查看更多>>摘要：The preparation of carbon quantum dots (CQDs) with excellent photoluminescence (PL) properties from biomass is a hot research topic. Herein, nitrogen-doped CQDs (N-CQDs) from lignin (C-source) using diethylenetriamine (DETA) as an N-source were synthesized via a facile, green, and large-scale solvothermal approach. The as-synthesized N-CQDs in ethanol (N-CQDs-ET) exhibit unique structures with abundant N-doping (similar to 7.2%), rich functional groups (especially C=O and pyrrolic-N), high degree of graphitization, and uniform particle size (similar to 5.0 nm). The N-CQDs-ET have excellent QL properties with high quantum yield, superior fluorescence stability, and long fluorescence lifetime, all of which are much better than N-CQDs obtained from a traditional hydrothermal process. The N-CQDs-ET display excellent sensitivity for Fe3+ and Co2+ detection with a good linear correlation ranging from 0.27 to 250 mu M and 0.45-500 mu M, respectively. In addition, the N-CQDs-ET exhibit excellent biocompatibility and multicolored cell imaging ability, showing great potential applications in biosensors.
查看更多>>摘要：Portulaca oleracea (PO) is a popular traditional Chinese medicine (TCM) used to cool the body and reduce toxins. Authentication of Chinese herbal medicines (CHM), such as medicinal crop PO, is important and is a key step for quality control during TCM production. Adulteration of CHM reduces the efficacy of TCM and can lead to side effects in patients. Therefore, it is urgent to develop a reliable method for the verification of CHM in the TCM market. In this study, a DNA molecular method was established for rapid authentication of PO. Herein, four molecular markers, ITS1, ITS2, rbcL, and trnL, were chosen for evaluation of the sequence similarity between PO and its frequently used adulterants. Based on the phylogenetic analysis results, ITS2 was selected as the most promising molecular marker for PO authentication. Furthermore, PCR-amplified ITS2 was used to establish an RFLP pattern to distinguish PO from its adulterants. The specific restriction enzyme HpyF3I was found to quickly and effectively distinguish PO from the commonly confused plant Bacopa monnieri (BM) and other adulterants. In conclusion, this DNA molecular method can be used for PO authentication and be practically applied to audit PO plants on the herbal market and in the field.
查看更多>>摘要：In this paper, a novel epoxy flame retardant PPDEG-EP (P-E) was synthesized from eugenol by nucleophilic substitution reaction and Prilezhaev epoxidation. The chemical structure was identified by nuclear magnetic resonance (NMR). The synthetic P-E was combined with curing agent diaminodiphenylmethane (DDM) and applied to wood surface coating decoration. To evaluate the thermal curing behavior of P-E, the P-E/DDM system was characterized by DSC. The results show that P-E/DDM has a lower reaction activation energy (E-a), and the curing temperature of the system is reduced with the incorporation of P-E. As a wood coating, P-E/DDM retains the excellent physical and chemical properties of epoxy resins. Thermogravimetric (TG) showed the char formation of P-E/DDM was improved, that the char residue of P-E/DDM+W was higher than both that of pure wood and P-E/DDM. And it produced significant flame retardancy that the UL-94 test reached V-0 rating and the value of LOI test was 32.1%. As expected, SEM shows that the internal structure of the burned wood was still intact. This eugenol-modified coating has been proved to be a good flame retardant for wood.
查看更多>>摘要：Lignocellulosic biomass is a valuable source of energy and raw materials. However, in order to unlock the full potential of this renewable source, it needs to be fractionated to separate its main components: cellulose, lignin and hemicellulose. Current extraction methods (Kraft, Organosolv) are very effective but are not entirely free of drawbacks, such as a high energy and water consumption and the use of potentially toxic chemicals. Ionic liquids (ILs) have been explored as a sustainable alternative for biomass treatment since they have shown selectivity during biomass fractionation. In this work, the ability of 6 ILs to selectively extract lignin from banana rachis was investigated, including choline lactate [Cho+][Lac-] which is acknowledged by its lack of toxicity, biodegradability and ease of synthesis from renewable resources. Recovered cellulose batches were characterised by X-ray diffraction and FT-IR spectroscopy and compared with cellulose from banana rachis obtained by traditional alkaline pulping process.
查看更多>>摘要：A novel, green and efficient in-situ cloud point-reinforced ionic liquid-assisted mechanochemical extraction (IS-CPR-IL-MCE) technique coupled with ultrahigh performance liquid chromatography was established to simultaneously extract, concentrate and separate five alkaloids (including liensinine, isoliensinine, neferine, Odemethyl nuciferine and nuciferine) from lotus leaf. The parameters affecting the extraction efficiency of target analytes, such as the amount of IL, surfactant and salt, grinding time, pH, enrichment temperature and time were systematically studied and optimized by single-factor and multifactor experiments. The highest extraction yield of alkaloids was obtained by IS-CPR-IL-MCE under the following conditions: 0.23 g of 1-dodecyl-3-methylimidazolium bromide, 0.37 g of Triton X-100, 7.73 of pH, 5 min of milling time, 2.5 g of (NH4)(2)SO4, 60. and 20 min of enrichment temperature and time. The developed method exhibited a good linearity in the range of 0.5-100.0 mu g/mL with the coefficients of correction more than 0.9992, low limit of detection of 8.0-11.2 ng/mL, acceptable reproducibility below 4.45%, and satisfactory recovery in the range of 80.4-93.7% The results demonstrated that the proposed method was successfully applied to the extraction of alkaloids from lotus leaf.
查看更多>>摘要：This article describes the technology of organic recycling of polylactide/halloysite biocomposites using the sugar -protein condensation theory. For this purpose, polymer biocomposites were produced with a polylactic acid structure and reinforced in the form of halloysite nanoparticles by 1; 2.5; and 5% by mass. A new method of decomposition of the produced biocomposites was developed. For this purpose, the composting process uses complex sugars in the form of beet molasses. This action is based on Stevenson's theory of protein-sugar condensation. Thus, the validity of this theory was confirmed, as research showed that this modification significantly influences the acceleration of the composting process of the produced biomaterials. For each phase of the process, the parameters of accelerated composting were defined by determining the temperature, degree of humidity, and quantitative scale of acidity and alkalinity. The degree of decomposition of biocomposites was assessed based on microbiological tests, hardness, weight loss, viscosity-average molecular weight tests, and structure assessment using macro and microscopic examinations (SEM). Based on the microbial tests, it was shown that composting also seems to be an alternative method of infectious waste disposal in the case of using biocomposites for products, e.g., medical products.
查看更多>>摘要：Utilizing renewable biomass components to design oil-water separation membranes is the hot spot of environmental remediation owing to their degradable and sustainable features and the increasing concern of large production of oily wastewater. Herein, the aminated lignin (AL) with multi-active sites to be constructed was loaded onto cotton fibers and then cross-linked with green ethyl cellulose (EC) to synthetize hydrophobic/ lipophilic ethyl cellulose cotton (AL@Cotton-EC). Considering that methyltrimethoxysilane (MTMS) can build low surface energy coatings, we further introduced and built the superhydrophobic AL@Cotton-EC/MTMS separation membranes. The EC can wrap on the surface of cotton and assemble an interpenetrated porous structure with excellent wetting properties. Combined with the low surface energy and superwettability of MTMS, the prepared AL@Cotton-EC/MTMS exhibited an excellent separation efficiency of 99.33% in oil-water separation with good cycling stability. In addition, by simulating outdoor acidic, alkaline and salt environments, it was found that AL@Cotton-EC/MTMS still met the superhydrophobic conditions. Thus, our materials showed huge potential for treating oily wastewater. This work completed the research on the properties of oil-water separation materials. It provided new directions for the design and development of innovative materials for green, recyclable, biodegradable and alternative energy sources.
查看更多>>摘要：The pericarps of genus Zanthoxylum (PZ) are used as a condiment in Chinese cuisine, while hydroxyl-sanshools (HS) are primary components evoking specific pungent sensations. This study developed a novel method for distinguishing the PZ species and detecting HS in PZ by combining dynamic surface-enhanced Raman scattering spectroscopy (D-SERS) with a homogeneous gold nanorods (AuNRs) substrate. Furthermore, principal compo-nent analysis (PCA) separated the D-SERS spectra data of 26 PZ samples into two groups. The concentration of hydroxyl-alpha-sanshool (alpha-SOH) in a range of 0.1-12 mg mL(-1) displayed an excellent linear relation with the peak intensity, while the detection limit at 0.03 mg mL(-1) the requirements for detecting HS in currently known PZ. Compared to high-performance liquid chromatography (HPLC) analysis, the established method demonstrated excellent accuracy in PZ samples. This study provided an alternative method based on D-SERS coupled with AuNRs for rapidly and accurately determinating HS in PZ samples.
查看更多>>摘要：With the growing concern on the plastic waste disposal crisis, there is a rapidly increasing interest in developing biopolymers that present specific properties for electronic devices. In this study, polybutylene adipate terephthalate/polylactic acid blend was reinforced with a surface-treated organic/inorganic hybrid filler for simultaneous enhancement of thermal conductivity and anti-flaming performance. The organic/inorganic hybrid filler was successfully produced by decorating SiC particles on the pores and surfaces of coffee husks (CHs) via mechanical and chemical techniques. CHs are comprised of lignocelluloses such as cellulose, hemicellulose, and lignin that are present as interlinked complex macromolecular structure. The hybridization and surface treatment helped to promote excellent interfacial interaction between the fillers and matrices. As a result, the thermal conductivity of the hybrid composite was measured to be 0.88 W m-1 K-1, showing a 300% enhancement compared to the blend. In addition, this hybrid composite possesses excellent anti-flaming performance thereby exhibiting the properties of a UL94 V-0 material. In general, this work demonstrates the applicability of the fabricated hybrid biocomposites on bio-based electronic devices and their promising future applications.
查看更多>>摘要：In this study, the carvone-loaded zein/pullulan electrospun nanofibers (Z/PUL/CAR NFs) were developed and characterized for the first time. The zein/pullulan hybrid NFs were produced at three different blending ratios of 90:10, 80:20, and 70:30 by electrospinning method. The zein/pullulan NFs at a ratio of 80:20 exhibited more homogeneous and bead-free, as well as the lowest average fiber diameter (508 +/- 159 nm). In this regard, this NFs was selected as the optimized sample for the incorporation of carvone. The Z/PUL/CAR NFs showed a bead free and cross-linked structure with an average fiber diameter of 588 +/- 288 nm. The compatibility among zein, pullulan, and carvone was approved by thermal gravimetric and X-ray diffraction analysis. Additionally, the Fourier transforms infrared spectroscopy indicated the formation of interactions among zein, pullulan, and carvone. The tensile strength and water contact angle values of Z/PUL/CAR NFs were 7.09 +/-& nbsp;0.85 MPa and 96.6 +/- 0.7, respectively. Moreover, the incorporation of carvone in the NFs provided DPPH scavenging activity (39.95 +/-& nbsp;3.81%) and inhibition activity against S. aureus (12.2 +/- 1.4 mm) and E. coli (9.6 +/- 1.2 mm) bacteria. The biocompatibility of developed NPs was approved by in-vitro cell cytotoxicity assay. In conclusion, the developed electrospun NFs have considerable potential for multiple applications such as food packaging and wound dressing.
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Elsevier