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Developing degradable bio-plastics has been considered feasible to lessen marine plastic pollution. However, unanimity is still elusive regarding the actual degradability of bio-plastics such as polylactide (PLA) and poly(hydroxybutyrate) (PHB). Thus, herein, we studied the degradability of fabrics made from PLA/PHB blends in marine seawater. The dry-mass percentage of the PLA/PHB fabrics decreased progressively from 100% to 85~90% after eight weeks of immersion. Two environmental aging parameters (UV irradiation and aerating) were also confirmed to accelerate the abiotic hydrolysis of the incubated fabrics. The variation in the molecular structure of the PLA/PHB polymers after the degradation process was investigated by electrospray ionization mass spectrometry (ESI-MS). However, the hydrolysis degradability of bulky PLA/PHB blends, which were used to produce such PLA/PHB fabrics, was negligible under identical conditions. There was no mass loss in these solid PLA/PHB plastics except for a decrease in their tensile strength. Finally, a deep learning artificial neural network model was proposed to model and predict the nonlinear abiotic hydrolysis behavior of PLA/PHB fabrics. The degradability of PLA/PHB fabrics in marine water under the synergistic destructive effects of seawater, UV, and dissolved oxygen provides a pathway for more sustainable textile fibers and apparel products. [ABSTRACT FROM AUTHOR]

Infectious microbial diseases are a major public health hazard, calling for more innovative antimicrobials. Herein, polylactic acid (PLA) oligomers have been explored and reported as a bio-safe and eco-friendly functional antimicrobial agent against pathogens, such as viruses (H1N1, H3N2, and SARS-CoV-2), bacteria (E. coli, S. aureus, K. pneumoniae, MRSA), and fungi (C. albicans). The PLA oligomers were prepared by direct catalyst-free condensation polymerization of l-lactic acid monomers and characterized by FT-IR and 1H-NMR. The antiviral results demonstrate that PLA oligomers possess robust (inhibiting rate > 99%) and rapid (<20 min) antiviral activity against two pandemic ssRNA viruses, including influenza A virus (IAV) and coronavirus (CoV). Furthermore, the PLA oligomers exhibit high antibacterial activities against both Gram negative (G−) and Gram positive (G+) bacteria. The PLA oligomers also perform efficiently in killing a large amount of C. albicans as high as 105 cfu/mL down to zero at the concentration of 10 mg/mL. Thus, the broad-spectrum antimicrobial activity endowed the PLA oligomers with a promising biocidal option, except antibiotics in a wide range of applications, such as medical textiles, food preservation, water disinfection, and personal hygiene, in light of their unique biodegradability and biocompatibility. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) have attracted many researchers' attention with their remarkable potential despite the fact that the practical implementation requires further improvement in their electric performance. In this work, a novel graphene phase two-dimension material, graphitic carbon nitride (g-C3N4), was employed for the development of a TENG material with enhanced features. An electrospun nanofibrous PA66 membrane doped with g-C3N4 was fabricated as a multifunctional TENG for harvesting different kinds of mechanical energy and detecting human motions. By utilizing the innovative 2D material in PA66 solution for electrospinning, the as-made TENG showed a two times enhancement in electrical performance as compared to the control device, and also had the advantages of lightweight, softness, high porosity, and rugged interface properties. The assembled TENG with 4 cm2 could light up 40 light-emitting diodes by gentle hand clapping and power electronic watches or calculators with charging capacitors. At a given impact force of 40 N and 3 Hz, the as-made TENG can generate an open-circuit voltage of 80 V, short current of ±3 µA, charge transfer of 50 nC, and a maximum power density of 45 mW/m2 at a load resistance of 500 MΩ. The UV light sensitivity of TENG was also improved via g-C3N4 doping, showing that charge transfer is very sensitive with a two times enhancement with dopant. For the demonstration of applications, the g-C3N4 doped TENG was fabricated into an energy flag to scavenge wind energy and sensor devices for detecting human motions. [ABSTRACT FROM AUTHOR]

Marine plastic pollution is emerging as a potential hazard to global ecosystems and human health. Micro-fibers derived from synthetic textiles contribute a considerable proportion of plastic debris. Bio-polymers/bio-plastics have been proposed for the application of apparel products, yet their degradability, fate, durability and related environmental parameters are still elusive and need further exploration. Herein, we report the degradation behavior of poly(lactide acid)/poly(hydroxybutyrate) (PLA/PHB) fabrics, made from PLA/PHB multi-filament yarns, in subtropics marine seawater. The degradation experiments were performed under various parallel conditions including static seawater, aerobic seawater in dark box, aerobic seawater under sunlight, static seawater under ultra-violet light and aerobic seawater under ultra-violet light. Continuous mass loss of PLA/PHB fabrics as the immersion time in the seawater increased was confirmed. The hydrolysis rate of PLA/PHB fabrics accelerated in the presence of UV light and dissolved oxygen in the seawater. Moreover, the tensile strength of the PLA/PHB yarns dropped rapidly by 38.54–68.70% in spite of the mass loss percentage being from 9.57% to 14.48% after 2 weeks' immersion. All the PLA/PHB fabrics after two weeks' immersion exhibited similar ATR-IR spectra. Therefore, the degradability of PLA/PHB fabrics, in the marine surface water under the synergistic destructive effect of seawater, UV and dissolved oxygen, provides a pathway for more sustainable textile fibers and apparel products. [ABSTRACT FROM AUTHOR]