Solvent Recycling Research Articles

High-yield hydrogen peroxide treatment of refined softwood in recyclable deep eutectic solvent to produce moisture-tolerant wood nanofiber films

In this study, a novel hydrogen peroxide treatment of refined softwood (thermomechanical pulp) in urea-LiCl-based deep eutectic solvent with negligible material loss (<2 %) was studied as a pre-treatment in the production of wood nanofibers (WNF). A short treatment time (2 min) was shown to slightly alter the structure of wood by increasing the oxygen content at the surface of the fibers and increasing the fine fiber fraction content due to the mild oxidation of surface of fibers potentially via hydrogen peroxide mediated formation of lithium hypochlorite. The mild alteration of the fiber structure resulted in the formation of a WNF film with 33 % higher tensile index compared to films obtained from WNF produced without hydrogen peroxide treatment. Furthermore, deep eutectic solvent recyclability was successfully demonstrated for five consequent treatments. In addition, hot pressing of the WNF films was investigated to improve the water tolerance (wet tensile strength) of the films. By studying various pressing conditions (time, temperature, and pressure), the wet tensile strength of films was increased from 1.0 kNm/kg to almost 20 kNm/kg with only ten minutes pressing time. The increase in wet tensile strength was effectively correlated to a decrease in the water uptake of the films during submersion in water. Simultaneously to the increased water tolerance, the dry tensile properties of the films decreased, but always remained above 40 kNm/kg.

Healable, Recyclable, and Ultra-Tough Waterborne Polyurethane Elastomer Achieved through High-Density Hydrogen Bonding Cross-Linking Strategy.

With the increasing popularity of elastomers in industry and daily life, their high performance and functionality have attracted widespread attention. However, it is a great challenge for them to possess both high mechanical properties and excellent healing and recovery capabilities due to the limitations of the preparation methods and the intrinsic microstructure of the elastomers. In this study, a strategy of ice-controlled interfacial stepwise cross-linking was proposed to prepare the waterborne polyurethane-based elastomers with ultrahigh-density hydrogen bonding interaction achieved by enhancing the utilization rate of phenol hydroxyl groups of tannic acid to the maximum extent. The elastomers have incredible mechanical properties, including ultrahigh toughness of 1.03 GJ m-3 (which represents the highest level among polyurethane elastomers prepared through common processing techniques to date), extremely high true fracture stress of ∼1.9 GPa, world-record fracture energy of 520 kJ m-2, and exciting multiple functional characteristics, such as highly efficient self-healing ability of 10 min, high resistance to physical damage and chemical corrosion, broad temperature and frequency damping effects, good shape memory effect, and excellent melt-processing recyclability and solvent recyclability. These robust multifunctional elastomers represent considerable potential in various fields, from defense and military industry and civil transportation to precision manufacturing, etc.

Dynamic Non-Covalent Bonds Powering Enhanced Temporary Shape Retention Temperature and Mechanical Robustness in Shape Memory Polyurethane.

Shape memory polyurethane (SMPU) with excellent mechanical properties holds significant application value in engineering. However, achieving high strength and toughness typically relies on hydrogen bonding for energy dissipation, which limits the application of such PUs due to their deformation temperature being below room temperature. Here, we introduce a rigid long-chain polyamide acid with a rich aromatic structure as a chain extender, combined with metal coordination, to develop a shape memory polyurethane with a phase transition temperature of 50 °C and outstanding mechanical performance. The presence of rigid segments of polyamic acid (PAA) and -COOH not only increases the rigidity of the polyurethane chains but also promotes the formation of hydrogen bonds and π-π conjugation, leading to physical cross-linking points and significant microphase separation, resulting in superior mechanical properties for PU-PAA. The dynamic bonding characteristics impart self-healing and solvent recyclability to PU-PAA. The coordination interactions enhance the cross-linking points, enabling PU-PAA-Eu to exhibit excellent shape fixation and recovery rates, as well as fluorescence properties. Additionally, due to the presence of -COOH, PU-PAA demonstrates remarkable adhesion to various metals. This work provides a strategy toward the development of high performance SMPU and holds promising potential for applications such as anticounterfeit coatings.

Life cycle assessment of recycling waste crystalline silicon photovoltaic modules: A comparison between traditional and green solvent recycling processes

Crystalline silicon photovoltaic (PV) modules that have reached the end of their service life, if not effectively recycled, result in the loss of valuable resources such as silicon, silver, aluminum, and others. Moreover, improper disposal can lead to long-term environmental pollution. Therefore, the development of efficient and green recycling technologies for waste PV modules has become a key focus of current research. In this study, a life cycle assessment (LCA) of green solvent recycling (GSR) and traditional recycling technologies was conducted using the ReCiPe 2016 Mid-point evaluation method. The energy and resources consumed, along with the environmental impacts generated, were comparatively analysed, and their resource recovery benefits were calculated. Results show that GSR performs well in terms of environmental impact and even better in terms of resource recovery benefits. Leaching with 1,3-dimethyl-2-imidazolidinone (DMI) solvents reduces global warming potential by 487 kg CO2 eq compared to nitric acid used in chemical recycling. Deep eutectic solvents (DES) achieve higher leaching rates of up to 99 %, compared to metals recovered via mechanical separation, and reduce terrestrial ecotoxicity by 742 kg of 1,4-DCB. Of all energy and resource inputs, electricity consumption contributes the most to environmental impacts. In summary, this study offers a more environmentally friendly and effective recycling solution for the PV industry, supporting its green transformation and sustainable development.

Simultaneous estimation of prasugrel and aspirin in bulk drugs by chemometric methods

A UV–Vis spectrophotometric method enhanced by chemometric techniques, specifically Principal Component Regression (PCR) and Partial Least Squares (PLS) regression, was developed and validated for the simultaneous quantification of prasugrel (PRA) and aspirin (ASP) in bulk drugs and pharmaceutical formulations. The method demonstrated high accuracy, precision, and robustness, achieving mean recoveries of 100.63% for PRA and 100.08% for ASP with relative standard deviations (RSD) below 3%. Both PCR and PLS models showed excellent predictive capabilities, with RMSEP values of 0.45–0.48 for PRA and 0.78–1.13 for ASP, indicating the models’ reliability. In line with green and white chemistry principles, the method minimizes environmental impact by reducing solvent consumption and waste generation compared to traditional chromatographic methods. The Analytical Eco-Scale score was 84, reflecting excellent compliance with green chemistry standards. The method’s simplicity, low energy consumption, and reduced chemical waste further support its alignment with sustainability goals. However, acetonitrile, a hazardous solvent, was still used in small quantities, and solvent recycling was not implemented, slightly affecting the eco-score. To evaluate the method’s greenness, the RGB12 algorithm was applied, achieving a high score of 94.4%, with the majority of parameters related to reagent consumption, waste production, energy efficiency, and safety scoring optimally. The method’s safety, cost-effectiveness, and minimal environmental footprint make it suitable for routine pharmaceutical analysis, particularly in quality control environments where resource efficiency and sustainability are prioritized. Thus, the developed method offers a sustainable, efficient, and environmentally friendly solution for the simultaneous analysis of prasugrel and aspirin in pharmaceutical formulations, making it a valuable tool for routine analysis in the pharmaceutical industry.

Protocatechualdehyde-based epoxy vitrimer with low dielectric, excellent flame retardancy, and recyclability

Conventional bisphenol A epoxy resins cannot meet the requirements of the new generation of electronic/electrical industries in terms of dielectric properties and flame retardancy and are challenging to reprocess after molding, resulting in waste of resources and environmental hazards. Therefore, a tetrafunctional active ester curing agent (TIE) was successfully synthesized by a one-pot method using biomass protocatechualdehyde as raw materials, followed by curing DGEBA to prepare an epoxy vitrimer (TIE/DGEBA). MHHPA/DGEBA was chosen for comparison since the –OH was also absent after curing. The results showed that TIE/DGEBA had good combinatorial performance, thanks to the unique structure of TIE, including active ester units, siloxane chains, and aromatic Schiff base groups. TIE/DGEBA possessed a lower dielectric constant (2.9 vs. 4.0) compared to MHHPA/DGEBA, which was attributed to the synergistic effect of the less-polar siloxane chain segments, bulky benzene structure, and lower cross-linking density (1971 vs. 733 mol/cm3) of TIE/DGEBA. The aromatic Schiff base not only imparted good thermal stability (T30% = 418.0 vs. 422.2 °C) to TIE/DGEBA but ensured that it allowed for recycling and reprocessing. After solvent recycling, the resin can be remolded without significant change in tensile strength (53.0 vs. 46.3 MPa). TIE/DGEBA displayed better flame retardancy with higher residual weight (28.2 % vs. 5.5 %), lower total heat release (29.6 vs. 43.5 kJ/g), and good resistance to thermal oxidization. The structural and performance characteristics of TIE/DGEBA offer a strategy for designing multifunctional epoxy-based materials in electrical/electronic applications.

Reconfiguring closed-loop desorption for industrial solvent recycling by retaining post-condensation volatile organic compounds

Massive emissions of volatile organic compounds (VOCs) from industrial solvent evaporation have exacerbated atmospheric pollution. As high-value pollutants, VOCs can be concentrated and condensed into liquid solvents for reuse instead of destructive elimination, minimizing environmental threats and treatment costs. However, classical thermal swing adsorption (TSA) using nitrogen as the purge gas are inclined to be in closed form to economize on nitrogen, which results in desorption residues at the outlet of the adsorber and leads to environmental risks. In this study, one-step closed-loop desorption (OCD) and two-step closed-loop desorption (TCD) were proposed for industrial solvent recovery by reconfiguring TSA and condensation to improve desorption efficiency and recovery performance. A detailed mathematical model was developed and validated experimentally to describe dynamic behaviors of closed-loop desorption. The results showed that the standby adsorber connected to the thermal desorption process effectively retained the post-condensation VOCs and reduced the desorption residual for the re-absorption efficiency. By using the orthogonal experimental design, desorption temperature, condensation temperature, and feed concentration were proved to be more significant on recovery capacity than packing height and purge velocity. A broader feasible recovery domain was achieved by the TCD cycle, with an increase of 48.15 % compared to the OCD cycle at low feed concentrations. The OCD cycle was more energy-efficient, except in scenarios of low adsorption loading and low-grade energy sources. The findings provide new insights and promising approaches for achieving synergies between industrial exhaust treatment and organic solvent recovery.

Green recycling of end-of-life photovoltaic modules via Deep-Eutectic solvents

Sustainable End-of-life (EOL) photovoltaic (PV) modules recycling is essential for achieving resource conservation and alleviating environmental issues. Ethylene vinyle acetate (EVA) adhesive films separation is a prerequisite for the realization of valuable component recovery of PV modules. However, the conventional wet chemical separation processes are usually accompanied by the challenges of low separation efficiency, high toxicity and difficult multiple recycling. Herein, a green, biodegradable, low-cost and recyclable deep eutectic solvent (DES) is firstly developed to efficiently separate EVA films in EOL PV modules. The high temperature stability and the acidic characteristic of DES can facilitate the separation of EVA film between component layers. At 175 ℃, the warping effect caused by the differential thermal contraction between the module component layers creates favorable conditions for the efficient reaction and separation by the DES. Additionally, the acidic medium reacts with the aluminum electrode layer of PV cells, which further enhances the separation efficiency of EVA films. The EVA separation rate reached 100%, the separation rate of the EVA containing aluminum (Al) up to 98.4% after 12.5 h at 175 ℃. Moreover, the developed DES exhibits excellent recyclable performance, the EVA separation rate remained 100% after 10 cycles. Compared to the traditional solvent toluene, DES has advantages in terms of economics, environmental impact, and efficiency. This strategy of design a green, biodegradable, low-cost and recyclable solvent to replace traditional solvents, and provides a promising route to efficiently separate EVA films in EOL PV modules.

Life cycle assessment of polysilicon photovoltaic modules with green recycling based on the ReCiPe method

Polysilicon photovoltaic (PV) modules are about to enter the end-of-life (EOL) stage on a large scale, and making the exploration of effective recycling methods and comprehensive evaluations their environmental impact through life cycle assessment (LCA) are key issues that need to be urgently tackled. In this study, we innovatively propose a recycling method utilising the green organic solvents 1,3-dimethyl-2-imidazolidinone (DMI) and deep eutectic solvent (DES). Additionally, an LCA of 1 m2 polysilicon PV modules - from industrial silicon production to waste recycling - was conducted using the ReCiPe 2016 method. The results indicate that the recycling process of polysilicon has the lowest environmental impact (1.02 Pt), whilst the production process has the highest environmental impact (4.22 Pt), leading to greater uncertainty. Sensitivity analyses showed that the sensitivity of the whole process was higher for electricity consumption and global warming (GW). Comparing the green organic solvent recycling to downcycling and landfill further demonstrates that environmental impact can be significantly reduced by employing this green organic solvent recycling approach, providing an important theoretical and practical pathway to promote the circular economy and sustainable development of the PV industry.

Green pharma supply chain: a review of existing practices and future directions

PurposeThe pharmaceutical industry is facing significant pressure to tackle antimicrobial resistance (AMR). Other ecological, societal and regulatory pressures are also driving the industry to “go green”. While such a (green) transition could be possible through appropriate green practices’ implementation, the present understanding about it is superficial and vague. A key reason is the lack of green practices’-related studies on pharmaceuticals, which are also insufficiently comprehensive. This knowledge gap is sought to be addressed.Design/methodology/approachA systematic literature review (SLR) was conducted with 73 carefully selected articles, then subjected to thematic content analyses for synthesising the relevant themes and sub-themes.FindingsAround 76 operational-level green practices covering all key stakeholders across the drug lifecycle were identified. It was revealed that designing drugs having accelerated environmental degradability is important to combat AMR. Also, redesigning existing drugs is environmentally more resource-intensive than developing new ones with significant cost-saving potential in solvent recycling and flexible manufacturing, both of which are not common at present. With regards to green-related barriers, stringent quality requirements on drugs (and therefore risks in making relevant green-oriented modifications) and time-consuming and costly regulatory approvals were found to be the key ones.Practical implicationsThe operational green practices’ framework developed for individual pharmaceutical supply chain stakeholders could help practitioners in benchmarking, modifying and ultimately, adopting green practices. The findings could also assist policymakers in reframing existing regulations, such as Good Manufacturing Practices or GMP-related, to promote greener drug development.Originality/valueThis work is the first systematic attempt to identify and categorise operational-level green supply chain practices across stakeholders in the pharmaceutical sector.Highlights•Biodegradability of drugs is more important than environmental degradability.•Flexible manufacturing process design (or quality by design) reduces resource wastage.•Ecopharmacovigilance is effective in combating PIE and AMR-related issues.•Upstream and downstream coordination is key to greening pharma operations.•Costly and time-consuming regulatory approval is a key barrier to greening pharma processes.

Establishment of efficient system for bagasse bargaining: Combining fractionation of saccharides, recycling of high-viscosity solvent and dismantling

Sugarcane bagasse (SCB) has a recalcitrant structure, which hinders its component dismantling and subsequent high value utilization. Some organic solvents are favorable to dismantle lignocellulose, but their high viscosity prevents separation of components and reuse of solvents. Herein, ethylene glycol phenyl ether (EGPE)-acid system is used as an example to develop green and efficient methods to dismantle SCB, purify polysaccharides and lignin, and reuse solvents. Results show that dismantling SCB at 130 °C, 0.5 % H2SO4, and 100 min can obtain 85.5 % cellulose recovery, 94.1 % hemicellulose removal and 83.7 % lignin removal. Different molecular weight saccharides are separated by membranes filtration and centrifugation, and lignin recovered by antisolvent precipitation. The solvent recovered by distillation, achieving high dismantling efficiency of 89.2 % cellulose recovery, 94.1 % hemicellulose removal and 94.4 % lignin removal after four recycles. Results show a promising approach for the closed-loop process of dismantling lignocellulose, fractionating saccharides, and reusing solvents in high-viscosity systems.

Electrochemical allylations in a deep eutectic solvent.

Electrosynthesis is a technique that is attracting increased attention and has many appealing features, particularly its potential greenness. At the same time, electrosynthesis requires a solvent and a supporting electrolyte in order for current to pass through the reaction. These are effectively consumable reagents unless a convenient means of recycling can be developed. As part of our interest in unusual solvents and electrochemistry, we explored the application of simple, inexpensive, and recyclable deep eutectic solvents to the allylation of carbonyls. While several sets of conditions were developed, the goal of avoiding stoichiometric amounts of metal has proven elusive. Still, a deep eutectic solvent can be used to plate out and thus recover the metal used, offering an interesting new option for electrochemical allylations.

Exploration of green catalytic Hantzsch process for synthesis of polyhydroquinoline derivatives and their in silico & in vitro evaluation as anti-tubercular agents

Polyhydroquinolines (PHQ) were long known for various pharmacological activities and numerous methods were reported for their synthesis by using different reaction conditions and catalysts. An attempt has been made to synthesize PHQs by following the environmental friendly green chemical approaches by using reusable and recyclable catalyst and solvent materials. Twelve compounds (2A-2L) were synthesized with varied substitutions on the aromatic ring by following the Hantzsch one-pot approach with bleaching earth clay and polyethylene glycol. Use of novel reaction conditions has improved the yield and drastically reduced the time required for the completion of the reaction. The DFT analysis revealed the structural features and the stability of the compound, and later the compounds were subjected to molecular docking against two key proteins of the M. tuberculosis H37 Ra InhA and DprE1. It was found that few of the compounds showed excellent binding interactions compared to the co-crystalized ligand. Later, all the synthesized compounds were subjected to the in vitro antimycobacterial activity using the Kirby-Bauer disk diffusion method, MICs were calculated by REMA assay and the hemolytic assay was performed to check cytotoxicity. Compounds 2K and 2E were found to show better inhibitory activity than the standard rifampin. The antimycobacterial activity of the PHQ compounds might be due to the interaction of the InhA and DprE1, which can be correlated positively and supported by the structural features and the in silico interaction data. Parallelly, molecular dynamic simulation studies were carried out with ligand 2K for the time frame of 100 ns against both targets InhA and DprE1 revealing the formation of stable complexes which further validate the ligand 2K as a potential lead molecule for further studies. The compounds can be further subjected to lead optimization for improved activity.

Reducing Solvent Consumption in Reductive Catalytic Fractionation through Lignin Oil Recycling.

Reductive catalytic fractionation (RCF) enables the simultaneous valorization of lignin and carbohydrates in lignocellulosic biomass through solvent-based lignin extraction, followed by depolymerization and catalytic stabilization of the extracted lignin. Process modeling has shown that the use of exogenous organic solvent in RCF is a challenge for economic and environmental feasibility, and previous works proposed that lignin oil, a mixture of lignin-derived monomers and oligomers produced by RCF, can be used as a cosolvent in RCF. Here, we further explore the potential of RCF solvent recycling with lignin oil, extending the feasible lignin oil concentration in the solvent to 100 wt %, relative to the previously demonstrated 0-19 wt % range. Solvents containing up to 80 wt % lignin oil exhibited 83-93% delignification, comparable to 83% delignification with a methanol-water mixture, and notably, using lignin oil solely as a solvent achieved 67% delignification in the absence of water. In additional experiments, applying the RCF solvent recycling approach to ten consecutive RCF reactions resulted in a final lignin oil concentration of 11 wt %, without detrimental impacts on lignin extraction, lignin oil molar mass distribution, aromatic monomer selectivity, and cellulose retention. Overall, this work further demonstrates the potential for using lignin oil as an effective cosolvent in RCF, which can reduce the burden on downstream solvent recovery.

A DES or LTTM: Eco-friendly solvent mediums for conversion of biomass to levulinic acid as a key chemical

In this study, the effect of using environmentally friendly, less toxic, low cost, and easily recyclable deep eutectic solvent (DES) and low-transition temperature mixture (LTTM), which are alternatives to ionic liquids, on the conversion of biomass to levulinic acid (LA) was investigated. The reaction conditions such as temperature, the amount of feedstock, and the water ratio were optimized to ensure maximum product formation in DES (ChCl-EG)-water medium. The highest amount of LA (143.2 ± 2.5 mg) under optimum reaction conditions was achieved by using glucose in a newlydesignedLTTM (SA:EG)-water solvent medium. Newly designed low-transition temperature mixture (SA:EG) characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and differential scanning calorimetry (DSC) analyses. A comprehensive theoreticalstudy was also performed to provide a deep understanding of the formation mechanisms of new LTTM by density functional theory (DFT), reduced density gradient (RDG), frontier molecular orbitals (FMOs), and molecular electrostatic potential (MEP) methods. The glucose conversion ratio increased from 70.2 % to 96.1 % in SA:EG-water medium. When microcrystalline cellulose, corn straw, and sorghum were used under the same conditions, 118.9 ± 5.4, 36.8 ± 9.4, and 32.6 ± 3.4 mg of LA were obtained per g of feedstock. A typical Brønsted acid; phosphotungstic acid (H3O40PW12) showed high catalytic activity, resulting in 229.0 ± 0.32 mg of LA per g of glucose in SA:EG-water medium. This shows that the use of SA:EG LTTM for cellulosic/lignocellulosic biomass sources can be used favorably in conversion reactions.

Alternate solvent for soybean oil extraction based on extractability and membrane solvent recovery.

Ethyl acetate, acetone, 2-propanol, 1-propanol, and ethanol were screened among the class 3 category solvents as an alternative to hexane based on operational and occupational safety and bio-renewability potential. All five solvents exhibited higher extractability (22.3 to 23.2%) than hexane (21.5%) with soybean flour. Additionally, there was no significant difference in the fatty acid and triacylglycerol (TAG) composition of the oils extracted using alternate solvents and hexane, indicating the oil quality was not affected. More importantly, ethyl acetate (2.1%) resulted in a marginally higher yield of TAG, while 2-propanol showed a nearly equal yield to hexane. Further, membrane desolventizing was attempted to mitigate the limitations of higher thermal energy requirements. One of the polydimethylsiloxane membranes exhibited good selectivity (TAG rejection 85.8%) and acceptable flux (59.3 L·m-2·h-1) with an ethyl acetate miscella system. Under plant-simulated recirculation conditions, a two-stage membrane process reduced the oil content in permeate to 2.5%. The study revealed that ethyl acetate could potentially replace hexane, considering its higher TAG extractability and suitability for the membrane-augmented solvent recycling process in the extraction plants.

Optimizing lean and rich Vapor compression with solar Assistance for post-combustion carbon capture in natural gas-fired power plant

The integration of post-combustion capture (PCC) CO2 technologies with power plants and high-emission industrial processes has become imperative for reducing carbon emissions and mitigating environmental impacts. This study focuses on addressing the significant energy consumption associated with PCC and explores the potential of using solar thermal energy to optimize configurations, thereby enhancing sustainability and reducing dependency on conventional power sources. Simulate various configurations under steady-state conditions using Aspen HYSYS V11 and Aspen Economic Evaluation software. The results indicate a substantial reduction in energy consumption to 2.1 GJ/ton CO2 after the initial optimization steps. The key innovations involve the integration of Lean Vapor Compression (LVC), Solvent Split Flow (SSF), Rich Solvent Recycle (RSR), and Rich Vapor Compression (RVC). Further optimization was conducted by integrating a reboiler with parabolic trough collectors (PTC), to reduce energy penalties. The LVC + RVC + RSR + SSF + PTC configuration results reveal a notable improvement in exergoeconomic factors, ranging from 3.13% to 7.8%, highlighting the economic feasibility of the optimized configurations. Simultaneously, the energy penalty decreased by 11.1%, signifying enhanced sustainability in the proposed PCC system. This study contributes to the gap in research by demonstrating the efficacy of solar thermal energy in optimizing PCC configurations, providing a pathway towards more sustainable and energy-efficient solutions for carbon capture in high-emission industrial sectors. The findings offer insights for researchers, engineers, and policymakers aiming to address the pressing issue of carbon emissions from industrial processes.

Pressure-driven membrane processes for the recovery and recycling of deep eutectic solvents: A seaweed biorefinery case study.

Deep eutectic solvents (DES) are green alternatives for conventional solvents. They have gained attention for their potential to extract valuable compounds from biomass, such as seaweed. In this framework, a case study was developed to assess the feasibility of pressure-driven membrane processes as an efficient tool for the recovery of deep eutectic solvents and targeted biomolecules. For this purpose, a mixture composed of the DES choline chloride – ethylene glycol (ChCl-EG) 1:2, water and alginate was made to mimic a DES extraction from seaweed. An integrated separation process design was proposed where ultrafiltration-diafiltration-nanofiltration (UF-DF-NF) was coupled. UF and DF were found to be effective for the separation of alginate with an 85 % yield. DES was likewise recovered by 93 %, proving the membrane filtrations’ technical feasibility. The NF performance to separate the DES from the water, for its recycling, laid by a 45 %-50 % retention and a final concentrated DES solution of 18 %(v/v).

Phase Separation‐Induced Electrical Conductivity for Liquid Metal‐Embedded Plastic Hybrid Composites with Metallic Conductivity and Recyclability

AbstractConductive fillers‐embedded plastic polymer hybrid composites are crucial electronic materials in modern technologies owing to their tunable conductive properties, low density, and corrosion resistance. However, the application of traditional rigid inorganic conductive fillers‐embedded plastic composites is constrained by their subpar electrical conductivity and mechanical properties. Consequently, liquid metals (LMs) including gallium and gallium‐based alloys, have recently emerged as the preferred conductive flexible fillers over traditional rigid fillers. This work employs a solvent evaporation method and phase separation‐induced conductivity mechanism. The resulting flexible and electrically conductive LM‐polycarbonate (PC) film circuits demonstrate ultrahigh metallic conductivity, robust mechanical performance, excellent solvent recyclability, and notable processability. The fluidic nature of LMs and the superior mechanical properties of the PC polymer confer high electrical stability and durability to the LM‐PC film circuits under diverse mechanical forces and environmental conditions. The LM‐PC film circuits are exceedingly promising and apt for use as flexible conductors in contemporary electrical applications, including electricity transmission and underwater working.

Designing green and recyclable switchable supramolecular deep eutectic solvents for efficient extraction of flavonoids from Scutellariae Radix and mechanism exploration

A green and recyclable switchable supramolecular deep eutectic solvent (SS-DES) was designed and prepared for effective extraction of flavonoids from Scutellariae Radix. The novel SS-DES has both excellent extraction performance of DES and the host guest inclusion of cyclodextrin, thereby showing superior extraction efficiency and selectivity. The characteristic of polarity switching can endow the SS-DES with achieving homogeneous extraction and rapid two-phase separation, shorting per-treatment time largely. Parameters affecting the extraction performance were investigated by the response surface methodology. The results indicated that the SS-DES showed better extraction yield of total flavonoids (157.95 mg/g) compared with pure DES (135 mg/g) and traditional organic solvent (60 % ethanol, 104.87 mg/g). Moreover, the switching mechanism of SS-DES was characterized by FT-IR and 1H NMR, and the extraction mechanism was studied by density functional theory and molecular docking analysis. After evaluating the ecological impact of the method, the cytotoxicity of SS-DES was investigated and the result displayed that its toxicity was very low or even negligible with the EC50>2000 mg/L. After being adsorbed by macroporous AB-8 resin, the regenerated SS-DES was recycled 5 times and the extraction efficiency still remained above 90 %, indicating the desirable reusability. Therefore, the proposed method was efficient and sustainable, and revealed favorable application prospect for the extraction of bio-active compounds from plant materials.