RSC sustainability最新文献

Lignin, a complex aromatic polymer from plant cell walls, has emerged as a promising material for organic electronics and bioelectronics due to its abundance, low cost, and renewability. Its unique chemical structure allows for the development of flexible, lightweight devices in organic electronics, from printed circuit boards, batteries and supercapacitors to field-effect transistors and solar cells, while its biocompatibility and low toxicity make it ideal for bioelectronic applications like in biosensors, artificial neural networks and cognitive computing. This perspective highlights lignin's potential to address sustainability challenges in the electronics industry and explores its current advancements and future prospects in these fields.

The polymer industry is increasingly focusing on nanocellulose-based polymer composites owing to their remarkable mechanical properties. However, achieving well-dispersed nanocellulose fillers remains challenging. This unique study compares one-step and two-step melt-blending processes for incorporating spray-dried nanocrystalline cellulose (SD-NCC) at 3 and 5 wt% into polypropylene with a 3 wt% MAPP coupling agent. Both the one-step and two-step compounding processes were evaluated for their effects on nanocellulose distribution and mechanical performance. One-step PP/SD-NCC3 achieved the best properties: 34.8 MPa tensile, 57.3 MPa flexural, and 2.08 kJ m⁻² impact strengths. SEM-EDX confirmed good SD-NCC distribution. Two-step 5 wt% SD-NCC showed slight improvements in mechanical, crystallinity, and thermal properties because of its better dispersion, but the one-step process was sufficient for achieving excellent performance. These findings suggest that spray-dried NCC can streamline compounding for large-scale applications.

A series of single-component nickel catalysts (L1-NiBr₂/L2-NiBr₂/L3-NiBr₂) with tetradentate aminopyridine ligands are presented, which exhibit excellent capabilities and selectivity for the synthesis of cyclic carbonates from epoxides and carbon dioxide. A green crystal of L1-NiBr₂ was obtained in CH₃CN, and the ligand adopted a cis-α conformation in the complex. The conversion of styrene oxide could reach 98%, providing 100% selectivity at 90 °C, 1 MPa CO₂ pressure and 5 mol% of L1-NiBr₂ under solvent-free conditions, while the yield and selectivity values were still as high as 92% and 99%, respectively, under 1 atm CO₂ and 0.5 mol% of the catalyst at the same temperature. The catalysts also exerted efficient catalytic coupling reactions of terminal epoxides (90–98% yields of cyclic carbonates), except those bearing a long aliphatic chain under mild conditions. The catalyst exhibited excellent recyclability and stability, which were further proved through ICP to test the catalyst leaching, TGA and IR spectra. Moreover, the catalytic cycloaddition reaction mechanism was investigated using density functional theory (DFT) calculations.

Electrochemical energy storage devices, such as rechargeable batteries and supercapacitors, have replaced conventional batteries and dielectric capacitors owing to their excellent charge storage abilities and other electrochemical performances. However, a major challenge exists in terms of their flexibility in application because most of the rechargeable batteries and supercapacitors available commercially are rigid and hence cannot be used in wearable electronic applications. The flexibility of the devices is mainly imparted by electrodes; hence, the preparation of electrodes is of utmost importance in determining their flexibility. During the fabrication of electrodes, electrode-active materials are coated over an electrically conducting substratum and it is further used as a current collector for the electrodes. The electrodes are flexible if the substratum used is flexible. In this respect, carbon fibers (CFs) have evolved as a suitable and sustainable substratum for the preparation of electrodes for rechargeable batteries to power flexible electronic devices. Micron-sized or nano-sized CFs are invariably used as substrata; hence, flexibility can easily be imparted to the devices assembled. This review outlines the development of rechargeable batteries manufactured from different electrode-active materials coated over this CF substratum. This article provides an in-depth insight into the preparation of flexible electrodes for rechargeable batteries, particularly for application in wearable electronics.

With growing environmental concerns and the depletion of petrochemical resources, biomass-derived chemicals have garnered significant attention. Biomass-derived plasticizers have been widely studied as alternatives to toxic petroleum-based plasticizers. However, the bioressources used for their synthesis, an inedible oil derived from agricultural waste, containing cardanol, cardol and anacardic acid, is attracting new interest. Recent research has focused on cardanol-based plasticizers for various polymers such as PVC, PLA, AC and rubber. Cardanol-based biobased plasticizers offer advantages such as renewability, solvent-resistant extraction and efficient plasticizing performance, making them potentially suitable for partial or total replacement of petroleum-based plasticizers. In this study, we discuss the different types of cardanol-based plasticizers according to their chemical structure, functional groups and applications in polymers. The aim of this study is to increase the interest of researchers in biobased plasticizers based on CNSL derivatives.

The environmental impact and safety of products have become increasingly prominent in recent years, with stringent legislation expected to persist. Polymeric coatings are pervasive in modern life, serving to impart desirable properties and protection to a wide range of surfaces. Traditionally dispersed in volatile organic solvents harmful to the environment and workers, modern coatings are shifting towards waterborne, minimizing harmful environmental emissions. Waterborne coatings have seen substantial commercial uptake in large sectors such as architectural and automotive coatings. Nevertheless, their performance still lags behind conventional systems, and, currently, some products lack commercially viable waterborne alternatives. This review focuses on the current state of commercialized waterborne polymer systems, scrutinizing their performance, composition, and market penetration. Additionally, it explores future trends aimed at addressing existing challenges and pioneering novel coating technologies, with an emphasis on achieving fully sustainable systems.

The current industrial process for recycling Waste Cooking Oils (WCOs) into vegetable lubricants relies on basic decantation and filtration methods, lacking the scientific foundation needed for technical optimization and sustainability. This research addresses these limitations by thoroughly evaluating the technical and environmental impacts of bentonite treatment and water washing techniques. Using a Design of Experiments (DoE) approach coupled with multivariate statistical analysis, key process parameters—temperature, bentonite content, pH, and oil-to-water ratio—were optimized to improve performance and sustainability. Results showed that bentonite had a negligible effect when water treatment was conducted at 75 °C and pH 6 or at 25 °C and pH 2. The efficiency of both recycling methods, as measured by nuclear magnetic resonance spectroscopy and rheological tests, was comparable. However, the green metrics (mass yield, mass productivity, E-factor, and process mass intensity), along with the EcoScale penalty ranking, indicated that water treatment at 75 °C and pH 6 offers the most viable solution. Linear regression of the data acquired through the multivariate analysis driven by the DoE approach provided a mathematical equation which relates the temperature, time, and the oil/water ratio to the equivalent of CO₂ eventually produced. This tool provides recycling industries with a practical framework for optimizing process conditions, balancing technical efficiency with minimized environmental impact, a crucial factor for compliance with green certification programs. The results present a scalable, scientifically validated pathway for the WCO recycling industry to enhance both operational performance and sustainability.

One promising carbon capture technology is the absorption of carbon dioxide (CO₂) by molten salt, specifically the molten mixture of calcium oxide and chloride (CaO + CaCl₂, COC), as it solves some of the key issues with alternative methods, including thermal stability and capture efficiency. The kinetics of CO₂ absorption in a column of COC is examined by deriving a simple kinetic model and determining the kinetic constants under various conditions. The model emphasises the importance of the oxide anion (O²⁻) concentration and CO₂ partial pressure in driving the absorption rates. Applying this model to reported experimental data on CO₂ absorption with varying molten salt height, or CaO wt% in molten CaCl₂ produced values for the kinetic constants with high accuracy. The fastest rate of absorption, with a rate constant of 0.00313 L mol⁻¹ min⁻¹ was achieved at a 15 cm molten salt height. Conversely, the slowest rate, 0.00062 L mol⁻¹ min⁻¹, occurred at 20 wt% CaO in CaCl₂. Comparative analysis with conventional amine-based CO₂ capture systems reveals a slower absorption rate for the molten salt. Nonetheless, there are further elements which need to be explored to perform a full comparison with the amine system, for example the desorption kinetics or absorption capacity. This reinforces the need for further research into molten salt absorption kinetics to gain a more holistic understanding of this technology and enable an optimal process design for further assessment of the feasibility and scalability of molten salt-based CO₂ capture in current and future processes. Ultimately, this will promote the adoption of carbon capture technology, cultivating more sustainable practices in industry.

Global warming potential (GWP, kg CO₂eq per kg product) is a core impact indicator when assessing the greenness of synthetic reactions in life cycle assessments (LCAs). GWP contributions arise from the production and transportation of chemicals, solvents, and catalysts to the chemical plant, from the reaction (upstream), from the purification steps (downstream), and from the energy invested in the process. For (bio)catalysis, water and spent organic solvents are the major waste contributors, from which CO₂ is generated through their processing via wastewater treatment or incineration. Assessing GWP in organic synthesis appears wearisome, demanding time, resources and expertise. However, GWP estimations at early process stages would rapidly identify the hotspots to improve the environmental impact. This paper proposes equations that can be combined depending on the reaction, to estimate the GWP by using readily available process parameters (substrate loading, conversion, reaction media, temperature, time, and thermodynamic values). Once equations are chosen for each reaction (e.g. process conducted in water or in organic media, type of downstream, etc.), estimated GWP can be obtained. Scenarios can be simulated by changing parameters, to assist practitioners at process early stages to understand how (bio)catalytic reactions can be established in a greener way.

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