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1.
ACS Nano ; 2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39129247

RESUMEN

Recycling spent lithium-ion batteries (LIBs) to efficient water-splitting electrocatalysts is a promising and sustainable technology route for green hydrogen production by renewables. In this work, a fluorinated ternary metal oxide (F-TMO) derived from spent LIBs was successfully converted to a robust water oxidation catalyst for pure water electrolysis by utilizing an anion-exchange membrane. The optimized catalyst delivered a high current density of 3.0 A cm-2 at only 2.56 V and a durability of >300 h at 0.5 A cm-2, surpassing the noble-metal IrO2 catalyst. Such excellent performance benefits from an artificially endowed interface layer on the F-TMO, which renders the exposure of active metal (oxy)hydroxide sites with a stabilized configuration during pure water operation. Compared to other metal oxides (i.e., NiO, Co3O4, MnO2), F-TMO possesses a higher stability number of 2.4 × 106, indicating its strong potential for industrial applications. This work provides a feasible way of recycling waste LIBs to valuable electrocatalysts.

2.
Chem Asian J ; : e202400764, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39136385

RESUMEN

The creation of hydrogen using the lower-cost feedstock, waste organics (WOs), e.g. kitchen waste bio-oil, is a win-win solution, because it can both solve energy problems and reduce environmental pollution. Ultrasound has received considerable interest in organic decomposition; however, the application of ultrasound alone is not a good choice for the hydrogen production from WOs, because of the energy consumption and efficiency. To boost the hydrogen production based on ultrasonic cavitation cracking of bio-oil, photothermal materials are introduced into the hydrogen production system to form localized hot spots. Materials carbon black (CB), carbon nanotubes (CNT), and silicon dioxide (SiO2) all exhibit significant enhancing effects on the hydrogen production from bio-oil, and the CB exhibits the most significant strengthening effect among these materials. When the dosage of CB is 5 mg, hydrogen production rate is 180.1 µmol · h-1, representing a notable 1.7-fold increase compared to the production rate without CB. In the presence of light and ultrasound, the hydrogen production rate can be increased by 66.7-fold compared to the situation where only light is present without ultrasound.

3.
Cureus ; 16(7): e63955, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39104981

RESUMEN

Introduction Surface roughness (Ra) significantly impacts the aesthetic and functional qualities of dental prosthetics. Traditional polishing involves pumice, a material routinely used in dental practice. This study introduces Algishine as a potential cost-effective eco-friendly alternative. Materials and methods A 3D design software (Geomagic) created a Standard Tesselation Language (STL) file of 10 mm x 10 mm x 2 mm. 30 STL file outputs were generated. The output was milled in wax. This was then flasked and processed. 30 acrylic resin specimens were fabricated and divided into two groups. Group A was polished using traditional pumice, and Group B was polished using Algishine. The Ra of each sample was measured using surface profilometry, with three readings per sample averaged for each group. Results Kruskal-Wallis test was performed to compare the two groups with the pre-testing samples, which showed p<0.05; indicating that there was a significant difference between the two groups. The average Ra value for unpolished acrylic was 7.105, while the specimens polished with pumice showed an Ra value of 2.218; specimens polished with novel material Algishine showed an Ra value of 1.743. This illustrates that Algishine achieves surface smoothness significantly superior to commonly used polishing agent and pumice. Discussion The results of our study demonstrate that Algishine, a novel polishing material derived from recycled alginate, effectively reduces the Ra of acrylic resin. This finding has significant implications, both clinically and environmentally. The primary clinical benefit of a smoother acrylic resin surface is the enhanced aesthetic appearance and increased patient comfort. A polished surface reduces plaque accumulation, thereby decreasing the risk of oral infections and improving the longevity of the dental prosthesis. The results show that Algishine achieves surface smoothness comparable to or better than pumice indicating that it can maintain, if not enhance, these clinical outcomes. Dental professionals can confidently use Algishine, knowing it meets the high standards required for patient care. Conclusion Algishine effectively reduces the Ra of acrylic resin, suggesting it is a viable, eco-friendly alternative to traditional pumice for dental polishing procedures. This indicates potential benefits in maintaining clinical outcomes while promoting environmental sustainability.

4.
Ecotoxicol Environ Saf ; 283: 116824, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39106573

RESUMEN

Volatile organic compounds (VOCs) pose potential hazards to human health and contribute significantly to odor pollution. This study examined VOC emissions from a representative recycled rubber industry, evaluating the occupational health risks for frontline workers in various workshops. Variables such as gender and workshop-specific concentration variations were considered using Monte Carlo simulation methods. Employees in the five production workshops and office areas face noncarcinogenic health risks with hazard indices (HIs) greater than 1, with the rubber compounding phase presenting the highest risk. Acetaldehyde is identified as the primary noncarcinogenic health risk substance, with hazard quotient (HQ) values exceeding 1 in all workshops. Carcinogenic health risks vary by area, with the highest risks found in compounding and refining workshops. Formaldehyde poses the greatest risk in rubber grinding workshops and offices, with cumulative weights exceeding unacceptable levels of M80.58 % and W77.56 % in grinding and M94.98 % and W92.24 % in the office. Male workers face 4-7 % greater noncarcinogenic VOC health risks than females and 5-14 % greater carcinogenic risks from individual VOCs, increasing their susceptibility to health risks caused by VOCs. Additionally, our analysis of odor identification and intensity classification revealed that 53 VOCs are capable of causing odor pollution, with several substances reaching odor levels of 2 or higher. The predominant perceived odors, as reflected in the odor wheel, include categories such as "solvent/aromatic" and "sweet/fruit," with aldehydes being the primary odor-causing substances. In summary, emissions of VOCs from rubber industrial processes not only pose substantial health risks to workers but also contribute significantly to odor pollution. Consequently, enterprises must prioritize optimizing workplace conditions to ensure the occupational health and well-being of their employees.

5.
ChemSusChem ; : e202401324, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39117578

RESUMEN

Microbial applications in agriculture and industry have gained significant attention due to their potential to address environmental challenges and promote sustainable development. Among these, the genus Pseudomonas stands out as a promising candidate for various biotechnological uses, thanks to its metabolic flexibility, resilience, and adaptability to diverse environments. This review provides a comprehensive overview of the current state and future prospects of microbial fuel production, bioremediation, and sustainable development, focusing on the pivotal role of Pseudomonas species. We emphasize the importance of microbial fuel as a renewable energy source and discuss recent advancements in enhancing biofuel generation using Pseudomonas strains. Additionally, we explore the critical role of Pseudomonas in bioremediation processes, highlighting its ability to degrade a wide spectrum of pollutants, including hydrocarbons, pesticides, and heavy metals, thereby reducing environmental contamination. Despite significant progress, several challenges remain. These include refining microbial strains for optimal process efficiency and addressing ecological considerations. Nonetheless, the diverse capabilities of Pseudomonas offer promising avenues for innovative solutions to pressing environmental issues, supporting the transition to a more sustainable future.

6.
Front Robot AI ; 11: 1324519, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39050487

RESUMEN

As robot numbers in the home increase, creating a market for second-hand robotic systems is essential to reduce the waste impact of the industry. Via a survey, consumer attitudes of United Kingdom participants towards second-hand robots were investigated; finding that second-hand robots with guarantees have an equal purchasing interest compared to new systems, highlighting the opportunity for manufacturers and retailers to develop certification standards for second-hand robots to move towards a circular economy. Consumer demographics also demonstrated that those most open to the purchase of both new and second-hand systems were women, those aged 18-25 years old, and those who have previously owned a robot for the home. Participants' prior ownership of second-hand electronic devices (such as phones and laptops) did not affect rates of interest for second-hand robotic systems suggesting that the technology is still too new for people to be able to project their experience of current second-hand electronics to that of a robot. Additionally, this research found the robotics industry can consider the potential market for second-hand robots to be more similar to the second-hand smartphone market than to the household electronics market, and lessons learnt from the concerns raised by consumers for other internet-enabled electronic devices are similar to those concerns for second-hand robots. This provides an opportunity for the industry to break down the barriers for a circular economy earlier in the technology maturity process than has been seen for other electronics.

7.
Angew Chem Int Ed Engl ; : e202409255, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38984684

RESUMEN

With the large-scale application of lithium-ion batteries (LIBs), a huge amount of spent LIBs will be generated each year and how to realize their recycling and reuse in a clean and effective way poses a challenge to the society. In this work, using the electrolyte of spent LIBs as solvent, we in-situ fluorinate the conductive three-dimensional porous copper foam by a facile solvent-thermal method and then coating it with a cross-linked sodium alginate (SA) layer. Benefiting from the solid-electrolyte interphase (SEI) that accommodating the volume change of internal CuF2 core and SA layer that inhibiting the dissolution of CuF2, the synthesized CuF2@void@SEI@SA cathode with a pomegranate-like structure (yolk-shell) exhibits a large reversible capacity of ~535 mAh g-1 at 0.05 A g-1 and superb cycling stability. This work conforms to the development concept of green environmental protection and comprehensively realizes the unity of environmental, social and economic benefits.

8.
Biosens Bioelectron ; 262: 116551, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-38971039

RESUMEN

Controllable assembly of DNA nanostructure provides a powerful way for quantitative analysis of various targets including nucleic acid molecules. In this study, we have designed detachable DNA nanostructures at electrochemical sensing interface and constructed a ligation chain reaction (LCR) strategy for amplified detection of miRNA. A three-dimensional DNA triangular prism nanostructure is fabricated to provide suitable molecule recognition environment, which can be further regenerated for additional tests via convenient pH adjustment. Target triggered LCR is highly efficient and specific towards target miRNA. Under optimal experimental conditions, this approach enables ultrasensitive exploration in a wide linear range with a single-base resolution. Moreover, it shows excellent performances for the analysis of cell samples and clinical serum samples.


Asunto(s)
Técnicas Biosensibles , ADN , MicroARNs , Nanoestructuras , MicroARNs/sangre , MicroARNs/análisis , Técnicas Biosensibles/métodos , Humanos , ADN/química , Nanoestructuras/química , Técnicas Electroquímicas/métodos , Reacción en Cadena de la Ligasa/métodos , Límite de Detección
9.
J Environ Sci (China) ; 146: 237-240, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38969451

RESUMEN

Exploring the vast extraterrestrial space is an inevitable trend with continuous human development. Water treatment and reuse are crucial in the limited and closed space that is available in spaceships or long-term use space bases that will be established in the foreseeable future. Dedicated water treatment technologies have experienced iterative development for more than 60 years since the first manned spaceflight was successfully launched. Herein, we briefly review the related wastewater characteristics and the history of water treatment in space stations, and we focus on future challenges and perspectives, aiming at providing insights for optimizing wastewater treatment technologies and closing the water cycle in future.


Asunto(s)
Eliminación de Residuos Líquidos , Aguas Residuales , Purificación del Agua , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Vuelo Espacial
10.
Saudi J Biol Sci ; 31(8): 104033, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38946846

RESUMEN

Plant phenolics have been known for various biological activities. This study aims to extract and examine the presence of phenolics in Bao mango (Mangifera indica L. var.) peel ethanolic extract (MPE). Further, antioxidant, anti-diabetic (α-amylase, and α-glucosidase inhibitory activity), and anti- Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ß-secretase (BACE-1) inhibitory activity) efficacy of MPE were determined. The results indicated that mangiferin (8755.89 mg/ 100 g extract) was the major phenolic compound in MPE. An antioxidant mechanism revealed that MPE had a higher radical scavenging ability (4266.70 µmol TE/g extract) compared to reducing power (FRAP) or oxygen radical absorption capacity (ORAC). Further in-vitro enzyme inhibitory assay against diabetic and AD involved enzymes showed that MPE had stronger inhibitory action against an enzyme involved in diabetes compared to their standard drug (Acarbose) (P < 0.05). While a lower IC50 value was observed against AD-involved enzymes compared to their standard drug (donepezil) (P < 0.05). The results show that Thai Bao mango peel byproduct can be a potential source of nutraceuticals to lower diabetes and improve cognitive health.

11.
J Environ Manage ; 366: 121863, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39033618

RESUMEN

This study focuses on developing a cost-effective Fe2O3 catalyst from oilfield iron waste to create a floating heterogeneous photo-Fenton system with anatase/rutile(A/R) TiO2 heterophase photocatalyst (cork-Fe2O3@A1-xRx-TiO2) for treating textile pollution in sunlight. Through controlling sol-gel (SG) microwave heating technique, the A/R ratio of A1-xRx-TiO2 crystal is tuned (A/R ratio = 1.13 and Eg = 3.02 eV) to improve adsorption-photocatalytic removal of anionic/cationic dyes with an apparent kinetic rate (kapp) of 0.0074 min-1 under UV-visible irradiation. The developed cork-Fe2O3@A53.1R46.8-TiO2 floated system also outperforms the classical photo-Fenton with Fe/H2O2 benchmark, showing a 2-fold enhancement in textile dye degradation (kapp = 0.216 min-1 and space-time yield (SY) of 1.7*10-4 mol/E.g at pH 5.65) with high stability over four reuse cycles. The formation of Fe2O3@A53.1R46.8-TiO2 Type-II heterojunction is confirmed by optical and electrochemical analyses, allowing the acceleration of direct electron transfer mechanism and oxidative degradation of dyes during photo-Fenton reaction. As a case study, the cork-Fe2O3@A53.1R46.8-TiO2 system demonstrates a high capability for efficient mineralization of textile pollution in a real effluent, achieving 82 ± 2% reduction in the total organic contents at an operational cost of 2.61 $/kg.m3 in sunlight. Thus, this research addresses challenges in conventional Fenton chemistry, iron waste recycling, and catalyst retention, offering new insights for sustainable treatment of textile effluents and environmental protection.


Asunto(s)
Peróxido de Hidrógeno , Hierro , Textiles , Titanio , Hierro/química , Catálisis , Peróxido de Hidrógeno/química , Titanio/química , Contaminantes Químicos del Agua/química , Luz Solar , Compuestos Férricos/química , Colorantes/química , Contaminación del Agua/prevención & control
12.
Sci Rep ; 14(1): 16660, 2024 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-39030233

RESUMEN

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.


Asunto(s)
Textiles , Óxido de Zinc , Óxido de Zinc/química , Óxido de Zinc/farmacología , Humanos , Nanopartículas del Metal/química , Streptomyces/metabolismo , Línea Celular , Residuos Industriales , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo
13.
Molecules ; 29(12)2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38930970

RESUMEN

A highly sensitive, selective and recyclable histidine detection method based on magnetic Fe3O4@mTiO2 (M-TiO2) nanocomposites with SERRS was developed. Mesoporous M-TiO2 nanoparticles were functionalized with 4-aminothiophenol and then coupled with histidine through an azo coupling reaction in 5 min, producing the corresponding azo compound. The strong and specific SERRS response of the azo product allowed for ultrasensitive and selective detection for histidine with an M-TiO2 device loaded with Ag NPs due to the molecular resonance effect and plasmonic effect of Ag NPs under a 532 nm excitation laser. The sensitivity was further enhanced with the magnetic enrichment of M-TiO2. The limit of detection (LOD) was as low as 8.00 × 10-12 mol/L. The M-TiO2 demonstrated applicability towards histidine determination in human urine without any sample pretreatment. Additionally, the M-TiO2 device can be recycled for 3 cycles with the photodegradation of the azo product under UV irradiation due to TiO2-assisted and plasmon-enhanced photocatalysis. In summary, a multifunctional and recyclable M-TiO2 device was synthesized based on azo coupling and SERRS spectroscopy for ultra-sensitive and specific histidine sensing. In addition, the proposed system demonstrated the potential for the multiplex determination of toxic compounds in the fields of food safety, industrial production and environmental protection, which benefit from the fingerprint property and universality of SERRS.


Asunto(s)
Histidina , Nanocompuestos , Titanio , Titanio/química , Histidina/química , Histidina/orina , Nanocompuestos/química , Límite de Detección , Humanos , Nanopartículas del Metal/química , Plata/química , Compuestos Azo/química
14.
Environ Technol ; : 1-20, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38853669

RESUMEN

High concentrations of ammonium, phosphate, and phenol are recognized as water pollutants that contribute to the degradation of soil acidity. In contrast, small quantities of these nutrients are essential for soil nutrient cycling and plant growth. Here, we reported composite materials comprising biochar, chitosan, ZrO, and Fe3O4, which were employed to mitigate ammonium, phosphate, and phenol contamination in water and to lessen soil acidity. Batch adsorption experiments were conducted to assess the efficacy of the adsorbents. Initially, comparative studies on the simultaneous removal of NH4, PO4, and phenol using CB (biochar), CBC (biochar + chitosan), CBCZrO (biochar + chitosan + ZrO), and CBCZrOFe3O4 (biochar + chitosan + ZrO + Fe3O4) were conducted. The results discovered that CBCZrOFe3O4 exhibited the highest removal percentage among the adsorbents (P < 0.05). Adsorption data for CBCZrOFe3O4 were well fitted to the second-order kinetic and Freundlich isotherm models, with maximum adsorption capacities of 112.65 mg/g for NH4, 94.68 mg/g for PO4 and 112.63 mg/g for phenol. Subsequently, the effect of CBCZrOFe3O4-loaded NH4, PO4, and phenol (CBCZrOFe3O4-APP) on soil acidity was studied over a 60-day incubation period. The findings showed no significant changes (P < 0.05) in soil exchangeable acidity, H+, Mg, K, and Na. However, there was a substantial increase in the soil pH, EC, available P, CEC, N-NH4, and N-NO3. A significant reduction was also observed in the available soil exchangeable Al and Fe (P < 0.05). This technique demonstrated multi-functionality in remediating water pollutants and enhancing soil acidity.

15.
Environ Technol ; : 1-12, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38861474

RESUMEN

ABSTRACTThe Ministry of Environment of Korea has proposed a ban on landfill disposal of municipal solid waste (MSW) from 2026. Thus, it is inferred that the amount of incineration ash will increase drastically. Against this backdrop, this study assessed the applicability of a plasma melting process to fly ash. Fly ash was collected from 14 incineration facilities to analyze its basic properties and perform melting experiments. Furthermore, scanning electron microscope (SEM) analysis and economic feasibility assessment were conducted. The molten fly ash slag exhibited a pH value of 9.9, and the ignition loss of fly ash was found to range from 14.5 to 25.7 wt.%. None of seven toxic elements (arsenic (As), cadmium (Cd), cyanide (CN), mercury (Hg), hexavalent chromium (Cr(VI)), copper, and lead (Pb)) was detected from the molten slag. In addition, 99.3 wt.% of chloride ion (Cl-), 97.9 wt.% of fluoride ion (F-), and 98.1 wt.% of sulphate ion (SO42-) were removed. The contents in the molten slag were found to be 0.19, 7.8, 27.8, 33.1, and 38 mg/kg for Cd, Pb, zinc, nickel, and F, respectively, and none of CN, Hg, and As was detected, thereby meeting the criteria for soil pollution. All of the environmental standards were met, and SEM analysis confirmed stable quality with high density and no surface pore. In the economic feasibility assessment, a profit of approximately 152.4 $/ton was also estimated compared to landfill disposal.

16.
ChemSusChem ; : e202400512, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38878218

RESUMEN

Massive accumulation of postconsumer plastic waste in eco-system has raised growing environmental concerns. Sustainable end-of-life managements of the indispensable plastic are highly demanding and challenging in modern society. To relieve the plastic menace, herein we present a full life cycle sustainable supramolecular bioplastic made from biomass-derived polyelectrolyte (chitosan quaternary ammonium salt, QCS) and natural sodium fatty acid (sodium laurate, SL) through solid-phase molecular self-assembly (SPMSA), by which the QCS-SL complexes, precipitated from mixing the aqueous solutions, self-assemble to form bioplastic film by mildly pressing at room temperature. The QCS-SL bioplastic films display superior hydroplasticity owing to the water-activated molecular rearrangement and electrostatic bond reconstruction, which allows facile self-healing and reprocessing at room temperature to significantly extend the service lifetime of both products and raw materials. With higher water content, the dynamic electrostatic interactions and precipitation-dissolution equilibrium endow the QCS-SL bioplastic films with considerable solubility in water, which is promising to mitigate the plastic accumulation in aquatic environment. Because both QCS and SL are biocompatible and biodegradable, the dissolved QCS-SL films are nontoxic and environmentally friendly. Thus, this novel supramolecular bioplastic is highly sustainable throughout the whole life cycle, which is expected to open a new vista in sustainable plastic materials.

17.
ChemSusChem ; : e202400843, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38804532

RESUMEN

Carbon circularity is crucial for achieving a circular economy but has wider implications and impacts with respect to the circularity of materials. It has an in-depth transformative effect on the economy. CO2 recycling is a critical component for this objective, with catalysis and inorganic chemistry playing a determining role in achieving this challenge. This concept paper presents some examples, as food for thought, of unconventional aspects in developing thermal and electro/photocatalysts for recycling CO2. The aspects discussed regard designing novel materials for CO2 thermo- or electro-conversion and developing novel nanostructured electrodes.

18.
Angew Chem Int Ed Engl ; 63(31): e202405653, 2024 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-38764409

RESUMEN

Dithioacetals are heavily used in organic, material and medical chemistries, and exhibit huge potential to synthesize degradable or recyclable polymers. However, the current synthetic approaches of dithioacetals and polydithioacetals are overwhelmingly dependent on external catalysts and organic solvents. Herein, we disclose a catalyst- and solvent-free acetal-thiol click-like reaction for synthesizing dithioacetals and polydithioacetals. High conversion, higher than acid catalytic acetal-thiol reaction, can be achieved. High universality was confirmed by monitoring the reactions of linear and cyclic acetals (including renewable bio-sourced furan-acetal) with aliphatic and aromatic thiols, and the reaction mechanism of monomolecular nucleophilic substitution (SN1) and auto-protonation (activation) by thiol was clarified by combining experiments and density functional theory computation. Subsequently, we utilize this reaction to synthesize readily recyclable polydithioacetals. By simple heating and stirring, linear polydithioacetals with M ‾ ${\bar M}$ w of ~110 kDa were synthesized from acetal and dithiol, and depolymerization into macrocyclic dithioacetal and repolymerization into polydithioacetal can be achieved; through reactive extrusion, a semi-interpenetrating polymer dynamic network with excellent mechanical properties and continuous reprocessability was prepared from poly(vinyl butyral) and pentaerythritol tetrakis(3-mercaptopropionate). This green and high-efficient synthesis method for dithioacetals and polydithioacetals is beneficial to the sustainable development of chemistry.

19.
Angew Chem Int Ed Engl ; 63(32): e202401746, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38757221

RESUMEN

Over 79 % of 6.3 billion tonnes of plastics produced from 1950 to 2015 have been disposed in landfills or found their way to the oceans, where they will reside for up to hundreds of years before being decomposed bringing upon significant dangers to our health and ecosystems. Plastic photoreforming offers an appealing alternative by using solar energy and water to transform plastic waste into value-added chemical commodities, while simultaneously producing green hydrogen via the hydrogen evolution reaction. This review aims to provide an overview of the underlying principles of emerging plastic photoreforming technologies, highlight the challenges associated with experimental protocols and performance assessments, discuss recent global breakthroughs on the photoreforming of plastics, and propose perspectives for future research. A critical assessment of current plastic photoreforming studies shows a lack of standardised conditions, hindering comparison amongst photocatalyst performance. Guidelines to establish a more accurate evaluation of materials and systems are proposed, with the aim to facilitate the translation of promising fundamental discovery in photocatalysts design.

20.
MethodsX ; 12: 102749, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38774684

RESUMEN

A major challenge in plastic recycling is to convert plastic waste into a useful product. For this transformation, sustainable technologies such as plastic recycling machines are required. Current technological concepts of plastic recycling are fairly similar. This study aims to develop a small and economical plastic recycling machine to enhance microenterprise by supplying simple equipment for recycling locally processed plastic waste into thread. Starting with a hopper at the input end, the machine incorporates an auger inside a barrel, which is then linked to a metallic perforated mold at the output end. With the help of the system, the plastic flakes melting process is facilitated by maintaining temperatures between 170 °C to 211 °C at equispaced locations of a uniform barrel, while the auger spin enables the flow of molten plastic forward towards the mold.The mold reshapes the liquid plastic into strings of thread. The machine exhibits higher efficiency, reaching approximately 75 % at a decreased screw speed, as low as 28 rpm. It also achieves an average throughput of 156 gm/hour at the lowest specific mechanical energy (SME) consumption. The prototype consumes 1.5 kW for an hour operation. The entire system requires minimal space, making it appealing to individuals with limited financial resources to start a new business venture.•A sustainable technology to recycle plastic waste into plastic thread.•This optimized, portable and robust system ensures safety and lower operating costs.•This system does not require prior knowledge for operation, hence encouraging small entrepreneurs.

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