JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2020
·
IF 3.905
Kai Li,Bo Wang,Dana Bolatibieke,Dong-Hong Nan,Zhen-Xi Zhang,Min-Shu Cui,Qiang Lu
Levoglucosenone (LGO) is a valuable chiral synthon and can be produced from pyrolysis of cellulose and biomass. In the present study, Ni-P-MCM-41 catalysts with various P-to-Ni ratios were prepared and employed for selective production of LGO from biomass. Both analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale experiments were conducted to explore the effects of several factors on the formation of LGO, including P-to-Ni ratio in Ni-P-MCM-41, catalyst/sample ratio and pyrolysis temperature. The results revealed that all the Ni-P-MCM-41 catalysts, especially the one with a P-to-Ni ratio of 5, exhibited excellent catalytic capability and selectivity for LGO production. For Py-GC/MS, the maximal LGO yields of 27.34 wt% and 14.30 wt% were achieved from cellulose and pine at 350 °C with catalyst/cellulose ratio of 3 and catalyst/pine ratio of 2, respectively. While in lab-scale experiments, the highest LGO yields from cellulose and pine were 21.37 wt% and 10.71 wt%, with the corresponding selectivity of 78.31% and 53.75%, respectively. The Ni-P-MCM-41 catalyst possessed much better catalytic efficiency on the LGO production than previously reported catalysts, including H 2 SO 4 , H 3 PO 4 , solid superacid, solid phosphoric acid and activated carbon.
研究领域:
化学工程
·
可再生能源
·
催化
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2016
·
IF 4.836
Jun Cheng,Qing Ye,Zongbo Yang,Weijuan Yang,Junhu Zhou,Kefa Cen
The response mechanisms of microalgal mutant Chlorella PY-ZU1 cells were investigated in their removal of antibiotic tilmicosin from wastewater under 15% CO 2 . Low concentrations (0.01–2 mg L −1 ) of tilmicosin in wastewater stimulated the growth of microalgal cells, whereas high concentrations (5–50 mg L −1 ) of tilmicosin significantly inhibited cell growth. When initial tilmicosin concentration increased from 0 to 50 mg L −1 , fractal dimension of microalgal cells monotonically increased from 1.36 to 1.62 and cell size monotonically decreased from 4.86 to 3.75 μm. In parallel, malondialdehyde content, which represented the degree of cellular oxidative damage, monotonically increased from 1.92 × 10 −7 to 7.07 × 10 −7 nmol cell −1 . Superoxide dismutase activity that represented cellular antioxidant capacity first increased from 2.59 × 10 −4 to the peak of 6.60 × 10 −4 U cell −1 , then gradually decreased to 2.39 × 10 −4 U cell −1 . The maximum tilmicosin removal efficiency of 99.8% by Chlorella PY-ZU1 was obtained at the initial tilmicosin concentration of 50 mg L −1 .
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Zhaosheng Hou,Jinwei Teng,Jinjian Wei,Tiantian Hao,Zhengqi Liu
The objective of this study is to offer a highly pH-sensitive biodegradable polyurethane for application as an intelligent drug delivery carrier. A new pyridinyl diol ((3-((2-(pyridin-4-yl)ethyl)thio) propane-1,2-diol, PyDH) was first synthesized via thiol-ene “click” reaction. Then, PyDH-based poly(ether-ester-urethane) (PEEU-Py) was designed and prepared through the condensation polymerization of PyDH diol, poly(ether-ester) diol and diisocyanate. The pendent pyridine groups and the polyester segments could endow the polymers with pH sensitivity and degradability, respectively. The bulk structures and physicochemical properties of PEEU-Py were characterized via 1 H NMR, FT-IR, GPC, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and tensile testing. The cast membranes exhibited a sharp transition of the equilibrium swelling ratio (ESR) at pH 8.5∼9.0, and ESR increases of more than twofold and eightfold at pH 1.5 relative to pH 7.4 and pH 12.0, respectively. In vitro drug release studies showed that the release efficiency from the membranes was increased with decreasing pH value. The pH-sensitive release behaviors were related mainly to the swelling ability, and the slow hydrolytic degradation rate of PEEU-Py membranes had minimal influence on it. In addition, the in vitro cytotoxicity was evaluated by an MTT assay with L929 fibroblasts, and a cell viability of more than 75 % indicated satisfactory cytocompatibility. All the results demonstrate the potential application of PEEU-Py as a biological on–off switch for drug carriers that is triggered by an external pH change.
研究领域:
材料科学
·
高分子化学
·
药学
·
生物医学工程
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产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Yifu Wang,Dan Wang,Jilin Wang,Lulu Wang
Ammonium functionalized anion exchange silica precursor (AESP) is synthesized by 3-(2-Aminoethylamino) propyltriethoxysilane and (2, 3-epoxypropyl) trimethylammonium chloride. Then the corresponding series of membranes based on pyridine functionalized polyvinyl alcohol (PVA-Py) with varying AESP content are prepared using sol-gel method. Obtained membranes show ion exchange capacities (IEC) ranging from 0.54 mmol·g −1 to 0.92 mmol·g −1 , but the opposite trend of water uptakes (WU) from 123.97% down to 69.09% because of the formation of organic-inorganic network. The hybrid membranes also exhibit good thermal stability (>140 °C), excellent mechanical properties (25.37 MPa) and high OH − conductivity (9.63 × 10 −2 S·cm −1 , 80 °C). Compared with the commercial Nafion®-117 membrane, the prepared hybrid membrane performs a much lower methanol permeability (7.57 × 10 −8 cm 2 ·s −1 for prepared membrane, 2.00 × 10 −6 cm 2 ·s −1 for Nafion®-117 membrane, 3 M methanol solutions, 30 °C). Only 10.7% decreases in OH − conductivity can be observed in 6 M 80 °C NaOH solutions after 360 h immersions, exhibiting excellent alkaline stability. The highest peak power density of the single cell with 5 M KOH + 3 M methanol fuel is 52.56 mW·cm −2 at 80 °C and 0.2 MPa O 2 .
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Yande Cai,Ze Wang,Jianjun Wang,Songgeng Li
The formation of chloride products in the process for pyrolysis of municipal solid wastes (MSW) with key model components was investigated by Py-GC/MS method. HCl and CH 3 Cl are identified as the most abundant chloride products for the individual pyrolysis of polyvinyl chloride (PVC) or corn straw (CS) in the range of 200–600 °C. For the pyrolysis of CS, a higher temperature is more favorable for the generation of HCl than that of CH 3 Cl. In the PVC pyrolytic products, chlorobenzene (Ph-Cl), benzyl chloride (Ph-CH 2 Cl), and 1-(chloroethyl)benzene (Ph-CHClCH 3 ) are also detected but in extremely low amounts. For the co-pyrolysis of PVC/CS, the formation of CH 3 Cl is significantly promoted. The synergistic effect in the PVC/CS co-pyrolysis process is mainly attributed to the reaction between the HCl derived from PVC and the decomposition products of lignin. The products of Ph-Cl and Ph-CH 2 Cl are mainly generated from the cyclization of Cl-containing chain species. CH 3 Cl and Ph-CHClCH 3 are mainly generated from secondary reactions between HCl and other pyrolytic products. No remarkable synergistic effect is observed on the formations of chlorides in the co-pyrolysis of PVC/PP (polypropylene), while the generation of Ph-CHClCH 3 is significantly enhanced in the co-pyrolysis of PVC/PS (polystyrene).
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Toxics
·
2025
·Vol. 13
·期 6
·452
·
IF 4.1
Shanshan Ji,Wei Wang,Yong Wang,Hexiang Bai,Zhuo Li,Zongli Huo,Kai Luo
The rapid increase in plastic production and consumption has intensified research into human exposure to micro- and nanoplastics (MNPs) and their health effects. This study quantitatively assessed MNP internal exposure levels in non-invasive human samples, focusing on the four most common types of MNPs (≥300 nm): polyethylene terephthalate (PET), polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS). Urine samples from 18 volunteers (4 males, 14 females) were analyzed using pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) with P(E-13C2) as an internal standard. The study developed a straightforward yet effective analytical approach for quantifying MNPs in biological fluids. MNPs were detected in all urine samples, with concentrations ranging from 0.098 to 0.986 μg/mL and an average concentration of 0.268 ± 0.235 μg/mL. LDPE, 0.074 μg/mL (interquartile range: 0.030–0.243 μg/mL), was the most abundant polymer, accounting for 67.72% of the total MNPs, followed by PS at 21.17%, while PP and PET accounted for 7.06% and 4.05%, respectively. The results also suggest that drinking water type may serve as a distinct source of MNPs in urine. This study provides novel evidence on MNP (≥300 nm) internal exposure in humans and the influence of drinking habits, highlighting the application prospects of this method in assessing the potential health risks of MNPs.
研究领域:
环境科学
·
分析化学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Xiong-Li Liu,Jing Lou,Xian-Qiao Zhu,Di-Cheng Pan,De-Wu Liu,Hui-Xian Jing,Wenjing Zhang,Hong-Xing Cen,Guo-Deng Guo-Deng Dong
The development of single chiral source-derived ligands to fine-switch enantioselectivity has continuously attracted the attention in asymmetric catalysis. Herein, we use the same chiral source L-prolinamide as the starting material, synthesizing chiral bidentate pyridine-type N-oxide ligands (denoted as Py-NO) and chiral monodentate phenyl N-oxide ligands (denoted as Ph-NO); their effectiveness was demonstrated in the switch of enantioselectivity in palladium(II)-catalysed Friedel-Crafts (FC) alkylation of indoles and 2,3-dioxopyrrolidines, and both enantiomers of structurally important indole derivatives can be prepared in good yields (up to 91% yield) and high enantioselectivities (up to 99% ee). Key to the success of switch of enantioselectivity is the existence of two different activation patterns in this palladium(II) catalytic system. Experiments demonstrated that a counteranion would plausibly coordinate to the palladium(II) center in the stereoselectivity-determining step. Preliminary mechanistic studies provide a rational explanation for the above observations. This study was the first example of monodentate ligand in asymmetric catalytic Friedel-Crafts alkylation.
研究领域:
不对称催化
·
有机合成
·
配位化学
·
对映选择性化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Longfei Wang,Yuanjun Tang,Guoneng Li,Jun Dong,Yao Fang,Wenwen Guo,Chao Ye
This study systematically investigates the effects of Fe-loading on the pyrolysis behavior of three key biomass components: cellulose , xylan , and lignin . Complementary analytical techniques, thermogravimetric analysis (TGA), thermogravimetry-mass spectrometry (TG-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), were utilized to assess the impact of Fe-loading on: ( i ) pyrolysis characteristics, ( ii ) the combined pyrolysis index ( CPI ), ( iii ) small-molecule gas evolution, and ( iv ) tar product distribution. Results demonstrate that the loading of Fe(NO 3 ) 3 significantly reduced the initial pyrolysis temperatures of cellulose and xylan by ∼140 °C and ∼62 °C, respectively, resulting in 58 % and 37 % decreases in CPI values. Conversely, lignin exhibited a 111 % CPI increase under Fe loading conditions, attributable to accelerated aryl-ether bond cleavage. The presence of Fe enhanced CO 2 evolution while suppressing H 2 O and CO generation in cellulose / xylan conditions. In contrast, it promoted CH 4 , H 2 , CO, and CO 2 evolution during lignin pyrolysis. Py-GC/MS analysis indicated that the presence of Fe drives aromatization through deoxygenation pathways while inhibiting ring-opening depolymerization, consequently shifting tar composition toward higher-carbon-number aromatic hydrocarbons. The findings can serve as a valuable reference for the application and promotion of the high-value valorization of waste biomass.
研究领域:
生物能源
·
生物质转化
·
热化学
·
分析化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2016
·
IF 4.292
Shiyou Xing,Haoran Yuan,Huhetaoli,Yujie Qi,Pengmei Lv,Zhenhong Yuan,Yong Chen
Characterizing the pyrolysis of inorganic matter-rich biomass is important for the preparation of bio-fuel precursors. Here, thermogravimetric and pyrolysis gas chromatography/mass spectroscopy (Py-GC/MS) were employed to elucidate the specific pyrolysis mechanisms of demineralized wood dust (AWD) impregnated with varying amounts of the inorganic compounds, copper and potassium . During the pyrolysis process, there was a dramatic decomposition of hemicellulose (at 200–320°C) and of cellulose (at 320–420 °C), along with slow lignin degradation. The decomposition of hemicellulose was substantially promoted with an increasing amount of copper. In addition, a decreased amount of aldehydes and phenols was observed, indicating a lower level of cellulose and lignin degradation, which led to more generation of bio-fuel precursors (C 5 –C 16 ). In contrast to copper, potassium substantially promoted the decomposition of cellulose and lignin, but had negligible effect on hemicellulose. In the presence of both copper and potassium, the latter had a more dominant role causing an increased amount of small molecular compounds (C 2 –C 4, i.e., from 10.91% to 22.12%), and decreased amounts of bio-fuel precursors (i.e., from 62.19% to 52.49%). The various decomposition pathways that might be involved in the catalytic pyrolysis of wood using copper and potassium are discussed.
研究领域:
能源与燃料
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Biomaterials Science
·
2021
·Vol. 9
·期 21
·7065-7075
·
IF 6.843
Xin Wang,Bingqing Deng,Meng Yu,Tao Zeng,Yuyu Chen,Jianqiang Hu,Qianqing Wu,Aiqing Li
Drug delivery nanoplatforms have been applied in bioimaging, medical diagnosis, drug delivery and medical therapy. However, insolubility, toxicity, instability, nonspecific targeting and short retention of many hydrophobic drugs limit their extensive applications. Herein, we have constructed a passive targeting and long retention therapeutic nanoplatform of core–shell gefitinib/poly (ethylene glycol)-polytyrosine nanocomplexes (Gef-PY NCs). The Gef-PY NCs have good water-solubility, non-toxicity (correspond to 1/10 dosage of effective gefitinib (hydrochloride) (Gef·HCl) (normal drug administration and slow-release) and high stability (120 days, 80% drug retention at 4 or 25 °C). The core–shell Gef-PY NCs present unexpected kidney targeting and drug slow-release capacity (ca. 72 h). The good water-solubility, non-toxicity and high stability of Gef-PY NCs effectively solve the bottleneck question that Gef-based therapy could be used only in intraperitoneal injection due to its insolubility and severe toxicity. Such excellent properties (e.g., water-solubility, non-toxicity, high stability, kidney targeting and long retention) of Gef-PY NCs create their prominent anti-fibrosis capabilities, such as decreasing approximately 40% tubulointerstitial fibrosis area and 68% expression of collagen I within 7 days. This therapeutic efficacy is well-matched with that of 10 times the dosage of toxic Gef·HCl. It is very hopeful that Gef-PY NCs could realize clinical applications and such a strategy offers an effective route to design high-efficiency treatments for kidney- and tumor-related diseases.
研究领域:
药学
·
纳米技术
·
治疗学
✓ 已验证
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Xiaona Lin,Lingshuai Kong,Hongzhen Cai,Qingfa Zhang,Dongmei Bi,Weiming Yi
The effects of the type and content of alkali/alkaline earth metals (AAEMs) on the co-pyrolysis of cellulose/high density polyethylene (HDPE) were studied using TGA and Py-GC/MS. AAEMs showed different effects on the decomposition characteristics of cellulose/HDPE mixtures. During cellulose/HDPE co-pyrolysis, AAEMs present in char could act as a base catalyst, with different catalytic effect on products distribution depending on the types of AAEMs. Na showed stronger catalytic cracking effect to promote alkenes formation compared to the use of K, Ca, and Mg. The comparison of experimental and calculated products distributions of raw cellulose/HDPE confirmed the existence of synergistic effect , which facilitated the cleavage of glycosidic linkages to form anhydrosugars and promoted the scission of HDPE chains to produce hydrocarbons. The effect of potassium on this synergy was also investigated. With increased potassium content, the yields of anhydrosugars and hydrocarbons decreased while the yields of furans and ketones increased, suggesting that potassium inhibited the cleavage of glycosidic bonds and promoted ring-opening reactions. This indicated that addition of potassium inhibited the synergy between cellulose and HDPE.
研究领域:
能源与燃料
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2020
·
IF 6.785
Bo Wang,Shuai Zheng,Yan Huang,Ying Wang,Zhenyu Zhu,Ran Ma,Yu Zhao,Xijie Yin,Jing Su,Juan Xiong,Benli Zhang,Youping Zhou
The 18O/16O (and 15N/14N) ratio of natural nitrate (NO3–) and nitrite (NO2–) can be used to extract valuable information about their source and fate as environmental contaminants, their metabolism as macronutrients in plants and animals, and their behavior in the N biogeochemical cycle. We developed an accurate, precise, sensitive (minimum sample size: 0.2 μg NO3–-equivalent), and reliable (minimal oxygen exchange, loss, or gain) method to selectively isolate and purify nitrate and nitrite from natural water, soil, air, and plant materials by strong anion exchange (SAX) for low- to normal-salinity samples or strong cation exchange (SCX) for high-salinity samples, followed by quantitative conversion to their respective benzyl esters, which can be separated and individually analyzed for δ18O (and potentially δ15N) by gas chromatography (GC)/pyrolysis/GC/isotope-ratio mass spectrometry (IRMS). The method compares favorably with the currently popular bacterial denitrification and chemical reduction methods, in terms of sensitivity and reliability, and has the potential to simultaneously measure δ15N and δ18O of nitrate and nitrite from natural samples of various origins.
研究领域:
环境科学
·
生物地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）