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Microplastics are an emerging anthropogenic pollutant risk with a significant body of research dedicated to understanding the implications further. To generate the databases required to characterize the impact of microplastics on our environment, and improve recovery and recycling of current plastic materials, we need rapid, in-line characterization that can distinguish individual polymer types. Here, autofluorescence spectroscopy was investigated as an alternative characterization method to the current leading techniques based on vibrational spectroscopy. It was confirmed that the autofluorescence of seven common textile polymers (acrylic, polyester, nylon, polyethylene, polypropylene, cellulose/cotton, wool) arose due to the cluster-triggered emission phenomenon. Both simulated polymer aging via photooxidation and dyeing of the polymers were found to affect the resultant autofluorescence spectra. A total of 1485 spectra from 39 unique sample groups (polymer type, colour, and degree of photooxidation) were analysed via machine learning (k-means cluster analysis). Correct identification of the polymer type was achieved in 71% of the cases from only eight input values (normalized intensity values at three autofluorescence emission wavelengths, the total autofluorescence emission intensity, the sample RGB colour values, and the sample shape). This represents a significant step towards automated polymer identification at the sub-second time scales required for the in-line characterization of microplastics. [ABSTRACT FROM AUTHOR]

The application and promotion of biodegradable plastics are hindered by the imbalance between their mechanical and degradation performance imbalance, as well as high costs. Herein, a series of poly(ethylene adipate‐co‐terephthalate) (PEAT) copolyesters with excellent mechanical and degradation properties are synthesized by one‐step melt polycondensation. The influence of the proportion of aliphatic groups in the molecular chain on the structure and properties, especially the degradation performance, of the copolyesters was studied. The molecular chain flexibility and degradability of PEAT increases with increasing of adipic acid content and decreasing of ET fragment length (LET). The comprehensive mechanical properties of PEAT60 can be comparable to traditional packaging material poly(butylene adipateco‐terephthalate) (PBAT). The degradation performance of PEAT can be adjusted the molecular chain structure. PEAT with LET < 3 exhibit degradation performance, and PEAT with LET < 2.2 exhibit significant degradation acceleration. The excellent mechanical and degradable properties of PEAT copolyester make it expected to be used in degradable packaging and other fields to help solve plastic pollution, while its lower cost will aid in the promotion of degradable materials. [ABSTRACT FROM AUTHOR]

Bioplastic is an emerging candidate for replacing traditional fossil‐based plastics due to its fewer carbon emissions, ease of recycling, and high degradability. Current research has shown that bioplastics benefit many applications, such as packaging, kitchenware, drug delivery, and sensors. However, high electrical resistance and poor stability of bioplastic are barriers to electronic components in robotic, bionic, and exoskeleton applications. Here, we introduce a novel bioplastic application as a strain sensor to estimate elbow angles for controlling exoskeletons. This study utilized extracted agar from red algae as the matrix, incorporating various concentrations of carbon nanotube (CNT) as a filler. The results were remarkable, with the increase in filler concentration not only improving strain from 0.8 to 1.1 but also stress from 35.2 to 45.8 kPa, surpassing commercial plastic by approximately two times. The optimized sensors have a response time of 0.16 s, a recovery time of 0.25 s, and stability over 10,000 cycles. Furthermore, the CNT‐bioplastic sensor is seamlessly integrated with the exoskeleton. Our work is a significant step toward using bioplastic in electronic applications. [ABSTRACT FROM AUTHOR]

Plastic waste has recently become a major global environmental concern and one of the biggest challenges has been seeking for alternative management options. Several studies have revealed the potential of several coleopteran species to degrade plastics, and this is the first research paper on plastic-degradation potential by lesser mealworms from Africa. This study evaluated the whole mitogenomic profile of the lesser mealworm to further identify the insect. The ability of the mealworm to consume Polystyrene (PS) was also evaluated alongside its associated gut microbiota diversity. Our results showed a complete circular mitochondrial genome which clustered closely to the Alphitobius genus but also suggested that our insect might be a new subspecies which require further identification. During the PS feeding trials, overall survival rates of the larvae decreased when fed a sole PS diet while PS intake was observed to increase over a 30-day period. The predominant bacteria observed in larvae fed PS diets were Kluyvera, Lactococcus, Klebsiella, Enterobacter, and Enterococcus, while Stenotrophomonas dominated the control diet. These findings demonstrated that the newly identified lesser mealworm can survive on a PS diet and has a consortium of important bacteria strongly associated with PS degradation. This work provides a better understanding of bioremediation applications, paving the way for further research into the metabolic pathways of plastic-degrading microbes and bringing hope to solving plastic waste pollution while providing high-value insect protein towards a circular economy. [ABSTRACT FROM AUTHOR]

The photocatalytic conversion of biomass and plastic waste provides opportunities for sustainable fuel and chemical production. Heterogeneous photocatalysts, typically composed of semiconductors with distinctive redox properties in their conduction band (CB) and valence band (VB), facilitate both the oxidative and reductive valorization of organic feedstocks. This article provides a comprehensive overview of recent advancements in the photorefinery of biomass and plastics from the perspective of the redox properties of photocatalysts. We explore the roles of the VB and CB in enhancing the value‐added conversion of biomass and plastics via various pathways. Our aim is to bridge the gap between photocatalytic mechanisms and renewable carbon feedstock valorization, inspiring further development in photocatalytic refinery of biomass and plastics. [ABSTRACT FROM AUTHOR]

The use of biodegradable plastics has been proposed as an alternative to mitigate the pollution problem caused by traditional non‐biodegradable plastics. However, the relative impacts of both types of microplastics on plant community productivity and diversity is not known. Moreover, it is unclear whether soil biota can differentially mediate the impacts of biodegradable and non‐biodegradable microplastics on plant communities. In this study, we investigated the effects of biodegradable and non‐biodegradable microplastics on plant community biomass production and diversity, and whether soil biota mediate these effects. We employed a fully crossed factorial design, growing six plant communities in the presence or absence of 10 individual microplastics, and in live soil versus sterilized soil. We hypothesized that: (1) Biodegradable microplastics have a less negative effect on plant community biomass production and diversity compared to non‐biodegradable microplastics. (2) Soil biota differentially mediate the effects of biodegradable and non‐biodegradable microplastics on plant community biomass production and diversity. Statistical analyses that included all 10 microplastics yielded two main findings. First, live soil ameliorated the negative effects of biodegradable microplastics on community shoot biomass. Second, the presence of microplastics, rather than their biodegradability, significantly reduced community diversity. Separate analyses of individual microplastics suggest that these patterns were driven by specific microplastics. The biodegradable microplastic polybutylene succinate (PBS) was the main driver of the pattern observed in community shoot biomass. In contrast, the biodegradable microplastic polycaprolactone (PCL) and non‐biodegradable microplastics ethylene‐vinyl acetate (EVA) and polyvinyl chloride (PVC) were the main drivers of the pattern observed in community diversity. Further analyses excluding PBS from the global models, but including the other nine microplastics, revealed no significant differences in community shoot biomass and diversity between biodegradable and non‐biodegradable microplastics in live versus sterilized soil. Synthesis and applications. Our findings suggest that biodegradable microplastics, often considered environmentally friendly, are not necessarily less harmful than non‐biodegradable microplastics to the growth and diversity of plant communities. Some individual biodegradable microplastics, such as PBS, still pose significant ecological risks to plant community structure and productivity. However, the results also suggest that soil biota may mitigate the negative effects of some biodegradable microplastics. [ABSTRACT FROM AUTHOR]

To improve the comprehensive properties of polybutylene furandicarboxylate (PBF), 2,5‐furandicarboxylic acid (2,5‐FDCA), and aliphatic chain diol 1,8‐octanediol and 1,4‐butanediol were used as monomers to synthesize a series of bio‐based polybutylene glycol‐octanediol 2,5‐furandicarboxylate (PBOF). The results showed that the chemical composition of PBOF could be controlled through the molar ratio of monomers. Compared with PBF, as the proportion of octanediol segments gradually increased, PBOF could gradually transform from semi‐crystalline thermoplastic to amorphous form, and the glass transition temperature (Tg) gradually decreased. The crystallization ability reduced but a part of the crystal area was still retained. The copolyesters still has a decomposition temperature above 370°C, indicating excellent thermal stability. The introduction of the octanediol segment significantly improved the tensile mechanical properties and flexibility of the POBF copolyester. These meet the requirements for the preparation of bio‐based engineering plastics. The water absorption rate of PBOF showed that it may have certain degradable potential. PBOF copolyesters have potential application prospects in bio‐based medical plastics and biodegradable packaging polymer materials after copolymerization modification. [ABSTRACT FROM AUTHOR]

Plant-based materials and edible films have emerged as promising alternatives to conventional packaging materials, offering sustainable and environmentally friendly solutions. This mini-review highlights the significance of plant-based materials derived from polysaccharides, proteins, and lipids, showcasing their renewable and biodegradable nature. The properties of edible films, including mechanical strength, barrier properties, optical characteristics, thermal stability, and shelf-life extension, are explored, showcasing their suitability for food packaging and other applications. Moreover, the application of 3D printing technology allows for customized designs and complex geometries, paving the way for personalized nutrition. Functionalization strategies, such as active and intelligent packaging, incorporation of bioactive compounds, and antimicrobial properties, are also discussed, offering additional functionalities and benefits. Challenges and future directions are identified, emphasizing the importance of sustainability, scalability, regulation, and performance optimization. The potential impact of plant-based materials and edible films is highlighted, ranging from reducing reliance on fossil fuels to mitigating plastic waste and promoting a circular economy. In conclusion, plant-based materials and edible films hold great potential in revolutionizing the packaging industry, offering sustainable alternatives to conventional materials. Embracing these innovations will contribute to reducing plastic waste, promoting a circular economy, and creating a sustainable and resilient planet. [ABSTRACT FROM AUTHOR]

This article discusses the importance of selecting the appropriate container for propagating native shrubs in ecological restoration projects. The study specifically focuses on the propagation of two shrub species native to the Mojave and Sonoran deserts in the southwestern USA. The researchers compared the survival and growth of seedlings in different container sizes and materials. They found that small, plastic cones were the most effective containers, resulting in the highest seedling survival and requiring the least amount of resources. The study highlights the need for further research on container selection and its impact on field outplanting success. [Extracted from the article]

Microplastics (MPs) are one of the major substantial pollutants in the environment and are stored in sediments worldwide, especially in marine environments. This study shed light on the abundance, distribution, sources and chemical composition of MPs present in the surface sediments collected from the shelf part of the southeast coast of India, Bay of Bengal. A total of twenty-seven surface sediment samples were collected to study MPs pollution. The abundance and morphological characteristics of MPs were determined by counting using an Olympus SXZ7 stereo microscope. Raman spectroscopy analysis was used to identify the polymer type of the MPs. The average abundance of MPs in the study area is 460±275 MPs/kg in dry sediment. Regarding colour, transparent particles were predominant (46.42%), followed by blue, green, brown, etc. With respect to particle shape and size, fibres and 500-µm sized MPs are abundant. Polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polystyrene (PS) are the polymer types characterised in the study area. The higher abundance of MPs in the study area can be attenuated to human interruptions, viz., tourism, fishing and inappropriate sewage disposal in the marine environment. In addition to this, population density also plays an important role in providing MPs to the marine environment. This study provides the most valuable data to extrapolate the research for mitigating MP pollution in oceans. It also informs mankind about their disastrous activities on the marine environment, which is expected to recuperate quickly and negatively impact human health and the functionality of the marine system. [ABSTRACT FROM AUTHOR]

Jackfruit seeds have been explored as one interesting alternative starch source to be used in the production of sustainable bioplastics. In this context, this work aimed to investigate the effect of sorbitol concentration, one alternative plasticizer to glycerol, and the starch properties of the films. A complete factorial experimental study was done based on five different concentrations of starch (2, 3, 4, 5, and 6% w/w) and sorbitol (40, 50, 60, 70, 80 g per 100 g of starch). The films were produced by casting technique and were characterized about thickness, optical properties, moisture resistance, mechanical properties, and morphology. The optical properties revealed opaque films, with opacity values ranging from 16.04 to 21.26%. Regarding moisture resistance, the less hydrophilic films showed lower plasticizer content. The water solubility varied from 25.48 to 38.93%; the water vapor permeability ranged from 9.99 to 11.82 × 10−9 (g/m s Pa) and the free energy of hydrophobic interactions varied from − 28.16 to 40.13 mJ m−1. Concerning the mechanical properties, the tensile strength of the films ranged from 3.55 to 9.25 MPa, and increasing the sorbitol concentration decreased the tensile strength and increased the elongation at break. The morphology and structure analysis showed that starch granules were not fully gelatinized, with microbubbles and grooves in the film matrix. This study showed the great potential of jackfruit seed starch and sorbitol in the manufacture of biodegradable films as alternative sustainable packaging. [ABSTRACT FROM AUTHOR]

Traditional food packaging coated paper is not environmentally friendly, and there have been many studies on oil- and water-resistant paper for food packaging. However, preparing oil- and water-resistant paper that is plastic-free, fluorine-free, and environmentally friendly is still a significant challenge. In this study, oil- and water-resistant paper for food packaging are prepared by layer-by-layer assembly and mixing coating methods. The layer-by-layer assembly coated paper exhibits excellent water resistance (Cobb 60 value of 20.5 g/m2, water contact angle value of 132°). The mixed coated paper not only has good water resistance (Cobb 60 value of 27.1 g/m2, water contact angle value of 131°), but also has excellent oil resistance (kit rating value of 8/12). The oil-resistant and waterproof mechanism of the coated paper is confirmed through scanning electron microscopy. In addition, the mechanical performance and coating adhesion of the mixed coated paper are the best, with an increase in the tensile index of 73.1 %. This study provides a feasible strategy for preparing biodegradable, plastic-free, and fluorine-free food packaging oil- and water-resistant paper, which is beneficial for reducing plastic pollution. [ABSTRACT FROM AUTHOR]

This study examined plastics and toxic metals in municipal solid waste compost from various regions in Sri Lanka. Plastics were extracted using density separation, digested using wet peroxidation, and identified using Fourier Transform Infra-Red Spectroscopy in Attenuated Total Reflection mode. Compost and plastics were acid-digested to quantify total Cd, Cu, Co, Cr, Pb, and Zn concentrations and analyzed for the bioavailable fraction using 0.01 M CaCl2. Notably, plastics were highly abundant in most compost samples. The main plastic types detected were polyethylene, polypropylene, and cellophane. However, the average Cd, Cu, Co, Cr, Pb, and Zn levels were 0.727, 60.78, 3.670, 25.44, 18.95, and 130.7 mg/kg, respectively, which are well below the recommended levels. Zn was the most bioavailable (2.476 mg/kg), and Cd was the least bioavailable (0.053 mg/kg) metal associated with compost. The Contamination factor data show that there is considerable enhancement of Cd and Cu, however, Cr, Cu, Co, and Pb are at low contamination levels. Mean geo accumulation index values were 1.39, 1.07, − 1.06, − 0.84, − 0.32, and 0.08 for Cd, Cu, Co, Cr, Pb, and Zn. Therefore, the contamination level of compost samples with Cd and Cu ranges from uncontaminated to contaminated levels, whereas Co, Cr, Pb, and Zn are at uncontaminated levels. Despite no direct metal-plastic correlation, plastics in compost could harm plants, animals, and humans due to ingestion. Hence, reducing plastic and metal contamination in compost is crucial. [ABSTRACT FROM AUTHOR]

Using biodegradable material derived from renewable resources as petroleum-based plastics replacement is a promising way towards sustainable development. However, the insufficient mechanical properties and complex manufacturing process of bioplastics still need to be improved for high-quality food packages. Herein, we report a top-down strategy to transform natural wood into a clear wood packaging film through scalable delignification and polyvinyl alcohol (PVA) infiltration. The wood packaging film demonstrates a laminated structure with completely collapsed cell walls and PVA intertwined together after energy-saving air drying, resulting in high light transmittance with low haze, good mechanical performance, and high barrier performance for oxygen and water vapor. Molecular dynamics simulations reveal the underlying fracture mechanism between cellulose and PVA, which effectively enhances the Young's modulus and strength of the wood packaging film. These findings contribute to the development of biodegradable and strong packaging materials, as well as other food-related applications, using sustainable wood. [ABSTRACT FROM AUTHOR]

Coconut fibers contain many lignocellulosic components; therefore, they have the potential to be used as cellulose‐based materials. This study aims to synthesize carboxymethyl cellulose (CMC) for bioplastic applications from coconut fiber cellulose obtained from South Tangerang, Indonesia. The isolation of cellulose was conducted in two key stages: alkaline treatment using a delignification reactor and bleaching with hydrogen peroxide (H2O2). The facile synthesis of CMC involved two important steps: alkaline treatment and carboxymethylation of isolated cellulose. The yield of cellulose isolated from coconut fiber was 16.39% for biomass and 64.84% for delignification products. The cellulose produced exhibited a crystallinity index (C.I.) of 89%. The yield of CMC was 14.67%, with a C.I. was 56.66%. The CMC obtained was categorized as having a medium molecular weight of 249,048 Da with a polymerization degree of 1046. Cellulose starts to decompose at a temperature interval of 292.05–381.45°C, whereas CMC decomposes at a lower temperature interval of 245.42–299.73°C. Thermochemical calculations were conducted by using the density functional theory (DFT), confirming a spontaneous reaction with a Gibbs free energy of −5.25 kJ mol−1. Bioplastics were fabricated in two stages: blending with carboxymethyl chitosan (CMChi) and plasticizing with glycerol. The addition of CMCh increased the C.I. and tensile strength, while the addition of glycerol to CMC/CMChi (80/20) blend‐based bioplastic reduced the C.I. and tensile strength, but enhanced the relative contact angle. Highlights: Cellulose was isolated from coconut fibers through a two‐stage process involving delignification and bleaching;Carboxymethyl cellulose was synthesized by reacting the cellulose of coconut fibers with monochloroacetic acid in isopropanol with NaOH as the catayst;The optimum condition for achieving the highest elongation at break among the blending compositions was found in the CMC/CMChi (80/20) blend bioplastic;Adding up to 30 wt% glycerol decreased the tensile strength and increased the elongation at break;The addition of glycerol enhanced the hydrophobic properties of CMC/CMCh blend‐based bioplastics. [ABSTRACT FROM AUTHOR]

Increasing human population demands more usage of consumable items thus causes more destruction to the environment by developing advanced materials and technologies. Synthetic plastic is one of the most used material in daily life which results in accumulation of non-degradable waste material that stays in the environment for thousands of years and creates plastic pollution. Many species on the earth suffer from pollution caused by plastic and it is one of the leading causes of global warming. For sustainable development, we need to protect our environment from plastic pollution by making use of biodegradable materials. In the past few years, biodegradable materials with plastic like properties have gained much attention. They have been made from biomass such as sugarcane, corn, wheat, rice, banana peels, etc. Such desirable properties are also present in PHAs (polyhydroxyalkanoates) synthesized by microorganisms. Several types of PHAs have been discovered from bacteria and used as a bioplastic candidate. However, there are major challenges also such as high production cost and expensive raw material which limits its commercial applications. Modern tools and strategies have allowed precise metabolic engineering of various microorganisms to produce PHAs using highly efficient microbial cell factories. This review article focuses on the research done on the microbial bioplastic production and its various applications. We have also discussed the future perspectives of bioplastic for sustainable development. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHA) are popular biopolymers due to their potential use as biodegradable thermoplastics. In this study, three aerobic sequencing batch reactors were operated identically except for their temperatures, which were set at 15 °C, 35 °C, and 48 °C. The reactors were subjected to a feast-famine feeding regime, where carbon sources are supplied intermittently, to enrich PHAaccumulating microbial consortia. The biomass was sampled for 16S rRNA gene amplicon sequencing of both DNA (during the enrichment phase) and cDNA (during the enrichment and accumulation phases). All temperatures yielded highly enriched PHA-accumulating consortia. Thermophilic communities were significantly less diverse than those at low or mesophilic temperatures. In particular, Thauera was highly adaptable, abundant, and active at all temperatures. Low temperatures resulted in reduced PHA production rates and yields. Analysis of the microbial community revealed a collapse of community diversity during low-temperature PHA accumulation, suggesting that the substrate dosing strategy was unsuccessful at low temperatures. This points to future possibilities for optimizing low-temperature PHA accumulation. [ABSTRACT FROM AUTHOR]

With the growing awareness of microplastics in the environment, the question of microplastics as remnants of biodegradable plastic (BDP) products is gaining momentum. BDP bags for kitchen waste collection are often certified as fully compostable as proof of industrial compostability. Frequently certification is done using under standardized laboratory conditions within 12 weeks. Composting plants often process biowaste into compost in a shorter time under inhomogeneous conditions. This study investigates the decomposition behavior of commercially available BDP bags for kitchen waste collection at an industrial composting plant within a practically realistic time frame of 6 weeks. The research determines the decomposition behavior under practice conditions. Four bag types, two made from thermoplastic starch (TPS) blends and two from polylactic acid (PLA) blends underwent composting. The decomposition was evaluated by examining the remaining macro- (> 8 mm), meso- (2-8 mm), and microparticles (1-2 mm) in the compost with different methods. After 6 weeks, the mass-based decomposition rate of TPS blend bags exceeded 95%. In contrast, PLA blend bags failed to reach a decomposition rate of 90%. The study did not depict very small particles <1 mm. However, they are present. The study findings indicate that composting time and conditions, inhomogeneities, as well as the bag type are crucial factors influencing the decomposition of BDP bags. Concerns are raised about the usefulness of DIN 13432 as certification scheme for industrial conditions. [ABSTRACT FROM AUTHOR]

Plastic pollution is worsening the living conditions on Earth, primarily due to the toxicity and stability of non‐biodegradable plastics (NBPs). Photocatalytic cracking of NBPs is emerging as a promising way to cleave inert C−C bonds and abstract the carbon atoms from these wastes into valuable chemicals and fuels. However, controlling these processes is a huge challenge, ascribed to the complicated reactions of various NBPs. Herein, we summarize recent advances in the CO2 and carbon‐radical‐mediated photocatalytic cracking of NBPs, with an emphasis on the pivotal intermediates. The CO2‐mediated cracking proceeded with indiscriminate C−H/C−C bond cleavage of NBPs and tandem photoreduction of CO2, while carbon‐radical‐mediated cracking was realized by the prior activation of C−H bonds for selective C−C bond cleavage of NBPs. Catalytic generation and conversion of different intermediates greatly depend on the kinds of active species and the structure of photocatalysts under irradiation. Meanwhile, the fate of a specific intermediate is compared with small molecule activation to reveal the key problems in the cracking of NBPs. Finally, the challenges and potential directions are discussed to improve the overall efficiency in the photocatalytic cracking of NBPs. [ABSTRACT FROM AUTHOR]

Plastic pollution is a problem that threatens the future of humanity, and various methods are being researched to solve it. Plastic biodegradation using microorganisms is one of these methods, and a recent study reported that plastic-degrading microorganisms activated by plasma increase the plastic decomposition rate. In contrast to microbial sterilization using low-temperature plasma, microbial activation requires a stable plasma discharge with a low electrode temperature suitable for biological samples and precise control over a narrow operating range. In this study, various plasma characteristics were evaluated using SDBD (Surface Dielectric Barrier Discharge) to establish the optimal conditions of plasma that can activate plastic-degrading microorganisms. The SDBD electrode was manufactured using low-temperature co-fired ceramic (LTCC) technology to ensure chemical resistance, minimize impurities, improve heat conduction, and consider freedom in designing the electrode metal part. Plasma stability, which is important for microbial activation, was investigated by changing the frequency and pulse width of the voltage applied to the electrode, and the degree of activation of plastic-degrading microorganisms was evaluated under each condition. The results of this study are expected to be used as basic data for research on the activation of useful microorganisms using low-temperature plasma. [ABSTRACT FROM AUTHOR]

The present study examines the use of waste cooking oil (WCO) as a substrate for medium-chain-length polyhydroxyalkanoates (mcl-PHA) production by Pseudomonas rhizophila S211. The genome analysis revealed that the S211 strain has a mcl-PHA cluster (phaC1ZC2DFI) encoding two class II PHA synthases (PhaC1 and PhaC2) separated by a PHA depolymerase (PhaZ), a transcriptional activator (PhaD) and two phasin-like proteins (PhaFI). Genomic annotation also identified a gene encoding family I.3 lipase that was able to hydrolyze plant oils and generate fatty acids as favorable carbon sources for cell growth and PHA synthesis via β-oxidation pathway. Using a three-variable Doehlert experimental design, the optimum conditions for mcl-PHA accumulation were achieved in 10% of WCO-based medium with an inoculum size of 10% and an incubation period of 48 h at 30 °C. The experimental yield of PHA from WCO was 1.8 g/L close to the predicted yield of 1.68 ± 0.14 g/L. Moreover, 1H nuclear magnetic resonance spectroscopy analysis confirmed the extracted mcl-PHA. Overall, this study describes P. rhizophila as a cell factory for biosynthesis of biodegradable plastics and proposes green and efficient approach to cooking oil waste management by decreasing the cost of mcl-PHA production, which can help reduce the dependence on petroleum-based plastics. [ABSTRACT FROM AUTHOR]

Lignocellulose is a major biopolymer in plant biomass with a complex structure and composition. It consists of a significant amount of high molecular aromatic compounds, particularly vanillin, syringeal, ferulic acid, and muconic acid, that could be converted into intracellular metabolites such as polyhydroxyalkanoates (PHA) and hydroxybutyrate (PHB), a key component of bioplastic production. Several pre-treatment methods were utilized to release monosaccharides, which are the precursors of the relevant pathway. The consolidated bioprocessing of lignocellulose-capable microbes for biomass depolymerization was discussed in this study. Carbon can be stored in a variety of forms, including PHAs, PHBs, wax esters, and triacylglycerides. From a biotechnology standpoint, these compounds are quite adaptable due to their precursors' utilization of hydrogen energy. This study lays the groundwork for the idea of lignocellulose valorization into value-added products through several significant dominant pathways. [ABSTRACT FROM AUTHOR]

Amid the current environmental crisis caused by plastic accumulation, one of the proposed solutions to manage this problem is using biodegradable polymers. However, the impact of adding biodegradable polymers to the well-established circular economy of recyclable polymers, such as HDPE, has not been fully considered. Therefore, there is a need to reconsider the way we consume, dispose of, and manage biodegradable polymers after use. This study evaluates the effect of varying the contents of a biodegradable polymer, taking poly(lactic acid) (PLA) as a model biodegradable polymer, on the thermal and mechanical properties of HDPE. The study highlights the importance of identifying and disposing of biodegradable polymers to avoid mixtures with HDPE, in order not to affect mechanical performance when considering reprocessing and a new life cycle of this conventional polymer. [ABSTRACT FROM AUTHOR]

This research improves the strength of plastic using avocado seed starch and PLA. The effect of blending avocado seed starch and PLA was optimized using the RSM approach by using two variables: water absorption and biodegradability. Mixing them using RSM gave the best result: 1.8 g of starch and 3 g of PLA. Degradable plastic has a tensile strength of 10.1 MPa, elongation at a break of 85.8%, and a Young's modulus of 190 MPa. Infrared spectroscopy showed that the plastic had a -OH bond at 3273.20 cm−1, 3502.73 cm−1, and 3647.39 cm−1, a CH2 bond at 2953.52 cm−1, 2945.30 cm−1, and 2902.87 cm−1, a C=C bond at 1631.78 cm−1, and a C-O bond at 1741.72 cm−1. The plastic decomposed in the soil. It was organic and hydrophilic. Thermal tests demonstrated that the plastic can withstand heat well, losing weight at 356.86 °C to 413.64 °C, forming crystals and plastic melts at 159.10 °C—the same as PLA. In the melt flow test, the sample melted before measurement, and was therefore not measurable—process conditions affected it. A water absorption of 5.763% and biodegradation rate of 37.988% were found when the samples were decomposed for 12 days. The starch and PLA fused in the morphology analysis to form a smooth surface. The RSM value was close to 1. The RSM gave the best process parameters. [ABSTRACT FROM AUTHOR]

Proper waste sorting is crucial for biodegradable plastics (BDPs) recycling, whose global production is increasing dynamically. BDPs can be sorted using near-infrared (NIR) sorting, but little research is available about the effect of surface contamination on their NIR spectrum, which affects their sortability. As BDPs are often heavily contaminated with food waste, understanding the effect of surface contamination is necessary. This paper reports on a study on the influence of artificially induced surface contamination using food waste and contamination from packaging waste, biowaste, and residual waste on the BDP spectra. In artificially contaminated samples, the absorption bands (ADs) changed due to the presence of moisture (1352–1424 nm) and fatty acids (1223 nm). In real-world contaminated samples, biowaste samples were most affected by contamination followed by residual waste, both having altered ADs at 1352–1424 nm (moisture). The packaging waste-contaminated sample spectra closely followed those of clean and washed samples, with a change in the intensity of ADs. Accordingly, two approaches could be followed in sorting: (i) affected wavelength ranges could be omitted, or (ii) contaminated samples could be used for optimizing the NIR database. Thus, surface contamination affected the spectra, and knowing the wavelength ranges containing this effect could be used to optimize the NIR database and improve BDP sorting. [ABSTRACT FROM AUTHOR]

Biodegradable biobased polymers derived from biomass (such as plant, animal, marine, or forestry material) show promise in replacing conventional petrochemical polymers. Research and development have been conducted for decades on potential biodegradable biobased polymers such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and succinate polymers. These materials have been evaluated for practicality, cost, and production capabilities as limiting factors in commercialization; however, challenges, such as the environmental limitations on the biodegradation rates for biodegradable biobased polymer, need to be addressed. This review provides a history and overview of the current development in the synthesis process and properties of biodegradable biobased polymers, along with a techno-commercial analysis and discussion on the environmental impacts of biodegradable biobased polymers. Specifically, the techno-commercial analysis focuses on the commercial potential, financial assessment, and life-cycle assessment of these materials, as well as government initiatives to facilitate the transition towards biodegradable biobased polymers. Lastly, the environmental assessment focuses on the current challenges with biodegradation and methods of improving the recycling process and reusability of biodegradable biobased polymers. [ABSTRACT FROM AUTHOR]

The ever-increasing presence of micropollutants necessitates the development of environmentally friendly bioremediation strategies. Inspired by the remarkable versatility and potent catalytic activities of microbial enzymes, researchers are exploring their application as biocatalysts for innovative environmental cleanup solutions. Microbial enzymes offer remarkable substrate specificity, biodegradability, and the capacity to degrade a wide array of pollutants, positioning them as powerful tools for bioremediation. However, practical applications are often hindered by limitations in enzyme stability and reusability. Enzyme immobilization techniques have emerged as transformative strategies, enhancing enzyme stability and reusability by anchoring them onto inert or activated supports. These improvements lead to more efficient pollutant degradation and cost-effective bioremediation processes. This review delves into the diverse immobilization methods, showcasing their success in degrading various environmental pollutants, including pharmaceuticals, dyes, pesticides, microplastics, and industrial chemicals. By highlighting the transformative potential of microbial immobilized enzyme biocatalysts, this review underscores their significance in achieving a cleaner and more sustainable future through the mitigation of micropollutant contamination. Additionally, future research directions in areas such as enzyme engineering and machine learning hold immense promise for further broadening the capabilities and optimizing the applications of immobilized enzymes in environmental cleanup. [ABSTRACT FROM AUTHOR]

Microplastics have become a pressing environmental issue due to their widespread presence in our ecosystems. Among various plastic components, polyethylene (PE) is a prevalent and persistent contaminant. Hydrothermal gasification (HTG), a promising technology for converting PE into syngas, holds great promise for mitigating the microplastic problem. In this study, we employ ReaxFF molecular dynamics simulations to investigate the HTG process of PE, shedding light on the intricate relationships between temperature, water content, carbon conversion efficiency, and product distributions. The results reveal that hydrothermal gasification of PE is a complex process involving multiple reaction pathways. Consistently with experimental findings, the calculations indicate that the gas phase exhibits a substantial hydrogen fraction, reaching up to 70%. Interestingly, our simulations reveal a dual role of water content in the HTG process. On one hand, water enhances hydrogen production by promoting the gas formation. On the other hand, it elevates the activation energy required for PE decomposition. Depending on the water content, the calculated activation energies range from 176 to 268 kJ/mol, which are significantly lower than those reported for thermal gasification (TG). This suggests that HTG may be a more efficient route for PE conversion. Furthermore, this study highlights the importance of optimizing both temperature and water content in HTG systems to achieve high yields of hydrogen-rich syngas. The results obtained from our ReaxFF MD simulations demonstrate the robustness of this computational methodology in elucidating complex chemical reactions under extreme conditions. Our findings offer critical insights into the design of advanced waste management strategies for microplastics and contribute to the development of sustainable practices for resource recovery. This work underscores the potential of HTG as a key technology for addressing the global challenge of plastic pollution. [ABSTRACT FROM AUTHOR]

Plastic packaging materials have caused significant environmental issues because they are nonrenewable and nonbiodegradable. Wax‐emulsified films from biomaterials, on the other hand, are renewable and biodegradable, making them promising packaging alternatives. The development of bioactive wax‐emulsified films (BWEFs) with antimicrobial and antioxidant properties has been a topic of extensive research. In this review, we provide an overview of wax emulsification, BWEF processing, and applications. BWEF contains several bioactive agents such as tannins, flavonoids, phenolic acids, and carotenes. The addition of emulsified wax and active agents to films not only enhances their antimicrobial and antioxidant properties but also reduces their hydrophilicity. Other reagents have been added to BWEF partially to increase hydrophobicity and mainly to improve mechanical properties. BWEFs prolong food shelf life, monitor wound healing, and control drug delivery. We have identified some research challenges that need to be solved to make BWEFs industrially attractive. [ABSTRACT FROM AUTHOR]

Pyrolysis of waste plastics can produce a product mixture with a high concentration of olefins (>50 wt%). The olefins, as building blocks in the petroleum industry, are potential precursors for valuable commodity chemicals with higher values (>$2000 per ton). In this work, we produce aldehydes by hydroformylation of the olefins present in pyrolysis oil from colored post-consumer recycled high-density polyethylene (PCR-HDPE). The obtained aldehydes in the oil are then converted into aliphatic amines via reductive amination with a Ru/C catalyst. The aminated oil was characterized by multiple analytical chemistry techniques including elemental analysis, nuclear magnetic resonance spectroscopy, high-resolution liquid chromatography-mass spectrometry, and gas chromatography-mass spectrometry with a Polyarc flame ionization detector. The concentration of metals in the PCR-HDPE and oil changes during the tandem processes, showing limited effects of these elements (e.g., Al, Ca, Fe, Mg, Ti, Zn) on hydroformylation and reductive amination. Additionally, we demonstrated that reductive amination of aldehydes with varied carbon numbers and branching properties can be achieved in the presence of a complex mixture, including paraffins and aromatics. The results indicate that waste plastics have the potential to serve as a renewable source for mono and di aliphatic amines, thereby diminishing reliance on fossil feedstocks as the current primary amine source. [ABSTRACT FROM AUTHOR]

Over 79 % of 6.3 billion tonnes of plastics produced from 1950 to 2015 have been disposed in landfills or found their way to the oceans, where they will reside for up to hundreds of years before being decomposed bringing upon significant dangers to our health and ecosystems. Plastic photoreforming offers an appealing alternative by using solar energy and water to transform plastic waste into value‐added chemical commodities, while simultaneously producing green hydrogen via the hydrogen evolution reaction. This review aims to provide an overview of the underlying principles of emerging plastic photoreforming technologies, highlight the challenges associated with experimental protocols and performance assessments, discuss recent global breakthroughs on the photoreforming of plastics, and propose perspectives for future research. A critical assessment of current plastic photoreforming studies shows a lack of standardised conditions, hindering comparison amongst photocatalyst performance. Guidelines to establish a more accurate evaluation of materials and systems are proposed, with the aim to facilitate the translation of promising fundamental discovery in photocatalysts design. [ABSTRACT FROM AUTHOR]

Highlights Poly(butylene adipate‐co‐terephthalate) (PBAT) is popular because of its low cost, biodegradability, good processing properties, flexibility, and mechanical features. In this study, we explore the potential of PBAT‐based bioplastics by adding AgVO3 nanorods with PBAT to reduce costs. We produced nanocomposite films of PBAT reinforced with 1, 3, and 5 wt% of AgVO3 nanorods using solvent casting. The inclusion of AgVO3 in the structure of PBAT was investigated through Fourier transform infrared spectroscopy, x‐ray diffraction, and scanning electron microscopy. The nanocomposite films demonstrate excellent properties, surpassing those of single‐component blends, enhancing mechanical properties, and improving the barrier properties of nanocomposite films. The water vapor transmission rate of AgVO3 reinforced (5 wt%) nanocomposite films improved by 42.45% compared to pure PBAT films. The tensile strength of the PBA‐3 film was 37.19 MPa, exhibiting higher strength than the films produced from clean PBAT (19.73 MPa). The AgVO3‐reinforced films demonstrated increased resistance to moisture and water, as indicated by their higher water contact angle values (88.04°). Food‐borne bacteria like Staphylococcus aureus and Escherichia coli have been stable to the antibacterial activity of the nanocomposites on the addition of AgVO3.The potential applications of these nanocomposite films in food packaging are promising, offering a sustainable and effective solution to food preservation. The AgVO3‐filled poly(butylene adipate‐co‐terephthalate) (PBAT) nanocomposite films exhibit superior mechanical, barrier, and resistance to moisture and water compared to neat PBAT films. The water vapor transmission rate of the film is significantly enhanced, with a 42.45% enhancement in films reinforced with 5 wt% AgVO3. AgVO3‐filled PBAT nanocomposites demonstrate effective antibacterial activity against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Large amounts of plastic waste are daily generated, becoming a global issue that needs to be addressed. Thus, new recycling alternatives have been explored, such as the depolymerization of poly(ethylene terephthalate) waste (wPET). These reactions can lead to the formation of oligomers and monomers, which can then be employed in new synthetic processes. The aim of this work is to use the products of the chemical recycling of wPET on the synthesis of hydrogels and evaluate the capacity of these materials to adsorb dyes aiming a wastewater treatment. The depolymerizations were done through glycerolysis reactions catalyzed by zinc (II) acetate under microwave radiation. Afterwards, the obtained oil was crosslinked with citric acid (CA) under tin (II) chloride catalysis to obtain the hydrogels. The water uptake capacity of the hydrogels ranged from 310% to 1442%, depending on the CA content. When placed in an indigo carmine solution, the hydrogels showed high adsorption capacity, removing up to 97% of the dye. The kinetic study revealed a physicochemical mechanism for the removal process, corroborated by Temkin isotherms. These results indicate that the chemical recycling of PET via glycerolysis is a viable alternative for producing hydrogels, reducing plastic waste while creating new tools for wastewater treatment. [ABSTRACT FROM AUTHOR]

Poly(butylene‐adipate‐co‐terephthalate) (PBAT) is recognized for its advantages as a biodegradable thermoplastic polyester. However, its application is often limited due to low strength and poor processability. In contrast, poly(4‐hydroxybutyrate) (P4HB) emerges as a fully biodegradable polyester characterized by high strength, excellent toughness, and facile processing. In this study, P4HB was employed to reinforce PBAT, and glycidyl methacrylate grafted onto poly(4‐hydroxybutyrate) (P4HB‐g‐GMA) was introduced as an effective compatibilizer to address their inherent incompatibility. The study explored the influence of P4HB‐g‐GMA content on the mechanical, thermal, morphological, and rheological properties of the blends. The findings revealed that P4HB‐g‐GMA significantly enhanced the compatibility, mechanical properties, and melt strength of PBAT/P4HB blends. Furthermore, various PBAT/P4HB foams were prepared through a batch foaming process, employing supercritical CO2 as a physical foaming agent. The volume expansion ratio and cell size of PBAT/P4HB foams increased with higher levels of the compatibilizer. [ABSTRACT FROM AUTHOR]

Polymeric methylene diphenyl isocyanate (pMDI) was used as a reactive compatibilizer to improve the mechanical properties of the PBAT/EVOH blend. Initially, pMDI was blended with pure polymers. Adding pMDI led to a 10‐fold rise in the viscosity of PBAT/pMDI compared to pure PBAT, with an enhancement in tensile properties, attributed to pMDI's chain‐extending effect in the PBAT phase. Conversely, a reduction in the elongation at the break of EVOH/pMDI indicated a cross‐linking role for pMDI in the EVOH phase. Notably, the blend with 1 wt% of pMDI showed a high tensile strength of 38 MPa by route II, much above 13.5 MPa for the one prepared by route I, and 14 MPa for the blank PBAT/EVOH blend without pMDI. Fourier transform infrared (FTIR) spectra, FE‐SEM images, and dynamic mechanical thermal analysis (DMTA) results confirmed the occurrence of effective reactions in route II. Modification of the blend with pMDI decreased the crystallinity of EVOH, the size of EVOH droplets, and the oxygen transmission rate (OTR) of the blends. However, an increase in the pMDI content above 0.5 wt% decreased OTR. Therefore, the modified blends of PBAT/EVOH with pMDI can be used as an efficient compatibilizer or adhesive layer in PBAT/EVOH blends or multilayer films for agricultural or food packaging applications. [ABSTRACT FROM AUTHOR]

The prevalent use of unsustainable polymers in current X‐ray scintillators poses a significant environmental concern. The advancement of biodegradable X‐ray scintillators holds promise in mitigating escalating environmental issues tied to electronic or medical waste and carbon footprints. Herein, a biodegradable and flexible X‐ray scintillation film is presented employing lead‐free 0D Cs3Cu2I5 perovskite nanoparticles integrated into densified‐delignified wood (Cs3Cu2I5@D‐Wood). The Cs3Cu2I5@D‐Wood film demonstrates precise and detailed X‐ray imaging capabilities, achieving a high spatial resolution of 10 line pairs per millimeter (lp·mm−1). To minimize the environmental impact associated with disposal, metal and halide ions (e.g., Cs+, Cu+, I−) from Cs3Cu2I5@D‐Wood can be easily retrieved by a simple solvent extraction process. The approach showcases the potential of biodegradable wood‐based X‐ray scintillation screens as alternatives to conventional, plastic‐based screens. This offers a significant contribution to environmental sustainability by reducing electronic or medical waste. [ABSTRACT FROM AUTHOR]

In recent years, there has been increasing interest in developing novel materials based on natural biopolymers as a renewable alternative to petroleum-based plastics. The availability of proteins derived from agricultural by-products, along with their favourable properties, has fostered a renewed interest in protein-based materials, promoting research in innovative technologies. In this study, we propose the use of rapeseed protein-rich meal as the main ingredient for the preparation of novel sustainable materials combining excellent environmental properties such as biodegradability and renewability. The application of sustainable products in the present high-tech society requires the modification of the basic native properties of these natural compounds. The original route proposed in this paper consists of preparation via the compression moulding of flexible biomaterials stabilized by crosslinkers/chain extenders. An investigation of the effects of different denaturing and disulfide bond reducing agents, crosslinkers, and preparation conditions on the material mechanical behaviour demonstrated that the novel materials have appreciable strength and stiffness. The results show the potential of utilizing full meal from vegetable by-products to prepare protein-based materials with guaranteed ecofriendly characteristics and mechanical properties adequate for specific structural applications. [ABSTRACT FROM AUTHOR]

Petroleum‐based plastics levy significant environmental and economic costs that can be alleviated with sustainably sourced, biodegradable, and bio‐based polymers such as polyhydroxyalkanoates (PHAs). However, industrial‐scale production of PHAs faces barriers stemming from insufficient product yields and high costs. To address these challenges, we must look beyond the current suite of microbes for PHA production and investigate non‐model organisms with versatile metabolisms. In that vein, we assessed PHA production by the photosynthetic purple non‐sulfur bacteria (PNSB) Rhodomicrobium vannielii and Rhodomicrobium udaipurense. We show that both species accumulate PHA across photo‐heterotrophic, photo‐hydrogenotrophic, photo‐ferrotrophic, and photo‐electrotrophic growth conditions, with either ammonium chloride (NH4Cl) or dinitrogen gas (N2) as nitrogen sources. Our data indicate that nitrogen source plays a significant role in dictating PHA synthesis, with N2 fixation promoting PHA production during photoheterotrophy and photoelectrotrophy but inhibiting production during photohydrogenotrophy and photoferrotrophy. We observed the highest PHA titres (up to 44.08 mg/L, or 43.61% cell dry weight) when cells were grown photoheterotrophically on sodium butyrate with N2, while production was at its lowest during photoelectrotrophy (as low as 0.04 mg/L, or 0.16% cell dry weight). We also find that photohydrogenotrophically grown cells supplemented with NH4Cl exhibit the highest electron yields – up to 58.89% – while photoheterotrophy demonstrated the lowest (0.27%–1.39%). Finally, we highlight superior electron conversion and PHA production compared to a related PNSB, Rhodopseudomonas palustris TIE‐1. This study illustrates the value of studying non‐model organisms like Rhodomicrobium for sustainable PHA production and indicates future directions for exploring PNSB metabolisms. [ABSTRACT FROM AUTHOR]

Microplastics have been recently detected in many environmental media and living organisms, yet their transfer and toxicity to humans are poorly known. Here, we review microplastic transfer in the food chain with focus on microplastic pollution sources, methods to analyze microplastics in food, health impact of food-related microplastic exposure, and remediation of microplastic pollution. Microplastic pollution sources include seafood, food additives, packaging materials, and agricultural and industrial products. Remediation techniques comprise the use of microbial enzymes and biofilms. Microplastic detection methods in food rely on separation and quantification by optical detection, scanning electron micrography, and Fourier-transform infrared spectroscopy. Human health impact following microplastic ingestion include cancers, organ and respiration damage, and reproductive impairments. Overall, microplastic toxicity is mainly due to their ability to enter the metabolism, adsorption into the circulatory system for translocation, and difficulty, if not impossibility, of excretion. [ABSTRACT FROM AUTHOR]

Bioplastics appear as an alternative to fossil fuel-derived plastics because bioplastics are carbon neutral and often biodegradable, thus potentially solving the issues of plastic pollution and climate change. In particular, polylactic acid is a substitute for traditional petrochemical-based polymers. Here, we review polylactic acid production with focus on surface modification and integration of bioactive compounds. Surface can be modified by chemical treatment, photografting, surface entrapment, plasma treatment, and coating. Bioactive compounds can be incorporated by encapsulation, impregnation, melt blending, solvent casting, electrospinning, and in situ polymerization. Biomedical and packaging applications are discussed. [ABSTRACT FROM AUTHOR]

Biopolymers are highly desirable alternatives to petrochemical-based plastics owing to their biodegradable nature. The production of bioplastics, such as polyhydroxyalkanoates (PHAs), has been widely reported using various bacterial cultures with substrates ranging from pure to biowaste-derived sugars. However, large-scale production and economic feasibility are major limiting factors. Now, using algal biomass for PHA production offers a potential solution to these challenges with a significant environmental benefit. Algae, with their unique ability to utilize carbon dioxide as a greenhouse gas (GHG) and wastewater as feed for growth, can produce value-added products in the process and, thereby, play a crucial role in promoting environmental sustainability. The sugar recovery efficiency from algal biomass is highly variable depending on pretreatment procedures due to inherent compositional variability among their cell walls. Additionally, the yields, composition, and properties of synthesized PHA vary significantly among various microbial PHA producers from algal-derived sugars. Therefore, the microalgal biomass pretreatments and synthesis of PHA copolymers still require considerable investigation to develop an efficient commercial-scale process. This review provides an overview of the microbial potential for PHA production from algal biomass and discusses strategies to enhance PHA production and its properties, focusing on managing GHGs and promoting a sustainable future. [ABSTRACT FROM AUTHOR]

Plastics have accumulated in open environments, such as oceans, rivers, and land, for centuries, but their effect has been of concern for only decades. Plastic pollution is a global challenge at the forefront of public awareness worldwide due to its negative effects on ecological systems, animals, human health, and national economies. Therefore, interest has increased regarding specific circular economies for the development of plastic production and the investigation of green technologies for plastic degradation after use on an appropriate timescale. Moreover, biodegradable plastics have been found to contain potential new hazards compared with conventional plastics due to the physicochemical properties of the polymers involved. Recently, plastic biodegradation was defined as microbial conversion using functional microorganisms and their enzymatic systems. This is a promising strategy for depolymerizing organic components into carbon dioxide, methane, water, new biomass, and other higher value bioproducts under both oxic and anoxic conditions. This study reviews microplastic pollution, the negative consequences of plastic use, and the current technologies used for plastic degradation and biodegradation mediated by microorganisms with their drawbacks; in particular, the important and questionable role of extremophilic multi-enzyme-producing bacteria in synergistic systems of plastic decomposition is discussed. This study emphasizes the key points for enhancing the plastic degradation process using extremophiles, such as cell hydrophobicity, amyloid protein, and other relevant factors. Bioprospecting for novel mechanisms with unknown information about the bioproducts produced during the plastic degradation process is also mentioned in this review with the significant goals of CO2 evolution and increasing H2/CH4 production in the future. Based on the potential factors that were analyzed, there may be new ideas for in vitro isolation techniques for unculturable/multiple-enzyme-producing bacteria and extremophiles from various polluted environments. [ABSTRACT FROM AUTHOR]

The fabrication of ultra-tough biodegradable nanocomposite films with antibacterial activity and antioxidant properties remains a huge challenge. Herein, we developed a super-tough antibacterial biodegradable poly(vinyl alcohol) (PVA) nanocomposite film by simply introducing highly effective antibacterial agent PDA@LS-Ag into PVA matrix. The antibacterial agent PDA@LS-Ag was synthesized from the mussel-inspired polydopamine (PDA) and green biomass sodium lignosulfonate (LS) via a facile microwave-assisted reduction strategy, in which PDA played the role of reducing agent and LS performed as the dispersant. The tensile strength of the PVA nanocomposite film with 5 wt% addition of PDA@LS-Ag reached up to 131.7 MPa, which was far higher than most of engineering plastics. The excellent mechanical performance was resulted from the synergistic effect of the unique nanoscale phase-separation structure and the dense hydrogen bonds between the PDA@LS-Ag nanoparticles and PVA matrix. Owing to the existence of silver nanoparticles and rich phenolic hydroxyl groups, the PDA@LS-Ag nanoparticles also endued the composite film with good antibacterial activity, outstanding antioxidant activity, and UV-shielding properties. As the biomass LS, PDA, and the PVA matrix are all biodegradable, this work provides a feasible way for preparing highly strong and super-tough biodegradable nanocomposite films with antibacterial and antioxidant properties. [ABSTRACT FROM AUTHOR]

The utilization of biodegradable hydrogels based on natural polysaccharides in the agricultural and biomedical sectors is anticipated to be a growing field of interest. Due to increasing environmental pollution, the current global goal is to synthesize sustainable materials based on natural polysaccharides to conserve natural resources for the future. In this study, we synthesized an amla-based hydrogel, denoted as AL-g-poly(MAA), using the graft-free radical polymerization method. Methacrylic acid (MAA) was employed as the monomer, N,N′-methylenebisacrylamide (MBA) served as the crosslinker, and ammonium persulfate (APS) acted as the initiator. The synthesized hydrogel, AL-g-poly(MAA), underwent optimization by adjusting seven parameters: initiator, solvent, time, monomer, power, pH, and crosslinker, to achieve the highest swelling percentage. The optimized values were as follows: solvent: 10 ml, time: 150 s, monomer: 0.039 mol/L, power: 60%, pH: 7, and crosslinker: 0.0648 mol/L. The cross-linking process was confirmed through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) techniques. The swelling behavior of the synthesized hydrogels was determined in saline solutions with varying ionic strengths and concentrations, revealing maximum swelling in solutions with lower ionic strengths and concentrations. Additionally, the density and porosity of the hydrogels were examined. The biodegradability of AL-g-poly(MAA) was tested through soil burial and vermicomposting experiments, demonstrating its significant potential for agriculture applications. Furthermore, both the backbone and the synthesized hydrogel were evaluated for antibacterial activity against four bacterial strains (Burkholderia gladioli, Klebsiella pneumoniae, Staphylococcus aureus, and Bacillus cereus), revealing strong potential as an antimicrobial agent and therefore having applications in the biomedical field. The mechanism underlying the inhibitory effect of synthesized AL-g-poly(MAA) hydrogel on bacterial cell membranes is also discussed. [ABSTRACT FROM AUTHOR]

Starch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix. [ABSTRACT FROM AUTHOR]

Context: Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable plastic. It was introduced to the plastics market in 1998 and since then has been widely used around the world. The main idea of this research is to perform quantum chemical calculations to study the potential toxicity of PBAT and its degradation products. We analyzed the electron transfer capacity to determine its potential toxicity. We found that biodegradable products formed with benzene rings are as good electron acceptors as PBAT and OOH•. Our results indicate that the biodegradation products are potentially as toxic as PBAT. This might explain why biodegradation products alter the photosynthetic system of plants and inhibit their growth. From this and other previous investigations, we can think that biodegradable plastics could represent a potential environmental risk. Methods: All DFT computations were performed using the Gaussian16 at M062x/6–311 + g(2d,p) level of theory without symmetry constraints. Electro-donating (ω-) and electro-accepting (ω +) powers were used as response functions. [ABSTRACT FROM AUTHOR]

Nowadays, there is a rising interest in the packaging industry regarding more environment‐friendly (i.e. biodegradable and/or compostable) polymer‐based solutions, especially for film blowing applications. However, replacing traditional, fossil resource‐based polymers typically used for such applications is not an easy task, since the more environment‐friendly solutions must have adequate features in terms of processability and final properties. In this work, three commercial biodegradable (and, at least partially, biobased) polymers were investigated by a preliminary rheological and mechanical analysis, in order to perform film manufacturing experiments in laboratory equipment. Furthermore, oxygen and water vapour barrier properties were studied by permeability measurements. The investigation was ultimately performed on films produced in industrial equipment, and the results were compared to those for a typical, standard polypropylene (PP) film used in flexible packaging applications. It was found that the mechanical properties were adequate (in some cases, even up to 25–30% higher than for the PP counterpart), as well as oxygen permeability. On the other hand, water permeability was significantly higher than that of PP films, and this should be taken into account in cases where high water vapour barrier properties are required. © 2024 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Microplastics and heavy metals are two different classes of pollutants that are often present in aquatic systems. However, the interaction between these two pollutants is poorly understood in freshwater systems. This research has examined the sorption of cadmium(II) ions onto polyethylene microplastic (PEMP) under freshwater conditions. The scanning electron microscope, X-ray diffraction, and Fourier transform infrared analyses confirmed the existence of different functional groups and the porous nature of the PEMP surface. The influences of physicochemical parameters such as the solution pH, contact time, and initial Cd(II) concentration have been examined. The Langmuir isotherm predicted the Cd(II) sorption capacity by PEMP at pH 5 as 1.37 mg/g. Several isotherm models were utilized, including the Freundlich, Langmuir, and Sips models. The results confirmed that the Sips model has been more appropriate for Cd(II)-PEMP isotherm based on percentage errors and correlation coefficient values. Furthermore, the pseudo-first kinetic model fitted Cd(II)-PEMP more accurately than the pseudo-second kinetic equation. Desorption experiments were conducted to release Cd(II) ions from Cd(II)-bearing PEMP using different chemical agents. The findings showed that using 0.01 M nitric acid resulted in a desorption efficiency exceeding 99.8%. This demonstrates that microplastics loaded with Cd(II) may release Cd(II) ions in highly acidic environments, potentially allowing for the uptake of Cd(II) ions by aquatic organisms in their digestive tracts. [ABSTRACT FROM AUTHOR]

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Approximately 99% of plastics produced worldwide were produced by the petrochemical industry in 2019 and it is predicted that plastic consumption may double between 2023 and 2050. The use of biodegradable bioplastics represents an alternative solution to petroleum-based plastics. However, the production cost of biopolymers hinders their real-world use. The use of waste biomass as a primary carbon source for biopolymers may enable a cost-effective production of bioplastics whilst providing a solution to waste management towards a carbon–neutral and circular plastics economy. Here, we report for the first time the production of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with a controlled molar ratio of 2:1 3-hydroxybutyrate:3-hydroxvalerate (3HB:3HV) through an integrated pre-treatment and fermentation process followed by alkaline digestion of cassava peel waste, a renewable low-cost substrate, through Cupriavidus necator biotransformation. PHBV was subsequently melt blended with a biodegradable polymer, polycaprolactone (PCL), whereby the 30:70 (mol%) PHBV:PCL blend exhibited an excellent balance of mechanical properties and higher degradation temperatures than PHBV alone, thus providing enhanced stability and controllable properties. This work represents a potential environmental solution to waste management that can benefit cassava processing industries (or other crop processing industries) whilst developing new bioplastic materials that can be applied, for example, to packaging and biomedical engineering. [ABSTRACT FROM AUTHOR]