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Bioplastics that are generated from renewable sources have been regarded as an alternative to conventional plastics. Polylactic acid (PLA) is one of the mostly produced bioplastics because of its long shelf life for various applications. Even though bioplastics have drawn attention recently, their ultimate fate in landfills is still unknown. In this study, a standardized laboratory-scale lysimeter experiment was performed for the simulation of landfill conditions in order to evaluate the biodegradability of PLA during municipal solid waste stabilization. The reactors were loaded with municipal solid waste (MSW) taken from an operating landfill, certified PLA cups, and seed sludge. Various phases of landfill stabilization were simulated; hence, the reactors were operated under aerobic, semi-aerobic, and anaerobic conditions, respectively. Throughout the operation, both leachate and biogas generation in the reactors were regularly monitored. At the end of each phase, bioplastic cups were removed from the reactors, gently cleaned, weighed, and examined under a scanning electron microscope (SEM). The experimental results indicated that bioplastics did not undergo significant biodegradation during the first two stabilization phases (aerobic and semi-aerobic). On the other hand, it was observed that the cups were much softer and whiter at the end of the anaerobic phase. The weight of cups decreased by 12.8% on average, and their surfaces were prominently damaged after the completion of the last phase indicating the potential signs of biodegradation. [ABSTRACT FROM AUTHOR]

The problem of environmental pollution by plastics is global in nature and needs to be addressed as soon as possible. Realization of the importance of this problem contributed to the study of degradation and biodegradation of synthetic polymers. It turned out that the driving force of plastic fragmentation along with abiotic factors can be biotic. Based on the above, we investigated the in vitro biodegradation of polypropylene (PP) fragments in digestive gland homogenates and crystalline styles of the bivalve mollusk Mizuhopecten yessoensis. Fourier transform infrared spectroscopy showed changes in the chemical composition of functional groups on the plastic surface. Enzyme complexes of crystalline styles enhanced the biodegradation of PP fragments to a larger extent than did digestive glands. The results obtained using M. yessoensis as an example suggest that marine phytophagous filter-feeding invertebrates may accelerate the biodegradation of synthetic polymers. The study provides a basis for rethinking the nature of relationships between marine invertebrates and microplastic polluting the marine environment. [ABSTRACT FROM AUTHOR]

Annual polymer waste generated in Malaysia has increased significantly to more than 1 million tonnes. The prolonged degradation periods required by diverse industrial polymer waste streams are a matter of significant concern, with some taking up to 1000 years to fully degrade. Pursuing a similar environmental concern, the use of bakau piles as supports for lightweight structures in Sarawak, including drainage systems, roads, sewerage, and other water-related structures, has become a matter of concern due to the deforestation of mangrove forests. Both bakau deforestation and polymer waste issues are significant environmental and global concerns. The idea of mitigating mangrove degradation and the non-biodegradable nature of polymer waste has led to the conceptualization of an alternative solution whereby recyclable thermoplastic polymer piles are utilized to supplant bakau piles in providing support for lightweight structures during civil engineering construction projects. Therefore, the study of polymer piles is conducted to examine their mechanical properties in the form of virgin (V) and recycled (R) thermoplastic polymers. In this study, high-density polyethylene (HDPE), polypropylene (PP), and polyvinyl chloride (PVC) are considered, and the possibility of being utilized in pile application has been discussed. Based on the results, all virgin types of thermoplastic polymers (HDPE, PP, and PVC), 50%V:50%R for PP, PP(R), and PVC(R), respectively, exceed the bakau ultimate tensile strength. Thermoplastic polymer piles showed great potential to be the substitution for bakau piles to serve in the construction industry, with the recorded experimental tensile and compressive strength tests. [ABSTRACT FROM AUTHOR]

The global urgency surrounding plastic waste-induced pollution has ignited significant interest in the biodegradable packaging sector, leading to a dynamic and expanding realm of biodegradable research. Nonetheless, effectively incorporating active agents into packaging materials faces hurdles related to stability and durability. This study takes a momentous leap in this context by shedding light on the transformative potential of integrating clove oil in macro and nanoencapsulation forms into carrageenan-glycerol matrices. A highlight emerges in the remarkable enhancement achieved through nanoencapsulation--a technique that substantially bolsters packaging performance. This improvement is evident in a noteworthy reduction of water vapor transmission, plummeting from an initial 11.011 to merely 6.903 g.mm m-2 d-1. This nearly fifty percent reduction underscores the efficacy of nanoencapsulation in enhancing packaging attributes. Concurrently, the study delves into the nuances of the carrageenan-clove oil composition, unveiling its profound influence on packaging strength, by systematically increasing the carrageenan-clove oil ratio, packaging strength triples, soaring from an initial 0.421 to an impressive 1.434 N/mm. Concerns of heightened brittleness due to increased carrageenan content are firmly dispelled, substantiated by consistent tensile stress values. In summary, this comprehensive investigation advances the core attributes of biodegradable packaging and presents a strategic and adept approach to address the intricate sustainability issues. Through adept manipulation of clove oil integration, the study pioneers the evolution of biodegradable packaging materials, paving the way for a more sustainable and environmentally conscious future. [ABSTRACT FROM AUTHOR]

Plastics have become the preferred materials for use due to their barrier properties and strength. This study aimed to determine the wettability, contact angle, and polymer chemical properties by comparing pure and mixed starch bioplastics with different plasticizers. Gamma radiation and electron beams are used in industrial applications. Gamma radiation is used because it is extreme in penetration, and Cobalt-60 is often used for sterilization. Most bioplastics with citric acid as the plasticizer produced a high contact angle and achieved hydrophobicity. Materials used in constant amounts are distilled water and glycerol. Others manipulate variables based on the presence of starch, such as corn, potato, rice, or a mixture of the two starches. The Samples were characterized using tensile and elongation tests, water contact angle, Fourier Transform Infrared (FTIR) analysis, topography using Atomic Force Microscopy (AFM), moisture content tests, and biodegradability tests. Potato and corn-rice bioplastics have low moisture contents. Meanwhile, the corn bioplastic degraded faster at 80.17%. Potato rice with citric acid lead tensile test with 4.095 MPa. However, potatoes with sorbitol lead with 34.57% for the elongation case. FTIR analysis identified the functional groups of the normal polymeric OH and C-H stretching of the methylene group at wavenumbers of 3280–3300 cm-1 and 2920–2935 cm-1, respectively. According to FTIR analysis, corn rice with the presence of citric acid bioplastic was chosen to undergo AFM to survey roughness in case to determine whether crosslinking might happen; the different average roughness between pre-irradiated and post-irradiated samples is 8.82 nm. Based on these findings, bioplastics may contribute tremendous benefits, especially in smart packaging applications. [ABSTRACT FROM AUTHOR]

Plastic waste has become a global environmental problem as it is difficult to decompose and harms the environment. The alternative solution to overcome this problem is to produce biodegradable plastics made from renewable materials. Cassava peel waste contains starch that can form a thin film but has poor mechanical properties. Therefore, it is necessary to include additional substances to enhance its strength. Carrageenan is a substance that can improve bioplastic mechanical properties. This study aims to determine the characteristics of bioplastic made from cassava peel waste starch and carrageenan formulation. Nine formulations were tested in this study using the randomized complete block design factorial with the two factors of cassava peel starch (S) and carrageenan (C) concentrations, both at three levels and carried out under three replications. Bioplastics characteristics are observed in thickness, swelling, biodegradation, tensile strength, elongation, and elasticity. The formulation S2C1 (starch 20%; carrageenan 5%) produced the bioplastic with the best mechanical properties, including a tensile strength of 1.1 MPa, elongation of 1.33%, and elasticity of 0.87. Meanwhile, the formulation S3C1 (starch 30%; carrageenan 5%) had the best results for swelling, thickness, and biodegradability, with a swelling value of 57.79%, thickness of 0.36mm, and 11-day biodegradability. [ABSTRACT FROM AUTHOR]

Biofilm is an environmentally friendly plastic that is easily biodegradable. However, not all biodegradable plastics have the desired properties for packaging because they are made from renewable natural materials. The biofilm in this study was made from renewable natural raw materials that had never been used before, namely taro starch and duck bone gelatin. Mixing the two materials improve their physical properties and biodegradabilily This study was to to investigate the effect of adding duck bone gelatin 0%, 5%, 15%, 25% and 35% on physicochemical properties, namely color, oxygen permeability, and metal content (Pb and Cd) as well as biodegradability of biofilms. The method used in this research was solution casting. The results obtained from the color parameter with the highest lightness (L) value were produced in the addition of 15% of 85.26, for the highest value of color a was produced in the addition of 0%, namely 0.94, and the value of color b with the addition of 35% resulted in the highest color value of 1.67. The highest percentage of biodegradability was produced on day 14 with the addition of 35% duck bone gelatin in compost soil to produce a percentage of 100%, while for barren soil the yield was 54.54%-66.66%. The content of Cd and Pb in the biofilm is below the SNI limit. Biofilm is impermeable which can be used as food packaging. [ABSTRACT FROM AUTHOR]

Polyhydroxy butyrate (PHB) is one of the best environment-friendly bioplastic alternatives for petroleum-based plastic due to its biodegradability. However, it has less commercial popularity owing to the high cost of downstream processing that involves repeated centrifugation and the use of costly harmful solvents, as well as a labor-intensive process. Hydrodynamic Cavitation (HC) offers easy and simple mechanisms for downstream processing. Also, biopolymer extracted for haloarchea show an advantage of least contamination under the halophilic condition on an industrial level. In this paper, a haloarchaeal consortium producing biopolymer isolated from commercial rock salt has been subjected to HC as well as distilled water lysis. A maximum of 23 g.L-1 PHB was extracted in 40 min run with 50 passes and 0.10 cavitation number at 3.9 bar pressure. The extracted biopolymer was characterized and was found to be PHB. Comparative analysis shows that HC results in a substantial reduction in the downstream processing time. Moreover, it has double the efficiency of PHB extraction as compared to the distilled water lysis method. This paper reports the HC process as a technocommercial alternative to industrial PHB extraction. [ABSTRACT FROM AUTHOR]

The present study focuses on how microalgae protein biomass, such as spirulina (SP), can be used to create thermoplastic blends and algal‐based bioplastics. Algal bioplastics can be customized for a variety of material properties and applications while remaining biodegradable. In this work, the casting approach has been performed to create spirulina‐starch‐glycerol composite films by adding SP to plasticized starch films. The characteristics and properties of the composite films were inspected by Fourier transform infrared (FTIR), scanning electron microscope (SEM), tensile strength, antimicrobial activity, and biodegradation analysis. The composite film with 3% SP was found to have the best combination of mechanical and chemical properties, and additional SP causes the mechanical properties to degrade. The results demonstrated that bio‐composites prepared by plasticized starch and containing SP could be promising in the development of new environmentally friendly bio‐nanocomposites for interesting applications in food packaging. [ABSTRACT FROM AUTHOR]

Currently, the packaging material is composed of fossil fuel-based plastics, which are non-biodegradable. Therefore, the biodegradable coating material developed from cellulose can be explored for applications like packaging, cutlery, bowls, straws, etc. The aim of the present study was to develop an agro-waste-based sustainable coating material using a waste-to-wealth approach. The study focused on transforming cellulose and cellulose nanofibre (CNF) derived from rice straw into biodegradable polymeric coatings. The cellulose and CNF were extracted from the rice straw using the alkali method and blended with gelatin, agar, and varied glycerol concentrations to initiate the study. Four polymeric coating variants were developed. Thus, the coating named NCG-2.5, incorporated with 1.2 g CNF, 2.5 ml glycerol, 1.15 g gelatin, and 0.55 g agar, exhibited significant improvements in properties as compared to the other samples. The polymeric coatings were characterized for their surface morphology, roughness, solubility, and physico-chemical properties using FTIR spectroscopy and TGA analysis. The NCG-2.5 exhibited the best potential in terms of promising coating and biodegradability properties, with 97% of weight loss within 7 days. Furthermore, the studies where the synthesized polymeric coating was applied to the surface of the banana proved a considerable delay in the enzymatic browning of the banana for up to 12 days. Thus, the study reflects the novel approach of value addition and utilization of waste agricultural resources for developing coating materials via a circular economy approach. [ABSTRACT FROM AUTHOR]

In the wake of escalating global concerns over the environmental impact of plastic pollution, there has been an unprecedented call for sustainable alternatives. The food-packaging industry, responsible for a staggering 40% of global plastic consumption, faces mounting challenges driven by environmental degradation and concerns about fossil fuel depletion. Motivated by these challenges, there is a growing interest in reducing reliance on traditional packaging and exploring eco-friendly solutions derived from renewable resources. Eco-efficient packaging, specifically derived from agricultural raw materials, emerges as a promising solution that aligns with ecological, economic, and social sustainability principles. Starch, abundant and versatile, emerges as a frontrunner among agricultural raw materials for biopolymers. Its inherent properties, including low cost, availability, biodegradability, and biocompatibility, make it a compelling choice. Starch-based bioplastics, with their potential to replace synthetic primary packaging materials, have gained traction due to their satisfactory mechanical and barrier properties. This review delves into the realm of starch-based films and coatings for food applications. It explores fundamental properties, advantages, and limitations, offering insights into potential improvements through various treatments or additive combinations. As technological advances drive the popularity of biodegradable starch-based packaging, this review aims to contribute to the ongoing discourse, providing a comprehensive overview and paving the way for more functional and widely applicable products in the ever-evolving landscape of sustainable packaging. [ABSTRACT FROM AUTHOR]

This study aimed to assess microplastics (MPs) in the digestive glands of Mytilus galloprovincialis mussels. Mussels were collected from pristine, aquaculture, and port areas of the northern Adriatic Sea (Slovenia and Croatia coastline). MPs were detected using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The characterized MPs were further categorized based on their shape, size, and color. The highest number of 32.85 ± 27.98 MPs per mussel digestive gland was found in the mussels sampled from the ACI marina Rovinj (Croatia). The predominant MPs found in the mussel digestive glands at all investigated locations belonged to the smallest analyzed category (5–10 μm in size) and exhibited spherical and fragment shapes. The most abundant MPs found in mussels by color were white particles. MPs were found in both wild and farmed mussels and, hence, the results point out that the abundance of microplastic pollution is omnipresent along the coastal waters of the northern Adriatic Sea. [ABSTRACT FROM AUTHOR]

The inherent weakness in the deformation resistance of plastic centrifugal pumps makes them prone to vibrations. This study explores the impact of flow components on the vibrations of such pumps. Utilizing the given parameters, the primary structural parameters of the plastic centrifugal pump were calculated. The study focused on the torsional vibrations within the pump shaft transmission system, employing a silicone oil damper for vibration mitigation. A dual-mass forced torsion vibration model was developed for the pump shaft transmission system with the added damper. The optimal damping coefficient for this damper was determined, and its structural design was completed, including the creation of three-dimensional models and two-dimensional part drawings. Utilizing a ZT-3 type rotor test bench, a mathematical model correlating centrifugal pump speed with deflection was developed, and the effectiveness of various polynomials was assessed. The analysis showed that the optimal damping value for the silicone oil damper is 0.22. Compared to the system without the damper, the vibration frequency reduced by 10.45%, and the vibration amplitude decreased by 49.29%, demonstrating excellent vibration reduction effectiveness. [ABSTRACT FROM AUTHOR]

Given the growing importance of lab-on-a-chip in a number of fields, such as medical diagnosis or environmental analysis, the fact that the current fabrication process relies mainly on oil-based polymers raises an ecological concern. As an eco-responsible alternative, we presented, in this article, a manufacturing process for microfluidic devices from chitosan, a bio-sourced, biodegradable, and biocompatible polysaccharide. From chitosan powder, we produced thick and rigid films. To prevent their dissolution and reduce their swelling when in contact with aqueous solutions, we investigated a film neutralization step and characterized the mechanical and physical properties of the resulting films. On these neutralized chitosan films, we compared two micropatterning methods, i.e., hot embossing and mechanical micro-drilling, based on the resolution of microchannels from 100 µm to 1000 µm wide. Then, chitosan films with micro-drilled channels were bonded using a biocompatible dry photoresist on a glass slide or another neutralized chitosan film. Thanks to this protocol, the first functional chitosan microfluidic devices were prepared. While some steps of the fabrication process remain to be improved, these preliminary results pave the way toward a sustainable fabrication of lab-on-a-chip. [ABSTRACT FROM AUTHOR]

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In this study, we investigated the influence of γ-irradiation (0, 50, and 100 kGy) doses on the chemical and mechanical properties of biodegradable poly(hydroxybutyrate-valerate)/poly(caprolactone) (PHBV/PCL) polymer blends rich in low-molar-mass PCL, which were prepared using a co-rotating twin-screw extruder. In parallel, the density functional theory (DFT) and the time-dependent DFT (TD-DFT) methods were used together with a model containing four monomer units to provide an insight into the electronic structure, chemical bonds, and spectroscopic (such as Nuclear Magnetic Resonance (NMR) and Ultraviolet-visible (UV-vis)) properties of PHBV and PCL blend phases, which are critical for predicting and designing new materials with desired properties. We found that an increase in γ-irradiation doses caused splitting instead of crosslinks in the polymer chains, which led to evident deformation and an increase in tensile strength at break of 2.0 to 5.7 MPa for the PHBV/PCL blend. Further, this led to a decrease in crystallinity and proved the occurrence of a more favorable interaction between the blend phases. [ABSTRACT FROM AUTHOR]

Poor waste management and unsustainable institutional and individual behaviors, have led to the accumulation of plastic litter in many habitats worldwide. Assessment of plastic pollution in Kenyan marine environment was conducted focusing on the impact of banning the single-use plastic carrier bags in Kenya. The quantification, composition, and distribution of plastics were determined at nine (9) beaches along Kenyan coastline using standing stock method. A total of 750 plastic items were collected and categorized with only 47 pieces being single-use plastic carrier bags. A great number of plastics (n = 383), were identified by their original use, with packaging plastics being the most common (n = 155). Macroplastics were the overall dominant plastics at 76%, mesoplastics, 21% and microplastics, 3%, which were altogether dominated by low-density polyethylene (LDPE) at (46%), followed by polypropylene (PP), 30%; polyethylene tetraphthalate (PET), 9%; polyvinyl chloride (PVC), 8%; and polystyrene (PS), 7%. The absence of identifiable single-use plastic carrier bags in 6 out of 9 beaches signified the effectiveness of the ban in Kenya. Monitoring of trends and sources of plastic debris is encouraged to help enhance the science-policy linkage aimed at reducing marine plastic pollution. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) pose a threat to ecosystems due to their capacity to bind with toxic chemicals. While the occurrence of MPs in aquatic environmental matrices like water, sediments, and biota is well studied, their presence in the atmosphere remains less understood. This study aimed to determine the presence of airborne MPs and their characteristics through ground-based sampling in the coastal city of Kuala Nerus, Terengganu, Malaysia. Airborne MP samples were collected using passive sampling technique in December 2019. MPs were manually counted and identified using a stereomicroscope based on their colour and shape. The average deposition rate of airborne MPs during the sampling period was 5476 ± 3796 particles/m2/day, ranging from 576 to 15,562 particles/m2/day. Various colours such as transparent (38%), blue (25%), black (20%), red (13%), and others (4%) were observed. The predominant shape of airborne MPs was fibres (> 99%). The morphology structure of MPs observed using a scanning electron microscope (SEM) showed a cracked surface on MPs, suggesting weathering and irregular fragmentation. Further elemental analysis using energy dispersive X-ray spectroscopy (EDS) showed the presence of heavy metals such as aluminium (Al) and cadmium (Cd) on the surface of MPs, attributed to the adsorption capacities of MPs. Polymer types of airborne MPs were analysed using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), which revealed particles composed of polyester (PES), polyethylene (PE), and polypropylene (PP). The preliminary findings could provide additional information for further investigations of MPs, especially in the atmosphere, to better understand their sources and potential human exposure. [ABSTRACT FROM AUTHOR]

New biodegradable paper-based films are a hot research topic in the development of green agriculture. In this study, a black paper-based film coated with cooked tung oil with excellent mechanical properties, a hydrophobic surface, high heat transfer and strong weather resistance was prepared by spraying high-pigment carbon black solution on the surface of base paper. The results showed that the surface-solidified oil film had a rough structure produced via the brush coating process using cooked tung oil. The base film of the black paper had a given hydrophobic structure, and the contact angle reached 98.9°. Cooked tung oil permeates into the inside of the paper base, and after curing, it forms a multi-dimensional network film structure. The maximum tensile stress of the black paper base film is about 123% higher than that of the original paper base film. The coloring of carbon black gives the black paper base film a heat conduction effect, and the average heat transfer rate reaches 15.12 °C/s. Cooked tung oil is combined with the paper-based fiber high-toughness layer to form a stable system. The existence of a cured film improves the basic mechanics and hydrophobicity, and the resistance to ultraviolet radiation and hot air is greatly improved. This study provides a feasible scheme for the application of a black paper base film coated with cooked tung oil. [ABSTRACT FROM AUTHOR]

The escalating utilization of plastics in daily life has resulted in pervasive environmental pollution and consequent health hazards. The challenge of detecting and capturing microplastics, which are imperceptible to the naked eye, is exacerbated by their diminutive size, hydrophobic surface properties, and capacity to absorb organic compounds. This study focuses on the application of peptides, constituted of specific amino acid sequences, and microneedles for the rapid and selective identification of microplastics. Peptides, due to their smaller size and greater environmental stability compared with antibodies, emerge as a potent solution to overcome the limitations inherent in existing detection methodologies. To immobilize peptides onto microneedles, this study employed microneedles embedded with gold nanorods, augmenting them with sulfhydryl (SH) groups at the peptides' termini. The sensor developed through this methodology exhibited efficient peptide binding to the microneedle tips, thereby facilitating the capture of microplastics. Raman spectroscopy was employed for the detection of microplastics, with the results demonstrating successful attachment to the microneedles. This novel approach not only facilitates localized analysis but also presents a viable strategy for the detection of microplastics across diverse environmental settings. [ABSTRACT FROM AUTHOR]

Recently, the concept of a circular economy for carbon neutrality is emerging. In particular, waste plastics are one of the key wastes, and efforts are being made to recycle them as energy rather than dispose of them. Accordingly, the technology of producing and utilizing pyrolysis oil from waste plastics attracts attention. As it is an early stage of technology development, however, there are not many demonstrations and papers that analyze the technology broadly. The goal of this study is to propose building a circular economy on a university campus through waste plastic pyrolysis oil technology. To show its feasibility, waste plastic pyrolysis oil technology is analyzed comprehensively from economic, environmental, and policy perspectives using the scenario analysis technique on the university campus level. A methodology of the scenario analysis technique enables predicting the uncertainties. Since plastic pyrolysis oil technologies and carbon neutrality are accompanied by many uncertainties, this technique is expected to be an appropriate methodology for this study. First, the amount of pyrolysis oil production from waste plastics from the campus is estimated. Then, the cost and carbon emissions from waste plastics are estimated if the pyrolysis oil technology is used instead of the traditional waste disposal process. As a result, the total economic profits of up to 425,484,022 won/year (354,570.01 $/year) are expected when a circular economy is built using waste plastic pyrolysis oil. In addition, it is also confirmed that greenhouse gas (GHG) emissions can be reduced by up to 840,891 kgCO2eq/year. The waste plastic pyrolysis oil satisfies Korea's gas pollutant standards and is consistent with the GHG reduction policy. It can be concluded that building a circular economy at the university campus level using waste plastic pyrolysis oil technology is suitable from economic, environmental, and policy perspectives. [ABSTRACT FROM AUTHOR]

The mucilage that accumulated in the Sea of Marmara in 2021 turned into an environmental disaster that threatened not only marine life but also the shipping and tourism industries. However, because of the partially organic structure of marine mucilage, it has the potential to be used as an additive for polymer films. In this study, bioplastic films were prepared from PVA with a series of mucilage content from 0% to 50% by mass, and their properties were investigated. The FT‐IR spectra revealed a shift in hydroxyl peaks, suggesting an interaction between the mucilage and PVA. SEM images showed the formation of crystal forms at the higher mucilage content of 20%, indicating ionic saturation of the PVA matrix. EDX and XRD analyses revealed that the crystal was NaCl coming from the mucilage composition. The tensile strength of the neat PVA film was measured as 9.86 MPa and improved to 14.56 MPa with 5% mucilage content, which is attributed to the ionic cross‐linking. The tensile properties were preserved up to 20% of the mucilage content, and then sudden decrements were observed. The transmittance percentage (T%) of the neat PVA film in UV–Vis spectra (800–200 nm) was detected as 75% at 500 nm and decreased down to 39% with increased mucilage content up to 50%. Furthermore, a rising limit of linearity (LOL) of the spectrums was observed from 350 to 580 nm, with increasing mucilage content from 5% to 50%. The biofilms showed antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. Hence, a robust and biodegradable film having UV protection and antibacterial activity was developed from the marine mucilage bio‐waste. Highlights: Poly(vinyl alcohol)/marine mucilage biocomposite films were prepared.Biocomposite films showed increased UV‐A, UV‐B, and UV‐C protection with increased mucilage content.Enhanced tensile strength of biocomposite films up to 20 wt% mucilage content was determined due to ionic crosslink formed by NaCl salt ions.Biocomposite exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Numerous plastic products are used in agriculture, including containers, packaging, tunnels, drip irrigation tubing, and mulches. Large amounts of plastics are used as mulches on the soil surface for vegetable and fruit production (tomato, cucumber, watermelon, strawberry, and vine) to reduce weed competition, increase water and fertilizer use efficiency, and enhance crop yield. Portugal uses around 4500 t/year of polyethylene to cover approximately 23,000 ha of agricultural land, and only a small amount is recovered for recycling or secondary uses because of issues of contamination with the soil, vegetation, pesticides, and fertilizers. Cleaning and decontaminating polyethylene mulch are costly, and commercial technology is often not accessible or economical. Most plastic mulch is composed of polyethylene that degrades slowly and produces a large quantity of residues in the soil, with a negative impact on the environment. In the present study, the effects of long-term cultivation of blueberry using green 100% high-density polyethylene mulch in the south Portugal were evaluated for soil chemical and biological changes. High-density green plastic mulch did not contaminate the topsoil with di(2-ethylhexyl) phthalate, and heavy metals, buttotal nitrogen, organic carbon concentrations, electric conductivity, and microbial activity were significantly reduced in the planting row compared with the bare soil without mulching. Furthermore, the presence of plastic mulch did not negatively affect the presence of nematodes, and the number of Rhabditida (bacterial feeders) increased in the planting and covered row. [ABSTRACT FROM AUTHOR]

In this work, we investigated the enhancement of corrosion resistance in a biodegradable Mg-0.7Zn-0.6Ca (wt. %) alloy (MgZnCa) by applying ZrO2 thin films deposited via reactive magnetron sputtering. We employed a fractional factorial experimental design to systematically examine the influence of the deposition power, deposition time, and O2 fraction on the effectiveness of the ZrO2 thin film in preventing corrosion of the Mg alloy. Our analysis revealed that the ZrO2 thin films exhibited a monoclinic crystal phase and maintained stoichiometry across various O2 fractions. Interestingly, we observed a 78% roughness reduction when using the lowest O2 fraction, while roughness increased with the deposition power and time. The corrosion response of bare and ZrO2-coated MgZnCa alloy was assessed by electrochemical techniques and detection of H2 production during the Mg corrosion via gas chromatography. The optimal set of deposition conditions, essential for enhancing the short-term corrosion resistance of magnetron-sputtered ZrO2 coatings, involves maximizing thickness through high power (400 W) and extended deposition time (90 min). It is crucial to balance these factors while maintaining an appropriate O2 fraction (20%) to ensure the formation of a stoichiometric film. Avoiding excess oxygen is imperative, as it can lead to undesirable intergranular porosity and surface roughness. This optimization resulted in a 46% reduction in the evolution of H2 gas compared to the bare MgZnCa alloy. Overall, this work sheds light on the potential of ZrO2 thin films as effective corrosion-resistant coatings for MgZnCa alloys, emphasizing the critical role of deposition parameters in achieving superior protection against corrosion. [ABSTRACT FROM AUTHOR]

Abstract Bioplastics has gained attention as a sustainable alternative to traditional petroleum-based plastics. Microalgae have become one of the more promising and environmentally benign feedstocks to produce bioplastics. The goal of this in-depth review study is to address both the possibilities and the difficulties of manufacturing microalgae-based bioplastics. The review begins by discussing the negative impacts that commercial plastics have on the environment, pollution, and resource depletion. It then introduces the idea of bioplastics and discusses their importance in reducing the previously mentioned issues brought on by plastics. The article discusses the distinctive qualities of microalgae as a sustainable biomass source, noting their rapid development, high lipid content, and low need for both land and water. The various production processes and procedures used to create microalgae-based bioplastics are thoroughly explored. To determine whether the mechanical, thermal, and barrier qualities were appropriate for different applications, they were examined. Biodegradability and shelf life are factors in environmental impact assessments that highlight their potential to help mitigate the negative effects of plastics. Economic viability is a crucial factor that is examined through cost analyses and discussions of the prospects and incentives for market growth. To provide a glimpse into the future of microalgae-based bioplastics as a sustainable material option, current trends and innovations are emphasized. This review advances our knowledge of microalgae-based bioplastics in the race for a more sustainable plastics industry by offering a fair evaluation of their advantages, disadvantages, and uses. Graphical Abstract

Background: This research was conducted to design a bionanocomposite film for meat packaging with regard to environmental aspects. Methods: Cellulose nanoparticles (CNPs) were used as nano-reinforcing factors were generated using non-edible agricultural by-products. The bionanocomposite film which was recently developed contains CNPs and chitosan (CS); then, the nanocomposites were explored via SEM, FTIR, agar disc diffusion tests and X-ray crystallography (XRD). Finally, the film was used to pack meat pieces. Results: Investigation of the morphological and physical reports of the solid films indicated that the CNPs are well scattered in bionanocomposite film. The addition of CNPs within a CS improved Young’s modulus by about 12135% and the tensile strength by 583%. In addition, XRD photographs indicated that CNP peak appeared after being added to CS context. Antimicrobial activity demonstrated that nanocomposites exerted restrictive effect on Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, and Staphylococcus aureus bacteria. Using CS-nanocellulose composite as a packing film on meat surface leads to decreasing bacteria growth compared to nylon packing materials at 4˚C after 8 days of storage. Conclusion: Findings indicated that the recently designed CNP-CS films are a better replacement for common food packaging substances.

In recent years, a great deal of attention has been focused on the environmental impact of plastics, including the carbon emissions related to plastics, which has promoted the application of biodegradable plastics. Countries worldwide have shown high interest in replacing traditional plastics with biodegradable plastics. However, no systematic comparison has been conducted on the carbon emissions of biodegradable versus traditional plastic products. This study evaluates the carbon emissions of traditional and biodegradable plastic products (BPPs) over four stages and briefly discusses environmental and economic perspectives. Four scenarios—namely, the traditional method, chemical recycling, industrial composting, and anaerobic digestion—are considered for the disposal of waste BPPs (WBPPs). The analysis takes China as a case study. The results show that the carbon emissions of 1000 traditional plastic products (plastic bags, lunch boxes, cups, etc.) were 52.09–150.36 carbon emissions equivalent of per kilogram (kg CO2eq), with the stage of plastic production contributing 50.71%–50.77%. In comparison, 1000 similar BPPs topped out at 21.06–56.86 kg CO2eq, approximately 13.53%–62.19% lower than traditional plastic products. The difference was mainly at the stages of plastic production and waste disposal, and the BPPs showed significant carbon reduction potential at the raw material acquisition stage. Waste disposal plays an important role in environmental impact, and composting and anaerobic digestion are considered to be preferable disposal methods for WBPPs. However, the high cost of biodegradable plastics is a challenge for their widespread use. This study has important reference significance for the sustainable development of the biodegradable plastics industry.

Graphene oxide nanosheet (GO) is a multifunctional platform for binding with nanoparticles and stacking with two dimensional substrates. In this study, GO nanosheets were sonochemically decorated with zinc oxide nanoparticles (ZnO) and self-assembled into a hydrogel of GO–ZnO nanocomposite. The GO–ZnO hydrogel structure is a bioinspired approach for preserving graphene-based nanosheets from van der Waals stacking. X-ray diffraction analysis (XRD) showed that the sonochemical synthesis led to the formation of ZnO crystals on GO platforms. High water content (97.2%) of GO–ZnO hydrogel provided good property of ultrasonic dispersibility in water. Ultraviolet-visible spectroscopic analysis (UV–vis) revealed that optical band gap energy of ZnO nanoparticles (∼3.2 eV) GO–ZnO nanosheets (∼2.83 eV). Agar well diffusion tests presented effective antibacterial activities of GO–ZnO hydrogel against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). Especially, GO–ZnO hydrogel was directly used for brush painting on biodegradable polylactide (PLA) thin films. Graphene-based nanosheets with large surface area are key to van der Waals stacking and adhesion of GO–ZnO coating to the PLA substrate. The GO–ZnO/PLA films were characterized using photography, light transmittance spectroscopy, coating stability, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopic mapping (EDS), antibacterial test and mechanical tensile measurement. Specifically, GO–ZnO coating on PLA substrate exhibited stability in aqueous food simulants for packaging application. GO–ZnO coating inhibited the infectious growth of E. coli biofilm. GO–ZnO/PLA films had strong tensile strength and elastic modulus. As a result, the investigation of antibacterial GO–ZnO hydrogel and GO–ZnO coating on PLA film is fundamental for sustainable development of packaging and biomedical applications. [ABSTRACT FROM AUTHOR]

Pt cocatalyst play bifunctions in the photoreforming of polyethylene terephthalate plastic waste by improving the charge transfer kinetics and regulating the adsorption-desorption of oxidation intermediates, thereby achieving efficient photocatalytic H 2 evolution rate and producing valuable commodities in the photoreforming reactions. [Display omitted] Upcycle polyethylene terephthalate (PET) waste by photoreforming (PR) is a sustainable and green approach to tackle environmental problems but with challenges to obtain valuable oxidation products and high purity hydrogen simultaneously. Noble metal cocatalysts are essential to enhance the overall PR reaction efficacy. In this work, TiO 2 nanotubes (TiO 2 NTs) decorated with single Pt atoms (Pt 1 /TiO 2) or Pt nanoparticles (Pt NPs /TiO 2) are used in the photoreforming reaction (in one batch), and the oxidation products from ethylene glycol (EG, hydrolysed product of PET) in liquid phase and hydrogen are detected. With Pt 1 /TiO 2 , EG is oxidized to glyoxal, glyoxylate or lactate, and hydrogen evolution rate (r H 2) reaches 51.8 μmol⋅h−1⋅g cat −1, that is 30 times higher than that of TiO 2. For Pt NPs /TiO 2 (size of Pt NPs: 1.97 nm), hydrogen evolution reaches 219.1 μmol⋅h−1⋅g cat −1, but with the oxidation product of acetate only. DFT calculation demonstrates that for Pt NPs, the reaction path for hydrogen evolution is preferred thermodynamically, due to the formation of Schottky junction. On the oxidation of EG, theoretical and spectroscopic analysis suggest that bidentate adsorption of EG at the interface is facile on Pt 1 /TiO 2 , compared to that on Pt NPs /TiO 2 (two Pt sites), but oxidation products, adsorb less strongly, compared to Pt NPs /TiO 2 , that eventually regulates the distribution of oxidation products. The results thus demonstrate the bifunctions of Pt in the PR reaction, i.e., electron transfer mediator for hydrogen evolution and reactive sites for molecules adsorption. The oxidation reaction is dominated by the adsorption-desorption behavior of molecules but the reduction reaction is controlled by the electron transfer. In addition, acidification of pretreated PET alkaline solution achieves separation of pure terephthalic acid (PTA), which further improves the reaction efficiency possibly by offering high density of active sites and acidic environment. Our work thus demonstrates that to upcycle PET plastics, an optimized process can be reached by atomic design of photocatalysts and proper treatment on the plastic wastes. [ABSTRACT FROM AUTHOR]

With a growing population of about 7.8 billion, humans are generating tons of waste in the form of non-biodegradable plastics on a daily basis that ends up in landfills and oceans. The introduction of packaging has been a blessing to mankind by facilitating the ease of convenience in transportation, delivery and general usage. The downside, however, is that majority of the packaging currently available is harmful to the environment and takes thousands of years to decay. This paper discusses the use of chitosan from shrimp shells and other marine animals' exoskeleton waste in food packaging industries. Chitosan extracted from marine organisms is modulated in the form of packaging material. Compared to conventional packaging, chitosan films are 73.4% biodegradable in soil under laboratory conditions whereas 100% degraded in an open field. Chitosan with metal oxides, essential oils, natural extracts, proteins and other polymers show enhanced tensile strength, water vapor permeability, oxygen and ultraviolet barrier. Chitosan and composite film show antimicrobial activity against gram positive and negative bacteria. Comparative approaches on environmental impacts between conventional plastics and chitosan films are enlightened, thereby highlighting the importance of natural polymers as packaging films that are considered economic based on the addition of additives. [ABSTRACT FROM AUTHOR]

To improve the shortcomings of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), such as brittleness, large grain size and high crystallinity, a kind of bio-based engineering polyester elastomer (BEPE) was incorporated into PHBV by melting blending method with benzoyl peroxide (BPO) as the initiator. With the addition of BPO, the interfacial adhesion between PHBV and BEPE was improved, and BPO hindered the crystallization and reduced the crystallinity of PHBV/BEPE blends. At the same time, the gel content, the dynamic complex viscosity and dynamic elastic modulus of blends were increased significantly in low-frequency region with 0.7-phr BPO. Compared to that of neat PHBV, the elongation at break and impact strength of PHBV/BEPE/BPO (0.7 phr) blends were increased by 373.6 and 158.7%, respectively. Compared to that of PHBV/BEPE blends, the elongation at break and impact strength of the PHBV/BEPE/BPO (0.7 phr) blends were increased by 44.3 and 122.7%, respectively. The above phenomena were resulted from the formation of chemical micro-crosslinking between PHBV and BEPE. The main mechanism can be explained, PHBV and BEPE polymer radicals were generated by BPO initiator, and then, PHBV and BEPE polymer radicals recombined to form carbon–carbon crosslinking. [ABSTRACT FROM AUTHOR]

In this study we prepared a poly(lactic acid)/ethyl cellulose (PLA/EC) bioplastic blend film by melt pressing after solvent casting and investigated the optical, thermal, and mechanical properties in relation to the structural changes revealed by various microscopies and scattering measurements. Despite the immiscibility of PLA and EC, the blend film exhibited good optical transparency due to the close match in their refractive indices. A second run of differential scanning calorimetry during heating revealed a decrease in the glass transition temperature ( T g PLA ) and melting point ( T m PLA ) of PLA with EC although EC had the higher values. Thermomechanical analysis suggested that these decreases were due to the negative pressure generated due to the suppression of PLA shrinkage below T g EC and above T g PLA during cooling. Furthermore, ductile drawing of the blend film (70/30) at an optimal temperature of 70 °C above T g PLA resulted in a uniform whitening near 100% strain. Delamination at the interface between the PLA matrix and EC domain led to the formation of micrometer-sized oriented voids, which enhanced the refractive index difference in the phase-separated structure, thereby scattering light and achieving the uniform and oriented white blend film. [ABSTRACT FROM AUTHOR]

Microplastics are micrometre-sized emerging pollutants produced by plastic fragmentation. They have been recently detected in most ecosystems, even in remote areas. Here, we review microplastics with emphasis on sources, occurrence, transport, detection methods, policies, toxicity, and management methods. In the transport section, we discuss sorption kinetics, layered microplastics, and influencing factors such as biofilm formation. Microplastic management can be done by adsorption, filtration, oxidation, and biodegradation. Microplastic interaction is influenced by temperature, pH, salinity, and dissolved organic matter. [ABSTRACT FROM AUTHOR]

Plastic pollution is becoming a major health issue due to the recent discovery of microplastics and nanoplastics in living organisms and the environment, calling for advanced technologies to remove plastic waste. Here we review enzymes that degrade plastics with focus on plastic properties, protein engineering and polymers such as poly(ethylene terephthalate), poly(butylene adipate-co-terephthalate), poly(lactic acid), polyamide and polyurethane. The mechanism of action of natural and engineered enzymes has been probed by experimental and computation approaches. The performance of polyester-degrading enzymes has been improved via directed evolution, structure-guided rational design and machine learning-aided strategies. The improved enzymes display higher stability at elevated temperatures, and tailored substrate-binding sites. [ABSTRACT FROM AUTHOR]

The global plastic production has steadily increased from 1.7 million tons in 1950 to over 400 million tons in 2022, with about 60% of plastic ultimately ending up in landfills and oceans. There is also growing evidence that microplastics exert negative effects on biota and ecosystems. Biodegradable plastics may represent a safe alternative, yet their potential adverse effects have not been comprehensively analyzed. Here, we reviewed biodegradable plastics, with focus on their conversion into microplastics, their interactions with pollutants, and their combined toxicity for aquatic biota. Biodegradable plastics include polylactic acid, polyhydroxyalkanoates, polybutylene succinate, poly(butylene adipate-co-terephthalate), and poly(ε-caprolactone). We found that some biobased plastics are hardly biodegradable. Some biobased plastics are compostable but require specific environmental conditions for their biodegradation. Biobased plastics can generate microplastics when released into the environment, which can impact biota. Contrary to the common public belief, biodegradable plastics may not only originate from biosources but can be synthesized from fossil fuels. Microplastics originating from biodegradable plastics can interact with pollutants, adsorbing and transporting these pollutants, resulting in synergistic or antagonistic effects on exposed organisms. Biofilm formation on microplastics impacts their degradation and pollutant interactions. [ABSTRACT FROM AUTHOR]

Ingestion of microplastics can lead to deleterious consequences for organisms, as documented by numerous laboratory studies. The current knowledge is based on a multitude of effect studies, conducted with conventional fossil-based and non-degradable plastics. However, there is a lack of information about the acceptance and the effects of novel bio-based and biodegradable plastics. Biodegradable plastics are considered an alternative to conventional plastics and are showing rapidly growing production rates. Biodegradable plastics can disperse into the environment in the same way as conventional plastics do, becoming available to marine organisms. This study aims to provide new insights into the uptake and effects of biodegradable microplastics on marine invertebrates. Rockpool shrimp, Palaemon elegans, were fed with algal flakes coated with polylactic acid (PLA), polyhydroxybutyrate-co-valerate (PHBV) and conventional low-density polyethylene (LDPE) microparticles. Live observations showed that all of the different types of microplastics were ingested. After dissection of the shrimp, less LDPE particles were found in the stomachs than PLA and PHBV particles. This indicates a longer retention time of biodegradable microplastics compared to conventional microplastics. Presumably, less LDPE particles were ingested or evacuated from the stomach, probably by regurgitation. The ingestion of microparticles of all types of plastics induced enzymatic activity of short-chain carboxylesterases in the midgut glands of the shrimp. However, only PLA induced enzymatic activity of medium-chain carboxylesterases. Palaemon elegans showed no oxidative stress response after ingestion of microparticles, irrespective of polymer type. From our results we conclude that biodegradable plastics might have different effects than conventional plastics. The longer retention times of biodegradable plastics might enhance exposure to leaching additives and other harmful substances. Our study provides new insights into how biodegradable plastics might affect aquatic fauna and indicate that the use of biodegradable plastics needs to be reconsidered to some extent.