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In this work, the oxygen barrier property of polyethylene terephthalate (PET) films was enhanced by optimizing the 'active' and 'passive' synergistic barrier approaches, that is, integration of high barrier material polyethylene naphthalate (PEN) and oxygen scavengers along with catalyst with PET before biaxially stretching the PET blended films. When the PEN content in the PET blended films reached 50wt%, the oxygen permeability coefficient was significantly reduced to 0.9687 cc*mil*[m.sup.-2]*[day.sup.-1] 0.1 [MPa.sup.-1], showing an enhancement of 117.4 times compared to the pure PET film. Furthermore, the water vapor permeability coefficient was reduced to 8.0208 g*mil*[m.sup.-2]*[day.sup.-1], representing a 45.5% reduction in comparison to the pristine PET film. It also maintained a higher transverse and longitudinal tensile strength (110.5 and 127.2 MPa) than PET film only with oxygen scavengers and catalyst (53.5 and 78.0 MPa). This work presents a viable and practical approach to endow PET materials with simultaneously enhanced oxygen, water barrier performance, and mechanical property. Highlights * The OPC of PET film was as low as 0.9687 cc*mil*[m.sup.-2]*[day.sup.-1]*0.1 [MPa.sup.-1]. * The 'active' and 'passive' barrier techniques together reduced the OPC of PET film. KEYWORDS blow molding, oxygen barrier, oxygen scavenging, polyethylene naphthalate, polyethylene terephthalate, water barrier, 1 | INTRODUCTION Polyethylene terephthalate (PET) is widely used as a thermoplastic polyester in food packaging due to its excellent mechanical property, affordability, as well as high transparency. (1,2) Although [...]

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]

Introduction: The development and optimization of novel diagnostic imaging prototypes heavily rely on experimental work. In radiology, this experimental work involves the use of phantoms. When testing novel techniques to demonstrate their advantages, anthropomorphic phantoms are utilized. The aim of this study was to investigate seven materials for 3D printing to replicate the radiological properties of breast lesions. Methods: To achieve this objective, we utilized three fused filament fabrication materials, namely, polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and polyethylene terephthalate glycol (PET-G), along with resins such as White v4 Resin, Flexible 80A v1 Resin, Model v2 Resin, and Wax40 v1 Resin, to 3D print seven irregularly shaped lesions. These lesions were used to prepare a set of seven physical phantoms, each filled with either water or liquid paraffin, and one of the printed lesions. The phantoms were then scanned using a mammography unit at 28 kVp. Additionally, six computational breast phantoms, replicating the shape of the physical phantoms, were generated. These computational models were assigned the attenuating properties of various breast tissues, including glandular tissue, adipose tissue, skin, and lesions. Mammography images were generated under the same experimental conditions as the physical scans. Both the simulated and experimental images were evaluated for their contrast-to-noise ratio (CNR) and contrast (C). Discussion: The results indicated that the studied resins and filament-based materials are all suitable for replicating breast lesions. Among these, PLA and White v4 Resin exhibited the densest formations and can effectively approximate breast lesions that are slightly less attenuating than glandular tissue, while ABS and Flexible 80A v1 Resin were the least dense and can represent fat-containing breast lesions. The remaining materials provided good approximations for malignant lesions. These materials can be utilized for constructing phantoms for experimental work, rendering the model a valuable tool for optimizing mammography protocols, ensuring quality control of mammography X-ray equipment, and aiding in the diagnosis and assessment of breast cancer. [ABSTRACT FROM AUTHOR]

A new type of hybrid polymer particles capable of carrying the cytostatic drug doxorubicin and labeled with a gallium compound was prepared. These microparticles consist of a core and a hydrogel shell, which serves as the structural matrix. The shell can be employed to immobilize gallium oxide hydroxide (GaOOH) nanoparticles and the drug, resulting in hybrid beads with sizes of approximately 3.81 ± 0.09 μm. The microparticles exhibit the ability to incorporate a remarkably large amount of doxorubicin, approximately 0.96 mg per 1 mg of the polymeric carrier. Additionally, GaOOH nanoparticles can be deposited within the hydrogel layer at an amount of 0.64 mg per 1 mg of the carrier. These nanoparticles, resembling rice grains with an average size of 593 nm by 155 nm, are located on the surface of the polymer carrier. In vitro studies on breast and colon cancer cell lines revealed a pronounced cytotoxic effect of the hybrid polymer particles loaded with doxorubicin, indicating their potential for cancer therapies. Furthermore, investigations on doping the hybrid particles with the Ga-68 radioisotope demonstrated their potential application in positron emission tomography (PET) imaging. The proposed structures present a promising theranostic platform, where particles could be employed in anticancer therapies while monitoring their accumulation in the body using PET. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET), a widely used polymer in the production of single-use plastics, is a significant contributor to the global plastic pollution problem. This work explores the synergistic effects between clay matrices and active Nb 2 O 5 catalytic species, emphasizing the enhanced catalytic performance for the aminolytic depolymerization of PET and polyester (PES) wastes. The materials were well characterized using XRD, SEM-EDS, FTIR, and UV-DRS studies. The surface parameters of Nb 2 O 5 were enhanced by forming a composite with kaolin, which is confirmed by BET isotherms. Kaolin provides a large surface area, which enhances the dispersion and interaction of the niobia catalyst. The combination of kaolin and niobia acts as an effective catalyst for the depolymerization of PET, breaking down the polymer into its monomeric constituents. The catalytic efficiency of Nb 2 O 5 (82 %) has been enhanced in the presence of kaolin support (95 %), forming depolymerized bis(2-hydroxyethyl)terephthalamide (BHETA) and excellent reusability and stability of up to five subsequent cycles thereby emphasizing their potential for sustained performance in industrial applications and contributing to the ongoing discourse on advancing catalyst technologies for enhanced environmental impact in the circular economy. [ABSTRACT FROM AUTHOR]

Background: Coronaviruses, a group of highly transmissible and potentially pathogenic viruses, can be transmitted indirectly to humans via fomites. To date, no study has investigated their persistence on carpet fibers. Establishing persistence is essential before testing the efficacy of a disinfectant. Methods: The persistence of BCoV and HCoV OC43 on polyethylene terephthalate (PET) and nylon carpet was first determined using infectivity and RT-qPCR assays. Then, the disinfectant efficacy of steam vapor was evaluated against both coronaviruses on nylon carpet. Results: Immediately after inoculation of carpet coupons, 32.50% of BCoV and 3.87% of HCoV OC43 were recovered from PET carpet, compared to 34.86% of BCoV and 24.37% of HCoV OC43 recovered from nylon carpet. After incubation at room temperature for 1 h, BCoV and HCoV OC43 showed a 3.6 and > 2.8 log10 TCID50 reduction on PET carpet, and a 0.6 and 1.8 log10 TCID50 reduction on nylon carpet. Based on first-order decay kinetics, the whole gRNA of BCoV and HCoV OC43 were stable with k values of 1.19 and 0.67 h− 1 on PET carpet and 0.86 and 0.27 h− 1 on nylon carpet, respectively. A 15-s steam vapor treatment achieved a > 3.0 log10 TCID50 reduction of BCoV and > 3.2 log10 TCID50 reduction of HCoV OC43 on nylon carpet. Conclusion: BCoV was more resistant to desiccation on both carpet types than HCoV OC43. Both viruses lost infectivity quicker on PET carpet than on nylon carpet. Steam vapor inactivated both coronaviruses on nylon carpet within 15 s. [ABSTRACT FROM AUTHOR]

In addition to sportswear and outdoor equipment, moisture-absorbent quick-drying fabrics are also widely used in everyday clothing and home textiles. In this study, three types of weft-knitted fabrics were designed using Coolmax fiber and polypropylene fiber. The Coolmax/PP fabric exhibits good stretchability with a strain of 180.5% and achieves a high cumulative individual transfer capability of 691.6%, with a water absorption rate of 50.2%/s. The moisture conductivity gradient presented good moisture and heat conductivity in a simulated human body temperature environment using an infrared camera. Furthermore, mathematical modeling was constructed and visual simulation analysis was conducted to explore moisture–thermal transfer behavior. The simulation results closely align with experimental data, providing insights into designing flexible and wearable quick-drying fabrics for thermal management. [ABSTRACT FROM AUTHOR]

Cryogenics is the science and technology of very low temperatures, typically below 120 K. The most common applications are liquified natural gas carriers, ground-based tanks, and propellant tanks for space launchers. A crucial aspect of cryogenic technology is effective insulation to minimise boil-off from storage tanks and prevent frost build-up. Rigid closed-cell foams are prominent in various applications, including cryogenic insulation, due to their balance between thermal and mechanical properties. Polyurethane (PU) foam is widely used for internal insulation in cryogenic tanks, providing durability under thermal shocks and operational loads. External insulation, used in liquified natural gas carriers and ground-based tanks, generally demands less compressive strength and can utilise lower-density foams. The evolution of cryogenic insulation materials has seen the incorporation of environmentally friendly blowing agents and bio-based polyols to enhance sustainability. Fourth-generation physical blowing agents, such as HFO-1233zd(E) and HFO-1336mzz(Z), offer low global warming potential and improved thermal conductivity. Additionally, bio-based polyols from renewable resources like different natural oils and recycled polyethylene terephthalate (PET) are being integrated into rigid PU foams, showing promising properties for cryogenic applications. Research continues to optimise these materials for better mechanical performance and environmental impact. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is widely used in plastic bottles, packaging, and textile fibers. However, PET is difficult to degrade in nature and rapidly accumulates into the environment, causing serious environmental pollution and threatening human health. At present, the recycling methods for PET mainly focus on physical recycling and chemical degradation, but these methods have severe limitations, resulting in the great loss of valuable materials and secondary pollution. In contrast, the biodegradation of PET is gradually attracting attention because of its environmental friendliness, high efficiency, and cost-effectiveness. Several PET-degrading enzymes (PDEs) have been previously identified, such as cutinase, IsPETase, lipase, and esterase. Thereafter, many efforts have been made to push the boundaries of evolution schemes, attempting to create stronger PDEs with improved activity and stability. Nevertheless, most of these enzymes show preferences toward low-crystallinity (<10%) PET, while in situ enzymatic degradation of high-crystallinity PET (30%–50%) remains a major challenge. Exploring and engineering PDEs that can efficiently degrade bottle-grade PET plastics has recently become a research hotspot. This review systematically introduces the current advances in PDEs and emphasizes the role of metagenomics in screening and identifying new PDEs. [ABSTRACT FROM AUTHOR]

Nano-plastics have been found in snow and evidence shows that they can act as nuclei. The aerosol water-uptake ability is an important property that will determine wet deposition, a potential main route for nano-plastics to fall to the ground. In this work, we measure the hygroscopicity of three nano-plastics: low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polyvinyl chloride (PVC), and a fourth compound, cellulose, with in-situ aerosol techniques via a cloud condensation nuclei counter. Cellulose is a high-molecular weight compound and a main component of commonly used paper products. Ultrafine nano-plastic particles in the range of 20 to 200 nm are explored. Nano-plastic materials LDPE, PET, and PVC form droplets more readily than cellulose nanoparticles. The high hygroscopicity of nano-plastics indicates that the nano-plastics are either oligomers or a polymer with properties for water adsorption. Furthermore, a single parameter hygroscopicity, κ, derived from different droplet activation models (Flory Huggins Köhler and Frenkel-Halsey-Hill adsorption theory) are reported. Moreover, the molecular weights of the leached oligomers are predicted by Flory Huggins Köhler theory assuming ideal polymer mixing. The observed intrinsic hygroscopicity is size-dependent, hence the adsorption-based hygroscopicity model could be applied. Nano-plastics can be incorporated into clouds, transported globally, and may also be removed from the atmosphere via wet deposition processes. The analysis of hygroscopicity help estimating the lifetime and transport of nano-plastic particles in the atmosphere. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is a known substance that is found in food contact materials as an intentionally added as well as a non-intentionally added substance. Traces of BPA were found as a non-intentionally added substance in recycled PET (rPET). In 2023, the EFSA proposed a new TDI of 0.0002 µg/kg bw/d, which is lower than the previous (temporary) TDI of 4 µg/kg bw/d by a factor of 20,000. The TDI of 0.0002 µg/kg bw/d would translate for a default 60 kg person eating one kilogram of food into a migration limit of 0.012 µg/kg in the food. This very low migration limit is a challenge to measuring BPA levels in food. A solution is to use migration modeling to establish maximum concentrations in rPET for different food contact applications. Precise diffusion coefficients for BPA in PET were determined within this study by use of migration kinetics. In June 2024, the European Commission proposed a new migration threshold limit for BPA of 1 µg/kg, which should be understood as a detection limit. From the results of this study, it can be concluded that a BPA concentration in the PET bottle wall of 297 mg/kg (3% acetic acid), 255 mg/kg (10% ethanol), and 192 mg/kg (20% ethanol) after storage for 365 d at 25 °C is in compliance with the migration threshold limit of 1 µg/kg. These maximum concentrations are far above the measured BPA concentrations on rPET bottles in Europe between 2019 and 2023. Therefore, the new proposed migration threshold limit for BPA cannot be exceeded. [ABSTRACT FROM AUTHOR]

The research addresses challenges in food safety related to the migration of contaminants from plastics to food. It focused on the physicochemical and sensory degradation of olive oils packaged in polyethylene terephthalate (PET) and subjected to thermal exposure at 40 °C and 60 °C for several weeks and a subsequent 12 months of storage, as well as the stability and migration of compounds from the PET packaging itself. Olive oils (OO) from Spanish supermarkets (a mixture of refined and virgin, with commercial identifications of mild and intense) were selected and subjected to thermal treatments at 40 °C and 60 °C for 1, 2, and 3 weeks, followed by 12 months of storage. The treatments were conducted through the following two independent experiments: Experiment A focused on immediate analysis post-thermal treatment, while Experiment B included a 12-month storage period post-thermal treatment. The presence of antimony (Sb) was analyzed using acid digestion with nitric acid (HNO3) and high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), while the metals cadmium (Cd), copper (Cu), lead (Pb), and iron (Fe) were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The PET characterization was assessed using Fourier transform infrared spectroscopy in the mid-infrared range (FT-IR/MIR), carbonyl index, and differential scanning calorimetry (DSC). The results showed increases in the acidity index by 0.29%, the peroxide value by 25.92%, and the K268 coefficient by 51.22% between the control sample and the most severe treatments, with more pronounced effects observed after 12 months. Sensory quality declined, with reduced intensity of the "fruity" attribute and increased presence of the "rancid" defect. PET degradation was reflected in an increase in the carbonyl index and greater structural amorphization. Fe was the predominant metal, and Sb concentration increased after thermal treatments. The lack of studies on the raw consumption of oils packaged in PET and the concerns about the migration of compounds from the packaging to the food highlight the relevance of this research. This study provides new insights into the effects of thermal exposure and storage on the migration of PET contaminants into oils, contributing to the development of strategies to ensure food safety and product quality. [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]

The simultaneous occurrence of various pollutants in the aquatic environment raises questions about their mutual interactions. There is a gap in research on the sorption of polar substances on microplastics. This study aimed to assess the adsorption of the antidepressants sertraline, fluoxetine and duloxetine on microplastic polystyrene, polyethylene terephthalate and polyvinyl chloride, each in two versions: virgin and aged. To assess the affinity of the tested drugs for plastic and planktonic organisms, the experiment was conducted in microplastic suspensions and in a mixture of microplastics with the protozoan Spirostomum ambiguum. The Fourier transform infrared technique assessed the identity of microplastics and changes during ageing. No significant differences were found between the sorption of the tested drugs on virgin and aged microplastics. The sorption of sertraline onto microplastics was 1.5–3 times lower in the presence of the protozoa than in samples with microplastics alone. Moreover, its concentration in the protozoan cells was 10–30 times higher than in the microplastics. Considering that the amount of plankton in freshwaters is much greater than that of microplastics, it should be concluded that microplastics have a negligible share in the transport of antidepressants in surface waters. [ABSTRACT FROM AUTHOR]

As an emerging contaminant, the spatial distribution characteristics of microplastics in source water reservoirs warrant further attention from researchers. In this study, the Luhun Reservoir, which is situated in the middle reaches of the Yellow River, was selected as the object. Field sampling and detection were conducted to ascertain the presence of microplastics in water and sediment. The results indicated that the abundance of microplastics in the water varied from 1.60 to 13.26 items/L, while in the sediment it ranged from 792.38 to 2352.00 items/kg. Polyethylene, polyethylene terephthalate, and polyamides exhibited higher levels in the water, whereas polyamides and polyethylene were more predominant in the sediments. Additionally, the surface layer exhibited the highest abundance of microplastics, followed by the bottom, while the intermediate layer displayed the lowest. As the depth increased, there was a gradual decrease in the proportion of polyethylene and an increase in the proportions of polyethylene terephthalate and polyamides. The risk assessment results showed that the Pollution Risk Index value of the water was 201.79, while the sediment had a value of 184.98, indicating a moderate potential ecological risk. This study provides valuable insights into the spatial distribution patterns of microplastics at different water depths and provides crucial data support for understanding the migration patterns of microplastics in source water reservoirs. [ABSTRACT FROM AUTHOR]

Plastic waste in marine waters will undergo a degradation process that breaks down large plastic pieces into smaller particles called microplastics. The abundance of microplastics, caused by their small size (<5mm) can be easily indirectly consumed by aquatic animals. Anadara granosa is one of the bivalves that is quite vulnerable to microplastic contamination because it has the nature of a filter feeder which means it can sift particles and organic matter around it. The purpose of this study was to determine the characteristics, abundance, and types of microplastic polymers in blood clams (A. granosa). The results of microplastic observations made on 60 blood clams were 153 microplastic particles identified from 47 individuals (78%) of contaminated blood clams with an average microplastic abundance of 0.591 ± 0.083 item/gr. Fiber-type microplastics are the most dominant form found and blue is the most dominant color found in the sample. Based on the average abundance of microplastics in Anadara granosa in the coastal area of Palopo City, it is lower than several studies that have been conducted previously. Fourier Transform-Infra Red was conducted to determine the type of polymer in microplastics. Three types of polymers were found in the Anadara granosa samples polyethylene terephthalate (PET), polystyrene, and polyester. The three types of polymers have effects on human health such as respiratory problems, skin irritation, and genotoxicity. Action is needed to prevent microplastic pollution in Palopo City's rivers before microplastic pollution becomes more severe in the future. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENG), which efficiently capture and convert mechanical energy, offer an innovative solution for developing green energy sources. In this work, we developed a zinc oxide (ZnO)-based TENG for use in vertical contact-separation mode by combining it with several polymers (polytetrafluoroethylene [PTFE], fluorinated ethylene propylene [FEP], polydimethylsiloxane [PDMS], polyethylene terephthalate [PET], polyethylene naphthalate [PEN], polyvinylidene difluoride [PVDF]) and mica. Radio-frequency (RF) magnetron sputtering was used to fabricate ZnO thin films with higher optical transmission and c-axis orientation. When combined with mica and PEN, ZnO behaves as a negative tribo layer, while when combined with the other polymers, it behaves as a positive tribo layer. ZnO with PVDF nanofibers generated maximum output, with an open-circuit voltage of 42 V. To determine the maximum power density and energy storage performance, the ZnO-PVDF TENG response was examined under various load conditions of resistance and capacitance. The power density was calculated using this device and found to be 62 µW/cm2. Furthermore, the manufactured TENG was demonstrated to power a digital watch and LEDs. [ABSTRACT FROM AUTHOR]

Electromechanical metal oxides, such as piezoceramics, are often incompatible with soft polymers due to their crystallinity requirements, leading to high processing temperatures. This study explores the potential of ceria-based thin films as electromechanical actuators for flexible electronics. Oxygen-deficient fluorites, like cerium oxide, are centrosymmetric nonpiezoelectric crystalline metal oxides that demonstrate giant electrostriction. These films, deposited at low temperatures, integrate seamlessly with various soft substrates like polyimide and PET. Ceria thin films exhibit remarkable electrostriction (M33 > 10-16 m² V-2) and inverse pseudo-piezo coefficients (e33 > 500 pmV-1), enabling large displacements in soft electromechanical systems. Our study explores resonant and off-resonant configurations in the low-frequency regime (<1 kHz), demonstrating versatility for three-dimensional and transparent electronics. This work advances the understanding of oxygen-defective metal oxide electromechanical properties and paves the way for developing versatile and efficient electromechanical systems for applications in biomedical devices, optical devices, and beyond. [ABSTRACT FROM AUTHOR]

Solar energy is the most promising source for generating residential, commercial, and industrial electricity. However, solar panels should be eco-friendly to increase sustainability during manufacturing and recycling. This study investigates the potential of using natural fibre composites as eco-friendly alternatives to conventional polyethylene terephthalate (PET) back sheets in solar panels. Furthermore, it examines the performance of sisal fibres coated with zeolite-polyester resin. The chemical composition, structural integrity, and crystalline properties of the composites were evaluated through extensive microstructural analysis. The results from the experimental analysis revealed significant improvements in voltage (8%) and current (6%) for the coated sisal fibre panels compared to conventional panels. Power output increased by 12%, and overall efficiency improved from 9.75 to 10.8%. Solar panels with sisal fibre sheets exhibit adequate tensile strength and impact resistance and reduce operating temperature by 2–3 °C, ensuring stable operation and minimizing heat loss. Statistical analysis confirmed the reliability and significance of these results. The life cycle analysis demonstrated a 60% reduction in CO2 emissions and a 50% decrease in energy consumption during the production, utilization and disposal of sisal fibre sheets. These findings underscore the viability of natural fibre composites in enhancing the performance and sustainability of solar panels. [ABSTRACT FROM AUTHOR]

Microplastics are one of the concerning environmental pollutants because of their ubiquity. Their capability to adsorb other environmental pollutants increases the risk even further. Existing identification approaches for microplastic characterization for polymer class and their surface-adsorbed heavy metal detection require the utilization of multiple resources and expertise. The article discusses the applicability of a custom-made hyphenated Laser Induced Breakdown Spectroscopy (LIBS)—Raman spectroscopic system in characterizing microplastics by comparing the analytical performance with conventional methods such as Attenuated Total Reflectance- Fourier Transform Infrared (ATR-FTIR) spectroscopy, confocal Raman spectroscopy, and Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy (SEM–EDS). Raman analysis identified polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) plastics, which is confirmed by confocal Raman and FTIR study of the same. LIBS study of microplastics detected heavy metals such as Al, Ni, Co, and Zn, along with Ca and Mg trace elements. The cross-examination with EDS validates these trace elements' presence on the microplastics' surface. The results of the reported LIBS-Raman analysis and its validity evaluated using conventional gold-standard methods show the applicability of the proposed methodology in characterizing microplastics from environmental resources with less or no sample preparation in short time. [ABSTRACT FROM AUTHOR]

Optoelectronic components are crucial across various industries. They benefit greatly from advancements in 3D printing techniques that enable the fabrication of intricate parts. Among these techniques, Material Extrusion (MEX) stands out for its simplicity and cost-effectiveness. Integrating 3D printing into production processes offers the potential to create components with enhanced electrostatic discharge (ESD) resistance, a critical factor for ensuring the reliability and safety of optoelectronic devices. Polyethylene terephthalate glycol-modified (PET-G) is an amorphous copolymer renowned for its high transparency, excellent mechanical properties, and chemical resistance, which make it particularly suitable for 3D printing applications. This study focuses on analyzing the mechanical, structural, and electrostatic properties of pure PET-G as well as PET-G doped with additives to evaluate the effects of doping on its final properties. The findings highlight that pure PET-G exhibits superior mechanical strength compared to doped variants. Conversely, doped PET-G demonstrates enhanced resistance to electrostatic discharge, which is advantageous for applications requiring ESD mitigation. This research underscores the importance of material selection and optimization in 3D printing processes to achieve desired mechanical and electrical properties in optoelectronic components. By leveraging 3D printing technologies like MEX and exploring material modifications, industries can further innovate and enhance the production of optoelectronic devices, fostering their widespread adoption in specialized fields. [ABSTRACT FROM AUTHOR]

This study aimed to compare the color changes in two different orthodontic clear aligner systems after submersion in various beverages for 14 days. The tested aligner systems were Taglus Premium made of polyethylene terephthalate glycol (the TAG group) and CA® Prodin+ made of a transparent copolyester and a thermoplastic elastomer (the PRO group). A total of 56 samples were firstly divided into two groups according to the tested system—TAG and PRO. Each group was subsequently divided in four subgroups according to immersion solution: A—artificial saliva, B—cola, C—coffee, D—red wine. Color measurements were performed on Days 1, 7 and 14 using a portable colorimeter and the CIE L*a*b* system. The obtained results showed significant color changes in both materials when exposed to coffee and red wine (p > 0.05). Samples in the PRO group showed a greater susceptibility to discoloration (higher ΔE values) when compared to the TAG group after submersion in cola (p = 0.025), coffee (p = 0.005) and red wine (p = 0.041) solutions. Statistical analysis revealed that all of the color parameters ΔL*, Δa*, Δb* and ΔE of both tested materials were affected by submersion in coffee solution for 14 days. In conclusion, the CA® Pro+ aligner system is more prone to staining compared to the Taglus material after submersion for 14 days in cola, coffee and red wine solutions. Submersion for 14 days in coffee solution alters all of the color parameters (ΔL, Δa, Δb and ΔE) of both tested aligner materials. [ABSTRACT FROM AUTHOR]

This paper examined the mechanical properties of wrist–hand orthoses made from polylactic acid (PLA) and polyethylene terephthalate glycol (PETG), produced through material extrusion with infill densities of 55% and 80%. These orthoses, commonly prescribed for wrist injuries, were 3D-printed flat and subsequently thermoformed to fit the user's hand. Experimental and numerical analyses assessed their mechanical resistance to flexion after typical wear conditions, including moisture and long-term aging, as well as their moldability. Digital Imaging Correlation investigations were performed on PLA and PETG specimens for determining the characteristics required for running numerical analysis of the mechanical behavior of the orthoses. The results indicated that even the orthoses with the lower infill density maintained suitable rigidity for wrist immobilization, despite a decrease in their mechanical properties after over one year of shelf life. PLA orthoses with 55% infill density failed at a mean load of 336 N (before aging) and 215 N (after aging), while PETG orthoses did not break during tests. Interestingly, PLA and PETG orthoses with 55% infill density were less influenced by aging compared to their 80% density counterparts. Additionally, moisture and aging affected the PLA orthoses more, with thermoforming, ongoing curing, and stress relaxation as possible explanations related to PETG behavior. Both materials proved viable for daily use, with PETG offering better flexural resistance but posing greater thermoforming challenges. [ABSTRACT FROM AUTHOR]

The effect of contamination of polypropylene (PP) with selected polymers is studied to simulate the effect of mis-sorting in recycling streams. Polystyrene (PS), polyethylene terephthalate (PET), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), and polylactic acid (PLA) were compounded with PP at different concentrations varying between 3 and 10%. Infrared spectroscopy proved the absence of chemical bonds between the constituents. Generally, melt flowability, except for the PP/PLA blend, and crystallinity were only slightly affected by the incorporation of the contaminating polymers. Samples of the polymer blends were injection moulded and further tested for their tensile and impact properties. Critical behaviour was induced by the introduction of a weld line as a result of the application of multiple gating points during injection moulding. Results generally show the applicability of PP mixtures within the investigated range of contamination, without much sacrifice in mechanical performance. However, in the case of ABS and PLA, more care should be taken when designing complex parts with weld lines, due to reduced toughness. [ABSTRACT FROM AUTHOR]

This research has developed a process for producing ZnO thin film from DEZn deposited onto a PET substrate with low-pressure, high-frequency Ar + O2 plasma using a chemical vapor deposition technique. The aim is to study the film production conditions that affect electrical properties, optical properties, and thin film surfaces. This work highlights the use of plasma energy produced from a mixture of gases between Ar + O2. Plasma production is stimulated by an RF power supply to deliver high chemical energy and push ZnO atoms from the cathode inside the reactor onto the substrate through surface chemical reactions. The results showed that increasing the RF power in plasma production affected the chemical reactions on the substrate surface of film formations. Film preparation at an RF power of 300 W will result in the thickest films. The film has a continuous columnar formation, and the surface has a granular structure. This results in the lowest electrical resistivity of 1.8 × 10−4 Ω. In addition, when fabricated into a DSSC device, the device tested the PCE value and showed the highest value at 5.68%. The reason is due to the very rough surface nature of the ZnO film, which increases the scattering and storage of sunlight, making cells more efficient. Therefore, the benefit of this research is that it will be a highly efficient prototype of thin film production technology using a chemical process that reduces production costs and can be used in the industrial development of solar cells. [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]

It is increasingly recognized that microplastics (MPs) are being transmitted through the food chain system, but little is known about the microorganisms involved in MP degradation, functional biodegradation genes, and metabolic pathways of degradation in the intestinal tract of foodborne animals. In this study, we explored the potential flora mainly involved in MP degradation in the intestinal tracts of Taoyuan, Duroc, and Xiangcun pigs by macrogenomics, screened relevant MP degradation genes, and identified key enzymes and their mechanisms. The pig colon was enriched with abundant MP degradationrelated genes, and gut microorganisms were their main hosts. The fiber diet did not significantly affect the abundance of MP degradation-related genes but significantly reduced their diversity. We identified a total of 94 functional genes for MP degradation and classified them into 27 categories by substrate type, with polystyrene (PS), polyethylene terephthalate (PET), and di(2-ethylhexyl) phthalate (DEHP) were the most predominant degradation types. The MP degradation functional genes were widely distributed in a variety of bacteria, mainly in the phylum Firmicutes and Bacteroidetes. Based on the identified functional genes for MP degradation, we proposed a hypothetical degradation mechanism for the three major MP pollutants, namely, PS, PET, and DEHP, which mainly consist of oxidoreductase, hydrolase, transferase, ligase, laccase, and isomerase. The degradation process involves the breakdown of long polymer chains, the oxidation of short-chain oligomers, the conversion of catechols, and the achievement of complete mineralization. Our findings provide insights into the function of MP degradation genes and their host microorganisms in the porcine colon. [ABSTRACT FROM AUTHOR]

Concrete production faces challenges due to the depletion of natural sand and the need for more sustainable practices. This study investigates the use of sugarcane bagasse ash (SCBA) and recycled polyethylene terephthalate (RPET) as partial replacements for cement and sand, respectively. SCBA was tested as a 5%, 10%, and 15% replacement by weight of cement, while RPET was used as a 5%, 10%, 15%, and 20% substitute for sand by volume. Concrete samples were cured in water for 7, 28, and 56 days. The mix with 5% SCBA and 10% RPET showed comparable compressive strength to conventional concrete and improved split tensile strength by 1.2% and 11.61% at 28 and 56 days, respectively. The compressive strength-to-weight ratio of this blend was less than 3% lower than conventional concrete. This combination also maintained similar water absorption and fire resistance characteristics. These results suggest that 5% SCBA and 10% RPET are effective in enhancing the sustainability of concrete while maintaining structural performance, contributing to more environmentally friendly construction practices. [ABSTRACT FROM AUTHOR]

Ideonella sakaiensis is a bacterium that can degrade and consume polyethylene terephthalate (PET), a plastic material that was previously considered non‐biodegradable. The degradation of PET requires two enzymes, namely poly (ethylene terephthalate) hydrolase (PETase) and mono (2‐hydroxyethyl) terephthalate hydrolase (MHETase), which break down PET into terephthalate (TPA) and ethylene glycol (EG), which serve as carbon sources for the bacterium. Previous studies have focused on the enzymatic properties, structure, and mechanism of action of PETase and MHETase. However, the regulation of PETase and MHETase gene expression has not been investigated. This study identified a protein that binds to the MHETase promoter DNA, MHETase gene‐regulating protein (MRP) in I. sakaiensis. PET or TPA induced the expression of PETase and MHETase genes. Furthermore, the induction of the MHETase gene was abolished by the deletion of the mrp gene, while the expression of the PETase gene was maintained. In addition, the genes involved in TPA metabolism were not induced in the mrp mutant. Furthermore, the growth of the PET and TPA deteriorated due to mrp mutation. Also, MRP binds to the promoter regions of the MHETase gene and TPA metabolizing genes, but not to the PETase gene promoter. These results suggest that MRP is a transcription factor that activates MHETase and TPA‐metabolizing genes. [ABSTRACT FROM AUTHOR]

Polylactic Acid (PLA) comes from renewable resources, has a reasonable biodegradability rate, and is used in biomedical, food packaging, textiles, and agricultural applications. PLA offers high mechanical strength and the ability to compost, similar to polyethylene terephthalate (PET) and nylon. However, the brittleness of PLA has always limited its usage. Therefore, bio-based plasticizers in the biopolymer matrices can increase flexibility (elasticity), durability, and workability. This study aims to determine the optimal blending ratio for the PLA blended with epoxidized waste cooking oil (EWCO) to enhance the mechanical and thermal properties of PLA/EWCO. The mechanical strength test consists of the hardness test (N/mm2), flexural strength (MPa), and impact energy (kJ/m2) adopted to evaluate the plasticizing characteristics. The thermal stability analysis involves glass transition temperature (Tg) (°C), cold-crystallization temperature (Tcc) (°C) and melting temperature (Tm) (°C). The blending ratio is 97.5PLA/2.5EWCO, 95PLA/5EWCO, 92.5PLA/7.5EWCO and 90PLA/10EWCO. As a result, 97.5:2.5 of PLA/EWCO reduces intermolecular interactions by stimulating more free volume in biopolymer chains' mobility and enhancing the flexibility and elasticity of the PLA blends. Ultimately, the brittleness of PLA decreased with increasing EWCO bio-based plasticizer. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The diffusion of microplastics in the food supply chain is prompting public concern as their impact on human health is still largely unknown. The aim of this study was to qualitatively and quantitatively characterize microplastics in skim-milk powder samples (n = 16) from different European countries (n = 8) through Fourier-transform infrared microspectroscopy in attenuated total reflectance mode analysis. The present study highlights that the use of hot alkaline digestion has enabled the efficacious identification of microplastics in skim-milk powders used for cheesemaking across European countries. The adopted protocol allowed detection of 29 different types of polymeric matrices for a total of 536 plastic particles. The most abundant microplastics were polypropylene, polyethylene, polystyrene, and polyethylene terephthalate. Microplastics were found in skim-milk powders in 3 different shapes (fiber, sphere, and irregular fragments) and 6 different colors (black, blue, brown, fuchsia, green, and gray). Results demonstrate the presence of microplastics in all skim-milk powder samples, suggesting a general contamination. Results of the present study will help to evaluate the impact of microplastics intake on human health. [ABSTRACT FROM AUTHOR]

Greener materials, particularly in sandwich panels, are in increasing demand in the transportation and building sectors to reduce environmental impacts. This shift is driven by strict environmental legislation and the need to reduce material costs and fuel consumption, necessitating the utilisation of more sustainable components in the transportation and construction sectors, with improved load-bearing capabilities and diminished ecological footprints. Therefore, this study aims to analyse and evaluate the structural performance of polyethylene terephthalate (PET) core and flax or basalt/flax FRP sandwich panels as an alternative to conventional synthetic materials. The novel eco-friendly sandwich panels were manufactured using the co-curing technique. Four-point bending, edgewise compression and core shear tests were performed and insights into how the skin properties affect the strength, stiffness and failure mode of specimens were provided. The stress–strain behaviour, facing modulus and strength, flexural rigidity, core shear strength and failure modes were evaluated. The flexural facing modulus of the flax and flax/basalt sandwich skins were found to be 5.1 GPa and 9.8 GPa, respectively. The flexural rigidity of the eco-friendly sandwich panel was compared with published results and demonstrated a promising structural performance. The environmental benefits and challenges were outlined and critically evaluated focusing on transportation and construction applications. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are present in ambient air in a respirable size fraction; however, their potential impact on human health via inhalation routes is not well documented. In the present study, methods for a lab-scale generation of MPs from regularly used and littered plastic articles were optimized. The toxicity of 11 different types of MPs, both commercially purchased and in-lab prepared MPs, was investigated in lung epithelial cells using cell viability, immune and inflammatory response, and genotoxicity endpoints. The underlying mechanisms were identified by microarray analysis. Although laborious, the laboratory-scale methods generated a sufficient quantity of well characterized MPs for toxicity testing. Of the 11 MPs tested, the small sized polyethylene terephthalate (PETE) MPs prepared from disposable water bottles induced the maximum toxicity. Specifically, the smaller size PETE MPs induced a robust activation of the interferon signaling pathway, implying that PETE MPs are perceived by cells by similar mechanisms as those employed to recognize pathogens. The PETE MPs of heterogenous size and shapes induced cell injury, triggering cell death, inflammatory cascade, and DNA damage, hallmark in vitro events indicative of potential in vivo tissue injury. The study establishes toxicity of specific types of plastic materials in micron and nano size. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Food Contact Materials (FCM) assessed the safety of the substances 'wax, rice bran, oxidised' and 'wax, rice bran, oxidised, calcium salt', used as additives up to 0.3% in polyethylene terephthalate (PET), polyamide (PA), thermoplastic polyurethane (TPU), polylactic acid (PLA) and poly(vinyl chloride) (PVC) in contact with all food types for long‐term storage at room temperature and below, after hot‐fill and/or heating. The substances consist of the chemical classes wax esters, carboxylic acids, alcohols and calcium salts of acids, along with an unidentified organic fraction up to ■■■■■ w/w. Migration into 10% ethanol and 4% acetic acid was below 0.012 mg/kg for each chemical class, and about 0.001 mg/kg for the unidentified fraction. In isooctane, migration was up to 0.297 mg/kg food for wax esters, below 0.01 mg/kg food for the other chemical classes and about 0.02 mg/kg food for the unidentified fraction. The contact with dry food and food simulated by 20% ethanol were considered covered by the migration tests with aqueous simulants. Based on genotoxicity assays and compositional analyses, the constituents of the chemical classes did not raise a concern for genotoxicity. The potential migration of individual constituents or groups of chemically‐related compounds of the unidentified fraction would result in exposures below (for aqueous food) and above (for fatty food) the threshold of toxicological concern for genotoxic carcinogens. Therefore, the FCM Panel concluded that the substances are not of safety concern for the consumer, if used as additives up to 0.3% w/w in PET, PLA and rigid PVC materials and articles intended for contact with all food types except for fatty foods, for long‐term storage at room temperature and below, including hot‐fill and/or heating up to 100°C for up to 2 h. [ABSTRACT FROM AUTHOR]

Simple Summary: Simple Summary: Microplastics have emerged as a pressing global environmental issue and have been alarmingly detected in both the feed and feces of ruminants. However, their effects on the ruminal and intestinal digestive tract have not yet been studied. Our study represents the first investigation of the effects of polyethylene terephthalate microplastics on the ability of the ruminal-gastro-intestinal system to degrade and digest mixed hay. Our findings reveal that polyethylene terephthalate significantly reduce the digestibility of crude protein in mixed hay. Notably, low levels of PET MPs negatively impacted the intestinal phase, while medium and high levels disrupted the ruminal phase. Moreover, medium and high concentrations of polyethylene terephthalate hindered the degradation of fiber fractions, specifically of neutral detergent fiber. These insights underscore the potential risks posed by polyethylene terephthalate microplastics to ruminal–gastro-intestinal functionality and highlight the urgent need for innovative strategies to combat this emerging environmental challenge, ensuring the sustainability and productivity of ruminant farming. Microplastics (MPs) raise environmental concerns. However, their effects on the ruminal–gastro-intestinal system have not yet been studied. This study aims to investigate the effects of polyethylene terephthalate (PET) MPs on the ability of the ruminal–gastro-intestinal system to degrade and digest mixed hay. Using a three-step in vitro ruminal–gastro-intestinal incubation system, PET MPs were introduced at concentrations of 0, 5, 10, and 15 g/L in ruminal and gastro-intestinal solutions. Ruminal fluid was collected from three 16-month-old Piedmontese bulls. The experiment was conducted on three mixed hays and was repeated three times, with triplicate incubations in each run. The results reveal that PET MPs reduced the degradability and digestibility of crude protein. Specifically, crude protein degradation was reduced by 9% at medium and 16% at high PET MP concentrations in the ruminal phase, while the crude protein digestibility of undegraded crude protein was reduced by 8% at the lowest PET MPs concentration in the gastro-intestinal tract. Additionally, PET MPs reduced the degradation of neutral detergent fiber at medium and high PET MP concentrations in the ruminal phase by 9% and 13%, respectively. These results highlight the risks of PET MPs contamination on ruminal–gastro-intestinal functions and underscore the urgent need to mitigate MPs contamination in the livestock sector. [ABSTRACT FROM AUTHOR]

One of the greatest challenges worldwide is containing the spread of problematic microorganisms. A promising approach is the use of antimicrobial coatings (AMCs). The antimicrobial potential of certain metals, including copper and zinc, has already been verified. In this study, polyethylene terephthalate and aluminum (PET-Al) foils were coated with copper, zinc, and a combination of these two metals, known as core–shell particles, respectively. The resistance of the three different types of coatings to mechanical and chemical exposure was evaluated in various ways. Further, the bacteria Staphylococcus aureus and the bacteriophage ϕ6 were used to assess the antimicrobial efficacy of the coatings. The best efficacy was achieved with the pure copper coating, which was not convincing in the abrasion tests. The result was a considerable loss of copper particles on the surfaces and reduced effectiveness against the microorganisms. The core–shell particles demonstrated better adhesion to the surfaces after abrasion tests and against most chemical agents. In addition, the antimicrobial efficiency remained more stable after the washability treatment. Thus, the core–shell particles had several benefits over the pure copper and zinc coatings. In addition, the best core–shell loading for durability and efficacy was determined in this study. [ABSTRACT FROM AUTHOR]

This study utilizes polyethylene terephthalate (PET) aggregate of different particle sizes (21 μm, 107 μm, and 244 μm) to replace natural aggregate in the preparation of PET-modified engineered cementitious composite (P-ECC). The impact of PET aggregate particle size on the performance of P-ECC is examined herein from micro to macro levels. The focus is on the influence patterns and mechanisms of P-ECC's workability, its basic mechanical properties, and its microstructure. Crack parameters are processed to quantitatively analyze crack development patterns. Using microscopic techniques, the interfacial transition zone (ITZ) between different aggregates and the cement matrix is compared, and the failure mechanism of P-ECC is analyzed. The results show that the incorporation of PET aggregate can improve P-ECC's workability and reduce its self-weight, but incorporation has a negative effect on compressive strength. Additionally, the particle size of PET aggregate significantly affects the uniaxial tensile performance of P-ECC. Compared to conventional ECC, the tensile strength of P-S (21 μm PET) increased the most markedly (18.1%), and the ultimate tensile strain of P-M (107 μm PET) increased the most markedly (66.0%), with both demonstrating good crack control and deformation energy dissipation capabilities. The uniaxial tensile performance of P-L (244 μm PET) was lower than that of the conventional ECC. Microscopic tests revealed that the increase in PET aggregate particle size enlarges the ITZ width and its surrounding pores. Appropriate pore enlargement is beneficial for enhancing tensile ductility, while excessive pores have a negative effect. The study results reveal the impact of PET aggregate particle size on the performance of P-ECC, providing new insights for the performance optimization of ECC. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) degradation by enzymatic hydrolysis is significant for addressing plastic pollution and fostering sustainable waste management practices. Identifying thermophilic and thermostable PET hydrolases is particularly crucial for industrial bioprocesses, where elevated temperatures may enhance enzymatic efficiency and process kinetics. In this study, we present the discovery of a novel thermophilic and thermostable PETase enzyme named Sis, obtained through metagenomic sequence-based analysis. Sis exhibits robust activity on nanoPET substrates, demonstrating effectiveness at temperatures up to 70 °C and displaying exceptional thermal stability with a melting temperature (Tm) of 82 °C. Phylogenetically distinct from previously characterised PET hydrolases, Sis represents a valuable addition to the repertoire of enzymes suitable for PET degradation. [ABSTRACT FROM AUTHOR]

Microplastic (MP) contamination in the aquatic environment is a cause of concern worldwide since MP can be taken up by different organisms, altering different biological functions. In particular, evidence is accumulating that MP can affect the relationship between the host and its associated microbial communities (the microbiome), with potentially negative health consequences. Synthetic microfibers (MFs) represent one of the main MPs in the marine environment, which can be accumulated by filter-feeding invertebrates, such as bivalves, with consequent negative effects and transfer through the food chain. In the mussel Mytilus galloprovincialis, polyethylene terephthalate (PET) MFs, with a size distribution resembling that of an MF released from textile washing, have been previously shown to induce multiple stress responses. In this work, in the same experimental conditions, the effects of exposure to PET-MF (96 h, 10, and 100 μg/L) on mussel hemolymph microbiome were evaluated by 16S rRNA gene amplification and sequencing. The results show that PET-MF affects the composition of bacterial communities at the phylum, family and genus level, with stronger effects at the lowest concentration tested. The relationship between MF-induced changes in hemolymph microbial communities and responses observed at the whole organism level are discussed. [ABSTRACT FROM AUTHOR]

In this study, ZnO films are prepared at a low temperature of 150 °C by using spatial atomic layer deposition (sALD) with diethylzinc and ozone as precursor and oxidant. The ozone flow rate is varied to systematically investigate its effect on optical, structural and electrical properties. The experimental results show that the self-limiting surface reactions can occur at the low ozone flow rate of 200 sccm, confirming ALD growth mode. All the ozone flow rates lead to ZnO (002) crystalline orientation, which is difficult to be obtained for conventional water-based ALD ZnO films at the low temperature. The increased ozone flow rate results in an increased amount of oxygen vacancies, enhanced carrier concentration and a reduced stress. The resistivity and carrier concentration can be tuned in the range of 4.75–0.08 Ω-cm and (1.1–5.5) × 1018 cm−3. Finally, the sALD ZnO film on polyethylene terephthalate reveals a high stability in the film property against bending. This study is beneficial for the utilization of ZnO films in optoelectronic devices that demand the (002) preferred orientation, especially under low-temperature conditions. [ABSTRACT FROM AUTHOR]

Introduction: Transparent orthodontic aligners have revolutionized dentistry and orthodontics since the 1990s, offering advantages over traditional fixed appliances in terms of hygiene, comfort, and aesthetics. With the increasing demand for invisible orthodontic treatments, clear aligners have gained popularity, prompting research into materials to enhance their efficacy and performance. Materials and Methods: A scoping review was conducted using electronic databases (Pubmed, Medline, Cochrane Library, Embase, and Scopus) to identify studies on clear aligner materials published in the last decade. Selection criteria focused on studies specific to dental materials, excluding those unrelated to materials or clear aligners. Results: The review included 11 relevant studies evaluating 17 different clear aligner materials. Materials such as polyvinyl chloride derivatives, thermoplastic polyurethanes (TPU), and polyethylene terephthalate glycol (PETG) were commonly used. The studies assessed mechanical, physical, chemical, and optical properties, as well as thermoforming effects, stress decay, and surface characteristics. Discussion and Conclusions: Various materials exhibited distinct properties, with PETG materials offering transparency and flexibility, while TPU-based materials like Smart Track providing durability and elasticity. Thermoforming affected mechanical properties, with both PETG and TPU materials showing decreased efficacy post-thermoforming. Polymer blending improved mechanical properties, but variations existed among different brands and materials. Clear aligner materials exhibit diverse characteristics, influencing their suitability for orthodontic use. PETG-based materials offer transparency and flexibility, while TPU-based materials provide durability and elasticity. However, both materials undergo mechanical changes post-thermoforming, emphasizing the need for further research to optimize material performance for clinical use. [ABSTRACT FROM AUTHOR]

Wine quality and safety is affected by the food contact materials (FCMs) used. These materials are expected to protect the beverage from any chemical, physical, or biological hazard and preserve its composition stable throughout its shelf-life. However, the migration of chemical substances from FCMs is a known phenomenon and requires monitoring. This review distinguishes the migrating chemical substances to those of (i) industrial origin with potential safety effects and those of (ii) natural occurrence, principally in cork (ex. tannins) with organoleptic quality effects. The review focuses on the migration of industrial chemical contaminants. Migration testing has been applied only for cork stoppers and tops, while other materials like polyethylene terephthalate (PET) bottles with aluminum cups, paperboard cartons, stainless steel vats, and oak casks have been examined for the presence of chemical migrating substances only by wine analysis without migration testing. The dominant analytical techniques applied are gas and liquid chromatography coupled to mass spectrometry (MS) for the determination of organic compounds and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and ICP-MS for elemental analysis. Targeted approaches are mostly applied, while limited non-target methodologies are reported. The identified migrating substances include authorized substances like phthalate plasticizers, monomers (bisphenol A), antioxidants (Irganox 1010), known but non-authorized substances (butylparaben), break-down products, oxidation products (nonylphenol), polyurethane adhesive by-products, oligomers, ink photoinitiators, and inorganic elements. A preliminary investigation of microplastics' migration has also been reported. It is proposed that further research on the development of comprehensive workflows of target, suspect, and non-target analysis is required to shed more light on the chemical world of migration for the implementation of an efficient risk assessment and management of wine contact materials. [ABSTRACT FROM AUTHOR]

This study investigates the effect of void features in additively manufactured polymers on water diffusion, focusing on polyethylene terephthalate glycol (PETG) composites. The additive manufacturing (AM) of polymers, specifically, material extrusion AM (MEAM), results in manufacturing-induced voids, therefore affecting the water resistance of the printed parts. The research analyses the effects of size, shape, orientation and the hydrophilicity of voids on moisture diffusion in PETG composites employing numerical (finite-element) simulations. Two void types were examined: voids of Type I that retard the moisture propagation and voids of Type II that enhance it. Simulations demonstrate that a higher volume fraction of voids and their orientation with regard to the diffusion direction significantly hinder the moisture transport for Type I voids. Conversely, due to their high diffusivity, Type II voids serve as channels for rapid moisture transmission. Consequently, for such materials, the global diffusion rates mainly depend on the volume fraction of voids rather than their shape. These findings indicate the critical role of voids in the design of AM parts for environments exposed to moisture, such as marine and offshore applications. Understanding the void effects is critical for optimising the durability and performance of MEAM components underwater exposure. [ABSTRACT FROM AUTHOR]

Microplastic pollution is a pervasive issue, with remarkably high concentrations observed even in the most remote locations such as Arctic sea ice and snow. The reason for such large microplastic abundances in sea ice is still speculative and applies mainly to saline or freshwater conditions. In this study, we investigated seasonal ice core samples collected in March 2021 from the northern Baltic Sea (Gulf of Bothnia) for their microplastic distributions. The Baltic Sea is characterized by low salinity and can be ice-covered for up to six months annually. Microplastics were analyzed in the melted ice samples using an adsorption technique and Raman microscopy to identify their abundances, colors, shapes, and sizes to calculate their masses. Due to the strong dynamic of the ice layer and the repeated melting and freezing processes during the ice formation, no discernible trends in microplastic abundances, masses, or polymer types were observed throughout the ice core length. The average microplastic abundance (±SD) in the Baltic Sea ice was determined to be 22.3 ± 8.6 N L−1, with 64.9% of the particles exhibiting a particulate shape and 35.1% having a fibrous shape. The most prevalent polymer type was polyethylene terephthalate (PET), accounting for 44.4% of all polymers. This is likely due to the high proportion of PET fibers (93.8%). The majority of particle-shaped microplastics were identified as polyethylene (PE; 37.2%), followed by PET (17.2%), polyvinyl chloride (PVC; 15.9%), and polypropylene (PP; 15.9%). No correlations were found between microplastic concentrations and proximity to land, cities, industries, or rivers, except for PP mass concentrations and particle sizes, which correlated with distances to industries in Luleå, Sweden. [ABSTRACT FROM AUTHOR]

In this study, a microbial–enzymatic strategy was pursued to address the challenge of degrading thermoplastic and thermosetting polymers. Environmental microorganisms were isolated, and their enzymatic activities were assessed using colorimetric assays to evaluate their potential for producing enzymes capable of degrading these polymers. Microorganisms demonstrating higher activity in the enzymatic assays were selected for a 30-day biodegradation experiment, in which epoxy resins, polyethylene terephthalate, or polystyrene served as the sole carbon source. The effectiveness of biodegradation was assessed through the ATR-FTIR analysis of the chemical composition and the SEM examination of surface characteristics before and after degradation. The results indicated that thermoplastic compounds were more susceptible to microbial degradation, exhibiting greater changes in absorbance. In particular, PET treated with Stenotrophomonas sp. showed the most significant efficacy, achieving a 60.18% reduction in the area under the curve with a standard error of ± 3.42 when analyzed by FTIR spectroscopy. Significant alterations in surface morphology were noticed in thermoplastic compounds. In contrast, thermosetting compounds demonstrated lower reactivity, as evidenced by the absence of band shifts in FTIR spectra and minor changes in bond absorbance and surface morphology. [ABSTRACT FROM AUTHOR]

The application of antimicrobial surfaces requires the proof of their effectivity by in vitro methods in laboratories. One of the most well-known test methods is ISO 22196:2011, which represents a simple and inexpensive protocol by applying the bacterial suspension with known volume and concentration covered under a polyethylene film on the surfaces. The incubation is then done under defined humidity conditions for 24 h. Another approach for testing of non-porous surfaces is the newly published ISO 7581:2023. A "dry test" is achieved through spreading and drying 1 µL of a bacterial suspension on the surface. In this study, low alloyed carbon steel, polyethylene terephthalate (PET), and glass specimens were tested uncoated (reference) and coated with zinc according to both ISOs to compare and to evaluate the advantages and disadvantages of each one of them. Although ISO 7581:2023 allows a more realistic test environment than ISO 22196:2011, the reproducibility of the results is not given due to the low application volume. In addition, not all bacterial strains are equally suitable for this testing type. Individual adaptations to the protocols, including incubation conditions (time, temperature, or relative humidity), testing strains and volume, seem necessary to generate conditions that simulate the final application. Nevertheless, both ISOs, if used correctly, provide a good basis for estimating the antimicrobial efficacy of non-porous surfaces. [ABSTRACT FROM AUTHOR]

The fibrous wastes generated from the mills of textile production can be recycled and converted into high add-values products to be implemented in several applications. The current study aimed to employ commercial free cellulase enzyme to partially hydrolyze (activate) the polyester cotton blended (PET/C) fibrous wastes by creation functional groups such as OH and COOH on their surfaces. The activated fibrous wastes were then modified by coating with ZnO nanoparticles (ZnO-NPs) biosynthesized by actinobacterial cultures free supernatant. The isolate was identified as Streptomyces pseudogriseolus with accession number of OR574241. The conditions that influence the actino-synthesis of ZnO-NPs were optimized and the product was characterized using spectroscopic vision, FTIR, XRD, TEM and SEM. The characteristic ZnO peaks were obviously observed by EDX analysis with 0.38 and 0.75% (wt%), respectively. TEM analyses proved the nanoscale of ZnO-NPs (5–15 nm) which was followed by cytotoxic evaluation for the produced NPs. Fortunately, the tested actino-ZnO-NPs didn't have any cytotoxicity against human normal fibroblast cell line (BJ1), which means that the product can be safely used in a direct-contact with human skin. The treated PET/C blended waste fabrics coated with ZnO-NPs showed high antimicrobial activity and ultraviolet protection values after functionalization by cellulase. EDX analysis demonstrates the presence of Zn peaks on the coated fabrics compared with their absence in blank and control samples, while SEM images showed the formation of a thin layer of ZnO-NPs on the fabric surface. The obtained smart textile can be applied several needed sectors. [ABSTRACT FROM AUTHOR]

Thickness affects the electrical breakdown strength (EBD) of insulation materials, and the variation of EBD with thickness (d) is an important basis for insulation design. In this paper, the effect of d on three kinds of organic insulation materials (OIMs), namely polymethyl methacrylate (PMMA), polyetheretherketone (PEEK), and polyethylene terephthalate (PET), on their breakdown characteristics under microsecond pulse voltage (MSPV) was studied, and a breakdown probability prediction model was established based on Weibull distribution. The breakdown mechanisms of the OIMs under MSPV were also discussed. The results showed that the EBD of all three materials decreased with increasing d. The relationship between characteristic EBD and d all satisfied the inverse power model, and their inverse power coefficients were all close to 1/2.3, which was much larger than 1/8 for that under nanosecond pulse voltage. A general breakdown probability prediction model of the OIMs was established by combining the Weibull distribution and β = 2.3 so as to guide engineering design in the absence of basic test data under MSPV. The breakdown mechanism of the OIMs under MSPV was an energy-related composite physical breakdown mechanism, which was verified by analysis of energy accumulation characteristics and experimental evidence of the little influence of pulse width on EBD under MSPV. The research results lay the foundation for the insulation design and further study on the breakdown modeling of OIM under MSPV. [ABSTRACT FROM AUTHOR]

Liquid crystal polymers (LCP) and polytetrafluoroethylene (PTFE) were in situ fibrillated to produce polyethylene terephthalate (PET)/LCP/PTFE composites using a simple and scalable extrusion drawing techniques. The PET/LCP/PTFE composites included high-aspect-ratio PTFE fibrils and rod-like LCP fibrils. The simultaneous in situ fibrillation of LCP and PTFE exerted synergistic effects on crystalline behaviour and viscosity of PET, especially for mechanical properties of PET and its foam. The tensile strength of PET/LCP/PTFE composites and impact strength representing improvements of 34% and 62% over those of PET. The improved mechanical properties can be attributed to the simultaneous abundance of orienting rod-like rigid LCP fibrils and tangling flexible PTFE fibrils in the PET matrix, which contributed to stress transfer from matrix to fibrils. A simultaneously in situ fibrillated PET/LCP/PTFE composite foam was fabricated using a batch foaming system with supercritical CO2 as blowing agent. The cell diameter of this foam decreased by 23% over that of standard PET foam, while its cell density increased twofold. The smaller cell diameter of PET/LCP/PTFE foam and superior mechanical properties of PET matrix collectively led to the good mechanical properties of PET/LCP/PTFE foam. Specifically, the compressive strength of the PET/LCP/PTFE foam represents a 35% increase over that of PET foam. [ABSTRACT FROM AUTHOR]