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The very slow degradation of biodegradable polymers in the marine environment is due to the lack of dedicated degradation enzymes in open seas. As a result, introducing monomers that have a fast hydrolysis process is required to accelerate seawater degradation. Poly(butylene succinate-co-glycolate) (PBSGA) copolyesters with glycolic acid (GA) units ranging from 5 to 40% were synthesized by our newly developed polymerizing method based on oligo(glycolic acid). The results of ¹H-NMR and GPC revealed that short GA segments were evenly distributed between BS segments, obtaining random copolyesters with a weight-average molecular weight over 6.24 * 10⁴ g/mol. The copolymerized GA units hinder its crystallization capability and increase hydrophilicity of the PBSGAs, which still displayed mechanical properties comparable or even better than most biodegradable polymers. Fast degradation in seawater and enzymatic environments (Candida antarctica lipase B enzymes) is proved experimentally. The quick decomposition in seawater was originated from accelerated hydrolysis. For instance, the weight loss of PBSGA40 (compositions of GA units) exceeded 22% after 49 days. Possible degradation mechanisms were proposed based on Fukui function analysis and frontier molecular orbital calculation. Additionally, the energy barrier for hydrolysis was calculated by the density functional theory method, indicating that the hydrolysis of the polymer chain became more and more easy with the increase in GA units. At last, the addition of GA units only had a mild effect on the shelf life of the PBSGAs.

The gradual degradation of polyester in daily use causes unpredictable failure and restricts its reliable applications. The realization of excellent stability in use and controlled degradation in a...

Background: As a functional food factor, quinoa saponins are valuable as additives and in medical care, pharmaceutical development, cosmetics and other fields. However, few studies have investigated the toxicity of saponins. The main purpose of this study was to evaluate the toxicity of crude saponins extracted from quinoa husks. Thus, acute toxicity and excretion experiments were carried out in rats. The Ames test, micronucleus test and mouse sperm aberration test were carried out in mice. Results: In the acute toxicity study, the obtained LD50 was more than 10 g per kg per bw for both sexes, the food intake of all rats decreased over a period of time, and some rats developed diarrhea. In the case of large-dose gavage, the saponin excretion time in rats was approximately four days. When the dosage was 10 mg kg−1, quinoa saponins were hydrolyzed into aglycone within 24 hours and excreted out of the body. The results of the mutagenicity experiment showed that saponins had no mutagenicity in mice. Conclusion: This work has demonstrated that quinoa saponins have limited acute toxicity effects, which provides a theoretical basis for their rational utilization.

Polylactic acid (PLA) is a biodegradable thermoplastic polyester produced from natural resources. Because of its brittleness, many tougheners have been developed. However, traditional toughening me...

An eco-friendly method has been used to synthesize ductile and toughen composites from completely renewable resources by exploring poly(lactic acid) (PLA)’s sophisticated properties in terms of strength, stiffness as well as its brittleness. Due to their excellent mechanical properties and potential for sustainable manufacturing, nano-cellulose as a bio-based organic filler, have been broadly used in a variety of polymer reinforcement. Herein, waste cellulose fibers (WCF) within the nanometer range were used as a filler to blend with PLA using lab-scale twin-extruder, with and without epoxidized soybean oil (ESO) as a reactive plasticizer. To investigate their effect on the mechanical properties like Young’s modulus, strength, toughness, and ductility, various constituents of ingredients were selected. An increase in elongation-at-break (5.1 to 60.8 %), bending strain (5.9 to 9.4 %) and impact strength (2.05 to 6.1 kJ/m2) in comparison to neat PLA was found in PLA/WCF/ESO ternary composites, leading to reduced glass transition (Tg) and crystallization temperature (Tc) as confirmed by a differential scanning calorimetry (DSC) measurements. An increase in char yield was also observed from the thermogravimetric analysis (TGA), which was clearly associated with the flame potency. Chemical interactions were investigated by Fourier transform infrared (FTIR) spectroscopy by examining shifts in peak positions. A scanning electron microscope (SEM) was utilized systematically to analyze the toughening mechanism.

Poly(propylene 2,5-furan dicarboxylate) (PPF) is an example of alipharomatic bio-based polyester which has a high potential for the replacement of its fossil-based terephthalate counterparts (PPT). PPF offers advantages over PPT owing to its brilliant properties. However, PPF often exhibits a slow rate of crystallization, which is a bottleneck for its successful synthesis. This has also caused limited research work on the use of PPF for the specific application. Therefore, in this study, PPF is melt compounded with microcrystalline cellulose (MCC) via twin-screw extrusion, which in turn enhances its crystallization. During its preparation, no toxic chemicals are used to modify the fibers or compatibilizers, indicating that the synthesis method follows green chemistry principles. The influence of the MCC on the thermal, structure and surface behaviors of PPF is analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry (DSC), thermo-gravimetric analysis and X-ray diffraction. The effect of the MCC on both non-isothermal and isothermal crystallization of PPF is also explored by using DSC. It is observed that crystallization is faster, while PPF is compounded with lower content of MCC. Similarly, the nucleating rate is intensified with the introduction of MCC. The incorporation of MCC significantly increased tensile modulus, strength and elongation of break of progressing PPF by 16%, 63% and 61%, respectively, at a content of 15 wt.% MCC. The blend also owned better oxygen and carbon dioxide barrier properties than neat PPF as a function of MCC content. This study is expected to spur further work on the synthesis of PPF composite for packaging applications.

Chiral molecules have the ability to rotate the polarization plane of polarized light. Polymers that own a chiral segment are called optically active polymers, and a rigid backbone is usually requi...

Coarse-grained molecular dynamics simulations were performed to investigate the mobility of nanoparticles (NPs) embedded in end-linked polymer networks, considering both the entangled and unentangl...

Photo-catalysts with three dimensional (3D) morphologies exhibit high photo-catalytic activities and received more attention because of their large surface area and more active sites. In this work, 3D-microspheres, flower-ball and weaving-like Bi4Ti3O12 particles were prepared through a facile hydrothermal route with the assistance of different surfactants, in which all of 3D structures were assembled by Bi4Ti3O12 nano-rods. The as-prepared 3D Bi4Ti3O12 samples were characterized through power X-ray diffraction (XRD), Fourier-transform infrared (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption techniques and UV–vis diffuse reflectance spectra (DRS) to identify their crystal structures, morphologies, surface structure and light absorption abilities. Furthermore, the photo-catalytic abilities of samples were evaluated through the degradation Rhodamine B (RhB) under the drive of visible light. Results indicated that flower-liked Bi4Ti3O12 not only displayed the best catalytic efficiency but also possessed the good reusability and stability.

Tetrazolium violet (TZV) is an important pharmaceutical intermediate for the preparation of various medicines, taking into account microbiological studies and TZV as a new inhibitor of heterocyclic compound. The corrosion inhibiting action of TZV for copper in 0.5 M H2SO4 solutions was assessed by potentiodynamic polarization and electrochemical impedance spectroscopy. The corroded copper surfaces were evaluated by scanning electron microscopy. Thereafter, the thermodynamics of TZV adsorption onto copper was computed and evaluated. As a result, the target TZV compound shows great corrosion inhibition performance to protect copper in sulfuric acid. Thermodynamic test results reveal that the Langmuir, Dhar–Flory–Huggins, and Bockris–Swinkels isotherm models provide a better description for the adsorption process of TZV on the metal surface. The calculated values of ΔGads0 indicate a spontaneous adsorption process of TZV on the copper surface accompanied by two kinds of interactions, physical adsorption and chemisorption.

The anthocyanins contents from red rice bran were characterized by HPLC/MS. Response surface methodology was used to optimize the ultrasound‐assisted extraction of red rice bran anthocyanin. The antioxidant activities were evaluated in terms of IC50. The tyrosinase inhibitory activities of the anthocyanin samples from red rice bran and the standard substances were determined by a spectrophotometric method. According to mass spectrometry information, the main component of anthocyanins is paeoniflorin (m/z = 480). The optimized anthocyanin level was 5.80 mg/g under the following conditions: solid–liquid ratio of 1:17.46; ethanol concentration of 78.37%; ultrasonication time of 55.23 min; and pH of 2.31. The IC50 value of the DPPH radical scavenging and the superoxide anion scavenging activities of the sample were 53.51 and 2,375 μg/ml; those of the standard were 14.60 and 64.74 μg/ml; and those of vitamin C were 24.45 and 136.25 μg/ml, respectively. The IC50 values of the tyrosinase inhibition activities of the sample and Vc were 4.26 and 2.18 μg/ml, respectively. There is a significant difference (p, The anthocyanins extracted from red rice bran can be applied to the health food, medical and beauty fields. Moreover, these results can not only improve the utilization rate of red rice bran but also provide new ideas for the development of natural pigments.

Polymer-based catalysts have been of special interest because of their several advantages such as easy processibility. Inorganic catalyst generally have been introduced into polymer-based media to endow catalytic activity. Surface decoration or sol–gel reaction have been performed so far, but inherent low affinity between organic/inorganic causes low efficiency in loading amount, resulting in low catalytic activity. Herein, we synthesized easily processible and highly functionalizable polyoxazoline as polymer nonwoven fiber-based catalytic supporter. Zr(OH)4 was grown on surface of fiber-web via sol–gel reaction. The Zr(OH)4 grown fiber exhibited not only excellent mechanical properties but also effective decontamination efficiency against organophosphate-based toxic agents.

RNA editing (DNA/RNA differences) as a post-transcriptional modification approach to enrich genetic information, plays the crucial role in regulating diverse biological processes in eukaryotes. Although it has been extensively studied in plant chloroplast and mitochondria genome, RNA editing in plant nuclear genome, especially those associated with Fusarium head blight (FHB), is not well studied at present. Here, we investigated the DNA/RNA differences associated with FHB through a novel method by comparing the RNA-seq data from Fusarium-infected and control samples from 4 wheat genotypes. A total of 187 DNA/RNA differences were identified in 36 wheat genes, representing the first landscape of the FHB-responsive RNA editome in wheat. Furthermore, all of these 36 edited genes were located in the FHB related co-expression gene modules, which may involve in regulating FHB response. Finally, the effects of DNA/RNA differences were systematically investigated to show that they could cause the change of RNA structure and protein structure in edited genes. In particular, the G to C editing (chr3A_487854715) in TraesCS3A02G263900, which is the orthology of OsRACK1, resulted that it was targeted by tae-miR9664-3p to control its expression in different genotype through different editing efficiency, suggesting RNA editing could mediate miRNA to participate in the regulation network of FHB tolerance. This study reported the first wheat DNA/RNA differences associated with FHB, which not only contribute to better understand the molecular basis underlying FHB tolerance, but also shed light on improving FHB tolerance through epigenetic method in wheat and beyond.

Utilization of modest to good strength and stiffness of polylactide (PLA) as well as overcoming its brittle phenomenon is the primary concern of this study. Therefore, melt-blending with a lab-scale two-screw extruder was conducted on PLA and micro-fibrillated cellulose (MFC) with and without epoxidized soybean oil (ESO) as a reactive plasticiser. Introducing ESO has a major effect on the blends’ toughness. A low span scanning electron microscope (SEM) was used to observe PLAs transition from brittle to ductile behavior. PLA/MFC/ESO ternary blends’ elongation-at-break, bending strain and notch impact strength were improved to 105, 9.7% and 7.20 kJ/m2 respectively. This assembly also helps in the increase of the plasticisation effect which leads to reduced glass transition Tg and crystallization Tc temperatures, observable using differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) shows an increase in ternary blends’ decomposition temperature compared with neat PLA which suggests the blends are thermally stable. Fourier transform infrared (FTIR) spectroscopy allowed significant changes in peak positions to explain the interactions among blended components. The entire process rests on a simple, effective methodology whereby improved PLA/MFC blend toughness by ESO is achieved.

Most biodegradable thermoplastic materials cannot be used as elastomers due to their relatively poor elasticity. Poly(butylene furandicarboxylate-co-e-caprolactone) (PBFCL) copolyesters were synthe...

Poly (butylene furandicarboxylate) based poly (ether ester), with poly (ethylene glycol) (PEG) molecular weight from 600 to 20 K g mol−1 and mass fraction of hard segments fixed at 50%, are synthesized through transesterification and melt polycondensation. When Mn (PEG) is less than 1500 g mol−1, the copolymers tend to be homogeneous. The tendency of microphase separation is facilitated by the increasing Mn (PEG). The mechanical properties and water swelling are influenced by Mn (PEG), equilibrium water-uptake and PEG crystals. Elastic modulus of samples with no PEG crystals vary from 34 to 64 MPa, with elongation at break exceeding 1000%. The hydrolytic degradation is strongly affected by Mn (PEG), degradation medium and alkalinity. The degradation of copolymers with short PEG (

An ideal photocatalyst not only offers high photo-generated electron-hole pairs separation ability, but also has suitable redox potential. Here, a direct Z-scheme core-shell structured WO3@SnS2 hetero-junction photo-catalyst was prepared via two-step hydrothermal method, in which the core-shell structure, rod morphology and micro-composition of hetero-junction were confirmed through X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) spectra, field emission scanning electron microscope (FE-SEM), transmission electron microscope (FEI-TEM) and X-ray photoelectron spectra (XPS). Their enhanced photo-catalytic abilities were evaluated by photo-degradation of Rhodamine (RhB), photo-reduction of dichromate (Cr6+) solution and photo-catalytic H2 production through comparing with pure WO3, SnS2 or the mixture of WO3 and SnS2 (WO3/SnS2). The absorption spectra and electrochemical properties were used to estimate the band gap of samples, the expanded spectral absorption capacity and improved electron-hole separation ability, which are important factors for enhanced photocatalytic performance. Furthermore, the direct Z-scheme charge transfer mechanism of WO3@SnS2 hetero-junction was determined through the combination of theoretical calculation and experimental characterizations, which played a decisive role for retaining excellent redox potential and increasing photo-catalytic ability of WO3 and SnS2.

Ti-doped graphitic carbon nitrides (g-C3N4) were obtained through calcining the mixture of melamine and tetrabutyl titanate. The structure and Ti atom position of Ti-doped g-C3N4 were identified through X-ray diffraction (XRD) patterns, X-ray photoelectron spectra (XPS) and first principle calculations. After doping, the degradation rate of Rhodamine B (RhB) was improved almost 4 times under visible light irradiation, which was further confirmed through theoretical and experimental analysis. According to photoluminescence (PL) spectra, photocurrent and ultraviolet-visible (UV–vis) absorption spectrum, enhanced separation rate of photogenerated carriers and modified electronic structure were estimated. These results supplement the current understanding on photocatalytic processes of doping system and the mechanism of layered photocatalysts.

The development of highly efficient non-noble metal catalysts for oxygen reduction reaction (ORR) is still a challenge in energy conversion and storage devices. Here we report a low-temperature strategy to synthesize ultrafine Fe and Fe3C nanoparticles anchored on nitrogen-doped mesoporous carbon (NMC). Iron precursors are synthesized through −60 °C liquid precipitation, then ultrafine and uniformly dispersed Fe and Fe3C nanoparticles are obtained by thermal treatment of the iron precursors. The prepared catalyst efficiently catalyzes 4-electron reduction of oxygen with half-wave potential (E1/2) of 0.88 V in 0.1 M KOH, superior to the 20 wt% commercial Pt/C catalyst (E1/2 = 0.86 V). The Fe/Fe3C-NMC electrocatalysts display remarkable stability and promising methanol tolerance. These new findings indicate potential new opportunities for exploring high ORR performance non-noble catalysts in electrochemical storage energy devices.

Thermoplastic poly(ether-ester-urethane)s were synthesized from poly(L-lactide) diols (PLLA diols), polytetrahydrofuran diol (PTMG diols), 4,4′-dicyclohexylmethane diisocyanate (HMDI), and 1,4-butanediol (BDO) by a two-step reaction, and the morphology and property of the resultant TPU could be adjusted by varying the PLLA contents. The soft segment was composed of PLLA and PTMG diols. By controlling the percentage of PLLA in the soft segment, the glass transition temperature and mechanical properties of the polyurethanes could be regulated. Based on the FTIR spectrum, we found that two kinds of hydrogen bonding existed individually in soft matrix and hard domain. The hydrogen bonding in soft matrix was unstable, which could be destroyed during elongation. With in situ stretching WAXS and SAXS experiments, we found that the PLLA crystal was destroyed and the PLLA domain oriented along the stretch direction. Finally, we proposed a schematic model to illustrate the microstructures of these elastomers before and after stretch.

A novel convenient dual-side initiator of lutidine dianion for anionic polymerization has been investigated in terms of their initiation and propagation kinetics. This lutidine dianion could be synthesized in quantitative yields reacting commercial products of 2,6-lutidine with sec-butyl lithium without any complex organic synthesis, and could be used effectively as the dual-side initiator to synthesize polyisoprene with various molecular weights via living anionic polymerization. In addition, this lutidine dianion can produce 50% of 1.4-microstructure contents in polyisoprene which is very important for elastomeric property of polydienes. All experimental evidences showed the living property and were consistent with quantitative yields without any side reactions when the anionic living polymerization proceeded using lutidine dianion as the initiator.

The MoS2/g-C3N4 heterojunction composite (marked as MoS2/g-C3N4-H) was successfully prepared via calcining the melamine coated MoS2 nano-sphere, where the thin g-C3N4 nano-sheets were tightly grown on the surface of MoS2 nano-sphere to form MoS2 inlaying in g-C3N4 heterostructure. The detailed charge transfer mechanism was discussed by combining theoretical calculation and experiments, in which the intrinsic cause of photo-generated charge separation and transfer was determined as the directional built-in electric field driven by different Fermi levels of MoS2 and g-C3N4. Comparatively, the enhanced photo-catalytic performance and stability of the sample were assessed by degrading the Rhodamine (RhB) and reducing the Dichromate (Cr6+) solutions under the irradiation of the simulated sunlight, which could be attributed to the widened spectral absorption range and improved electron-hole separation rate. Based on above results, the photo-catalytic mechanism involving redox reactions was also clearly proposed.

Functional polymers such as polyvinylidene fluoride (PVDF) and its copolymers, which exhibit room-temperature piezoelectricity and ferroelectricity in two-dimensional (2D) limit, are promising candidates to substitute hazardous lead-based piezoceramics for flexible nanoelectronic and electromechanical energy-harvesting applications. However, realization of many polymers including PVDF in ultrathin 2D nanostructures with desired crystal phases and tunable properties remains challenging due to ineffective conventional synthesis methods. Consequently, it has remained elusive to obtain optimized piezoelectric performance of PVDF particularly in sub-10 nm regimes. Taking advantage of its high flexibility and easy processing, we fabricate ultrathin PVDF nanoflakes with thicknesses down to 7 nm by using a hot-pressing method. This thermo-mechanical strategy simultaneously induces robust thermodynamic α to electroactive β-phase transformation, with β fraction as high as 92.8% in sub-10 nm flakes. Subsequently, piezoelectric studies performed by using piezoresponse force microscopy reveal an excellent piezoelectric strain of 0.7% in 7 nm film and the highest piezoelectric coefficient ( d

A series of biobased poly(neopentyl glycol succinate/furandicarboxylate) (PNSF) copolyesters were synthesized via a transesterification and melt polycondensation process. The 1H NMR and analysis using the Fox equation suggested the formation of random microstructures. PNSFs displayed poor crystallization capability with a slow crystallization rate. The copolymerization destroyed the spherulite morphology of the homopolyester PNF, and the melting temperature (Tm) also decreased with decreasing neopentyl glycol furandicarboxylate content (mNF). Rheological tests revealed the slight increase in the free volume with the addition of succinic acid. The crystallization induced by thermal annealing enhanced the elastic modulus and tensile strength. PNSF50–PNSF70 possessed modulus and strength greater than 1000 and 27 MPa, respectively, exceeding those of most biodegradable packaging materials. On the other hand, PNSF80 and PNSF90 possessed high modulus of 3.0 GPa and strength of 100 MPa, which were comparable to ...

Aliphatic polycarbonates are an attractive research subject in the field of degradable materials. However, their relatively poor thermal properties limit their application. Here, poly(butylene carbonate) (PBC) was modified with 1,4-cyclohexanedicarboxylic acid (CHDA), a biomass-derived aliphatic ring monomer. Thermal degradation of short butylene carbonate segments was effectively avoided by one-step melt polycondensation of the oligomers. All the PBCCEs were random copolymers, and the trans content of CHDA in all cases was no less than 90%; this ensured the crystallizability of the butylene cyclohexanedicarboxylate (BCE) units. The glass transition temperature, melting temperature and thermal stability increased with the number of BCE units. The PBCCEs were semi-crystalline after thermal equilibrium was reached, and PBCCE50 to PBCCE90 contained PBCE crystals while PBCCE20 possessed XRD diffraction peaks similar to those of PBC. Small-angle X-ray scattering suggested that the randomly oriented lamellar structure of the PBCCEs became more ordered as the number of BCE units increased. PBCCE70-PBCE revealed a t1/2 of less than 30 s, indicating the rapid crystallization rate of the BCE units. The mechanical properties were closely related to the crystallization ability, and PBCCE50 to PBCCE90 showed good elastic moduli (87 to 520 MPa), high tensile strengths (22.8 to 39.5 MPa) and large elongations at break (930% to 413%). The gas barrier properties gradually increased with the number of BCE units, showing results several times higher than those of commercial poly(butylene adipate-co-terephthalate) (PBAT). Moreover, the addition of aliphatic rings slightly weakened the biodegradability, and obvious weight loss could be observed for PBCCE70. This result was higher than those of most aliphatic-aromatic copolyesters, which are degradable when their aromatic diacid content is less than 60%. PBCCE50 displayed a weight loss greater than 90% after 30 days, which is much faster than that of PBC. The results of this study indicate that PBCCE copolyesters exhibit great potential for applications in the plastics industry, such as green packaging and tissue engineering.

Defects in metal oxides can significantly improve their physical and chemical properties. However, the conventional methods to generate defects often require complex procedures and harsh conditions. In this study, we design a simple and room-temperature preparation route to prepare defective metal oxide nanoparticles with high yield. The formation of defects is attributed to the generation of oxygen vacancies (VO) and hydrogenation caused by charge transfer at a Mg-metal oxide junction structure. Defective TiO2 exhibits excellent performance toward wastewater cleaning and water splitting. The proposed route is promising in terms of convenience, low cost, and large-scale production.

Although soft micro/nanoreactors obtained from amphiphilic block co-polyolefin are intensively used for metallic nanoparticle synthesis, the intricate crosslinking after self-assembling of copolymers is an indispensable step. In this work, an amphiphilic block copolymer made of aromatic macromolecular with rigid backbone structures (i.e. polyarylene ether nitrile, PEN) is explored to formulate a robust micro/nano-reactor for direct silver nanoparticles (Ag NPs) synthesis without any crosslinking step. We show that the polymeric micro/nanoreactors can be fabricated in both microemulsion and reverse microemulsion system. More importantly, Ag NPs with modulated morphology and optical properties can be in-situ synthesized using these PEN micro/nanoreactors, which is due to the coordination between Ag+ and pendant cyano/sulfonate groups of PEN. Interestingly, the anisotropic polygonal plate-like hybrid nanostructures are obtained via the optimization of nucleation and growth kinetics of Ag NPs using PEN nanoreactor in the water-in-oil W/O reverse microemulsion. Based on these results, the present work would open the way for the facile fabrication of soft micro/nanoreactors for plasmonic nanostructures synthesis using amphiphilic block-copolymers with rigid molecular structures.

The melt polycondensation of glycolic acid based copolymers with high molecular weights remains a big challenge. In this work, poly(butylene furandicarboxylate-co-glycolate) (PBFGA) and poly(butylene furandicarboxylate)-b-poly(glycolic acid) (PBF-b-GA) copolyesters were synthesized via melt oligomer polycondensation and melt bulk transesterification, respectively. Herein, melt oligomer polycondensation is a better method with mild preparation conditions and products with higher molecular weights (Mw). The analysis of GPC demonstrated that PBFGAs possessed a Mw of up to 8.95 × 104 g mol−1. The PBFGAs also possessed excellent thermal stability (>320 °C), which endowed the copolymers with a wider processing window than thermolabile PGA. DSC analyses displayed that PBFGA40–PBFGA10 were semi-crystalline materials that melted between 84.5 and 156 °C, while PBFGA50–60 were amorphous. Tensile tests indicated a high elastic modulus of 524–1262 MPa, tensile strength of 16–44 MPa and good elongation at break over 220% of PBFGAs, exceeding most biodegradable packaging materials. The increase of GA units slightly impacted the barrier properties, with reduced CO2 (53×) and O2 (15×) permeability coefficients than those of commercial PBAT films, and also better than those of PET. The hydrolysis of the glycolate was restrained by steric hindrance of furan rings, while in enzymatic degradation PBFGAs displayed obvious weight loss with GA units >20 mol%. With superior thermal, tensile, barrier and degradable properties, PBFGAs have the potential to serve as promising and innovative bio-based polymers for eco-friendly and sustainable plastic packaging.

The development of efficient and stable earth-abundant water oxidation catalysts is vital for economically feasible water-splitting systems. Cobalt phosphate (CoPi)-based catalysts belong to the relevant class of nonprecious electrocatalysts studied for the oxygen evolution reaction (OER). In this work, an in-depth investigation of the electrochemical activation of CoPi-based electrocatalysts by cyclic voltammetry (CV) is presented. Atomic layer deposition (ALD) is adopted because it enables the synthesis of CoPi films with cobalt-to-phosphorous ratios between 1.4 and 1.9. It is shown that the pristine chemical composition of the CoPi film strongly influences its OER activity in the early stages of the activation process as well as after prolonged exposure to the electrolyte. The best performing CoPi catalyst, displaying a current density of 3.9 mA cm-2 at 1.8 V versus reversible hydrogen electrode and a Tafel slope of 155 mV/dec at pH 8.0, is selected for an in-depth study of the evolution of its electrochemical properties, chemical composition, and electrochemical active surface area (ECSA) during the activation process. Upon the increase of the number of CV cycles, the OER performance increases, in parallel with the development of a noncatalytic wave in the CV scan, which points out to the reversible oxidation of Co2+ species to Co3+ species. X-ray photoelectron spectroscopy and Rutherford backscattering measurements indicate that phosphorous progressively leaches out the CoPi film bulk upon prolonged exposure to the electrolyte. In parallel, the ECSA of the films increases by up to a factor of 40, depending on the initial stoichiometry. The ECSA of the activated CoPi films shows a universal linear correlation with the OER activity for the whole range of CoPi chemical composition. It can be concluded that the adoption of ALD in CoPi-based electrocatalysis enables, next to the well-established control over film growth and properties, to disclose the mechanisms behind the CoPi electrocatalyst activation.

Nowadays, the promotion and application of aliphatic-aromatic copolyesters, such as poly (butylene adipate-co-terephthalate) (PBAT), are growing into a general trend. Although the structures of diacids exerted substantial impacts on degradation behavior, the underlying mechanisms have rarely been studied. In this work, 2,5-Furandicarboxylic acid was combined with succinic acid (PBSF), adipic acid (PBAF) and diglycolic acid (PBDF) to prepare three kinds of copolyesters. They showed unique degradation behaviors in buffer, enzyme environment and artificial seawater. These characteristics are closely related to the structural compositions of diacids. PBAFs displayed impressive biodegradability when catalyzed by Candida antarctica lipase B (CALB), while the more hydrophilic PBDFs exhibited faster hydrolysis in both buffer and artificial seawater. PBSFs, with hydrophobic and short segments, obtained relatively slower rate of hydrolysis and enzymatic degradation. The reactivity sites and hydrolytic pathway were revealed by the combination of DFT calculation and Fukui function analysis. MD simulations, QM/MM optimizations and theozyme calculations showed that PBAF-CALB was prone to form a pre-reaction state, leading to the reduced energy barrier in the acylation process. This work revealed the effects of different structural features of diacids on polymer degradation and paved a way to design target biodegradable polymers in different degradation conditions.

Listeria monocytogenes widely exists in the natural environment and does great harm, which can cause worldwide public safety problem. Infection with L. monocytogenes can cause rapid death of Kupffer cell (KCs) in liver tissue and liver damage. American ginseng saponins is a natural compound in plants, which has great potential in inhibiting L. monocytogenes infection. Therefore, American ginseng stem-leaf saponins (AGS) and American ginseng heat-transformed saponins (HTS) were used as raw materials to study their bacteriostatic experiments in vivo and in vitro. In this experiment, female Kunming mice were randomly divided into five groups: control group, negative group, AGS group, HTS group (10 mg/kg/day in an equal volume via gastric administration) and penicillin group, each group containing six mice. Profiles AGS and HTS components were evaluated by high-performance liquid chromatography (HPLC) analysis. The bacteriostatic effect of AGS and HTS on L. monocytogenes was evaluated by inhibition zone test, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bacteriostatic effect of AGS and HTS pretreatment on mice infected with L. monocytogenes were studies by animal experimental. The results showed that the content of polar saponins in AGS was 0.81 ± 0.003 mg/mg, less polar saponins was 0.08 ± 0.02 mg/mg, the content of polar saponins in HTS was 0.10 ± 0.01 mg/mg, less polar saponins was 0.76 ± 0.02 mg/mg. The in vitro bacteriostatic diameter of HTS (16.6 ± 0.8 mm) is large than that of AGS (10.2 ± 1.2 mm). AGS and HTS pretreatment could reduce the colony numbers in the livers of mice infected with Listeria monocytogenes. The levels of alanine aminotransferase (ALT), IL-1β, IL-6, TNF-α and IFN-γ in the livers of mice in the pretreatment group were significantly lower than those in the negative group. There were obvious leukoplakia, calcification and other liver damage on the liver surface in the negative control group, and obvious inflammatory cell infiltration in HE sections. AGS and HTS pretreatment can reduce liver injury caused by L. monocytogenes and protect the liver. Compared with AGS, HTS has higher content of less polar saponins and better bacteriostatic effect in vitro. The count of bacterial in liver tissue of HTS group was significantly lower, the survival rate was significantly higher than that of AGS group. Less polar saponins had better bacteriostatic effect. Collectively, less polar saponins pretreatment has a protective effect on mice infected with L. monocytogenes, to which alleviated liver damage, improved anti-inflammatory ability and immunity of the body, protected liver may contribute.

We report a fluorogenic probe for naked-eye sensing of hydrazine in solution and in the gaseous phase. The probe based on tetraphenylethylene (TPE) with aggregation-induced emission (AIE) characteristics shows OFF-ON fluorescence as observed by thin-layer chromatography (TLC) upon treatment with hydrazine. Specifically, the fluorescence of the probe was quenched due to the attached N[double bond, length as m-dash]N group, which can be reduced to -NH-NH- in the presence of hydrazine to turn on the fluorescence. The reduced intermediate can be easily oxidized in air to regenerate the original probe for recyclable usage. Both fluorometric and colorimetric readings were achieved by TLC with high sensitivity and excellent selectivity. This study thus represents a simple example of a reusable and naked-eye molecular probe for monitoring environmental hazards. Finally, the probe has also been applied to detect hydrazine in live cells.

This critical review considers the extensive research and development dedicated, in the last years, to a single polymer, the poly(ethylene 2,5-furandicarboxylate), usually simply referred to as PEF. PEF importance stems from the fact that it is based on renewable resources, typically prepared from C6 sugars present in biomass feedstocks, for its resemblance to the high-performance poly(ethylene terephthalate) (PET) and in terms of barrier properties even outperforming PET. For the first time synthesis, properties, and end-life targeting-a more sustainable PEF-are critically reviewed. The emphasis is placed on how synthetic roots to PEF evolved toward the development of greener processes based on ring open polymerization, enzymatic synthesis, or the use of ionic liquids; together with a broader perspective on PEF end-life, highlighting recycling and (bio)degradation solutions.

A stretchable electronic skin (e-skin) requires a durable elastomeric matrix to serve in various conditions. Therefore, excellent and balanced properties such as elasticity, water proof capability, toughness, and self-healing are demanded. However, it is very difficult and often contradictory to optimize them at one time. Here, a polyurethane (BS-PU-3) containing a polydisperse hard segment, hydrophobic soft segment, and a dynamic disulfide bond was prepared by one-pot synthesis. Unlike the normal two-pot reaction, BS-PU-3 obtained through the one-pot method owned a higher density of self-healing points along the main chain and a faster self-healing speed, which reached 1.11 μm/min in a cut-through sample and recovered more than 93% of virgin mechanical properties in 6 h at room temperature. Moreover, a remarkable toughness of 27.5 MJ/m3 assures its durability as an e-skin matrix. Even with a 1 mm notch (half of the total width) on a standard dumbbell specimen, it could still bear the tensile strain up to 324% without any crack propagation. With polybutadiene as the soft segment, the shape, microstructure, and conductivity in BS-PU-3 and BS-PU-3-based stretchable electronics kept very stable after soaking in water for 3 days, proving the super waterproof property. An e-skin demo was constructed, and self-healing in pressure sensitivity, mechanical, and electrical properties were verified.

This study aimed to improve nitrogen utilization and alleviate the inhibition of straw decomposition during early tillering and the growth of paddy after straw return. Specifically, three different nitrogen fertilizer (base fertilizer) application methods were tested under full straw return: applying the compound fertilizer once (J1), applying the compound fertilizer twice (J3) and applying the ammonium carbonate fertilizer plus compound fertilizer (J2). Full straw return without fertilizer (CK1) and no straw return without fertilizer (CK2) were used as the controls. The results showed that treatment with ammonium carbonate fertilizer combined with compound fertilizer (J2) significantly enhanced straw decomposition, light interception and dry matter accumulation at an early stage of tillering, but reduced tiller occurrence at a late tillering stage. Grain yield was affected due to reduced dry matter accumulation, nitrogen use efficiency and number of effective panicles. There were no significant differences in rice growth, nitrogen use efficiency and grain yield between the one-time or two-time compound fertilizer application methods. In contrast, treatment with ammonium carbonate fertilizer combined with compound fertilizer (J2) under full straw return effectively improved straw decomposition and accelerated the return of green and tillering. In addition, the proportion of ammonium carbonate fertilizer affected the nutrient utilization efficiency and yield at later stages.

Ionic liquids (ILs) are widely used in various chemical processes. However, a growing number of studies have found that ILs are potentially toxic to different types of living organisms, including crops. The present study analysed the effects of 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) on the photosynthetic system and metabolism of maize seedlings. Results showed that [C4mim]Cl could significantly reduce maize leaf chlorophyll level and cause extensive leaf bleaching. The activity of photosystem II (PSII) was significantly inhibited when seedlings exposed to higher concentration of [C4mim]Cl. The maximum quantum yield of PSII and the potential efficiency of PSII were reduced by 63% and 88% under 800 mg/L [C4mim]Cl treatment in comparison with the control treatment. The RNA sequencing analysis performed to examine gene expression profiles of maize leaves under [C4mim]Cl treatment revealed 639 differentially expressed genes (DEGs), 115 of which were categorized into different metabolic pathways. Among these DEGs, the seven genes involved in the photosynthetic Calvin cycle were down-regulated by [C4mim]Cl exposure. For carbohydrates and amino acids metabolism, the genes for starch synthesis were down-regulated, while the genes for amino acids and protein degradation were up-regulated. The changes observed in these major metabolic pathways might be an important reason for [C4mim]Cl toxicity.

Antibiotics, a highly prevalent class of environmental organic pollutants, are becoming a matter of global concern. Clay minerals that are ubiquitous in subsurface environments may play an important role in the fate and transport of antibiotics. Taking ciprofloxacin (CIP) as a model antibiotic, this work explored the role of clay colloids (kaolinite and montmorillonite) on the adsorption and transport of CIP under different chemical solution conditions. The adsorption isotherms showed that montmorillonite colloids had a larger CIP sorption capacity than kaolinite colloids. The results of transport experiments indicated that montmorillonite colloids could promote CIP transport in saturated sand columns, but the addition of kaolinite colloids affected CIP mobility to a much smaller extent. The much stronger transport-enhancement effect of montmorillonite colloids was due to CIP adsorbed strongly to the colloids and desorption hysteresis of colloid-adsorbed CIP, likely stemming from the intercalation of this antibiotic in the interlayer of montmorillonite. Interestingly, transport of clay colloids increased with the increasing pH from 5.0 to 9.0; however, CIP transport decreased with the increasing pH in the presence of clay colloids. The observations were likely attributable to pH-dependent ciprofloxacin adsorption/desorption to clay minerals. Increasing the concentrations of NaCl and CaCl2 generally decreased the contaminant-mobilizing ability of montmorillonite colloids, mainly by increasing the aggregation of colloids and thus, decreasing the transport of colloid-adsorbed CIP. Moreover, under the test conditions (1 mM NaCl and pH 7.0), the presence of CIP inhibited the transport of clay colloids due to the increase in aggregate size of clay colloids with the addition of CIP. Overall, these findings suggest that clay colloids with high adsorption abilities for antibiotics in the subsurface environment may act as a carrier for certain antibiotic compounds.

Fully biobased poly(butylene 2,5-furandicarboxylate)-co-poly(lactic acid)s (PBFLAs) of lactic acid composition from 10% to 40% are synthesized. They are subjected to molecular, thermal, diffractometric, degradable and mechanical characterizations. Thermogravimetric analysis shows that PBFLA are thermally stable at least 350 °C, much higher than PLA. After the incorporation of lactic acid units, both Tm and crystallization rate decrease with respect to homopolymers. X-ray diffraction measurements indicate that no PLA crystal is present during crystallization. All samples perform better barrier properties with respect to PLA, implying potential application in packaging. These samples behave like semicrystalline plastic in the tensile tests. PBFLA copolyesters show Young’s modulus, maximum tensile strength and breakage elongation higher than 1000 MPa, 38 MPa, and 230%, respectively. Such comprehensive mechanical behaviors exceed most biodegradable materials. Lastly, biodegradability could be significantly im...