JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Chao Fan,Kaijun Quan,Jia Chen,Hongdeng Qiu
Three reversed-phase liquid chromatography (RPLC) stationary phases were obtained by using long-chain 1-octadecene (OD) co-grafted with three short-chain monomers, including N-vinylpyrrolidone (NVP), 1-vinylimidazole (VIm) and 4-vinylpyridine (VPy), respectively (noted as Sil@ODNVP, Sil@ODVIm and Sil@ODVPy). Peak broadening phenomenon in RPLC mode which resulted by short-chain was examined carefully. Compared with Sil@ODNVP, both of Sil@ODVIm and Sil@ODVPy had smaller peak width and higher column efficiency in the separation of 10 polycyclic aromatic hydrocarbons (PAHs), 7 alkyl benzenes, 7 aromatic acids, 7 aromatic esters and 9 phenols. In addition, VPy has the strongest ion exchange capacity than other two short-chains. In this case, we can see that VPy and VIm maybe more suitable to be used as functional monomeric modifiers of new chromatographic stationary phases.
研究领域:
分析化学
·
色谱技术
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Yun-Jiao Ma,Xiao-Yuan Wang,Bei-Wei Zhu,Ming Du,Liang Dong,Xiu-Ping Dong,Xian-Bing Xu
Vinylpyrazine compounds are widely present in foods , especially in hot-processed foods, as a class of flavor compounds ; however, their formation mechanism in food systems is still unclear. Therefore, in this study, 2-vinylpyrazine and 2-vinyl-6-methylpyrazine were identified in the Maillard model reaction of d -glucose and glycine. The Maillard model reaction of glucose–glycine was constructed to explore the effects of reaction parameters on vinylpyrazines and the related products. The Maillard reaction of [U- 13 C 6 ] glucose and glycine was established, and alkylpyrazines and formaldehyde were determined via isotope tracing technique as the precursors of vinylpyrazines. The formation of vinylpyrazines was verified by building a model reaction between alkylpyrazines and formaldehyde. The H/D exchange experiment confirmed that the active site of alkylpyrazines was on the methyl group , which was the reaction site for the condensation reaction of alkylpyrazines with formaldehyde. Results suggest that vinylpyrazines are formed by the condensation reaction of alkylpyrazines and formaldehyde.
研究领域:
食品科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 8
·49872
·
IF 2.52
Wanjie Luo,Lulu Wang,Ruijiang Feng,Chongfeng Zhao,Jilin Wang,Tianzhou Cai
A series of composite anion exchange membranes was synthesized via in-situ copolymerization of various ratios N-vinyl formamide (NVF) and divinylbenzene (DVB), supported by porous polytetrafluoroethylene (PTFE) polymer matrix, and followed by alkaline hydrolysis, and quaternization of the composite membranes with epoxypropyltrimethylammonium chloride (EPTMAC). FTIR and SEM analyses revealed that the composite membranes were successfully prepared. Moreover, the hydrophilic property of the composite membrane improved by introduction of the quaternized poly(NVF-co-DVB) copolymer. Water uptake, swelling ratio, and conductivity showed upward trends by increase of NVF amount. The copolymer with 95% of NVF showed the highest elongation at break (102%, room temperature) and conductivity (5.15 × 10 −2 S/cm, 80°C). After immersion of the PNDB 95% -N membrane in 5 mol/L NaOH solution for 96 h at room temperature, the conductivity (60°C) of the membrane decreased to 3.99 × 10 −2 S/cm. Moreover, the membrane registered weight loss under 4.5%, caused by degradation of the quaternary ammonium groups in NaOH solution. All in all, in 3 mol/L methanol solutions, the composite membranes showed permeability ranging from 7.6% to 19.7%, if compared to the Nafion®-115 membrane, showing good alcohol resistance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Yuqing Li,Sha Liu,Qiaoyan Zhang,Wan Gong,Hua Yin,Bo Yang,Luping Qin,Qiming Zhao,Yan Zhu
Novel poly(ethylvinylbenzene-divinylbenzene) (EVB-DVB) agglomerated with ultrasmall carbonaceous spheres (UCSs) anion-exchange packings for ion chromatography (IC) were constructed. Hydrophilic UCSs with mean sizes of 62–98 nm were synthesized in quantity by the polydiallyl dimethyl ammonium chloride aided hydrothermal carbonization of fructose. The green strategy based on the thiol-ene click reaction with cysteamine in aqueous system was first designed for the hyperbranched polyquaternary amine (HPA) grafting of UCSs with negligible damage on their monodispersity. The HPA modified UCSs were evenly distributed on sulfonated EVB-DVB substrate to form one uniform layer of functional nanospheres without observable coagulum. Seven typical anions ( F − , Cl − , NO 2 − , Br − , NO 3 − , SO 4 2- and PO 4 3− ) were baseline separated on constructed packing in 5 min with high efficiencies in the range of 44,800–71,100 plates m − 1 . The rapid separation of polarizable anions, small organic acids and saccharides could be also accomplished under isocratic elution with competitive peak symmetry and efficiency. Good reproducibility was demonstrated by consecutive injection. Thiosulfate in water reducer was further detected on prepared packing in 4 min with detection limit of 0.04 mg L − 1 (S/ N = 3) and good repeatability.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Yichang Ma,Jianxian Zeng,Yajie Zeng,Hu Zhou,Guoqing Liu,Yuan Liu,Lingwei Zeng,Jian Jian,Zhengqiu Yuan
In order to separate palladium (II) from electroplating wastewaters, poly(4-vinylpyridine)-b-polysulfone-b-poly(4-vinylpyridine) (P4VP-PSF-P4VP) / polysulfone blend membranes were fabricated by combining non-solvent induced phase separation, surface segregation and self-assembly of block copolymer . Amphiphilic P4VP-PSF-P4VP was used as the membrane base material, which was synthesized by introducing the functional monomer of 4-vinylpyridine (4-VP), and polysulfone as the additive. Effects of blend ratio and 4-VP content on membrane performance, such as structure, hydrophilicity, pure water flux and adsorption capacity towards Pd (II), were investigated. The membranes exhibited dense surface structure and low roughness due to surface segregation and self-assembly of P4VP-PSF-P4VP. The presence of 4-VP increased hydrophilicity and water flux of membrane, and it also provided good adsorption capacity towards Pd (II) (up to 103.1 ± 5.15 mg/g). Further, the membrane was used to separate Pd (II) from simulated wastewaters during filtration. It showed good rejection ability and high selectivity towards Pd (II) in co-existence of Cu (II) and Ni (II), and selectivity coefficients of Pd/Cu and Pd/Ni are 41.9 ± 1.88 and 97.8 ± 4.32, respectively. In filtration process of actual electroplating wastewater, the membrane also exhibited excellent rejection performance (Pd (II) rejection reached up to 96.8 ± 2.71%). Perhaps it is suitable for future practice applications.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2023
·Vol. 136
·期 2
·771-786
·
IF 1.8
Su Haitang,Yang Zhixiu,Xiao Guomin,Gao Lijing,Wei Ruiping,Zhang Jin
A series of cost-effective (X) K 2 CO 3 /γAl 2 O 3 catalysts for efficient conversion of vinyltrimethoxysilane (VTMOS) to vinyltris(β-methoxyethoxy)silane (VTMOEOS) were synthesized. The microstructure and active site of the synthesized catalysts were analyzed by BET, XRD, FT-IR, SEM, and CO 2 -TPD. The results showed that the synthesized catalysts formed K–O–Al strong basic sites while maintaining the original structure, which greatly improved the basic strength of the catalysts. It was found that the 60%K 2 CO 3 /γAl 2 O 3 possessed the highest the catalytic activity under the activation temperature of 600 °C by optimizing the preparation conditions of K 2 CO 3 /γAl 2 O 3 . Moreover, the optimal reaction process conditions were also determined by optimizing the experimental reaction temperature, reaction time, catalyst dosage, and reactant molar ratio under (60%, 600 °C) K 2 CO 3 /γAl 2 O 3 catalysis. Under the optimal reaction conditions, the conversion of VTMOS was 92.5% and the yield of VTMOEOS was 65%. Meanwhile, the 60%K 2 CO 3 /γAl 2 O 3 catalyst was satisfactorily reusable and maintained a high catalytic activity after four cycles of catalytic reactions.
研究领域:
材料化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Jintao Li,Mingzu Zhang,Jinlin He,Peihong Ni
Deep eutectic solvent (DES) represents a kind of eutectic mixture made of two or more substances in a certain ratio with a melting point lower than that of either individual component. As a typical green solvent, DES has been used in polymerization reactions such as condensation polymerization, free radical polymerization, electrochemical polymerization, ring-opening polymerization and oxidative polymerization, but little research has been reported in anionic polymerization. In this work, we explored the anionic homopolymerization, random and block copolymerizations of several vinyl monomers in DES, including styrene (St) and its derivatives (ClSt, MeOSt), isoprene (Ip), and 2-vinylpyridine (2VP). The microstructures and molecular weights of (co)polymers were characterized by nuclear magnetic resonance ( 1 H NMR, 13 C NMR), Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), while the thermal properties of the copolymers were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results showed that the polymerization products with certain molecular weights, favorable yield and molecular weight distribution could be prepared in DES. In addition, the experimental results indicated that DES can be recycled for polymerization and has little effect on the final product. The anionic polymerization with DES as the reaction medium exhibits mild reaction conditions, which reduces the operational difficulty of traditional anionic polymerization and broadens the application scope of active organolithium reagents.
研究领域:
高分子科学
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 31
·8066-8073
·
IF 4.696
Shunyu Jin,Yan Tian,Fei Liu,Jun Chen,Shaozhi Deng,Ningsheng Xu
Although 9,10-bis(4-(1,2,2-triphenylvinyl)styryl)anthracene (TPE-An) with excellent aggregation-induced emission (AIE) properties can effectively enhance the luminescence efficiency of light-emitting materials, the practical TPE-An-emitting electroluminescent (EL) devices have not been successfully fabricated until now. In our paper, the energy-band diagram of TPE-An is determined by the combination of ultraviolet-visible (UV-Vis) spectroscopy and cyclic voltammetry (CV) techniques. Subsequently, the space-charge-limited-current (SCLC) method is firstly used to obtain the hole mobility of TPE-An and design a better EL device structure. By calculation, the maximum hole mobility of the 50 nm TPE-An film can arrive at 4.00 × 10−4 cm2 V−1 s−1 at 0.1 MV cm−1 field. Finally, TPE-An-emitting EL devices have been, respectively, fabricated on glass and flexible PET substrates. Both of these two EL devices exhibit an intense green-light emission at 515 nm. Moreover, the maximum luminance of the EL device on glass can reach 24721.8 cd m−2 at 10.0 V, and its maximum current efficiency is as high as 14.7 cd A−1 at 131.6 mA cm−2. It is noted that the flexible EL device on the PET substrate maintains a stable emission and nice working performance even if the bending angles arrive at 140°. Therefore, it suggests that TPE-An should have a promising future in EL device applications.
研究领域:
材料科学
·
光学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
RADIATION PHYSICS AND CHEMISTRY
·
2022
·
IF 2.776
Wenchao Zhao,Zhen Dong,Long Zhao
In this report, the cross-linked Vinyl-POSS gel (CVPG) polymer was firstly synthesized through a facile one-step ionizing radiation method. The structure and composition of the CVPG were characterized, and the results indicated that the CVPG contained a certain amount of unreacted vinyl group which can be further functionalization to tune the properties and expand the application range of the gel polymer.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 11
·1564-1574
·
IF 1.42
Li Ming,Zhang Li-fen,Tao Mei-xia,Cheng Zhen-ping,Zhu Xiu-lin
In this work, a fluorescent monomer 2-(9-carbazolyl) ethyl vinyl ether (CEVE) was synthesized in our lab, and its photo-induced living cationic copolymerization behavior with isobutyl vinyl ether (IBVE) was investigated in detail using diphenyliodonium chloride (DPICl)/2,2-dimethoxy-2-phenylacetophenone (DMPA) and zinc bromide (ZnBr 2 ) initiating system in dichloromethane solution at 5 °C, −5 °C, and −15 °C, respectively. The living nature of this copolymerization system was confirmed by adding fresh comonomer method after the copolymerization almost finished. In addition, the obtained fluorescent copolymer poly(IBVE- co -CEVE) has a low glass transition temperature ( T
g ), below −10 °C.
研究领域:
高分子化学
·
功能高分子
·
光响应材料
·
聚合反应机理
·
荧光材料
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Huimin Li,Bin Wu,Zhimin Zhu,Chenyang Li,Zhihan Liu,Fuweng Zhang,Huidong Zheng,Longfei Yan
Ethylene sulfate (DTD) is a new type of solid electrolyte interphase (SEI) film-forming additive for lithium-ion batteries. DTD was typically synthesized in the industry by oxidation of ethylene sulfite (ES) with NaClO via a RuCl 3 -catalyzed reaction. However, this route generates significant amount of Cl-containing wastes, and the recovery of RuCl 3 is costly and technically challenging. Herein, we present a green and heterogeneous route for synthesizing DTD from ES, utilizing the Titanium Silicalite-1 (TS-1) and H 2 O 2 as catalysts and green oxidants, respectively. Our research reveals that the tetra-coordination framework of Ti in TS-1 serves as the main active site for the oxidation of ES, achieving a remarkable yield of DTD up to 92 % under optimized reaction conditions. Additionally, we developed a continuous green oxidation process for synthesizing DTD from ES, which is the first of its kind and has been successfully operated continuously for over 300 h. This work provides a cost-effective, green, and efficient route for synthesizing DTD from ES.
研究领域:
绿色化学
·
催化化学
·
材料科学
·
化学工程
·
储能技术
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 10
·2284
·
IF 3.426
Rui Huang,Jinshui Yao,Qiuhong Mu,Dan Peng,Hui Zhao,Zhizhou Yang
Silicone resin is a high-temperature resistant material with excellent performance. The improvement of its thermal stability has always been the pursuit of researchers. In this paper, a sequence of silicone resins containing trifluorovinyl ether groups were prepared by the co-hydrolysis-polycondensation of methyl alkoxysilane monomers and {4-[trifluorovinyl(oxygen)]phenyl}methyldiethoxysilane. The structures of the silicone resins were characterized by FT-IR and1H NMR. The curing process of them was studied by DSC and FT-IR spectra, and results showed that the curing of the resins included the condensation of the Si-OH groups and the [2 + 2] cyclodimerization reaction of the TFVE groups, which converted to perfluorocyclobutane structure after curing. The thermal stability and thermal degradation behavior of them was studied by TGA and FT-IR spectra. Compared with the pure methyl silicone resin, silicone resins containing TFVE groups showed better thermal stability under both N2and air atmosphere. Their hydrophobic properties were characterized by contact angle test. Results showed that PFCB structure also improved the hydrophobicity of the silicone resin.Keywords:silicone resin;trifluorovinyl ether group;thermal stability;degradation
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）