ChemSusChem
·
2021
·Vol. 14
·期 19
·4242-4250
·
IF 8.928
Shenglu Lu,Yaxuan Jing,Bo Feng,Yong Guo,Xiaohui Liu,Yanqin Wang
Graphical Hidden hydrogen : Polyethylene terephthalate (PET) is the most widely used synthetic polyester, and its degradation is increasingly recognized as essential to develop the future provision of energy and reduce environmental pollution. Reported herein is a salient example of H 2 -free conversion of PET back to BTX stream with alkyl aromatics as the main products by unlocking hidden hydrogen in the structural ethylene glycol part in a selective manner. The strong desire for a circular economy makes obtaining fuels and chemicals via plastic degradation an important research topic in the 21st century. Here, the first example of the H 2 -free polyethylene terephthalate (PET) conversion to BTX (benzene, toluene and xylene) was achieved by unlocking hidden hydrogen in the ethylene glycol part over Ru/Nb 2 O 5 catalyst. Among the whole process (hydrolysis, reforming and hydrogenolysis/decarboxylation), the parallel hydrogenolysis and decarboxylation were competing and the rate-determining step. Ru/Nb 2 O 5 exhibited superior hydrogenolysis and poorer decarboxylation performance in direct comparison with Ru/NiAl 2 O 4 , accordingly contributing to the distinct selectivity to alkyl aromatics among BTX. Ru species on Nb 2 O 5 , unlike those on NiAl 2 O 4 , showed more Ru δ + species owing to the strong interaction between Ru and Nb 2 O 5 , restricting the undesired decarboxylation. Along with NbO x species for C−O bond activation, excellent reactivity towards the H 2 -free conversion of PET back to BTX with alkyl aromatics as dominant species was achieved. This H 2 -free system was also capable of converting common real PET plastics back to BTX, adding new options in the circular economy of PET.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Xinxing Zhang,Qingyin Wang,Shaoying Liu,Lilei Zhang,Gongying Wang
A new Schiff base flame retardant monomer with nitro group ( NO 2 ), 5-((4-nitrobenzylidene) amino) isophthalic acid (NBA) was firstly synthesized to prepare fire-safety PET copolyester (NBA n PET). The group of NO 2 passivated the cross-linking reactivity of Schiff Base by affecting the formation of the intermediate states of the cross-linking reaction and further to improve the cross-linking temperature of NBA n PET to the temperature range (347–372 °C) from that of (250–348 °C), which showed better machinability in a broad processing temperature zone. In additional findings, the new synthesized NBA Schiff Base helped to shorten the time of polycondensation of PET with the advantage to save 58% of the reaction time by its acid structure. And the group of NO 2 enhanced the thermal stability of NBA n PETs, which improved its residue char in high temperature to enhance its flame retardancy. NBA 10 PET with NBA (7.9 mol%) processed LOI of 32% and V-0 of UL-94 without drip. The analysis of mechanism showed that the group of NO 2 in NBA did not decompose into the gas phase and NBA performed the mechanism of condensed phase during combustion of Schiff Base modified PET. The newly prepared NBA n PET with these better properties could possess wider application prospects.
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2023
·Vol. 13
·期 20
·5868-5879
·
IF 5
Guixiang Peng,Xueyang Qi,Wenbin Qu,Xiaoli Shao,Lixin Song,Pingfan Du,Jie Xiong
As a new type of pollutant, microplastics, especially microfibers in textiles, pose a great threat to the environment and human health. It remains challenging to remove such emerging organic pollutants. Photocatalytic technology is an effective strategy for H2 fuel production and pollutant reuse using solar energy due to its low cost and environmental friendliness. In this work, the flexible Ni5P4/TiO2/C nanofiber (NF) film photocatalysts were fabricated by electrospinning, hydrothermal treatment and low-temperature phosphating. With the addition of Ni5P4 onto TiO2/C NFs, the light absorption of composite nanofibers was improved, restraining the recombination of carriers simultaneously. Accordingly, the photocatalytic activity of the NFs was improved. The hydrogen evolution of the Ni5P4/TiO2/C NFs for photocatalytic degradation of PET microfibers reached 76.66 μmolH2 gsub−1 in 12 h, which is three times that of TiO2/C NFs. The weight loss rate of PET microfibers reached 6.23% after Ni5P4/TiO2/C NF catalysis, which was nearly 5 times higher than that without a catalyst (1.2%). In addition, the nanofiber film is easy to recycle and avoids secondary pollution. This work provides new ideas for achieving the goal of reducing microplastic fibers and microplastics in an efficient and environmentally friendly way.
✓ 已验证
产品关联
DOI
高影响因子
Regenerative Biomaterials
·
2023
·
IF 6.7
Chen Qin,Fu Xiaomin,Cai Huawei,Fu Shengxiang,Cai Zhongyuan,Li Mufeng,Wu Xiaoai,Tian Rong,Ai Hua
Precise diagnosis of lymph node metastasis is important for therapeutic regimen planning, prognosis analysis and probably better outcomes for cancer patients. In this work, 68Ga-labeled amphiphilic alternating copolymers nanoparticles with different rigid ligands were synthesized as positron emission tomography (PET) probes for lymph node metastasis imaging. The labeling efficiency and stability of nanoparticles was improved with increased rigidity of coordination unit. PU(68Ga-L-MDI-PEG) nanoparticles (PU(68Ga-L-MDI-PEG) NPs) with the strongest rigidity of coordination unit exhibited the lowest critical micelle concentration, the best 68Ga labeling efficiency and stability. During in vivo lymph node metastasis imaging, PU(68Ga-L-MDI-PEG) NPs led to different accumulations in normal lymph nodes (N-LN) and tumor metastasized sentinel lymph nodes (T-SLN), which resulted in different PET signal presentation, making it feasible to differentiate N-LN from T-SLN. In comparison, small molecule probe 68GaL had poor lymph node accumulation, not only making it difficult to find lymph nodes on PET/computed tomography scan, but also tough to distinguish N-LN from metastatic ones. Overall, this work provides a reference for design of 68Ga labeled polymeric nanoparticles with high chelation efficiency and stability, as sensitive PET probes for lymph node imaging.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 7
·1713
·
IF 5
Bo Xu,Shouao Zhu,Siheng Zhao,Xiangdong Wang
A high-phosphorus-content polyphosphonate (PBDA), containing two phosphorus-based structures: phosphaphenanthrene (DOPO) and phenyl phosphonate groups, was synthesized and used in flame retardant polyethylene terephthalate (PET). Good self-extinguishing property (high UL 94 grade and LOI value), superior flame retardancy (lower heat/smoke release), and high quality retention (high carbon residue) were endowed to PET by PBDA. When 10 wt% PDBA was added, the peak heat release rate (pHRR), total heat release (THR), and total smoke rate (TSR) of PDBA/PET were found to be significantly reduced by 80%, 60.5%, and 21%, respectively, compared to the pure PET, and the LOI value jumped from 20.5% for pure PET to 28.7% with a UL-94 V-0 rating. The flame-retardant mode of action in PET was verified by thermogravimetric analysis-Fourier transform infrared (TGA-FTIR), pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), real-time FTIR, and scanning electron microscopy (SEM). Phosphaphenanthrene and phosphonate moieties in PDBA decomposed in sequence during heating, continuously releasing and keeping high-content PO· and PO2· radicals with a quenching effect and simultaneously promoting the formation of viscous crosslinked char layers causing a high barrier effect. PDBA mainly acted in the gas phase but the condensed-phase flame retardant function was also considerable.Keywords:flame retardant;polyphosphonate;poly(ethylene terephthalate);high phosphorus content
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Yuhang Wu,Guocong Ma,Anying Zhang,Weiwen Gu,Jianfei Wei,Rui Wang
Environmentally friendly polyethylene terephthalate-based carbon dots (PET-CDs) with ultrahigh fluorescence quantum yield were prepared with waste PET textiles as raw materials. First, oligomers were prepared from the reaction of waste PET textile and ethylene glycol by the microwave method. Then, the mixture without isolation and purification as well as pyromellitic acid and urea were adopted as precursors for the preparation of PET-CDs by the hydrothermal method. It was found that the as-prepared PET-CDs had a spherical structure with an average particle size of 2.8 nm. The carbon core of PET-CDs was a graphene-like structure doped with nitrogen atoms in the form of pyrrole nitrogen and the surface contained −NH2, which is convenient for modification and functionalization with various materials in the form of chemical bonds. The as-prepared PET-CDs exhibit excitation-independent emission properties in the range from 340 to 440 nm, and the best excitation and emission wavelengths of PET-CDs are 406 and 485 nm, respectively, while the fluorescence quantum yield is 97.3%. In terms of the application, the as-prepared PET-CDs could be adopted as a fluorescence probe for the detection of Fe3+, and the limit of detection is as low as 0.2 μmol/L. The mechanism of PET-CDs by Fe3+ was found to be the static quenching mechanism. In addition, PET-CDs can be used in LEDs and fluorescent anticounterfeiting.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Zhiqiang Jiang,Dongxia Yan,Jiayu Xin,Fei Li,Mengquan Guo,Qing Zhou,Junli Xu,Yufeng Hu,Xingmei Lu
The methanolysis of polyethylene terephthalate (PET) was investigated using poly(ionic liquid)s (PILs) synthesized with 1-vinyl-3-ethylimidazole acetates ([VEIm]Ac) and acrylic acid metal salts, and the activities of the PILs were screened. The effects of reaction temperature, reaction time, methanol amount, catalyst amount and PET sources on the methanolysis of PET were investigated using the optimized catalyst PIL-Zn 2+ . Under the optimal conditions the conversion of PET was 100% and the yield of dimethyl terephthalate (DMT) was 89.1%. In addition, the catalyst has very good applicability for methanolysis of different PET raw materials. More importantly, the PIL-Zn 2+ catalyst could be recycled by simple filtration after the reaction, and could be reused six times without significant decrease in PET conversion and DMT yield. The catalysts were analyzed by TGA, FT-IR, XRD and ICP before and after recycling, the results showed no change in the structure of the catalyst, reflecting the good stability of the catalyst. The reaction kinetics of PIL-Zn 2+ was first-order with an activation energy of 107.6 kJ/mol. This work mainly provides a way to design efficient, stable and recyclable catalysts for PET methanolysis.
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2023
·
IF 3.8
Renwen Tian,Yan Sun
Extensive use of polyethylene terephthalate (PET) has brought about global environmental problems. A recently reported PET hydrolase (PETase) discovered from Ideonella sakaiensis showed high potential for degrading PET at moderate temperatures, but its activity and stability need further improvement for practical applications. Herein, we proposed to use α-synuclein (αS) as a fusion chaperone and created six PETase-αS fusion enzymes with linkers of different types and lengths. All the fusion enzymes exhibited improved enzymatic performance, presenting 1.5 to 2.6-fold higher activity towards bis-2(hydroxyethyl) terephthalate than PETase, as well as significantly increased stabilities. Fluorescence spectroscopy indicated that the chaperone fusion tightened the overall conformation and resulted in the opening of the substrate binding pocket, which led to the improved thermal stability and catalytic activity of the fusion enzymes. Remarkably, one of the fusion proteins, PETase-[(GS)(EK)] 10 -αS, showed 3.2 to 5.1 times higher PET degradation capability than PETase. The significantly boosted PET degradation performance was not only attributed to the enhanced enzymatic activity and stability, but also possibly due to the binding affinity of the fused αS domain for PET. These findings demonstrated that αS was an effective fusion chaperone for significantly enhancing the enzymatic performance of PETase.
✓ 已验证
产品关联
DOI
高影响因子
Coatings
·
2021
·Vol. 11
·期 12
·1451
·
IF 2.881
Wen Zhong,Xiaobin Yang,Jikun Sun,Hongwei Gao,Yongping Bai,Lu Shao
Polymeric barrier materials are critical in contemporary industries for food, medicine, and chemical packaging. However, these materials, such as PET films, are impeded by the optimization of barrier properties by virtue of molecular design. Herein, a new methyl methacrylate-methyl acrylate-diallyl maleate-maleic acid (MMA-MAc-DAM-MA) was synthesized to tailor the surface properties of PET films for maximizing oxygen barrier properties. During the MMA-MAc-DAM-MA coating and curing process, the chemical structure evolutions of MMA-MAc-DAM-MA coatings were characterized, indicating that the cross-linking conversion and proportion of –COOH groups are critical for the oxygen barrier properties of coatings. The inherent –COOH groups are transformed into designed structures, including intramolecular anhydride, inter-chain anhydride and retained carboxylic acid. Therein, the inter-chain anhydride restraining the activity of coated polymer chain mainly contributes to enhanced barrier properties. The thermal properties of novel coatings were analyzed, revealing that the curing behavior is strongly dependent on the curing temperatures. The impacts of viscosity of the coating solution, coating velocity, and coating thickness on the oxygen permeability (Po2) of the coatings were investigated using a gas permeability tester to explore the optimum operating parameters during practical applications, which can reduce thePo2of PET film by 47.8%. This work provides new insights on advanced coating materials for excellent barrier performance.Keywords:film;barrier property;surface modification;cross-linking;gas transport
✓ 已验证
产品关联
DOI
高影响因子
APPLIED RADIATION AND ISOTOPES
·
2012
·
IF 1.172
Zhen-feng Liu,Guo-lin Wang,Meng-jie Dong,Qian Zhang,Jia-jun Li,Kui Zhao,Shu-ye Yang,Xiang-tong Lin
10-[ 11 C]methoxy-20(S)-camptothecin was synthesized automatically. The radiochemical yield was 30%–50% (all calculated at EOB, n =20) with [ 11 C]methyl triflate as a methylating agent. The radiochemical purity was greater than 96%, and the specific activity was 8.72±2.18 GBq/μmoL at EOS . Biodistribution showed that 10-[ 11 C]methoxy-20(S)-camptothecin is characterized by quick clearance from the blood and by significant uptake in the liver (5.72±1.92% ID/g at 15 min), intestines (2.43±0.38% ID/g at 15 min), and kidney (1.57±0.85% ID/g at 15 min). Micro-PET imaging clearly showed high radioactivity accumulation in liver, intestines and bladder, indicating that the primary modes of excretion of the radiotracer are through the hepatobiliary system and, to a lesser extent, through the renal system.
研究领域:
药理学
·
核医学
·
肿瘤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2017
·
IF 2.536
Fenfen Zhou,Hongqing Wang,Pengying Liu,Qinghua Hu,Yuyuan Wang,Can Liu,Jiangke Hu
A reversible Schiff's base fluorescence probe for Al 3+ , (3,5-dichloro-2- hydroxybenzylidene) quinoline-2-carbohydrazide ( QC ), based on quinoline derivative has been designed, synthesized and evaluated. The QC exhibited a high sensitivity and selectivity toward Al 3+ in EtOH-H 2 O (v/v = 1:9, pH = 6) by forming a 1:1 complex with Al 3+ and the detection limit of QC for Al 3+ was as low as 0.012 μM. Furthermore, these results displayed that the binding of QC Al 3+ was broken by F − , so this system could be used to monitor F − in the future. The enhancement fluorescence of the QC could be attributed to the inhibition of PET and ESIPT and the emergency of CHEF process induced by Al 3+ . More importantly, QC was not only successfully used for the determination of trace Al 3+ in the tap water and the human blood serum, but was valid for fluorescence imaging of Al 3+ in the Hela cells.
研究领域:
分析化学
·
生物医学
✓ 已验证
DOI
PubMed
高影响因子
FIBERS AND POLYMERS
·
2025
·
IF 2.3
Zuo Hongmei,Du Yuting,Zhou Zihao,Xu Yaning,Shi Jie,Zou Lihua,Xie Yanxia
In order to develop elastomer composite with high thermal conductivity based on polyester (PET) fabric and further prolong the service life and improve service safety, modified PET fabric was prepared. Initially, different content of carbon black was added into butadiene latex and phenolic resin to prepare complex emulsion. Then, the emulsion was coated on the fabric by dipping and rolling technique. The results showed that carbon black possessed excellent stability and could be dispersed in butadiene latex uniformly. Meanwhile, the viscosity of the complex emulsion was low. The absolute value of zeta potential exhibited that carbon black could promote the reaction of complex emulsion. In addition, the tensile properties and thermal conductivity were both improved after adding carbon black. When adding 5.3 wt% carbon black, the tensile strength of carbon black modified emulsion film could reach 6.57 MPa and the thermal conductivity could reach 3.16W/(m∙K). As a result, the thermal conductivity of 5.3 wt% carbon black modified emulsion-coated PET composite reached 3.43 W/(m∙K), which was 38.31% higher than that of pure emulsion modified PET composite. The results showed that carbon black was an excellent and low-cost nano-filler, which could be used to improve the thermal conductivity of PET-related elastomer composite.
研究领域:
材料科学
·
纺织工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）