POLYMER
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2022
·
IF 4.432
Shuai Zhang,Qiusha Li,Jiajia Ye,Hongyi Sun,Xiaobo Liu
Aromatic heterocyclic polymers play key roles in high performance polymers . Among the various unsaturated functional groups, alkynyl and cyano groups stand out because they may form rigid and thermally stable six-membered rings such as benzene and triazine rings. In this work, monocyclic benzoxazine is used as a platform to integrate the alkynyl and/or cyano groups and the polymerization of these compounds are studied in detail. The curing behavior is investigated by differential scanning calorimetry (DSC), the chemical structures of the polymers are studied by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Moreover, the thermal and dielectric properties of the polymers are also probed. It is found that trimerization of alkynyl groups occur more easily than cyano groups. As the ratio of the two functional groups varies, pyridine rings can be formed more easily than pyrimidine rings. Moreover, more cyano groups may lead to reduction of glass transition temperature ( T g ) because of the low reactivity of cyano groups, but formation of pyridine rings could greatly improve the thermal stability of the polymer and char yield could reach 69%, which is much higher than the other polybenzoxazines prepared in this work.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2017
·
IF 2.865
Yingjie Li,Wenfeng Li,Qingnan Liu,Hong Meng,Yingzhou Lu,Chunxi Li
For the first time, a series of alkynyl carbon materials (ACMs) were prepared via the mechanochemical reaction of CaC 2 with six polyhalogenated precursors, namely CCl 4 , C 2 Cl 6 , C 2 Cl 4 , C 6 Cl 6 , C 6 Br 6 , and C 14 H 4 Br 10 (ACM-1, ACM-2, ACM-3, ACM-4, ACM-5, and ACM-6, respectively) and used for the adsorptive removal of mercury from aqueous solutions. Based on preliminary investigations, the adsorption of mercury on ACM-5 was studied in depth. Specifically, the effect of pH on mercury adsorptivity , adsorption kinetics, thermodynamics, isotherms, and recyclability was studied. The adsorptivity of mercury on ACMs was found to be closely related to the hydrocarbon precursor, specific surface area of sorbent , and the alkynyl content. ACM-5 showed the best performance and is among the best raw carbonaceous sorbents reported so far, with a Langmuir saturated adsorption capacity of 191.9 mg g − 1 . The promising mercury adsorption performance mainly arises from the strong Lewis soft acid–soft base interactions between the alkynyl groups and mercury ions. The adsorption isotherms could be satisfactorily correlated with the Langmuir equation. The results show that the ACMs can be used as efficient sorbents for the removal of mercury and may also be useful for the adsorption of other heavy metals.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2022
·
IF 2.676
Tong Zhang,Yuyu He,Fanghua Liang,Ran Chen,Pei Chen,Xinbing Chen,Zhongwei An
A series of benzimidazole-based liquid crystal compounds containing laterally difluoro-substituted and ethynyl linking groups, namely, 2-(4-(2-(2,3-difluoro-4-(alkoxy) phenyl)ethynyl)phenyl)-1-methyl-1 H-benzimidazolem derivatives (nPF(2,3)EPMx), are synthesised and investigated for their mesomorphic properties. These compounds mainly display enantiotropic nematic mesophases in the ranges of 32.0–44.5°C (heating process) and 50.0–64.0°C (cooling process). 10PF(2,3)EPMx exhibits lower clearing points and broader nematic phase ranges than nonfluorinated reference compound 10PEPMx, because of their slightly increased dipole moment. nPF(2,3)EPMx displays much larger theoretical birefringence (0.43–0.55) and experimental birefringence (0.42–0.53) than the common tolane-based liquid crystals, which is ascribed to its large π-conjugated molecule composed of benzene core, ethynyl linking group and benzimidazole terminated unit. The theory results of three-dimensional molecular conformations with dipole moment (µ), ratio of length to width (L/W), polarisability anisotropy (Δα) and average polarisability (Δα) calculated with density functional theory are also helpful in explaining the experimental results.
研究领域:
材料科学
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化学
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DOI
高影响因子
RUSSIAN JOURNAL OF GENERAL CHEMISTRY
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2024
·Vol. 94
·期 7
·1710-1719
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IF 0.9
Han D.,Wang J.,Yang H.,Ran T.,Lu H.,Wang L.,Yan Z.
Abstract In the present study, carbon dots (CDs) were synthesized by solvothermal method using 1,4-diethynylbenzene as carbon source. The CDs exhibited the spherical particles as observed from transmission electron microscopy (TEM) image with the average particle size of 2.25±0.51 nm. The fluorescence quantum yield of the final CDs was 13% under excitation at 460 nm. The fluorescence intensity of CDs is diminished at both acidic and basic conditions, while a good linear relationship was realized at pH = 2–7 with the coefficient of determination ( R 2 ) of 0.9984 and the minimum detection limit (LOD) of 0.6 with good reversibility and cyclicity for pH detection. trans -resveratrol (t-res) was found to enhance the fluorescence of CDs well and the fluorescence intensity showed a good linear relationship to t-res within the concentration range of 10–100 μM with the coefficient of determination R 2 of 0.9993 and the LOD of 3 μM. The recoveries of the wines ranged from 100.36–102.40% with the relative standard deviations (RSD) of 2.56–3.48%. Thus, the CDs are extremely sensitive to t-res. Alkynyl ligand is used to prepare CDs, which illustrate the potential application for pH and t-res detection.
研究领域:
化学
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分析化学
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DOI
高影响因子
Polymer Chemistry
·
2015
·Vol. 6
·期 20
·3747-3753
·
IF 5.52
Bo Zhao,Yaochen Zheng,Zhulin Weng,Shengying Cai,Chao Gao
This paper firstly revealed the electrophilic effect of thiol groups on thiol–yne polymerization. For this, we designed and synthesized five kinds of α-thiol-ω-alkynyl AB2 type intermediates with thiols with different electrophilicities. The thiol electrophilic effect can be assessed by chemical shift (δ) and measured directly by nuclear magnetic resonance (NMR) spectroscopy. As the evidence from gel permeation chromatography (GPC) and NMR tracking measurements shows, the polymerization rate and molecular weight (MW) were significantly enhanced as the thiol electrophilic effect reduced. On the contrary, with increasing electrophilicity of the thiol, the resultant degrees of branching (DBs) increased. The semiquantitative relation between reactive rate constant (k) and δ (or electrophilicity of thiol) can be expressed by k = 2.41–1.34δ. Therefore, important features of thiol–yne polymerization and HPTEs, such as rate constant (k), MW, DB, etc., can be roughly estimated in advance by the NMR measurement of the thiol's electrophilic effect.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2014
·
IF 6.451
Jian Rong Zhang,Wei Tao Huang,Ai Lian Zeng,Hong Qun Luo,Nian Bing Li
Ethynyl triggered enhanced fluorescence quenching effect was first reported based on photoinduced electron transfer (PET) between fluorophore and ethynyl. Ethynyl and 6-carboxyl-fluorescein (FAM) were labeled at the 5′- and 3′-termini of a poly d(T) sequence containing three thymine units, respectively. In the presence of Hg 2+ , Hg 2+ binds to two thymine residues through T–Hg 2+ –T interactions and the formed T–Hg 2+ –T base pairs bring FAM and ethynyl from two matched sequences into close proximity . On the one hand, π-stacked T–Hg 2+ –T mediates and accepts electron transfer of the excited state of FAM and quenches the fluorescence through PET. On the other hand, π-stacked interactions between ethynyl and FAM also provide a de-excitation process for the excited state of FAM via PET and trigger an enhanced fluorescence quenching. On the basis of fluorescence quenching, a simple, rapid, and sensitive Hg 2+ sensor was constructed; under optimum conditions, a good linear relationship was obtained over the concentration range of 5–150 nM for Hg 2+ and a very low detection limit (0.42 nM) was reached. The developed system was further designed as a cysteine (Cys) sensor based on fluorescence recovery resulted from the strong interaction between Cys and Hg 2+ ; the proposed Cys sensor has a linear range of 10–550 nM and a detection limit of 2.5 nM. The two sensors were used for analysis of real samples and the satisfactory results were achieved.
研究领域:
生物化学
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分析化学
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DOI
PubMed
高影响因子
ENERGY & FUELS
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2017
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IF 3.091
Wenfeng Li,Yingjie Li,Yong Chen,Qingnan Liu,Yingzhou Lu,Hong Meng,Chunxi Li
Carbon-based materials are a kind of promising sorbent for the desulfurization of fuel oils, especially for polycyclic aromatic sulfur heterocycles (PASHs), and development of new sorbents is of great significance. In this paper, six alkynyl carbon materials (ACM-1 to ACM-6) were prepared for the first time through mechanochemical reaction of calcium carbide with six full halogenated hydrocarbons, i.e., CCl4, C2Cl6, C2Cl4, C6Cl6, C6Br6, and C14H4Br10, respectively. Their carbon content and specific surface areas (SSAs) were analyzed, and their adsorption performance for thiophenic sulfurs was studied. The ACMs are mesoporous materials with relatively high SSAs and favorable adsorptive performance for PASHs with the order of DBT > BT > 3-MT. Their adsorptivity is virtually consistent with the SSA values and follows the order of ACM-6 > ACM-5 > ACM-4 > ACM-1 > ACM-3 > ACM-2. ACM-6 has the highest SSA (712 m2 g–1) and saturated adsorbance of 21.1 mg-S·g–1 for DBT in octane, as well as 6 mg-S·g–1 for real diesel. As a whole, ACM-6 represents the best ADS sorbent among all mesoporous carbon materials and may be applicable for real oils after some further modification.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
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2018
·
IF 5.158
Lijian Sun,Guifa Xiao,Xueren Qian,Xianhui An
We report a facile and effective method to fabricate clickable alkyne-functionalized cellulose fibers (ACFs) through in situ chemical oxidation copolymerization of 3-ethynylaniline and aniline under acidic aqueous solution. The effects of process variables on copolymer deposition onto CFs were investigated and suitable preparation conditions were identified. It was found that aniline significantly facilitated the polymerization of 3-ethynylaniline and shortened the preparation time of ACFs from 48 to 6 h. Antibacterial-modified cellulose fibers were prepared by binding β-cyclodextrin (β-CD) to cellulose fibers via click chemistry, followed by the inclusion of ciprofloxacin hydrochloride (CipHCl). The loading and releasing behaviors of CipHCl into/from click product (ACFs@Azide-β-CD) were also revealed. The load amount of CipHCl into ACFs@Azide-β-CD increased remarkably, and the release of CipHCl from ACFs@Azide-β-CD was prolonged. The ACFs@Azide-β-CD loaded with CipHCl exhibited higher and longer-term antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus ( S. aureu ) compared with CFs and ACFs.
研究领域:
材料科学
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化学工程
·
生物材料
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药学
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产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2020
·
IF 2.908
Mengting Zhang,Shenghua Du,Diao Yuan,Pei Chen,Guoqing Liu,Jiazhen Dang,Xinbing Chen,Zhongwei An
New kinds of heterocyclic mesogenic compounds containing benzoxazole, ethynyl, and laterally fluorinated phenyl groups, namely 2-[4-[2-[4-alkoxyphenyl]ethynyl]-2,3-difluorophenyl]-benzoxazole derivatives (nPEDFPBx), are synthesized and evaluated. The compounds nPEDFPBx except nitro-substituted ones have enantiotropic nematic mesophases with mesophase ranges of 16–86°C and 29–108 °C on heating and cooling, respectively. The results show that introduction of two lateral fluorine atoms into molecule results in enhanced nematic mesophase stability. Meanwhile, nPEDFPBx displays much higher birefringence (0.507–0.624) than common tolane-based liquid crystals, which is ascribed to its large π-conjugated molecule composed of benzene, ethynyl, and benzoxazole mesogenic unit. The nPEDFPBx has a high potential to serve as a dopant for liquid crystal mixture.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
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2020
·
IF 4.673
Xianqing Deng,Mingxia Song
Two series of aminoguanidines containing an alkynyl moiety were designed, synthesised, and screened for antibacterial and anticancer activities. Generally, the series 3a–3j with a 1,2-diphenylethyne exhibited better antibacterial activity than the other series (6a–6k) holding 1,4-diphenylbuta-1,3-diyne moiety antibacterial activity. Most compounds in series 3a–3j showed potent growth inhibition against the tested bacterial strains, with minimum inhibitory concentration (MIC) values in the range 0.25–8 µg/mL. Compound 3g demonstrated rapid and persistent bactericidal activity at 2 × MIC. The resistance study revealed that resistance of the tested bacteria towards 3g is not easily developed. Molecular docking studies revealed that compounds 3g and 6e bind strongly to the LpxC and FabH enzymes. Moreover, excellent activity of selected compounds against the growth of cancer cell lines A549 and SGC7901 was also observed, with IC50 values in the range 0.30–4.57 µg/mL. These findings indicate that compounds containing the aminoguanidine moiety are promising candidates for the development of new antibacterial and anticancer agents.
研究领域:
药理学
·
药物化学
·
微生物学
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
POLYMER
·
2021
·
IF 4.43
Zhengyuan Zhang,Hongyu Yan,Zejun Yin,Yuechuan Wang
The acetylene functional groups on polymer chains provide a photochemical access to modulate or actuate the properties of the polymer. We report here a photochemical way to actuate a polyacrylate to elastomers . High molecular weight acetylene functionalized homo- and copolymers of are prepared with a novel monomer , 2-(dimethylpropargyloxy)ethyl methacrylate , DMPOEMA, by photo-initiated free-radical polymerization (FRP) in solution at room temperature . The acetylene groups are tolerant of the solution photo FRP at 50 wt% concentration, but not tolerant to thermal FRP and photo FRP at 80 wt% concentration. Copolymers P(DMPOEMA- co -EA) with‾M n in 12,500–15,100 g/mol were prepared with conversion up to 90% at 50% concentration and three monomer feed ratios. The feed ratio of DMPOEMA had slight effects on the polymerization rate, but effects on PDI at higher monomer conversion with prolonged photo-irradiation. The acetylene functionalized polyacrylates become photo-sensitive and are photo cross-linkable or photo clickable after solvent is removed. Real-time FT-IR study reveals that the photo cross-linking with a tri-thiol compound follows the normal thiol-yne photochemistry , and the photo cross-linking catalyzed with only photoinitiator results in diene units in the cross-linked polymer networks . These photo-treated polyacrylate exhibited designable elastomer properties: with T g in −24 to −11 °C, more than 10 times increase of relative cross-linking density and resistant to solvents, improved stress, strain and elongation properties. This work paves a way for the acetylene functionalized (meth)acrylates as advanced photo-reactive material.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2012
·Vol. 51
·期 3
·708-715
·
IF 3.919
Yong Shen,Yinan Ma,Zhibo Li
We report a highly efficient approach to prepare dendrimers by taking advantage of the orthogonal characteristic of aza-Michael addition and thiol-yne reactions. A fifth generation dendrimer was synthesized within five steps without protection/activation procedures. The reactions proceed under benign conditions without byproducts, and the target products can be easily purified via extraction or precipitation without chromatography. The structure of each generation dendrimer was characterized using NMR spectroscopy, size exclusion chromatography, and mass spectrometry. The obtained dendrimers can have peripheral amine or alkyne groups. We demonstrated that these groups can be used for selective and specific conjugation with various functional groups. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
研究领域:
材料科学
·
有机化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）