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Polyethylene terephthalate (PET) fabric was enzymatically modified with polyethylene glycol (PEG). Lipase from Aspergillus oryzae was used as a catalyst. The wetting behavior of the modified PET fabric was characterized by the water contact angle, water adsorption dynamics and moisture regain. The initial water contact angle of the modified fabric decreased from 129.3° to 74.9°. The water absorption dynamics results indicated that the equilibrium water absorption amount of the modified fabric was approximately 10 times greater than that of the untreated sample. The initial absorption rate (V init) of the modified fabric was almost 30 times higher than that of the untreated fabric. The moisture regain reached 3.52 % after modification. Scanning electron microscopy revealed granular and sheet coatings on the surface of the modified fabric. Chemical linkage of PEG onto the PET fibers was confirmed by attenuated total reflection–Fourier transform infrared spectroscopy. The modification had no significant effect on the thermal properties of the PET fabrics according to the thermogravimetric curve and differential scanning calorimetry results. The mechanical properties of the modified fabric were slightly improved. Therefore, in situ enzymatic transesterification between PET and PEG could be a potential novel modification approach for adding value to PET fiber textiles. [Display omitted] • Polyethylene glycol was chemically linked onto polyethylene terephthalate(PET) fiber. • PET fibers was hydrophilic modified by lipase-catalyzed transesterification reaction. • The water contact angle of modified PET fabric decreased from 129.3° to 74.9°. • The moisture regain of modified PET fabric reached (3.52±0.02)%. • The mechanical properties of PET fabric were slightly improved after modification. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis of polyethylene terephthalate (PET) for surface modification of polyester fibers has attracted considerable research attention in recent years. However, the high crystallinity of polyester fibers, combined with limited enzyme activity and stability, challenges the surface modification study of enzymes. Deep eutectic solvents (DES) can create a favorable environment for proteins and are a new generation of biodegradable solvents. Few studies have been conducted on the use of DES to enhance enzymatic degradation. Therefore, we attempted to hydrolyze PET with DES-activated enzymes to increase the hydrolysis yield and thus improve PET modification. Using betaine and choline chloride as hydrogen bond acceptors and polyols as hydrogen bond donors, we investigated the effects of DES type, molar ratio, and concentration on enzymatic hydrolysis. Humicola insolens cutinase (HiC) was used as the biocatalyst for PET fabric hydrolysis, the role of DES as an additive in improving the yield of enzymatically hydrolyzed PET fabric was investigated. The results showed that under the conditions of an enzyme concentration of 6.5% v/v (volume of enzyme on the total volume), a temperature of 60 °C, and a reaction time of 72 h, the low concentration (20% v/v) of DES (betaine: sorbitol; 1:2 molar ratio) increased the hydrolysis yield by more than 1.5 times. Enzymatic hydrolysis in DES aqueous solution (betaine: sorbitol; 1:2 molar ratio) and DES single-component aqueous solution (betaine, sorbitol without synthesis of DES) indicated that the increase in hydrolysis yield was mainly due to the formation of hydrogen bonds between betaine and sorbitol, rather than the superposition of individual components. Further analysis revealed that HiC exhibited high relative enzyme activity and stability at low DES concentrations. Additionally, CD spectroscopy and fluorescence spectroscopy analyses demonstrated the effective preservation of HiC structure by DES. Our work provides insights into the development of efficient and sustainable methods to enhance HiC hydrolysis of PET fabric, unlocking new opportunities and potential for the comprehensive utilization of DES in the bio-modification of PET fabric. [ABSTRACT FROM AUTHOR]

The rampant use of plastics, with the potential to degrade into insidious microplastics (MPs), poses a significant threat by contaminating aquatic environments. In the present study, we delved into the analysis of effluents from textile industries, a recognized major source of MPs contamination. Data were further discussed and compared with a municipal wastewater treatment plant (WWTP) effluent. All effluent samples were collected at the final stage of treatment in their respective WWTP. Laser diffraction spectroscopy was used to evaluate MP dimensions, while optical and fluorescence microscopies were used for morphology analysis and the identification of predominant plastic types, respectively. Electrophoresis was employed to unravel the prevalence of negative surface charge on these plastic microparticles. The analysis revealed that polyethylene terephthalate (PET) and polyamide were the dominant compounds in textile effluents, with PET being predominant in municipal WWTP effluents. Surprisingly, despite the municipal WWTP exhibiting higher efficiency in MP removal (ca. 71% compared to ca. 55% in textile industries), it contributed more to overall pollution. A novel bio-based flocculant, a cationic cellulose derivative derived from wood wastes, was developed as a proof-of-concept for MP flocculation. The novel derivatives were found to efficiently flocculate PET MPs, thus allowing their facile removal from aqueous media, and reducing the threat of MP contamination from effluents discharged from WWTPs. [ABSTRACT FROM AUTHOR]

Enzymatic degradation of poly(ethylene terephthalate) (PET) into its corresponding monomers provides an attractive route for green plastic recycling and environmental remediation applications. However, the binding of PET hydrolases toward the PET surface is a rate-limiting step in PET degradation. Hence, we selected three anchor peptides and four linker peptides to fuse the previously engineered leaf-branch compost cutinase for facilitating enzyme binding and improving degradation of real post-consumer PET wastes of Coca Cola and C′eastbon PET bottles, with using the amorphous PET as a control. The systematical characterization of the seven cutinases revealed that the anchor peptide with moderate hydrophobicity plus chaperone activity and the flexible linker peptide with small hydrophobicity but long length were more suitable for each domain to serve its own role, affording the facilitated PET binding affinities and enhanced PET degradation performance. Thus, the optimal fusion cutinase possessed up to 3.3 times higher catalytic efficiency (k cat / K m) and 76 % increased long-term degradation performance than the parental cutinase, respectively. Further, complete degradation of C′eastbon PET wastes and 77 % degradation of Coca Cola PET wastes were achieved by the optimal cutinase of 33.3 nmol·g−1 PET in 96 h, proving its superiority against the real post-consumer PET wastes. [Display omitted] • Varying anchor and linker peptides were fused to an engineered variant of cutinase. • Real polyethylene terephthalate (PET) wastes were degraded by seven cutinases. • Effects of anchor and linker peptides on enzymatical PET degradation were explored. • Catalytic efficiency was enhanced 3.3 times by the optimal fusion strategy. • Optimal cutinase of 33.3 nmol·g−1 PET completely degraded C′eastbon PET wastes in 96 h. [ABSTRACT FROM AUTHOR]

Plastics are essential in modern civilization due to their affordability, simple manufacturing, and properties. However, plastics impact the environment as they decompose over a long period and degrade into microplastics. The construction sector has been exploring substituting conventional bricks with plastic bricks, as concrete and clay bricks consume natural resources and pollute the environment. The introduction of recycling plastic, and using plastic waste and sand mixtures to create Lego-like bricks has become a new trend. The bricks have superior properties to conventional bricks, such as a smoother surface, finer edges, easy application, crack-free, higher compression strength, almost zero water absorption, and reduced energy consumption. The study: compares the results of PE with sand and PET with sand samples to previous studies, confirms alignment, works as a control sample for PET and PE novel research, and validates the concept. Three plastic mixtures using two types of plastic waste (PE and PET) and sand were used. The plastic waste with sand was heated up to 200 °C. Plastic acts as a binder, while sand acts as a filler material. Optimized durability and cohesiveness were achieved at 30–40% plastic weight ratios. A mixture of PE and sand showed a maximum compressive strength of 38.65 MPa, while the PET and sand mixture showed 76.85 MPa, and the mix of PE and PET in equal proportions with sand resulted in 26.64 MPa. The plastic samples showed ductile behavior, with elongation between 20 and 30%, water absorption between 0 and 0.35%, and thermal conductivity from 0.8 to 1.05 W/(m/K). Carbon dioxide emissions are significantly reduced as compared to standard bricks. The CO2 per brick (kg) was 0.008 and 0.0085 in the PE; 0.0085 and 0.009 in the PET; and 0.0065 and 0.007 in the PE mixed with PET. [ABSTRACT FROM AUTHOR]

From both economic and environmental perspectives, ethylene glycol, the principal constituent in the degradation of PET, emerges as an optimal feedstock for microbial cell factories. Traditional methods for constructing Escherichia coli chassis cells capable of utilizing ethylene glycol as a non-sugar feedstock typically involve overexpressing the genes fucO and aldA. However, these approaches have not succeeded in enabling the exclusive use of ethylene glycol as the sole source of carbon and energy for growth. Through ultraviolet radiation-induced mutagenesis and subsequent laboratory adaptive evolution, an EG02 strain emerged from E. coli MG1655 capable of utilizing ethylene glycol as its sole carbon and energy source, demonstrating an uptake rate of 8.1 ± 1.3 mmol/gDW h. Comparative transcriptome analysis guided reverse metabolic engineering, successfully enabling four wild-type E. coli strains to metabolize ethylene glycol exclusively. This was achieved through overexpression of the gcl, hyi, glxR, and glxK genes. Notably, the engineered E. coli chassis cells efficiently metabolized the 87 mM ethylene glycol found in PET enzymatic degradation products following 72 h of fermentation. This work presents a practical solution for recycling ethylene glycol from PET waste degradation products, demonstrating that simply adding M9 salts can effectively convert them into viable raw materials for E. coli cell factories. Our findings also emphasize the significant roles of genes associated with the glycolate and glyoxylate degradation I pathway in the metabolic utilization of ethylene glycol, an aspect frequently overlooked in previous research. [ABSTRACT FROM AUTHOR]

In this paper, the aim is to discuss the applicability of polyethylene terephthalate fiber-reinforced polymer (PET FRP) in DSTC structures. PET FRP can improve the strength and stability of structures by providing constraints for concrete. Herein, experimental and response surface analyses of the axial compressive properties of PET FRP–concrete–steel double-skin tubular stub columns (DSTCs) based on 26 DSTC specimens subjected to axial compression testing are presented. The height of each DSTC specimen is 600 mm, the outer diameter is between 305 and 315 mm, and the thickness of the added concrete is 43 mm. The main parameters are the number of layers on the PET FRP, the compressive strength of the concrete, and the thicknesses of the steel tubes. The experimental results show that the ultimate load and ultimate axial strain can be significantly increased by increasing the number of PET FRP layers, reaching 27.34% and 28.79%, respectively. When the compressive strength of the concrete increases from C30 to C40, the ultimate load and ultimate axial strain values of the DSTCs increase by 12.54% and 8.99%, respectively. In addition, as the thickness of the steel tube increases from 6 to 8 mm, the ultimate load and ultimate axial strain increase by 34.95% and 118.90%, respectively. These results indicate that the introduction of PET FRP significantly improves the overall performance of DSTCs. Increasing the number of PET FRP layers helps to limit the circumferential strain of DSTCs. P6-S8-C40 has the best ultimate load-bearing capacity and ultimate axial strain capacity, which reach 3356.18 kN and 0.1992, respectively. The main purpose of this paper is to study the influences of the PET FRP thickness (in different layers), steel tube thickness, and concrete strength on the properties, damage mode and damage process of DSTCs. [ABSTRACT FROM AUTHOR]

Despite the extensive use of recycled polyethylene terephthalate (rPET) in food contact materials (FCMs), research on the presence of heavy metals (HMs) and rare earth elements (REEs) during various recycling stages (e.g., flakes, granules, and preforms) remains limited. This study aimed to address these gaps by validating a rapid and sensitive analytical method to quantify 26 HMs and 4 REEs in PET and rPET matrices. An ICP-MS method was validated per EURACHEM guidelines, assessing linearity, limits of detection (LOD), limits of quantification (LOQ), accuracy, and repeatability. The method was employed for initial screening of HMs and REEs classified as non-intentionally added substances (NIASs) in PET and rPET samples. The findings showed high accuracy and reliability, with recovery rates between 80% and 120%. Analysis revealed varying concentrations of HMs and REEs, with the highest levels in 100% rPET preforms, notably Zn, Cu, and Al among HMs, and La among REEs. The study identified critical contamination points during the recycling process, highlighting the need for targeted interventions. This research provides a crucial analytical framework for assessing HMs and REEs in PET and rPET, ensuring FCM safety compliance and supporting efforts to enhance rPET product safety, promoting public health protection and advancing the circular economy. [ABSTRACT FROM AUTHOR]

Abstract From both economic and environmental perspectives, ethylene glycol, the principal constituent in the degradation of PET, emerges as an optimal feedstock for microbial cell factories. Traditional methods for constructing Escherichia coli chassis cells capable of utilizing ethylene glycol as a non-sugar feedstock typically involve overexpressing the genes fucO and aldA. However, these approaches have not succeeded in enabling the exclusive use of ethylene glycol as the sole source of carbon and energy for growth. Through ultraviolet radiation-induced mutagenesis and subsequent laboratory adaptive evolution, an EG02 strain emerged from E. coli MG1655 capable of utilizing ethylene glycol as its sole carbon and energy source, demonstrating an uptake rate of 8.1 ± 1.3 mmol/gDW h. Comparative transcriptome analysis guided reverse metabolic engineering, successfully enabling four wild-type E. coli strains to metabolize ethylene glycol exclusively. This was achieved through overexpression of the gcl, hyi, glxR, and glxK genes. Notably, the engineered E. coli chassis cells efficiently metabolized the 87 mM ethylene glycol found in PET enzymatic degradation products following 72 h of fermentation. This work presents a practical solution for recycling ethylene glycol from PET waste degradation products, demonstrating that simply adding M9 salts can effectively convert them into viable raw materials for E. coli cell factories. Our findings also emphasize the significant roles of genes associated with the glycolate and glyoxylate degradation I pathway in the metabolic utilization of ethylene glycol, an aspect frequently overlooked in previous research.

In the present work, mechanical, physical, wettability, and microstructure characterization were employed to evaluate the performance of composite material. Uniform distribution with a good interfacial layer of SAC and Si3N4 was observed for PET/8.75%Si3N4+8.75% wasteSAC powder composite material. Results showed significant improvements in tensile (60.55%), hardness (150.99%), bending (228.47%), and compressive strength (105.56%) compared to neat PET-based composites after the addition of 8.75%Si3N4+8.75% wasteSAC powder. Therefore, studied composite could be a replacement of metals and ceramics, in various structural and functional applications due to their improved mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

In present study, titanium diboride (TiB2) and glass powder waste utilized as reinforcement particles with Polyethylene terephthalate (PET) matrix material in development of a polymer-based composite. The % reinforcement of TiB2and glass powder waste varied from 2.5% to 20%. Micrographs of PET/8.75% TiB2/8.75% glass wastecomposite revealed uniform distribution of TiB2and glass powder in PET-based MMC. Proper wettability between matrix and reinforcement particles were observed for PET/8.75% TiB2/8.75% glass wastecomposite. Results showed that by adding 8.75% of TiB2and 8.75% of glass powder, mechanical properties of PET were improved. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate has been widely used in the packaging industry. Degraded PET micro(nano)plastics could pose public health concerns following release into various environments. This study focuses on PET degradation under ultraviolet radiation using the NIST SPHERE facility at the National Institute of Standards and Technology in saturated humidity (i.e., ≥95% relative humidity) and dry conditions (i.e., ≤5% relative humidity) with varying temperatures (30 °C, 40 °C, and 50 °C) for up 20 days. ATR-FTIR was used to characterize the chemical composition change of degraded PET as a function of UV exposure time. The results showed that the cleavage of the ester bond at peak 1713 cm−1 and the formation of the carboxylic acid at peak 1685 cm−1 were significantly influenced by UV radiation. Furthermore, the formation of carboxylic acid was considerably higher at saturated humidity and 50 °C conditions compared with dry conditions. The ester bond cleavage was also more pronounced in saturated humidity conditions. The novelty of this study is to provide insights into the chemical degradation of PET under environmental conditions, including UV radiation, humidity, and temperature. The results can be used to develop strategies to reduce the environmental impact of plastic pollution. [ABSTRACT FROM AUTHOR]

In the United States, polyethylene terephthalate (PET) bottle collection rates have not increased in a decade. Recycling rates remain abysmal while industry commitments and policy targets escalate the demand for recycled plastics. We investigate the PET bottle recycling system, where collection is a critical bottleneck and recycled PET supply is not meeting the expected demand. We characterize demand for recycled PET (R‐PET), analyze scenarios of expanding deposit return systems (DRS), and quantify cost barriers to improving PET bottle recycling. We find that a nation‐wide DRS can increase PET bottle recycling rates from 24% to 82%, supplying approximately 2700 kt of recycled PET annually. With stability in demand, we estimate that this PET bottle recycling system can achieve 65% bottle‐to‐bottle circularity, at a net cost of 360 USD/tonne of PET recycled. We also discuss environmental impacts, stakeholder implications, producer responsibility, and complimentary policies toward an efficient and effective recycling system. [ABSTRACT FROM AUTHOR]

BACKGROUND: Environmental and ecological hazards caused by the accumulation of polyethylene terephthalate (PET) are becoming a global concern. The use of enzymes to address the plastic crisis has achieved many successes, but the difficulty in degrading high‐crystallinity PET has limited its application. Numerous studies have investigated the degradation of PET with arbitrary crystallinity to bis‐2‐(2‐hydroxyethyl) terephthalate (BHET) using chemical pre‐treatment methods such as glycolysis, but few have tested its biocompatibility with enzymatic alliances. RESULTS: Herein, we report the enzymatic characterization and subsequent engineering of the state‐of‐the‐art IsPETasePA and MHETase (where MHET is mono(2‐hydroxyethyl) terephthalate), a dual‐enzyme system which can be used for the degradation from BHET to a single‐product terephthalate (TPA). Modulators, including surfactants, organic solvents and metal ions, enhanced the enzyme activity of IsPETasePA and MHETase by up to 1.1‐fold and 2.3‐fold, respectively. 100% TPA yield (BHET of 25 g L−1) was achieved within 5 h. We also analyzed the mechanism of optimal ion modulator modification by dynamics simulation, and it synergistically achieved enhancement of MHET degradation ability by improving stability and binding energy. CONCLUSION: The introduction of modulators improves the efficiency of the dual‐enzyme system in degrading BHET. This work provides a valuable strategy for the complete degradation of BHET to TPA, laying the groundwork for the realization of PET recycling. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Terephthalic acid (TPA) was recovered by alkaline hydrolysis of waste polyethylene terephthalate (PET) bottles. TPA recovered was used to prepare Sn-based catalyst by solvothermal method. For comparison, commercial TPA was also used to prepare Sn-based catalyst. The catalysts were used for the electrochemical reduction of CO2 to formate. Both the catalysts were found to possess nanoflake morphology, and were highly porous in nature with Brunauer–Emmett–Teller (BET) surface area of 211.4 and 239.4 m2/g for commercial and PET derived TPA-based Sn catalysts, respectively. The catalyst made from the waste PET bottles derived TPA was found to be more effective than the one obtained from the commercial TPA. The Faradaic efficiency obtained for the formation of formate was 68.4% at potential − 1.8 V (vs Ag/AgCl) and current density of 13.5 mA/cm2, when catalyst was synthesized using waste PET derived TPA. High activity of the electrocatalysts was attributed to higher capacitance, and lower resistance of the catalysts. [ABSTRACT FROM AUTHOR]

Starch utilization system (Sus)D-homologs are well known for their carbohydrate-binding capabilities and are part of the sus operon in microorganisms affiliated with the phylum Bacteroidota. Until now, SusD-like proteins have been characterized regarding their affinity toward natural polymers. In this study, three metagenomic SusD homologs (designated SusD1, SusD38489, and SusD70111) were identified and tested with respect to binding to natural and non-natural polymers. SusD1 and SusD38489 are cellulose-binding modules, while SusD70111 preferentially binds chitin. Employing translational fusion proteins with superfolder GFP (sfGFP), pull-down assays, and surface plasmon resonance (SPR) has provided evidence for binding to polyethylene terephthalate (PET) and other synthetic polymers. Structural analysis suggested that a Trp triad might be involved in protein adsorption. Mutation of these residues to Ala resulted in an impaired adsorption to microcrystalline cellulose (MC), but not so to PET and other synthetic polymers. We believe that the characterized SusDs, alongside the methods and considerations presented in this work, will aid further research regarding bioremediation of plastics. [ABSTRACT FROM AUTHOR]

Within this study, multi-walled carbon nanotubes (MWCNTs) (weight percentages were 0 and 0.9 wt %) and modified MWCNTs (MWCNTs-Carboxylic acid (COOH)) (weight percentages were 0 and 0.9 wt %) were incorporated into the thermoplastic polymer of polyethylene terephthalate (PET) and reinforcement fibers of the glass fiber (GF) to fabricate hybrid composites with non-crimp fabrics (NCFs) with higher mechanical properties compared to the pristine. NCF reinforcements had fibers which were laid in 0° and 90° directions. The three-point bending tests were performed to understand the mechanical properties of the fabricated composite samples in 0° and -45° directions. The micro-structure and morphology of the composites were studied by using a scanning electron microscope (SEM) and optical microscopy (OM). The specimens with MWCNTs-COOH exhibited highest value of flexural properties with an improvement of 58.6% flexural modulus and 14.4% flexural strength compared to the specimens without MWCNTs-COOH in 0° direction [ABSTRACT FROM AUTHOR]

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In the era of the global drive for sustainability in line with the United Nations Sustainable Development Goals (UN SDGs), sustainability measures are encouraged to be taken at all levels. This study explores a novel mix design integrating Reclaimed Asphalt (RAP) with waste Polyethylene Terephthalate (PET) to enhance pavement performance and sustainability. It adopts a holistic approach by investigating the technical, economic, and environmental aspects of the proposed mix to assess its sustainability. Industry experts emphasize the necessity of mitigating the resource intensiveness of pavement construction to foster sustainable infrastructure. RAP enables resource-efficient pavement construction by promoting asphalt recycling. However, increasing RAP quantity in the mix compromises asphalt structural stability, making it more susceptible to moisture damage and rutting. In this study, PET-modified Bitumen (PMB) is incorporated in higher RAP quantities in the asphaltic mix without compromising asphalt's structural performance and durability. Various PMB amounts (2% to 10% by mass of mixture) were tested with 40% RAP (by mass of mixture), evaluating performance in terms of moisture damage, Marshall stability, rutting, etc. Optimal results were achieved with 6% PET and 40% RAP, showing a 7%, 57%, and 23% improvement in moisture resistance, rutting resistance, and Marshall stability, respectively, compared to unmodified asphalt (technical aspects). The novel asphalt mix demonstrated a 17% reduction in material cost (economic aspect) and a 53% decrease in CO2 emissions (environmental aspect) using Building Information Modeling (BIM). This study devises a prospective solution for the construction of resilient, resource-efficient, cost-effective, environmentally friendly, and sustainable pavements in line with UN SDGs and circular economy goals. [ABSTRACT FROM AUTHOR]

Objective: Nanoplastics (NPs) are consider as emerging persistent environmental pollutants. Widespread distribution of these nanoparticles is a global problem. However, their toxic effects in mammalian tissues and cells remain mainly unknown. This study aims to investigate the cytotoxicity of PET nanoplastics (PET-NPs) in the human hepatocarcinoma (HepG2) cell line. Methods: Toxic effects after 72h of exposure to different concentrations of PET-NPs (10–500 µg/mL) were evaluated by morphological alterations, cell internalization, cell viability (MTT), lactate dehydrogenase (LDH) release assays, induction of oxidative stress (total antioxidant capacity, TAC), and genotoxicity (comet assay). Results: Cell viability reduced at all treatment concentrations in a dose–response manner, and 616.7 µg/mL was determined as IC50. No cell membrane damages detected by LDH assay. TAC reduced significantly after 12 h exposure to > 400 μg/mL PET-NPs. Dose-dependent DNA damages were observed after 72 h. Conclusion: These findings indicated that PET-NPs have significant cytotoxic effects, particularly on genotoxicity and induction of oxidative stress. The results obtained here showed a significant impact of PET-NPs at the tested concentrations suggest a potential impact on humans. Other studies are currently underway to confirm these toxic effects. [ABSTRACT FROM AUTHOR]

Honey, renowned for its nutritional and therapeutic properties, has recently come under scrutiny due to its contamination by microplastics, in multiple ways. Bees' exposure to plastic pollution impacts the whole hive's ecosystem, and plastic tends to accumulate in hive products. Plastic packaging as polyethylene terephthalate (PET) is used to store honey in small flexible packages, which also increases the risk of microplastic migration. This study aims to establish three practical detection methods for PET microplastics and nanoplastics in honey, using readily available laboratory equipment without the need for chemical digestion or costly pretreatment protocols, in a laboratory-based simulation. The first method utilizes Raman micro-spectroscopy, offering high-resolution identification of PET microplastics on cellulose acetate filters with Raman mapping, eliminating the need for organic solvents or dyes. The second method employs optical microscopic observation under fluorescence with the aid of 4-dimethylamino-4′-nitrostilbene dye and ultraviolet radiation to enhance microplastic visibility, making it suitable for laboratories with standard optical microscopes. To isolate MPs from the solid honey particles, a density separator has been introduced using pentane. Lastly, the third method employs the use of electrospray ionization mass spectrometry for the detection of nanoplastics (<200 nm) in honey samples, through the examination of the different extraction phases of density separation. All the aforementioned methods contribute to efficient microplastic detection in honey, ensuring its quality and safe consumption. [ABSTRACT FROM AUTHOR]

The valorization technique successfully transformed waste polyethylene terephthalate (PET) into valuable carbon nanomaterial (CN)/graphene, while doped and undoped ZnO nanopowders were synthesized via sol–gel methods. Utilizing XRD, BET, TEM, EDX, FTIR, and TGA analyses, the synthesis of sp2 2D sheet, pristine, and doped ZnO nanostructures was confirmed. Solid-state gas sensor devices, tested under 51% relative humidity (RH), 30 °C ambient temperature, and 0.2 flow rate, exhibited a 3.4% enhanced response to H2 gas compared to CO2 at 50 ppm concentrations over time. Notably, the ZnO/CN sensor surpassed CN and ZnO alone, attributed to CN dopant integration with decreasing order of response performance as ZnO/CN > CN > ZnO. This study underscores the efficacy of valorization techniques in generating high-value carbon nanomaterials and their efficacy in bolstering gas sensor performance, with ZnO/CN demonstrating superior response capabilities. [ABSTRACT FROM AUTHOR]

Microbial strains with potential hydrolytic enzymes are excellent hosts for the biodegradation of polyethylene terephthalate (PET). However, knowledge of the best working conditions for enzymatic actions is essential to suggest the most suitable condition for the bio-transformation process. In this research, PETase and lipase produced by Serratia marcescens under PET exposure were screened and their physicochemical properties were evaluated. Furthermore, the biodegradation efficiency of the cell-free extract produced from S. marcescens on a PET sheet was studied via scanning electron microscope (SEM) and Fourier transform infrared spectrophotometer (FTIR). The result showed maximum production of PETase activity (8.80 U mL-1) and lipase activity (7.48 U mL-1) by S. marcescens on the sixteenth and tenth day of cultivation. The physicochemical study showed that they were active and stable over a wide range of pH (5.0–11.0) and temperature (30 °C–80 °C), with optimum PETase activity at pH 7.0 and 50 °C. At the same time, lipase had optimum activity at pH 9.0 and 60 °C. PETase activity was inhibited by Ca2+ and Cu2+ and significantly enhanced when exposed to Mg2+ and Ba2+ while lipase activity was significantly enhanced with the addition of Ca2+ and Mg2+. However, EDTA chelated the activities of both enzymes. The SEM profile of the PET sheet surface after enzymatic degradation revealed the presence of cracks while FTIR spectra of the PET sheet showed the creation, disappearance, and shiftings of peaks at different wavelengths when compared with control. In conclusion, this study shows the capacity of S. marcescens to produce PETase and lipase and reveals the cell-free extract to hold great prospects that can be utilized for industrial and domestic remediation of PET wastes to achieve a cleaner environment.

Indonesia has the second-highest level of ocean plastic pollution. Polyethylene terephthalate (PET) plastic, used in food and beverage packaging, is the most accessible plastic for recycling. Recycling PET plastic waste can address the issue of waste management and support a circular economy, while protecting the environment. However, consumer participation is crucial for maintaining recycling programs. In this study, we determined the driving forces of customer participation with respect to post-consumption PET waste. The Theory of Planned Behavior (TPB) was used to understand the factors that motivate the consumers’ recycling intentions. We conducted a survey to assess the post-consumption behavior related to PET usage (with 294 respondents), using a questionnaire; to analyze the survey results, we used a structural equation model with partial least squares (SEM-PLS). The attitudes, moral norms, and consequence awareness of the consumers significantly affected their recycling intentions. Perceived behavior and subjective norms did not affect this desire. In Indonesia, consumer behavior after PET consumption primarily involves disposal. This study improves the understanding of consumer behavior and can help businesses and governments to implement strategies that encourage consumers to return used PET goods. In addition, this study enriches the literature on reverse logistics from a consumer perspective.

Polyethylene terephthalate (PET) is widely used as a primary plastic packaging material in the global socio-economic system. However, research on the metabolic characteristics of the PET industry across different countries, particularly regarding the entire life cycle supply chain of PET, remains insufficient, significantly hindering progress in addressing plastic pollution worldwide. This study employs the Life Cycle Assessment-Material Flow Analysis (LCA-MFA) method to comprehensively analyze the environmental impacts of PET plastics, with a focus on the processes from production to disposal in 12 regions (covering 41 countries) in 2020. By constructing 13 scenarios and analyzing the development trajectory of PET plastics from 2020 to 2030, this study provides scientific evidence and specific strategies for waste reduction and emission reduction measures in the PET industry. Overall, in 2020, the 12 regions (41 countries) consumed 7297.7 kilotons (kt) of virgin PET resin and 1189.4 kt of recycled PET resin; 23% of plastic waste was manufactured into recycled PET materials, 42% went to landfills, and 35% was incinerated. In 2020, the entire PET plastic supply chain emitted approximately 534.6 million tons (Mt) of carbon dioxide equivalent per year, with production emissions accounting for 46.1%, manufacturing stage emissions accounting for 44.7%, and waste treatment stage emissions accounting for 9.2%. Research indicates that under a scenario of controlled demand, resource efficiency improvement and emission reduction are the most effective, potentially reducing carbon emissions by up to 40%. [ABSTRACT FROM AUTHOR]

As transparent, flexible, and wearable organic electronics degrade under normal outdoor environmental conditions (e.g., water vapor, oxygen, and UV light) and extreme environments, including washing or rain, a customized encapsulation technology is required to improve device reliability. Herein, a simple process is presented for fabricating multifunctional hazy substrates (MFHSs) with excellent gas diffusion barrier (GDB), flexibility, UV reflectance, light scattering, and waterproof properties. First, a spiky polyethylene terephthalate (PET) surface is produced with 76.0% optical haze through ion‐beam treatment followed by the formation of a hydrophobic layer to achieve a waterproof effect (contact angle: 153.3°). Then, a multifunctional multibarrier film is fabricated based on a nano‐laminated distributed Bragg reflector and functional polymer on the functional PET substrate to serve as a GDB and UV filter. This multibarrier film has excellent mechanical and chemical stabilities, in addition to having a water vapor transmission rate of 10−6 g m−2 day−1 and UV transmittance of <3%. The so‐fabricated MFHS not only increases the device efficiency by 73% but also enables a highly flexible and environmentally stable organic light–emitting diode. The surface treatment and encapsulation technologies developed in this study are expected to increase the lifetime of organic devices and facilitate high outdoor usability. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is the conventional plastic used for packaging but disposal of PET in the natural environment poses significant threats to the ecological system. In the biological process, the degradation of PET plastic using PET-degrading enzyme (PETase) has attracted scientific interest, thus increasing the exploration of PETase evolution. This study aims to exploit a new PETase from a greenhouse farm in Tainan, Taiwan. The in-silico approach of shotgun metagenomic analysis, enzyme structural prediction, molecular docking and simulations were applied, thus narrowing the cleft and identifying a potential PETase-like enzyme, denoted as F148. The heterologous expression of F148 in Escherichia coli strains was capable of breaking down PET into terephthalate monomer (TPA). Furthermore, the PET-degrading ability of F148 was optimized using the incorporation of MHETase and Colicin E7 via in vitro and in vivo digestion methods, respectively. The in vivo system served as a concise approach due to allowing simultaneous F148 secretion, thus achieving the highest TPA amount of 0.56 mg, equivalent to 11.2% weight loss of PET. This study not only contributes promising insights into the exploration of a distinctive gene but also successfully invents an efficient PETase using a one-step in vivo process in genetically modified E. coli. [Display omitted] • A novel F148 PETase was discovered from untapped source of local soil metagenomics. • Escherichia coli Lemo21 was consigned as an efficient host for expression of F148. • In vitro reaction of MHETase and F148 synergistically promotes PET degradation. • Co-expressing colicin E7 lysis and F148 invents a one-step PET degradation method. • The highest degradation efficiency is 0.56 mg-TPA/g-protein via in vivo process at 120 h. [ABSTRACT FROM AUTHOR]

Morphology and phase regulation shed light on the tuning of microwave absorbing characteristics, as well as magnetic and optical features. Not only is the development of electromagnetic wave absorbing materials the best way to equip us against harmful electromagnetic waves in the technology era, but the widespread applications of microwave absorbers in military and civilian fields have also enhanced their importance. Hence, MgFe 2 O 4 nanoparticles were synthesized, and then (1) its main crystalline phase was divided into Mg, Fe 2 O 3 , and Fe 3 O 4 , and (2) its morphology was manipulated to evaluate the influence of morphology and phase on the microwave absorbing performance, optical characteristics, and magnetic capability. The novel precursors, along with modified sol-gel and solvothermal scenarios, were applied to regulate the structures toward strengthening the features. Interestingly, polyethylene terephthalate (PET) was chosen as the recyclable plastic to fabricate the final composites to evaluate the microwave absorbing/shielding characteristics due to its fascinating susceptibilities as building materials, minimizing environmental hazards and implementing green and sustainable manufacturing. Noticeably, Mg/Fe 3 O 4 /PET nanocomposite gained a brilliant RL of −95.50 dB at 21.80 GHz meanwhile the one-pot-synthesized Fe 2 O 3 /MgFe 2 O 4 composited by PET attained a maximum RL of −71.32 dB at 23.06 GHz and an ultra-high efficient bandwidth (RL ≤ −20 dB) of 8.50 GHz with only thickness of 0.50 mm. Interestingly, the PET-based microwave absorbers were fabricated with a low filling ratio of 10 wt%. More significantly, the samples illustrated proper shielding efficiency, desirable for practical applications in the modern era. [Display omitted] [ABSTRACT FROM AUTHOR]

Over the past few years, polymer nanocomposites have garnered a significant amount of interest from both the scientific community and industry due to their remarkable versatility and wide range of potential uses in various fields, including automotive, electronics, medicine, textiles and environmental applications. In this regard, this study focuses on the influence of a compatibilizer rubber on a nanocomposite incorporating graphene nanoparticles (GNPs), with a polymer matrix based on a blend of polypropylene (PP) and polyethylene terephthalate (PET). This effect has been investigated on both isotropic samples and on anisotropic/spun fiber samples. The influence of the compatibilizer rubber on morphological, rheological and mechanical properties was analysed and discussed. Mechanical and morphological properties were evaluated on both isotropic samples obtained by compression moulding and melt-spun fibers. The addition of the rubbery compatibilizer increased the viscosity, improving interfacial adhesion, and the same effect was observed for the melt strength and breaking stretching ratios. Mechanical properties, including the elastic modulus, tensile strength and elongation at break, improved in both types of samples but more significantly in the fibers. These improvements were attributed to the orientation of the matrix, the formation of PET microfibrils, and the reduction in the size of graphene nanoparticles due to the action of the elongational flow. This reduction, facilitated by the elongation flow and the action of the compatibilizer, improved matrix–nanofiller adhesion due to the increased contact area between the two polymeric phases and between the filler and matrix. Finally, a transition from brittle to ductile behaviour was observed, particularly in the system with the compatibilizer, attributed to defect reduction and improved stress transmission. [ABSTRACT FROM AUTHOR]

While the effects of chronic exposure to microplastic particles (MPs) are extensively studied, the outcomes of a single treatment have received relatively less attention. To investigate MPs' potential acute toxicity, including their impact on general health status (victual consumption, sensorimotor deficits, and clinical toxicity signs) and serum biochemical parameters (markers of organ/tissue function and oxidative stress indicators), we administered thoroughly characterized MPs (1.4, 35, or 125 mg/kg), generated from polyethylene terephthalate (PET) bottles, to adult male Wistar rats via oral gavage. The MPs' short-term effects were assessed with well-established tests and methods. The results point to the absence of sensorimotor deficits and clinical toxicity signs, while levels of markers of liver, heart, and kidney function were altered in all MP groups. Decreased victual consumption and increased levels of oxidative stress indicators were evident following treatment with the two higher MP doses. Presented data indicate that examined MPs are able to initiate the development of local changes in tissues and organs within a short time frame, potentially leading to their damage and dysfunction. This study may increase the awareness of the detrimental effects of plastic contamination, as even a single exposure to MPs may provoke adverse health outcomes. [ABSTRACT FROM AUTHOR]

This work explores the definition and characterization of synthetic polymeric oligomers, chemical substances comprising a small number of repeated organic molecules. It highlights the lack of clarity surrounding the range of repeated units that can be classified as an oligomer, and how this definition is field-dependent. The present study focused on PET cyclic oligomers and revealed that the progression of the ring length from smaller to longer oligomers followed the well-known odd-even effect. This phenomenon affects the physical and chemical properties of oligomers and can also be observed with analytical techniques such as differential scanning calorimetry (DSC), high resolution mass spectrometry (HR-MS) and NMR. Similarities between PET and PBT oligomers were also observed, and an alternative potential definition for oligomers in the polymeric field is suggested based on physical behaviour of the longer cyclic oligomers. [ABSTRACT FROM AUTHOR]

Coffee pods and capsules require packaging that guarantees the optimal coffee preservation. The chemical composition of coffee can undergo quality decay phenomena during storage, especially in terms of lipidic and volatile components. Amongst coffee packaging, aluminum multilayer materials are particularly widely diffused. However, aluminum is a negative component because it is not recoverable in a mixed plastic structure and its specific weight gives significant weight to packaging. In this study, a multilayer film with a reduced content of aluminum was used to package coffe pods and capsules and compared to a standard film with an aluminum layer. Their influence on the peroxides and volatile organic compounds of two coffee blends, 100% Coffea arabica L., 50% Coffea arabica L., and 50% Coffea canephora var. robusta L., were studied during their 180-day shelf life. The predominant volatile organic compounds detected belonged to the class of furans and pyrazines. Both packaging materials used for both coffee blends in the pods and capsules showed no significant differences during storage. Thus, the alternative packaging with less aluminum had the same performance as the standard with the advantage of being more sustainable, reducing the packaging weight, with benefits for transportation, and preserving the coffee aroma during the shelf life. [ABSTRACT FROM AUTHOR]

Since we rely entirely on plastics or their products in our daily lives, plastics are the invention of the hour. Polyester plastics, such as Polyethylene Terephthalate (PET), are among the most often used types of plastics. PET plastics have a high ratio of aromatic components, which makes them very resistant to microbial attack and highly persistent. As a result, massive amounts of plastic trash accumulate in the environment, where they eventually transform into microplastic (

The reason for conducting this research was to examine asphalt mixtures and the influence of additives obtained from recycled Polyethylene Terephthalate (PET) on their mechanical properties. Due to this, after the chemical recycling of PET, the substance resulting from the chemical reaction was added to the asphalt binder in different contents. In order to evaluate the mechanical performance of mixtures containing additives, a variety of different mechanical tests were carried out. In order to accomplish this goal, tests including dynamic creep, indirect tensile strength (ITS), and indirect tensile modulus (IDTM) were carried out to determine rutting, moisture susceptibility, and resilient modulus, respectively. The SCB test is used to determine how well a material resists cracking when subjected to low temperatures. The results showed that the addition of an additive derived from recycled PET could increase the rutting resistance, significantly improve resistance against moisture damage and increase cracking resistance at low temperatures. In accordance with the findings of the indirect tensile strength tests, indirect tensile modulus and SCB was the best performance related to the asphalt mixture containing 2% recycled PET. However, this result was different in the dynamic creep test, and the asphalt mixture containing 1% additive showed the best performance. The results of data analysis with one-way analysis of variance showed that all the data obtained in this study are statistically significant considering the confidence factor of 95%, so it can be said that the addition of recycled PET additive has a significant effect on the mechanical properties of the asphalt mixture.

The widespread utilization of polyethylene terephthalate (PET) has caused a variety of environmental and health problems. Compared with traditional thermomechanical or chemical PET cycling, the biodegradation of PET may offer a more feasible solution. Though the PETase from Ideonalla sakaiensis (IsPETase) displays interesting PET degrading performance under mild conditions; the relatively low thermal stability of IsPETase limits its practical application. In this study, enzyme-catalysed PET degradation was investigated with the promising IsPETase mutant HotPETase (HP). On this basis, a carbohydrate-binding module from Bacillus anthracis (BaCBM) was fused to the C-terminus of HP to construct the PETase mutant (HLCB) for increased PET degradation. Furthermore, to effectively improve PET accessibility and PET-degrading activity, the truncated outer membrane hybrid protein (FadL) was used to expose PETase and BaCBM on the surface of E. coli (BL21with) to develop regenerable whole-cell biocatalysts (D-HLCB). Results showed that, among the tested small-molecular weight ester compounds (p-nitrophenyl phosphate (pNPP), p-Nitrophenyl acetate (pNPA), 4-Nitrophenyl butyrate (pNPB)), PETase displayed the highest hydrolysing activity against pNPP. HP displayed the highest catalytic activity (1.94 μM(p-NP)/min) at 50 °C and increased longevity at 40 °C. The fused BaCBM could clearly improve the catalytic performance of PETase by increasing the optimal reaction temperature and improving the thermostability. When HLCB was used for PET degradation, the yield of monomeric products (255.7 μM) was ∼25.5 % greater than that obtained after 50 h of HP-catalysed PET degradation. Moreover, the highest yield of monomeric products from the D-HLCB-mediated system reached 1.03 mM. The whole-cell catalyst D-HLCB displayed good reusability and stability and could maintain more than 54.6 % of its initial activity for nine cycles. Finally, molecular docking simulations were utilized to investigate the binding mechanism and the reaction mechanism of HLCB, which may provide theoretical evidence to further increase the PET-degrading activities of PETases through rational design. The proposed strategy and developed variants show potential for achieving complete biodegradation of PET under mild conditions.

The shear behavior of simply supported RC beams strengthened with polyethylene terephthalate (PET) fiber-reinforced polymer (FRP) was studied in this paper. The test variables include strengthening schemes (i.e., U-wrapping and full-wrapping) and FRP reinforcement ratios. A comprehensive and meticulous investigation was conducted on the failure mode of RC beams, shear force-deflection curves, the development process of shear cracks, the evolution of FRP strain, and the interaction between FRP and concrete. The shear capacity and deformation were increased by 42.5–123.2% and −16.34–96.89% using the fully wrapped scheme, respectively. The improvement in shear capacity was 42.5–72.55% when the U-wrapped scheme was adopted. The PET FRP fully wrapped beams exhibited a type of ductile shear failure. The strain of PET FRP in the fully wrapped specimen exceeded 4% without fracture, ensuring the deformation capacity after the peak load. The shear deformation caused the increase in post-peak mid-span deflection. The U-wrapped specimens showed debonding failure, with the debonding strain of PET FRP being more than that of conventional FRP. Finally, six design guidelines for PET FRP shear contribution were evaluated for both U-wrapped and fully wrapped schemes.

This paper presents a wide incident angle, wideband, and polarization-insensitive unit cell frequency-selective surface (FSS) on single- and double-glazing glass. The 5G signal losses due to the shielding of building materials lead to high penetration losses that degrade the data rates, energy, and spectral density. The transmission coefficient of glass is lower than that of the materials used in buildings. So, investigating and enhancing radio frequency signal losses on glassy windows at sub-6GHz frequency band is crucial to increase the transmission coefficient. This paper uses three different transparent materials: ITO-PET film, silver nanowires (AgNWs) on a polymer substrate, and silver on a pet substrate as an FSS coating material for glassy windows to enhance the transmission coefficient at the n77 and n78 bands. The optimization of unit cell parameters was implemented using the Trust Region Framework (TRF) algorithm. The investigation for single and double glazing has shown that the thicker the glass, the lower the transmission coefficient. Moreover, the simulation result of the proposed FSS can support up to ${85}^{o}$ and ${75}^{o}$ for single- and double-glazing glass, respectively. A maximum of 17 dB enhancement was obtained from single-glazing glass, and a maximum of 10 dB enhancement was obtained from double-glazing glass. Thus, the designed FSS structure can enhance 5G signal transmission from outdoors to indoors.

The inclusion of particles in a polymeric substrate to achieve certain properties is a well-known practice. In the case of textile substrates, this practice may deeply affect the structure of the produced yarns, as even a filament with no textile applications can be obtained. In this manuscript, titanium dioxide (TiO2) particles were incorporated into polyester (PET) chips and the influence of these fillers on the properties of yarn and fabric, and the ultraviolet protection factor (UPF) was assessed. For this purpose, rutile and anatase crystalline forms of TiO2, as well as the size of the particles, were evaluated. Moreover, parameters such as mechanical properties, orientation of the macromolecules and thermal behavior were analyzed to ensure that the textile grade is maintained throughout the production process. The results showed that the inclusion of micro- and nanoparticles of TiO2 decreases the molecular weight and tenacity of PET. Also, although orientation and crystallinity varied during the textile process, the resulting heatset fabrics did not present important differences in those parameters. Finally, the attainment of textile-grade PET-TiO2 fabrics with UPF indexes of 50+ with both rutile and anatase and micro- and nano-sized TiO2 forms was demonstrated. [ABSTRACT FROM AUTHOR]

The degradation of plastics upon UVC irradiation in aqueous solution and the formation of microplastic (MP) particles were investigated. Polypropylene (PP) and recycled and virgin polyethylene terephthalate (PET) were irradiated with a UV lamp emitting light at 254 nm. Irradiation was performed for 15 and 30 min, respectively, at an intensity of about 0.3 W cm−2. The formation of MP was studied by Raman spectroscopy. The results showed that MP particles were formed after irradiation and that their number was significantly higher in the recycled PET than in the virgin material. The number of PP MP formed was lower compared to PET and was not significantly different after 15 and 30 min. In addition, ethanol was used as an alternative solvent to investigate how its chemical properties and interactions with UVC irradiation affect the degradation of PET and PP plastics. The use of ethanol and recycled PET resulted in a lower number of MP particles at both irradiation times. When ethanol was used after 30 min of irradiation, significantly more PP MP formed. The different chemical structures of PET and PP combined with the different solvent properties of water and ethanol contribute to the differences in their susceptibility to UVC degradation. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is a chemical compound widely used especially in the production of polycarbonate plastics and epoxy resins. BPA is a carcinogen and comes into foods due to plastic materials that come into contact with foodstuffs. The aim of this research was to determine the change in the BPA level in Savak brined white cheese during cold storage in polyethylene terephthalate (PET) packages. For this purpose, two groups were assigned as control (standard cheese produced by raw cow's milk) and BPA (cheese produced from the raw cow milk with 1 mg/L BPA added). The cheese samples were packed in PET packages containing, an 18% brine solution, and stored at +4°C for 270 days. The statistically significant difference was found in BPA levels between the control and BPA‐added group in PET packages (P ≤ 0.05). The BPA levels in the brine solution and cheese of the control group were determined between 0.443–0.747 μg/L and 0.927–1.237 μg/kg, respectively. BPA levels in the brine and cheeses of the BPA‐added group were between 1387–1894 μg/L and 3702–4205 μg/kg, respectively. The results showed that the using of BPA in cheese production leads to very high levels of BPA even during long storage and poses a risk to consumer health. [ABSTRACT FROM AUTHOR]

Many researchers have investigated the solutions for the problem of solid waste in different ways. An example of that is reusing polyethylene terephthalate (PET) as reinforcement to concrete. Strapping plastic belts used to tie clay bricks while transportation in trucks are one of the common waste of construction that could be beneficial in enhancement of concrete flexural behaviour due to its high tensile strength. This paper is a trial to investigate the effect of utilizing waste strapping plastic belts on the flexural behavior of concrete. Concrete prisms (100*100*500mm) were reinforced with plastic belts as the main reinforcement for flexural strength. Five amounts of reinforcement were added to the concrete section in the tension zone (81, 67.5, 54, 40.5, 27 sqr mm). The reinforcement was included in concrete sections internally or externally using suitable glue. The behavior of the reinforced prisms was compared to plane concrete prisms (containing no reinforcement). Tests results showed an enhancement in flexural strength of concrete section while reinforcement ratio is increased externally. The addition of 81 mm² of plastic straps externally, increased the flexural strength by 21% compared to sections with 27 mm² reinforcement. The enhancement in flexural strength as internal reinforcement is added was limited. According to the flexural test of reinforced concrete prizms. Adding 81 mm² of plastic straps internally, reduced the flexural strength by 18% compared to sections with 54 mm² reinforcement due to the splitting of the cover as the area of the reinforcement increases. Increasing the number of belts in the section results in a sever reduction in the spacing between each two belts, leading to increase concrete cover tendency to split. For that, increasing the amount of plastic diversely affects connectivity for the internally reinforced sections. [ABSTRACT FROM AUTHOR]

Microplastics are a major environmental issue. In marine systems, these break down into small fragments that may lodge within organisms, but they behave as vectors for chemicals when pollutants such as metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, and pharmaceuticals are absorbed by the particles. The rate and extent of uptake of organic compounds onto microplastics is dependent on a range of factors such as the sites available on the surface, the type of plastic, and the compound being sorbed, with hydrophobicity an important property. Laboratory experiments determined the uptake of pyrene and acenaphthene (and sometimes phenanthrene) onto pellets of polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyoxymethylene (POM), polypropylene (PP) and polystyrene (PS). The kinetics of uptake in the experiments reveals half-lives ~10 h. The extent of partition onto the plastic pellets was similar for pyrene and phenanthrene, though lower for acenaphthene. This was not surprising because the octanol-water distribution coefficient of acenaphthene is about an order of magnitude smaller than that of pyrene, suggesting it is less hydrophobic. The PAHs are distributed most strongly into PP but only weakly into PVC. The fragmentation and oxidation of microplastics means that they sorb increasing amounts of organic material as they age. [ABSTRACT FROM AUTHOR]