Sustainable Materials and Technologies最新文献

Bacterial infections pose a serious worldwide public health concern and play an important role in slowing or dramatically delaying wound healing. However, traditional antibiotics are faced with obstacles such as bacterial resistance and unsatisfactory biocompatibility, which has impeded further clinical translation. In recent years, antimicrobial nanomaterials have emerged as viable alternatives for combating bacterial infections, and carbon dots (CDs) have received particularly widespread attention due to their superior characteristics. In this work, a simple and eco-friendly one-step hydrothermal method was employed using the natural herbal medicine Eucommia ulmoides as a biomass carbon source to synthesize an Fe-doped CDs nanozyme (Fe-CDs) with good peroxidase-like (POD-like) activity, high biocompatibility, and strong antimicrobial activity for safe and effective antimicrobial therapy and the promotion of wound healing. L929 cells co-cultured with Fe-CDs did not show significant cytotoxicity and favored cell proliferation at appropriate concentrations. In addition, Fe-CDs catalyzed the decomposition of low-concentration H₂O₂ to ·OH, leading to enhanced antimicrobial activity. Both in vitro and in vivo experiments demonstrated that Fe-CDs exhibit potent antibacterial properties, the ability to promote cell migration and angiogenesis, and significant potential for promoting the healing of infected wounds. In summary, a green and safe antimicrobial nanozyme based on a biomass herbal medicine was developed in this work, offering promising insight into the development of novel antimicrobial materials and tissue regeneration engineering.

A facile pathway of upcycling waste/discarded polysulfone (WPSF) membranes has been proposed using deep eutectic solvent (DES) system composed of choline chloride and ethylene glycol (CC:EG) in 1:1 ratio as a green template. This approach offers a viable solution for addressing polymer membrane waste management challenges while simultaneously promoting feasible method, resource efficiency and economic viability. The WPSF was doped with Mn ions prior to the solvothermal conversion at 200 °C and pyrolysis at 900 °C. The obtained functional porous carbon showed superior adsorption capacity towards Malachite green (MG) (423.72 mg/g), Eriochrome black-T (EBT) (326.79 mg/g), Diclofenac (DCF) (195.31 mg/g), and Ofloxacin (OFX) (121.8 mg/g). The adsorption followed pseudo second order kinetics and well agreed with Langmuir isotherm. Further, the optimised carbon material i.e., Mn-WPSF-01 was used as an adsorptive-based membrane water filtration system, in which a remarkable water flux about 965 L.m⁻².h⁻¹ for different feed streams with outstanding rejection of >90% even after ten cycles of regeneration was obtained. Therefore, Mn-doped carbon materials integrate the advantages of easy preparation, robustness, and effective adsorption performances, as well as good recyclability. Furthermore, the utilized or secondary carbon materials were used as electrode system in supercapacitors after the pyrolysis, where they displayed a specific capacitance of 110.88 F/g at 0.1 A/g of current density with capacity retention 90.85% for about 20,000 cycles with a current density increased to 5 A/g. Therefore, this approach promises to recycle the WPSF via potential applications in water treatment and energy applications through greener way.

Abstract

Polymers have attracted attention for their use in enabling biodegradable electronics. However, many polymers suitable as substrates either have no adhesion or suffer from weak and unstable adhesion. Addressing this challenge, we report a simple method to achieve tunable adhesion on various surfaces for wide applications. We achieve this by combining poly(vinyl alcohol) (P), dopamine (DA) and citric acid (CA) to produce modified poly(vinyl alcohol) adhesive films. These films are derived from bio-based constituents through an environmentally benign, easily reproducible and scalable fabrication process. They offer strong adhesion to various surfaces, such as stainless steel (138–191 kPa) and Polytetrafluoroethylene (PTFE) (67–93 kPa) and facilitate easy detachment with water. Notably, the modified films showed a better degradation compared to pristine P films under anaerobic conditions. The extent of degradation was characterized both quantitatively and qualitatively. The biokinetic parameters of anaerobic digestion process were estimated using three different kinetic models. It is anticipated that DA and CA molecules penetrate the interplanar distance of P chains as supported by powder X-ray diffraction (XRD) studies, thus, accelerating the degradation process. Additionally, the inclusion of CA enhanced the stability of DA molecules against oxidation, increased the extent of H-bonding and acted as a plasticizer. The addition of DA and CA bestowed the films with self-healing property due to the presence of multiple H-bonds. Tensile experiments revealed that the strength of self-healed samples approached that of pristine samples. The findings of this study hold promise for the development of innovative, biodegradable poly(vinyl alcohol)-based self-healing adhesive films with potential applications across various domains like smart packaging, soft robotics, on-skin electronic tattoos and self-healing electronics.

Starting from spent coffee grounds, the use of coffee-derived biochar (CB) as a flame retardant (FR) additive was explored following a waste-to-wealth approach. CB was employed alone and in combination with ammonium polyphosphate (APP) and a ternary (Si-Ti-Mg) mixed oxide to enhance the thermal, fire, and mechanical performances of a bisphenol A diglycidyl ether (DGEBA)-based epoxy resin modified with (3-aminopropyl)-triethoxysilane (APTES) and cured with a cycloaliphatic amine hardener. The presence of silicon-modified epoxy chains guaranteed the uniform distribution of CB throughout the resin. The combined FR action of fillers (CB, APP, and Si-Ti-Mg oxide) and the acidic characteristics of hybrid epoxy moieties enabled the achievement of a no dripping UL 94-V-0 classification for epoxy resin containing 20 wt% CB and 1 wt% of phosphorus loading, significantly increasing the flexural modulus (by ∼15%). Although it is not self-extinguishing, compared to pristine resin, the silicon-modified epoxy nanocomposite filled only with CB exhibited a remarkable decrease in the peak of heat release rate (pHRR) (by ∼65%) and a beneficial smoke suppressant effect with a notable decrease (∼11%) in the total smoke production. Cone calorimetry tests, pyrolysis combustion flow calorimetry analysis, and microscopy measurements helped to outline the combined mode of action of CB, APP, and Si-Ti-Mg oxide in the flame retardation of the hybrid epoxy resin, highlighting a strong FR action in the condensed phase, with the formation of a stable aromatic ceramic char, as well as the smoke suppressant character due to the basic nature of the ternary metal oxide and the ability of porous biochar to adsorb the generated gases.

Lignocellulosic materials, despite their abundance and attractiveness, have long been marred with challenges in optimising the cost-functionality-quality trade-off. This comprehensive authoritative review paper explores how various lignocellulosic feedstock have been utilised to prepare marketable and sustainable bioplastics, as potential substitutes to conventional petroleum-based packaging. Dependence on hydrocarbon-derived plastics is increasingly being supplanted by both consumer-driven and sustainability-oriented materials design. This comprehensive paper encompasses a broad review relating to recent research (2013−2023) on the innovations and heuristic approaches to modify lignocellulose for the production of packaging films. The review paper holds extensive focus across various lignocellulosic materials such as - but not limited to - cellulose nanomaterials, cellulose esters and grafted cellulose. Advances in processes reported to date such as mechanochemical, chemical, thermochemical, biochemical and other novel methods have been studied. The materials design and process implications in terms of its cost, energy input and sustainability in its true sense, for all known techniques have been extensively investigated in this review paper. The review paper has further provided an elaborate process-structure-property-performance framework that characterises how material properties could be fine-tuned via different process considerations. A techno-economic feasibility overview for said processes and materials' use is also described herein.

To efficiently and completely remove organic pollutants from water, developing composite catalysts with both adsorption and photocatalytic/Fenton catalytic degradation is a very feasible solution. Herein, a new Cu_xO and g-C₃N₄ codoped bamboo charcoal (BC) composite (Cu-g-C₃N₄/BC) was prepared by the in-situ pyrolysis of Cu²⁺/melamine modified bamboo powders in N₂ atmosphere. Under the catalysis of Cu-g-C₃N₄/BC(600)/H₂O₂ system, the methylene blue (MB) and rhodamine B (RhB) dyes can be completely degraded within 10 min, and the methyl orange (MO) can be degraded within 30 min, indicating a high catalytic efficiency of the catalyst. Electron paramagnetic resonance (EPR) tests and active species trapping experiments suggested that ∙OH was the main active species in the degradation process, while the ·O₂⁻ and h⁺ played a minor role. The synergy of Cu₂O, CuO and g-C₃N₄ active sites in Cu-g-C₃N₄/BC increases the density of photogenerated electrons and promotes the separation of electron-hole pairs via the heterojunctions. The bamboo charcoal matrix plays an important role in the process of adsorbing the dyes and H₂O₂, which greatly promotes the activation of H₂O₂ and the degradation of dyes. In addition, the high conductivity of bamboo charcoal facilitates the charge transfer from the active sites to H₂O₂. The as-prepared Cu-g-C₃N₄/BC catalyst exhibits good reusability due to its structural stability. This work offers a promising bamboo charcoal catalyst with multiple active sites for the rapid elimination of persistent organic pollutants.

Tetracycline (TC) pharmaceutical compound is the third most used antibiotic after penicillin and quinolones, which developed bacterial resistance against them and environmental toxicity due to partially metabolized within humans and animals. At the same time, waste products (WPs) including food, agriculture, and plastic waste significantly increased day-by-day with the growing population. Therefore, there is a pleading requirement to develop a solar active agent that effectively degrades environmental pollution as well as reduces the burden of WPs. In this context, the present works focus on the development of waste-derived bimetallic (Fe/Ca) Oxy-iodide (WD-BMOX) encapsulated with PVDF-based nanosphere (WD-BMOX-P) as a solar active agent for the degradation of TC antibiotics. The band gap values of the synthesized WD-BMOX-P-based nanosphere are easily altered by changing the ratio of Fe/Ca. The lowest band gap values were observed to be ∼1.95 eV of the WD-BMOX-P-1:2, whereas upon increasing the Ca within the nanosphere band gap value significantly increases. The incorporation of PVDF polymer within the WD-BMOX-P aided advantages to formed nanosphere and improved oxygen vacancy, thereby high degradation efficiency. The highest degradation of TC antibiotics ∼96.8% and ∼ 69% was observed using WD-BMOX-P-1:2 nanosphere at 1 mg/L and 10 mg/L, of TC antibiotics within 60 min of solar irradiation, respectively. Moreover, ∼88% and 100% photodegradation of TC antibiotics was observed at pH 10 and the presence of H₂O₂ at 10 mg/L, respectively. The data indicate that the synthesized WD-BMOX-P-based nanosphere might be promising solar active agents, which effectively degrade TC antibiotics from water.

The increase in electronic waste (e-waste) is a significant global concern due to fast technological development in which products rapidly become obsolete. To mitigate this problem in the field of electrochromic devices, four different types of solid polymer electrolytes (SPEs) were developed based on iota-carrageenan, a water-soluble biopolymer, and 40 wt% concentration of different ionic liquids (ILs): 1-butyl-3-methyl-imidazolium thiocyanate ([BMIM][SCN]), 1-ethyl-3-methyl-imidazolium thiocyanate ([EMIM][SCN]), 1-butyl-3-methyl-imidazolium dicyanamide ([BMIM][N(CN)₂)]), and 1-ethyl-3-methyl-imidazolium dicyanamide ([EMIM][N(CN)₂)]). The resulting composites present a uniform and compact morphology, with a good distribution of the ILs within the polymer matrix, thermal stability up to ∼100 °C, and suitable mechanical properties. Their ionic conductivity at room temperature is in the range of ∼10⁻⁴ S.cm⁻¹ in the solid state and around ∼10⁻³ S.cm⁻¹ in the liquid state. Each of the developed electrolytes was integrated on a printed electrochromic device (ECD) fabricated with poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) as a working electrode and their performance was evaluated using spectroelectrochemical techniques. All four ECDs operate at voltages between -1 V and 1 V, providing coloration efficiencies between 253 and 571 cm².C⁻¹ for the oxidation process and between −435 and − 847 cm².C⁻¹ for the reduction process at 98% full contrast, and presenting switching times between the bleached and colored states around 3.2–4.8 s at 98% full contrast. These low-cost SPEs provide a suitable approach for the development of high-performance sustainable ECDs.

Hydraulic fracturing for oil and gas production generates a substantial amount of wastewater, and photocatalysis is a potential method for treating fracture flowback fluids due to its low cost and efficiency. This study utilized the hydrothermal method to synthesize layered α-Ni(OH)₂ with a controllable microstructure by substituting various nickel sources, including Cl⁻, SO₄²⁻, OAc⁻, and NO₃⁻ interlayer ions, to focus on the photocatalytic degradation of hydroxypropyl guanidine gum, the primary constituent of fracturing fluid. The results indicate that α-Ni(OH)₂/OAc⁻ exhibits the most effective photocatalytic activity under optimal experimental conditions. The stability of the catalyst was confirmed through cycling studies. Possible degradation mechanisms were hypothesized based on DFT adsorption energy calculations and capture tests. The field performance of the application demonstrates that this work offers novel perspectives on the photocatalytic degradation of fracturing fluids.

Laser-induced breakdown spectroscopy (LIBS) is a commonly employed technique in commercial plastic recycling for purposes including classification, sorting, identification, and elemental analysis. However, understanding the molecular-level kinetics, thermodynamic interactions, bonding cleavage, and process parameter impacts is crucial for identifying necessary modifications to enhance plastic recycling. A review of the literature revealed that LIBS can also facilitate plastic pyrolysis, a significant research area that remains largely unexplored. Based on theoretical hypotheses, it can be concluded that laser-induced pyrolysis may offer advantages over traditional pyrolysis, which requires understanding the chemistry of plastic bond-breaking during degradation, identifying resistant bonds, and uncovering the root causes of these challenges. This approach is described in detail in sections 9 and 10, focusing on high-density polyethylene (HDPE) under controlled conditions. The identified research gaps could be further investigated, and advancements could be made toward establishing efficient plastic recycling and designing laser-induced pyrolysis reactors.