading to an effective sample size of 150 suppliers. Structural Equation Modeling (SEM) was used to analyse data in AMOS. The five steps in SEM, that is: model specification, model identification, parameter estimation, model evaluation and modification were done. Findings: The findings in this study revealed that green sourcing leads to improved procurement performance in terms of total cost of ownership, quality of the materials sourced, and delivery performance. Implications for theory and practice: It was therefore recommended that practically the restaurant industry should explore various options of green packaging material ranging from recyclable and reusable plastic, paper, aluminium and steel material. Originality and value: Although the study was done in a single market, there is dearth in literature on green sourcing in frontier markets, of which the study provides empirical evidence from the restaurant industry in Sub-Saharan Africa.
The increasingly serious environmental pollution caused by petroleum-based nondegradable plastics has evoked intense research interest in the development of sustainable and degradable bioplastics. ...Starch is one of the most promising biopolymers for the preparation of bioplastic. However, it is still a great challenge to develop starch bioplastics with high strength, low water sensitivity, and excellent water resistance. Herein, we reported a facile chemical modification method for the synthesis of a novel starch bioplastic. In this process, an easily available starch derivate, dialdehyde starch (DAS), is cross-linked using diamine based on dynamic imine chemistry to prepare DAS-based polyimine (DAS-PI). This DAS-PI exhibits excellent thermal malleability, and it can be easily thermoformed into novel starch bioplastic without using any plasticizer. The resulting starch bioplastic shows high mechanical strength (40.6 MPa), high thermal stability, and excellent water/chemical resistance, as well as heat-induced self-healing ability. Moreover, it can be easily chemically degraded and recycled. This work provides a novel method of producing high-performance starch bioplastics without using plasticizers.
In this study, a diversified waste recycling system and a green processing technology are proposed. This research not only finds feasible solutions to alleviate environmental problems of plastic ...pollution and straw burning but also provides new reuse methods for oyster shell waste and hogwash oil. The developed noval biocomposite material is conducive to the green development of express industry. This paper evaluates the performance of materials from many aspects: X-ray computed tomography characterization, fundamental physical properties, mechanical properties, microscopic morphology, SEM morphology, and comprehensive performance of products. Two kinds of products with economic value are found. One is sample 4, which is suitable for making granular products due to its low cost (0.328$/500 g). Another is sample 13, which is suitable for manufacturing green packaging materials due to its excellent mechanical properties (tensile strength 14.15 MPa; elongation at break 12.68%; Young’s modulus 8189.89 MPa). Based on the experimental results, the process of the composite is simulated to study the different strengthening mechanisms of arabic gum and poly(methyl vinyl ether-alt-maleic anhydride). Arabic gum uses chemical reaction and principle of similarity and intermiscibility to fuse with biomass to form homogeneous hybrid in the form of liquid gel. Poly(methyl vinyl ether-alt-maleic anhydride) indirectly adheres filler to the matrix through ring-opening reaction and structural similarity. The new emulsification system caused by arabic gum promotes the arabic gum and nano-fluid coupling cross-linking system to produce a decentralized cross-linked network and inhibit the pernicious molecular chain entanglement.
PDF
