JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Yueping Liu,Suning Li,Yongcheng Yang,Yongxiang Liang,Fei Wang,Xuetong Li,Deng Zhao,Yanjun Lu,Hui Liu,Shuai Guo
The aim of this study is to investigate the role of different carbon-based structures on the pyrolysis pathway and gas product distribution of polypropylene (PP). Using in situ DRIFTS coupled with thermogravimetric mass spectrometry, this study investigated the synergistic mechanisms between polypropylene (PP) and common plastics and biomass at the molecular level. The following mechanisms were revealed: 1) Polyethylene erephthalate (PET) induces demethylation of PP through oxygenated fragments, which weakens the stability of its main chain and synergistically reduces the pyrolysis temperature. The high-temperature polyene structure of polyvinyl chloride (PVC) promotes further breakage of the PP main chain, synergistically driving the directional conversion of gas products to unsaturated hydrocarbons and chlorine-containing compounds. The phenyl groups in polystyrene (PS) trigger PP activation at low temperatures, improving the yield of toluene gas. 2) PP inhibits the decomposition of blended components through physical entanglement at low temperatures. At high temperatures, polyenes, phenyl groups and other cleavage products reorganize with PP hydroxyl fragments, promoting the enrichment of olefins, aromatics and chlorinated compounds. 3) In PP-biomass systems, it is hypothesized that the PP pyrolysis pathway is altered, enhancing the selectivity for short-chain hydrocarbons and monocyclic aromatics. This effect is likely mediated through ash-catalyzed reactions and induction by oxygen-containing fragments. This study employs in situ Fourier-transform infrared (FTIR) spectroscopy to monitor in real time the molecular-level evolution of PP-based mixed waste plastics and biomass pyrolysis, revealing fundamental carbon-chain structure-property relationships. These findings establish a mechanistic framework for the rational design of high-efficiency pyrolysis systems with precisely controlled product distributions through synergistic interactions.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Yu Sun,Mengyi Qing,Luxin Chen,Jun Liu,Fei Zhong,Ping Jiang,Guowei Wang,Linghua Zhuang
Two Brönsted acidic ionic liquids (1-methy-3-(3-sulfopropyl) imidazolium acetate, as mPSAc, and 1-butyl-3-(3-sulfopropyl) imidazolium acetate, as bPSAc) were synthesized for chitosan dissolution. Physical properties, including density, pH value, viscosity, Hammett acidity (H 0 ), and Kamlet-Taft parameters (β and π*) of Brönsted acidic ionic liquids (BAILs), were studied and analyzed. The dissolution performance and regeneration properties of chitosan in BAILs were studied and compared with other ordinary ionic liquids ([Emim]Cl, [Bmim]Cl, [Amim]Cl, [Emim]Ac, [Bmim]Ac, [Amim]Ac). 1% chitosan was dissolved in two BAIL aqueous solutions (5% w /w) at 30 °C (35 min and 37 min, respectively). The regenerated chitosan was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Molecular weight and deacetylation degree results showed that mPSAc endowed slight hydrolysis upon chitosan, only dissolution of chitosan at lower temperature. Density functional theory (DFT) simulations were performed to study the interactions between sulfopropyl imidazolium acidic ionic liquids and chitobiose. Four types of hydrogen bonds (C-H…O, O-H…O, N-H…S, N-H…O) and many strong hydrogen bonds were found in BAIL-chitobiose, suggesting strong interactions between BAILs and chitobiose. DFT simulation results indicated that the active hydrogen atom of imidazole ring, sulfonate ion and acetate ion played important roles in the chitosan dissolution process by the disruption of native hydrogen bonds of chitobiose.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2015
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IF 2.912
Xianghe Meng,Lei Li,Qin Ye,Frederik van de Voort
A primary Fourier transform infrared (FTIR) method capable of determining acidity in ester-based oils is described and evaluated. Absolute free fatty acid (%FFA) and acid value (AV) calibrations were devised by spiking oleic acid into a refined, acid-free oil and measuring νCOO– at ∼1569 and νphenolate– at ∼1588 cm–1, respectively, in the second-derivative differential spectra. The FTIR acidity predictions were compared to the AOCS titrimetric method using acid mixtures as well as acid containing used vendor oils of undefined makeup and provenance, using two spectroscopically divergent reference oils as AC0. Relative to the AOCS reference method, the FTIR procedure was found to be both more accurate (±0.107 vs ±0.122) and reproducible (±0.025 vs ± 0.077) in determining %FFA and similar in predicting AV. The FTIRphenolate method overcomes a variety of limitations of earlier FTIR-based methods, being particularly simple and well suited to routine, semiautomated acidity analysis of ester-based oils using a basic FTIR spectrometer.
研究领域:
分析化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2023
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IF 4.4
Gaoqiang Lv,Didi Shan,Yongge Ma,Wenya Zhang,Duobujie Ciren,Shuo Jiang,Bojun Dang,Jiashun Zhang,Weihong Sun,Hanping Mao
Pesticide residues on plant surfaces pose a severe threat to food security, yet most research has focused on monitoring the liquid matrix, with few reports conducting in-situ analysis of the residues. This study was the first to attempt to utilize portable attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) for in-situ characterization of broad-spectrum fungicide boscalid residues on plant surfaces. ATR-FTIR scanning of tomato fruits with pre-determined concentrations of boscalid residues was conducted without any pre-treatment, and the obtained spectra were then processed using chemometrics methods. The results demonstrated a negative correlation between the residual concentrations and their corresponding absorption intensities of several well-resolved peaks from the spectra, resulting in a high accuracy of 93.33% for the classification model created by probabilistic neural network (PNN) coupled with principal component analysis (PCA). By employing correlation analysis and the interval partial least squares method (iPLS), quantitative analysis was conducted on the wavenumber ranges of 1000–1800 cm −1 and 2700–2900 cm −1 from the spectra. The regression model, established through partial least squares regression (PLSR), demonstrated exceptional performance with an R 2 value of 0.80, RMSE of 1.02 μg/cm 2 , RPD of 2.0, and RPIQ of 2.1 for validation. Meanwhile, the detection limit (LOD) of the model was calculated as 3.06 μg/cm 2 . This report highlights the potential of using portable ATR-FTIR for conducting qualitative and quantitative monitoring of pesticide residues both in-situ and on-site. It also provides references for other measuring techniques.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
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2020
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IF 4.032
Menghao Chen,Bo Liang,Yuhang Guo,Chengfeng Li,Xian He,Jianghuai Hu,Renke Li,Ke Zeng,Gang Yang
The pyrolysis mechanism and pyrolysis behavior of adenine-containing polyimide (API) were studied by thermogravimetric analyzer with Fourier transform infrared analysis and mass spectrometry (TG-FTIR-MS) and pyrolysis-gas chromatography-mass spectroscopy (Py-GC-MS). TG-FTIR-MS and Py-GC-MS were employed to continuously track the release of volatile products during the pyrolysis process. Thermogravimetric analysis (TG) indicated that API presented outstanding thermal stability. Additionally, it was observed that the volatile products were formed during the pyrolysis of API, including CO 2 , CO, HCN, benzonitrile , aniline and phenyl isocyanate . A probable pyrolysis mechanism of the API has been proposed according to the results of TG-FTIR-MS and Py-GC-MS.
研究领域:
材料科学
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化学工程
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生物分子化学
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DOI
高影响因子
SPECTROSCOPY LETTERS
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2019
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IF 1.081
Jing-Wen Hao,Nai-Dong Chen,Xu-Cheng Fu,Jian Zhang
An attenuated total reflectance Fourier transform infrared spectroscopy method combined with partial least square regression was established to rapidly quantify the total polysaccharide and its major monosugars in Dendrobium huoshanense. The results showed that the optimal predictive methods were the models established by the infrared spectroscopy files pretreated by standard normal transformation combined with the second derivative; the accuracy of the models selecting wavelength regions based on the assignments of Fourier transform infrared spectroscopy signals of polysaccharide was obviously higher than the models selecting wavelength regions suggested by Thermofisher Quantity Analyst software and other possible wavelength region selecting modes. The external validation and the complete external validation confirmed the robustness and reliability of the developed attenuated total reflectance Fourier transform infrared model. Our study might provide an efficient technique tool for the rapid, green, low-cost, and nondestructive quantification of the total polysaccharide and the main monosaccharides in Dendrobium huoshanense and other rich-in-polysaccharide plant food or medicines.
研究领域:
植物学
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分析化学
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药学
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DOI
高影响因子
POLYMER INTERNATIONAL
·
2014
·Vol. 63
·期 7
·1154-1158
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IF 2.247
Longqiang Xiao,Yan Li,Xiangxiang Jia,Liqiong Liao,Lijian Liu
The present contribution describes an innovation in the copolymerization of cyclic monomers, ε -caprolactam ( ε -CL) and 2,2-dimethyltrimethylene carbonate (DTC), with ethyl diazoacetate (EDA). The characterizations of the obtained copolymers, poly(EA- ran -EDA- ran-ε -CL) and poly(EA- ran -EDA- ran -DTC) (where EA refers to the ethyl acetate group from EDA after nitrogen release), were performed using 1 H NMR and 13 C NMR spectroscopies and size exclusion chromatography. Under optimized conditions, the copolymer of ε -CL with EDA possessing a number-average molar mass ( M n ) of 1300 g mol −1 and dispersity of 2.12 as well as that of DTC with EDA with M n of 8000 g mol −1 and dispersity of 1.47 were obtained. The incorporation of the azo group in the obtained copolymers was determined from the results of elemental analysis (3.30–10.22% nitrogen) and Fourier transform infrared spectroscopy. Furthermore, the thermal properties of the obtained copolymers were examined using differential scanning calorimetry. X-ray diffraction results showed that the synthesized copolymers were amorphous. © 2014 Society of Chemical Industry
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2014
·Vol. 131
·期 15
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IF 1.64
Hangjun Deng,Zhongquan Shen,Lifeng Li,Hong Yin,Jizhong Chen
The polymerization of tetrahydrofuran (THF) was carried out in CH 2 Cl 2 by using phosphotungstic heteropolyacid as initiator and epichlorohydrin as promoter. This cationic ring-opening polymerization process was monitored by in situ mid-infrared spectroscopy system (ReactIR) to further study the thermodynamics and kinetics of THF polymerization. It was observed that the sharp infrared peak of C O C stretching vibrations will shift from about 1068 to 1109 cm −1 in THF ring-opening step. The changes in absorbance intensity of the two characteristic peaks were used for determining instantaneous concentration of linear polymer and ring monomer. The experimental results demonstrated that the kinetics of THF polymerization proved to be typically first-order. Thermodynamic parameters were determined from the temperature dependence of the monomer equilibrium concentration [M] e over the range from −5 to 25°C. The values of k app were obtained via the plots of ln{([M] 0 −[M] e )/([M] t −[M] e )} vs reaction time, for polymerization under specific conditions. The apparent activation energy ( E a ) and frequency ( A ) were determined from the Arrhenius plot of k app vs. T −1 . Besides, the in situ kinetic investigation revealed that more chain-transfer occurred at higher temperatures, leading to a reduction in propagation species concentration and a deviation from first-order propagation at the later stage of polymerization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40503.
研究领域:
高分子化学
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物理化学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 2
·1884-1897
·
IF 2.993
Xu Fang,Zhong Ling,Xu Yuan,Feng Shaoyang,Zhang Cheng,Zhang Fengxiu,Zhang Guangxian
The flame resistance of kraft paper was greatly modified by an eco-friendly, phosphorus-containing and reactive flame retardant, ammonium phosphite, which was grafted on kraft paper via pad-bake method. The results showed that the limiting oxygen index of treated kraft paper could increase from 19.1 to 48.2%. The results of vertical flammability tests imply that the char length of treated sample decreased from 210 to 45 mm. Thermogravimetry analysis showed that treated kraft paper had the lower initial decomposition temperature and more residues than control sample. Thermogravimetry analysis/infrared spectrometry indicated that the flammable volatile species of treated kraft paper reduced obviously compared with that of control sample. Fourier transform infrared spectroscopy suggested that ammonium phosphite was grafted on the cellulose molecules by P–O–C covalent bonds and the flame retardant is reactive in condensed phase. Scanning electron microscopy showed that the modification had little effect on the surface of kraft paper and the residual carbonized frame of treated kraft paper retained the fiber shape after combustion. EDX results showed that the flame retardant introduced a large amount of phosphorus and nitrogen into kraft paper. X-ray diffraction indicated that the modification did not significantly affect the crystal structure of kraft paper. And the strength of kraft papers slightly declined after the modification, but it still remained well.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF CULTURAL HERITAGE
·
2025
·
IF 3.3
Mingrui Zhang,Zonghuan Ba,Jie Liu,Yong Lei,Mǎdǎlina Georgiana Albu Kaya,Keyong Tang
Due to the variations in deterioration and the diversity of tanning processes, the identification of leather artifacts is a challenge. In the present work, a non-destructive and rapid identification method is provided by combining Fourier transform infrared spectroscopy (FTIR) with principal component analysis (PCA). By analyzing a total of 4 types, encompassing with 30 model sets, this method has been proven effective in eliminating interference related to the deterioration and overcoming key obstacles in identifying the leather manufacturing process of the leather artifacts. Two pieces of leather artifacts representing different periods, regions, and animal types were studied using the proposed method. Further high-performance liquid chromatography (HPLC) was performed to verify the identification results and method accuracy. In addition, by evaluating against the models, the alkaline treated sample showed higher reliability compared to the acid treated one. This method effectively addressed the challenges in accurately identifying the leather tanning processes and demonstrated the importance of analyzing and conserving a wider range collagen-based artifacts.
研究领域:
文物保护
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化学分析
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材料科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Bingqiao Yang,Mengyuan Zeng,Huanyu Zhu,Pengliang Huang,Zhili Li,Shaoxian Song
The effective separation of molybdenite from chalcopyrite is a challenging job. In this work, an environmental-friendly reagent pectin was investigated as a novel molybdenite depressant in the flotation separation of Cu-Mo sulfides. The micro-flotation results indicated that pectin selectively depressed molybdenite, and satisfactory separation results were achieved using sodium butyl xanthate (SBX) as collector even in the presence of kerosene. The addition sequence of pectin and kerosene influenced the depression of molybdenite significantly but hardly affected the flotation of chalcopyrite. The pre-adsorption of kerosene prior to pectin on molybdenite surface slightly attenuated the depression effect, while the pre-adsorption of pectin before kerosene moderately diminished the depression effect. Zeta potential , contact angle and Fourier Transform Infrared Spectroscopy (FTIR) suggested that pectin was adsorbed on molybdenite and chalcopyrite surface mainly through hydrophobic interaction and electrostatic attraction, respectively. SBX replaced the adsorbed pectin from chalcopyrite surface and restored its hydrophobicity . However, SBX hardly adsorbed on pectin treated molybdenite and molybdenite surface maintained hydrophilic.
研究领域:
矿物加工工程
·
环境科学
·
表面化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2015
·
IF 2.858
Wei Liu,Jinnan Xu,Rui Zhu,Yiqing Zhu,Yang Zhao,Pei Chen,Chun Pan,Wenbing Yao,Xiangdong Gao
Techniques including ultraviolet–visible spectra (UV), high performance size-exclusion chromatography (HPSEC), Fourier-transform infrared spectroscopy (FT-IR) and pre-column derivatization high-performance liquid chromatography (PCD-HPLC) were used in the fingerprinting analysis of Lycium barbarum polysaccharides (LBPs) from different locations and varieties. Multiple fingerprinting profiles were used to evaluate the similarity and classification of different LBPs with the help of chemometrics. The results indicated that sixteen batches of LBPs had good consistency, and fingerprinting techniques were simple and robust for quality control of LBPs as well as related products. In addition, fingerprinting techniques combined with chemometrics could also be used to identify different cultivation locations of LBPs samples. Finally, four monosaccharides (galacturonic acid, glucose, galactose and arabinose) and the absorptions of stretching vibration of ester carbonyl groups as well as N H variable angle vibration of CONH could be selected as herbal markers to distinguish different samples.
研究领域:
植物学
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）