Two novel wide‐bandgap copolymers, PBDT‐TDZ and PBDTS‐TDZ, are developed based on 1,3,4‐thiadiazole (TDZ) and benzo1,2‐b:4,5‐b′dithiophene (BDT) building blocks. These copolymers exhibit wide ...bandgaps over 2.07 eV and low‐lying highest occupied molecular orbital (HOMO) levels below −5.35 eV, which match well with the typical low‐bandgap acceptor of ITIC, resulting in a good complementary absorption from 300 to 900 nm and a low HOMO level offset (≤0.13 eV). Compared to PBDT‐TDZ, PBDTS‐TDZ with alkylthio side chains exhibits the stronger optical absorption, lower‐lying HOMO level, and higher crystallinity. By using a single green solvent of o‐xylene, PBDTS‐TDZ:ITIC devices exhibit a large open‐circuit voltage (Voc) up to 1.10 eV and an extremely low energy loss (Eloss) of 0.48 eV. At the same time, the desirable high short‐circuit current density (Jsc) of 17.78 mA cm−2 and fill factor of 65.4% are also obtained, giving rise to a high power conversion efficiency (PCE) of 12.80% without any additive and post‐treatment. When adopting a homotandem device architecture, the PCE is further improved to 13.35% (certified as 13.19%) with a much larger Voc of 2.13 V, which is the best value for any type of homotandem organic solar cells reported so far.
Two novel 1,3,4‐thiadiazole‐based wide‐bandgap copolymers, PBDT‐TDZ and PBDTS‐TDZ, are developed for efficient nonfullerene organic solar cells. The single‐junction devices processed by a green solvent of o‐xylene exhibit a high power conversion efficiency (PCE) of 12.80% with a low energy loss of 0.48 eV. The PCE is finally improved to 13.35% when using a homotandem device architecture.
•Green solvent extraction techniques reviewed for antibiotic residue analysis.•Food and environmental water sample matrices discussed.•Comparison of different extraction, chromatographic and ...detection techniques for antibiotics.
Antibiotic residues are being continuously recognized in the aquatic environment and in food. Though the concentration of antibiotic residues is typically low, adverse effects on the environment and human health have been observed. Hence, an efficient method to determine numerous antibiotic residues should be simple, inexpensive, selective, with high throughput and with low detection limits. Liquid-based extractions have been exceedingly used for clean-up and preconcentration of antibiotics prior to chromatographic analysis. In order to make methods more green and environmentally sustainable, conventional hazardous organic solvents can be replaced with green solvents. This review presents sampling strategies as well as comprehensive and up-to-date methods for chemical analysis of antibiotic residues in different sample matrices. Particularly, solvent-based sample preparation techniques using green solvents are discussed along with applications in antibiotic residue analysis.
•A green and highly efficient extraction method for flavonoids from Malus hupehensis was established on deep eutectic solvents (DESs).•The DES-based HSCCC solvent systems was investigated, and ...developed for the separation of pure compounds for the first time.•Five flavonoids were isolated from the DES extract.•The DES-based HSCCC solvent system was prepared by using the recovered DES, and the HSCCC separation was re-operated.
In the present experiment, a green and highly efficient extraction method for flavonoids established on deep eutectic solvents (DESs) was investigated by using the response surface methodology. The DES-based high-speed countercurrent chromatography (HSCCC) solvent systems were developed for the separation of high purity compounds from the DES extract of Malus hupehensis for the first time. Under the optimal conditions (liquid-to-solid ratio of 26.3 mL/g, water content of 25.5%, and extraction temperature of 77.5°C), the yield of flavonoids was 15.3 ± 0.1%, which was superior to that of the methanol extraction method. In accordance with the physical property of DES-based HSCCC solvent systems and K values of target compounds, DES-based HSCCC solvent systems composed of choline chloride/glucose-water-ethyl acetate (ChCl/Glu-H2O-EAC, 1:1:2, v/v) was selected for the HSCCC separation. Thus, five flavonoids (two novel compounds 1-2, 6´´-O-coumaroyl-2´-O-glucopyranosylphloretin and 3´´´-methoxy-6´´-O-feruloy-2´-O-glucopyranosylphloretin; three know compounds 3-5, namely, avicularin, phloridzin, and sieboldin) were efficiently separated from Malus hupehensis. DESs are the environment friendly and highly efficient solvents as the components of extraction solvent and HSCCC solvent system, and can be re-utilized many times. However, ethyl acetate can be soluble with a few hydrogen bond donors, such as urea, carboxylic acid and polyol, through the shake flask test. It is the great difficulty for the efficient and rapid separation of target compounds from the DESs extract because of the DESs residual in the HSCCC fractions. ChCl and Glu are the great choices of DESs without this problem. In addition, K values increased with the increase of the molar ratio of ChCl/Glu and the content of water, which could effectively guide us to choose the suitable DES-based HSCCC solvent system. The twice HSCCC separation results indicated that DES was the valuable and green solvent for the HSCCC separation of pure compounds from the extract for the first time, and showed the recycle superiority of DES-based HSCCC solvent system.
•Biodiesel was purified through liquid-liquid extraction and column chromatography.•Purification was performed with 2-MeTHF and CPME.•Purified biodiesel was characterized through chemical and ...physicochemical analyses.•Purified biodiesels presented purity level higher than 96.5%.•The biodiesels purified with CPME present great potential to replace hexane.
Biodiesel purification through acid-catalyzed in situ transesterification of dry biomass of Chlorella pyrenoidosa was evaluated by liquid-liquid extraction and column chromatography, using the solvents hexane, 2-methyltetrahydrofuran (2-MeTHF), and cyclopentyl methyl ether (CPME). The purified biodiesel were characterized through their chemical composition and physicochemical characteristics. The results showed that the purified biodiesel presented a purity level higher than 96.5%, and the purities obtained with CPME were very close to those obtained with hexane. Concerning physicochemical characteristics, biodiesel purified with green solvents showed higher densities and viscosities, but compliant with the European and North American quality standards. The difficulty to evaporate residual water from biodiesel purified with 2-MeTHF after the liquid-liquid extraction process required that biodiesel was left in decantation for 24 h, which resulted in a biodiesel with water content exceeding 0.05%mass. Biodiesel purified with green solvents, mainly by column chromatography using CPME as eluent, show great potential to replace hexane in the biodiesel purification process, and the price of these solvents is the only factor limiting their large-scale use.
Tobacco cultivation and industrialization are characterized by the production of trillions of pre-harvest and post-harvest waste biomasses each year with the resulting negative effects on the ...environment. The leaves of blunt, pre-harvest waste, could be further used to obtain bioactive metabolites, i.e., polyphenols and alkaloids, for its potential cosmetic use. This study was conducted to obtain bio-compounds from pre-harvest tobacco leaf waste (var. Virginia) by applying conventional and green solvents (NaDES). Leaves and ground leaf waste were characterized based on their microscopic features. Conventional solvents, such as water, acetone, ethanol, and non-conventional solvents, such as Natural Deep Eutectic Solvents (NaDES), i.e., sucrose:lactic acid (LAS), frutose:glucose:sucrose (FGS), lactic acid:sucrose:water (SALA), choline chloride:urea (CU), and citric acid: propylene glycol (CAP) were used for bioactive extraction from tobacco waste powder. CU, FGS, and acetone/ethanol had similar behavior for the best extraction of alkaloids (6.37-11.23 mg ACE/g tobacco powder). LAS, FGS, SALA, and CU were more effective in phenolic compound extraction than conventional solvents (18.13-21.98 mg AGE/g tobacco powder). Because of this, LAS and SALA could be used to obtain phenolic-enriched extracts with lower alkaloid content rather than CU and FGS. Extracts of the powder obtained with conventional solvent or CU showed a high level of sugars (47 mg/g tobacco powder) The ABTS antioxidant capacity of tobacco leaf powder was higher in the extracts obtained with CU, FGS, and acetone (SC
1.6-5 µg GAE/mL) while H
O
scavenging activity was better in the extracts obtained with LAS, CAP and SALA (SC
3.8-8.7 µg GAE/mL). Due to the biocompatibility of the NaDES with the components of tobacco leaf waste, the opportunity to apply these extracts directly in antioxidant formulations, such as cosmetics, phytotherapic, and other formulations of topic use seems promising. Furthermore, NaDES constituents, i.e., urea and organic acid can also have beneficial effects on the skin.
Detailed investigations into the stepwise bis‐functionalization of a pillar5arene‐containing rotaxane building block have been carried out. Upon a first stopper exchange, the pillar5arene moiety of ...the mono‐acylated product is preferentially located close to its reactive pentafluorophenyl ester stopper, thus limiting the accessibility to the reactive carbonyl group by the nucleophilic reagents. Selective mono‐functionalization is thus very efficient. Introduction of a second stopper is then possible to generate dissymmetrical rotaxanes with different amide stoppers. Moreover, when dethreading is possible upon the second acylation, the pillar5arene plays the role of a protecting group allowing the synthesis of dissymmetrical axles that are particularly difficult to prepare under statistical conditions. Finally, detailed conformation analysis of the rotaxanes revealed that the position of the pillar5arene moiety on its axle subunit is mainly governed by polar interactions in nonpolar organic solvents, whereas solvophobic effects play a major role in polar solvents.Dedicated to Prof. Maurizio Prato on the occasion of his 70th birthday.
The effect of methanol, ethanol, acetone,
N
,
N
-dimethylformamide (DMF), dimethyl sulfoxide and Nujol on the growth of
Escherichia coli
DH5α,
Bacillus subtilis
and
Saccharomyces cerevisiae
D273 was ...investigated. All of the tested cultures appeared susceptible to the organic media they were treated with, which evinced in apparent hindering of cell development. The observed diverse solvent tolerance, except from their different biochemical activity, may also be related to the changes in cell membrane fluidity induced by the solvent species. Parallel electron paramagnetic resonance investigations using egg yolk lecithin model liposomes revealed that the fluidity of the phospholipid system in cell membranes may either be considerably decreased (Nujol, DMF, ethanol) or increased (acetone), thus rendering difficult the intracellular nutrient supply. Hence, even the chemically neutral Nujol produced a distinct cell-growth inhibitory effect. These results are fairly consistent with the outcome of the survival tests, particularly for the bacteria strains.
Of late, DESs have occupied the centre stage due to their eco-friendly and resource-efficient nature and their low toxicity. In this work, we have investigated the structural and thermal stability of ...hemoglobin (Hb) in two choline chloride (ChCl)-based DESs namely urea ChCl-urea (DES1) and ChCl-glycerol (Gly); (DES 2). Different biophysical techniques reveal that the presence of DESs facilitates the stability of Hb in a concentration-dependent manner and the extent of stability is more pronounced in ChCl-Gly as compared to ChCl-urea. Additionally, for a better understanding of the role of DESs in modulating the thermal and structural stability of Hb, studies have been performed on Hb in the presence of individual constituents of DESs,
, ChCl, urea, and Gly. Altogether, it was observed that the effect on the stability of Hb was by the presence of the DESs rather than their individual constituents. For instance, urea itself is a destabilizing co-solvent for biomolecules. However, the harmful effects of urea were surpassed when a DES is formed in the presence of ChCl. Therefore, overall, it can be concluded that both DESs can be described as potential non-harmful, green, and promising solvents for enhancing the structural and thermal stability of Hb.
The solvent‐cast direct‐write fabrication of microstructures is shown using a thermoplastic polymer solution ink. The method employs the robotically controlled microextrusion of a filament combined ...with a rapid solvent evaporation. Upon drying, the increased rigidity of the extruded filament enables the creation of complex freeform 3D shapes.
Although formononetin has a considerable biological activity, its therapeutic use is limited by its low solubility. Formononetin was dissolved in ethanol, methanol, N, N-dimethylformamide (DMF), and ...dimethyl sulfoxide (DMSO) in this investigation, the antisolvent precipitation procedure with the assistance of an external ultrasonic probe was used to manufacture the formononetin nano-particles. The ideal parameters for response surface BBD optimization are as follows: feed volume flow rate of 6 mL/min; ultrasonic power of 860 W; and liquid-liquid ratio of 1:12.5. The formononetin nano-particles have a smaller particle diameter than raw sample; the lowest size can be as small as (329 ± 1.99) nm, which is 45 times smaller than raw. An in vitro digestion test using a solution that simulated intestinal solution revealed that the release rate of the nano-particle was 1.75 times than that of the raw formononetin. The formononetin nano-particles generated by the aforementioned four solvents have the following order of diameter: ethanol > methanol > DMF > DMSO. This study provided a technical reference for the functional food components in deep processing.
•The formononetin nano-particles was prepared using ultrasonic-assisted antisolvent precipitation.•Compared with other solvents, DMSO has the smallest particle size in the antisolvent process.•Formononetin nano-particles with a minimum size of 329 nm was obtained.•Nano-particles has a greater level of antioxidant activity than raw formononetin powder.
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