ANALYST
·
2020
·Vol. 146
·期 1
·75-84
·
IF 3.978
Lei Li,Jiancheng Yu,Chengyi Xie,Chenlu Wang,Pengfei Guan,Jun Jack Hu,Keqi Tang
3-Pyridinylboronate, a zwitterionic boronic acid, displayed effective in situ ESI for reversible covalent tagging of saccharides in both cation and anion modes. The ion mobilities of thus-generated ions were examined with the Bruker timsTOF fleX instrument. Nine disaccharides were examined using this method. They have identical mass-to-charge ratios, differing only in monomer compositions, regio-linkages, and anomeric configurations (α or β). The IMS separations of the disaccharides from this method were compared with those from sodium adducts reported in the literature. The differentiation effects of this method on the disaccharide isomers were increased on average by an order of magnitude. Using this method, all the pairs of disaccharides selected from nine isomers were completely identified by comparing the mobility spectra of single-tagged and double-tagged ions.
研究领域:
分析化学
·
质谱学
·
碳水化合物化学
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产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2020
·
IF 3.333
Yuchun Huang,Yujian Liu,Saleem Muhammad,Qun Jia,Yuansheng Ding,Yougen Chen
The present work describes the detailed macromolecular design, synthesis, and characterization of a series of mono- and bi-terminal functionalized polystyrenes (PSs) by the combination of atom transfer radical polymerization (ATRP) and copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. We further study the effect of the incorporated end groups on the glass transition behavior of the resulting polymers. The mono and bi functionalized polystyrenes were synthesized by using 1-phenylethyl bromide and 1,4-bis(bromomethyl)benzene as the initiators to form bromo mono-end functionalized PS (PS-Br) and bromo bi-terminal functionalized PS (Br-PS-Br), respectively. PS-Br and Br-PS-Br were then transformed to azido mono- and bi-terminal functionalized PSs (PS-N 3 and N 3 -PS-N 3 ) by S N 2-type reaction with sodium azide . PS-N 3 and N 3 -PS-N 3 were then subjected to CuAAC reactions with various alkynes like 1-decyne, 1-hexyne, trimethylsilylacetylene, phenylacetylene , and 4-ethynyl-1,1′-biphenyl respectively to give a series of alkyl or aromatic mono- and bi-terminal functionalized PSs (PS-Rs and R-PS-Rs), such as PS-Rs of PS-C 8 H 17 , PS-C 4 H 9 , PS-SiMe 3 , PS-Ph, PS-biPh, and R-PS-Rs of C 8 H 17 -PS-C 8 H 17 , C 4 H 9 -PS-C 4 H 9 , SiMe 3 -PS-SiMe 3 , Ph-PS-Ph, and biPh-PS-biPh. PS-SiMe 3 and SiMe 3 -PS-SiMe 3 were then transformed to the corresponding PS-H and H-PS-H through the detrimetylsilylation reaction with tetra- n -butylammonium fluoride (TBAF). Among the five end groups, -C 8 H 17 and -C 4 H 9 were with great flexibility; -H was viewed as a standard; and -Ph and -biPh groups represented the typical rigid moieties. The effect of these end groups on glass transition behavior was thoroughly investigated based on the above macromolecular design.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 43
·48147
·
IF 2.188
Huajun Duan,Wenjing Dong,Xin Wang,Xiaoxiao Tao,Huiru Ma
In this article, aiming to develop the high performance ultraviolet (UV)-curable resin used in the polymer matrix composite, a series of polyurethane acrylate (PUA) resins with the different numbers of allyl terminal groups were elaborately designed and synthesized, in which the contents of hard segments and soft segments were also adjusted simultaneously. The effects of allyl number on properties of PUA were systemically investigated. It was found that allyl number had the negligible effect on the processability as well as positive effect on thermal performances, and all PUA resins exhibited the low viscosity and rapid UV polymerization. Besides, with the change of allyl number in the range of 2–4, PUA resin casting with three allyls possessed the preferable mechanical properties such as 85.1 MPa tensile strength, 3.94 GPa tensile modulus, and 20.7 kJ m −2 impact strength. More importantly, the high strength and high modulus of the composite further demonstrated the wide potentials of the as-prepared PUA resin as the ideal resin matrix candidate for the fiber reinforced polymer composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 48147.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 50
·期 21
·6920-6925
·
IF 2.371
Wang Jing,Yan Han,Lu Yun
A novel thiophene derivative (Fe–Th) with ferricyanide end group is successfully synthesized. The polythiophene derivative (Fe–PTh) is additionally obtained in aqueous solution by polymerization of Fe–Th, and shows a nanoparticle structure with a diameter from 10 to 100 nm. A simple solid-state electrochromic device is fabricated using the Fe–PTh as electrochromic material, and displays a novel three-color electrochromism from blue, green, and red with the increased potential.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER INTERNATIONAL
·
2018
·Vol. 68
·期 4
·675-683
·
IF 2.352
Bing Yang,Yu Zhou,Wenjie Yu,Song Zhang,Hongxiang Chen,Ju Ye
In order to improve the dispersity and stability of the nano-SiO 2 aqueous system with high solid content, a kind of polyacrylic acid dispersant with methoxysilicon end groups (KH590-PAA) was synthesized by photopolymerization of acrylic acid (AA) initiated with (3-mercaptopropyl)trimethoxysilane (KH590). After adding KH590-PAA into the nano-SiO 2 aqueous dispersion system (20 wt% solid content), the viscosity and the curing time of the system were measured with a rotational viscometer and the inverted bottle method. Moreover, the dispersion mechanism of KH590-PAA for the nano-SiO 2 aqueous system was researched by measuring the adsorption capacity, the particle size and the zeta potential of the nanoparticles with a conductivity meter, dynamic light scattering, SEM and TEM, respectively. The results showed that the methoxysilicon groups in KH590-PAA could react with hydroxyl groups on the surface of nano-SiO 2 in the process of stirring, which enhanced the adsorption capacity of the dispersant and then increased the surface charge of the particles. Therefore, electrostatic repulsion and steric hindrance effects between the SiO 2 nanoparticles could be further enhanced by adding the KH590-PAA dispersant, and then the nano-SiO 2 aqueous system exhibited better dispersity and stability. Besides, the dispersion properties of SiO 2 nanoparticles in water were closely related to the addition amount and the molecular weight of the KH590-PAA dispersant. © 2018 Society of Chemical Industry
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
MACROMOLECULES
·
2023
·
IF 5.5
Simeng Liu,Guoqiang Han,Mengmeng Zhang,Bijin Xiong,Jiangping Xu,Jintao Zhu
Grafting polymer ligands on gold nanoparticles (AuNPs) by gold–sulfur (Au–S) bond is a facile way commonly employed to fabricate gold–polymer hybrid NPs (AuNP@polymer). By using the reversible addition–fragmentation chain transfer (RAFT) radical polymerization, it is convenient to present sulfur-containing end groups to polymer ligands, such as dithioester and trithioester groups, which can be usually transferred to thiol/thiolactone/disulfide groups by aminolysis reaction. However, these groups show different bonding effects to AuNPs. Especially for the thiolactone-terminated polymer, the weak bonding between thiolactone and AuNPs results in unstable AuNP@polymer conjugates, which further affects their assembly behavior. Here in this work, the effects of the end group on the surface-grafting of AuNPs were investigated by using poly(methyl methacrylate) (PMMA) ligands containing thiolactone/dithioester/disulfide/thiol end groups. By tuning the solvent property and the concentration of PMMA ligands, the thiolactone-terminated PMMA can be successfully grafted on the AuNPs, which has been regarded as a great challenge due to the weak bonding between gold and thiolactone. The grafting density of thiolactone-terminated PMMA can reach 0.5 chains/nm2, which is similar to that of disulfide/thiol-terminated PMMA. Moreover, the grafting density shows critical influence on the interfacial assembly behavior of AuNP@PMMA conjugates. By optimizing the assembly parameters, a superlattice film of AuNP@PMMA conjugates could be constructed, which may have promising applications in memory devices and sensors.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2025
·
IF 2.7
Hong Yin,Xiaoyan Wu,Yanyu Jia,Huimin Wang,Shihui Wang,Yao Chen,Xiaofeng Chen,Hangjun Deng,Jiaming Qin,Zhirong Chen,Shenfeng Yuan,Qilei Zhang
Poly(phenylene sulfide) (PPS) produced by the sodium sulfide method contains ionized end groups such as sodium mercaptide (-SNa) and sodium 4-(methylamino)butanoate (-SMAB), which can be exchanged to proton or other cations by ion-exchange process. Depending on the type of cation and the extent of replacement, PPS performances can vary significantly. In this study, PPS samples with different extents of sodium ionization are prepared by adjusting the p H of PPS aqueous dispersion, then the melt stability is systematically investigated by capillary rheometer. It is found that neutral PPS possesses the best melt stability, while melt viscosity increases with the p H. Moreover, molecular weights before and after melt stability test are compared, neutral and alkaline PPS demonstrate similar minor decrease in molecular weight, while acidic PPS suffers severe degradation. Furtherly, electron paramagnetic resonance spectroscopy (EPR), rotational rheometer, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) are applied to reveal the mechanism behind. Loss of ionized end groups weakens ionic interactions in alkaline PPS, which accounts for reduction of melt viscosity, while protonated end groups in acidic PPS accelerate the formation of free radicals, leading to severe degradation of PPS chains.
研究领域:
高分子化学
·
材料科学
·
聚合物物理
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流变学
·
功能材料
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Pibo Liu,Hongwei Ma,Li Han,Lincan Yang,Heyu Shen,Chao Li,Yang Li
Three amine-functionalized 1,1-diphenylethylene (DPE) derivatives (DPE-(NMe 2 ) 2 , DPE-NMe 2 and DPE-SiH/NMe 2 ) were used to study the end-capping reactions of poly(styryl)lithium (PS-Li) for investigating the effect on end-capping of electron-donating groups in DPE structures. In situ 1 H NMR was used to measure the kinetic parameters of end-capping reactions. When the DPE derivative was held constant in the PS-Li capping reaction, the kinetic parameter (k SD ) did not change with the variance of either concentration or degree of polymerization of PS-Li. Additionally, the k SD value changed dramatically when various electronic properties of the DPE derivative substituents were modified. Electron-withdrawing groups accelerated the end-capping reaction, while electron-donating groups decelerated it. The k SD experimental values of DPE-(NMe 2 ) 2 , DPE-NMe 2 and DPE-SiH/NMe 2 were found to be 0.155 × 10 −3 , 1.26 × 10 −3 , and 6.24 × 10 −3 L 1/2 mol −1/2 s −1 , respectively. An intuitive model was established to simulate the precision of the sequence-controlled copolymerization with DPE derivatives based on investigations of end-capping kinetics. The model depicts the degree of fictitious styrene propagation for the chain insertion of one DPE derivative unit. The fictitious degrees of polymerization of styrene (FDPs) for DPE-NMe 2 and DPE-SiH/NMe 2 were calculated to be 37 and 13, respectively, suggesting that using DPE derivatives containing an electron-withdrawing group in the synthesis of sequence-controlled polymers might lead to a more precise structure.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2009
·
IF 2.039
Yunpu Wang,Jiucun Chen,Jiming Xiang,Hongjun Li,Yongqian Shen,Xianghu Gao,Yan Liang
This article describes a divergent strategy to prepare grafted polymer chains with functional end groups for surface modification of nanoparticles with other functional groups. This preparation is achieved through a combination of surface-initiated atom transfer radical polymerization (ATRP) and click chemistry. First, the surface of the silica nanoparticles was modified with polystyrene (PSt) brushes via the “grafting from” approach. The terminal bromides of PSt-grafted silica nanoparticles were then substituted with azido groups . These azido-terminated PSt brushes on the nanoparticle surface were reacted with various alkyne-terminated functional end groups via click reactions. In all cases, FTIR and 1 H NMR spectra indicated quantitative transformation of the chain ends of polystyrene brushes on silica nanoparticles into the desired functional group.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Xiaohui Wu,Junchi Zheng,Bingyong Han,Liqun Zhang,Jianmin Lu,Xin Ye
Constructing a chemical interface between rubber and silica is necessary for preparing a nanosilica/rubber composite used in tire industry. In our research, epoxy-terminated polybutadiene (ETPB) was designed and synthesised by anionic polymerisation to realize the construction of a chemical interface between nanosilica and diene-rubber without volatile organic compounds emission. We verified that the ETPB had a molecular weight of 438 and a narrow molecular weight distribution . We also used differential scanning calorimetry and thermal gravimetry analyser to confirm that the ETPB could be fully grafted with silica and chemically cross-linked with diene-rubber. Therefore, a chemical interface as a coupling bridge has been formed between the silica and rubber. Dynamic and static mechanical testing demonstrated that the ETPB-modified nanosilica/NR composite had an excellent comprehensive performance, which is quite suitable for green tires.
研究领域:
材料科学
·
聚合物化学
·
可持续工程
✓ 已验证
产品关联
DOI
高影响因子
MOLECULAR CRYSTALS AND LIQUID CRYSTALS
·
2015
·
IF 0.493
Changcheng Wu
A novel series of cholesterol-based liquid crystalline (LC) dimers with a menthyl terminal group in the biphenyl base side have been synthesized. The chemical structures and LC properties of this series of compounds are characterized by FT-IR, 1H-NMR, elemental analysis, hot-stage coupled polarizing microscopy and differential scanning calorimetry. All the dimers exhibit enantiotropic mesophases. These dimesogenic compounds with a short spacer are chiral nematic LCs, while with long spacers, they are SmA and chiral nematic LCs. Some of these LC dimers exhibit iridescent colors in their chial nematic (N*) states.
研究领域:
材料化学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
Energy Storage Materials
·
2022
·
IF 20.831
Xuewen Hu,Qicheng Zhang,Ning Gong,Xifan Chen,Lan Wang,Wenchao Peng,Yang Li,Fengbao Zhang,Xiaobin Fan
MXenes, a new family of two-dimensional materials, have been recognized as promising candidates for supercapacitors because of their unique chemical and physical properties. It has been proven that the terminal groups on MXenes play a decisive role in the pseudocapacitance . In this study, we report a highly efficient strategy to remove the –F terminal groups of Ti 3 C 2 T x . Our initial purpose was to explore the application of Ti 3 C 2 T x in sodium-ion batteries, whereas we found that almost all the –F terminal groups on Ti 3 C 2 T x could be eliminated by reaction with Na metal at high temperature, and abundant terminal –O was introduced after the subsequent washing step. The mechanism involved is clarified by combining systematical spectra analysis and density functional theory (DFT) calculations. In addition, the modulated Ti 3 C 2 T x MXene shows an extraordinarily high specific capacitance of 521 F·g −1 (at scan rate of 2 mV·s −1 ) or 578 F·g −1 (at a discharge rate of 1 A·g −1 ) in 1 м H 2 SO 4 , and 92% capacity could be retained even after 10000 cycles. This study should provide new insight into the surface chemistry of MXenes and facilitate its applications in a variety of fields.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 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）