JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Jiancheng Zhao,Rui Liu,Zhenzhou Zhang,Qianqian Xing,Honghong Chang,Xianglin Hou,Yingxiong Wang
The tautomer structure of monosaccharides plays an important role in its conversion and utilization, which is mainly manifested in the selectivity of the product and the reaction mechanism. The tautomer distributions of N -acetyl- D -glucosamine (GlcNAc), a natural nitrogen-containing monosaccharide were investigated by quantitative 1 H NMR ( 1 H qNMR) and 13 C NMR ( 13 C qNMR) at 298 K under the condition commonly utilized for biorefinery. Catalysts used for biorefinery, i.e. BaCl 2 , KCl, ZnCl 2 , MgCl 2 , B(OH) 3 , SnCl 4 ·5H 2 O and amino acid ionic liquid were introduced into D 2 O or DMSO‑ d 6 to explore the tautomer distributions of GlcNAc. The introduction of ZnCl 2 and SnCl 4 ·5H 2 O promoted the conversion of α-pyranose to β-pyranose. The introduction of amino acid ionic liquid has little effect on the percentage of tautomers in D 2 O. However, when the amino acid ionic liquid, such as [Thr]Cl, was introduced into DMSO‑ d 6 , the proportion of β-pyranose increased to 29.06%, compared with no catalyst introduced. Besides, we also studied the tautomer distributions of GlcNAc in commonly utilized reaction solvents for biorefinery, such as N,N -dimethylformamide, N , N -dimethylacetamide, N -methyl-2-pyrrolidinone, ethylene and glycerol. In these solvents, the proportion of β-pyranose in N,N -dimethylformamide and glycerol was reduced to 25.84% and 38.38%, respectively. This study provides the basic experimental data of tautomer distributions of GlcNAc, and guided the conversion and utilization of GlcNAc in the future.
研究领域:
生物化学
·
分析化学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY
·
2018
·
IF 4.374
Xichuan Yang,Weihan Wang,Yanyun Zhang,Licheng Sun
P-type doping is a rational strategy for the enhancement of hole transporting properties of the organic semiconductors as well as the device performance of organic photo-electric devices. We originally introduce a stable and solution processed p-type dopant based on N-oxoammonium salts termed 2,2,6,6-tetramethyl-1-oxopiperidinebromide salt (TEMPO-Br) for 2,2′,7,7′-tetrakis(N, N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene (Spiro-OMeTAD) based solid state dye sensitized solar cells (ssDSC). By introducing TEMPO-Br doped Spiro-OMeTAD and a commercialized D-π-A sensitizer into ssDSCs, a promising device performance of 6.83% is achieved under simulated AM 1.5G solar irradiation (100 mW cm −2 ), which is significantly better than the control devices (∼1.7 times). The doping effect of TEMPO-Br on the photophysical and electrochemical properties of Spiro-OMeTAD, solid state device performance, cationic dye regeneration kinetics and preliminary long-term stability have been systematically investigated. This work indicates a potential application of N-oxoammonium salts as chemical P-type dopants for triphenylamine based hole transporting materials in solid state photo-electric devices.
研究领域:
材料科学
·
光电化学
✓ 已验证
DOI
高影响因子
Chemistry Africa-A Journal of the Tunisian Chemical Society
·
2021
·Vol. 5
·期 1
·79-87
·
IF 0
Naz Farah,Ciprian Matteo,Luo Zhixiong,Yan Shilin,Iqbal Shahzad Zafar,Zhu Meifang,Chaemchuen Somboon,Verpoort Francis
The synthesis and use of MOF-derived Co/NCF (N-doped carbon framework) material as a heterogeneous catalyst for copolymers synthesis via ring-opening polymerization (ROP) are reported for the first time. The Co/NCF material is applied for the copolymerization of L -lactides (LA) and ε-caprolactone (ε-CL) as monomers via ROP in bulk without any solvent or co-catalyst. The as-prepared catalyst is characterized using XRD, TPD, XPS, SEM, and TEM analytical techniques. At the same time, 1 H and 13 C-NMR spectroscopy were used to analyze the microstructure of the copolymer confirming the random copolymer structure. The average r values calculated from the heterodiad analysis of the 1 H NMR, data were r LA = 0.96 and r CL = 0.93 and L value calculated from the triads analysis of 13 C NMR, data were L LA = 3.17 and L CL = 2.79, respectively. It has been observed that the melting temperature and glass transition temperature of the copolymer increases with higher LA content. The XRD and DSC analyses also confirmed that the as-synthesized copolymer possesses two phases corresponding to the polylactide and polycaprolactone, respectively. Additionally, the activity of Co/NCF is also compared with other Co-based heterogeneous catalysts to demonstrate its ability. Graphic Abstract
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Kangfeng Pang,Wei Sun,Feng Ye,Lihui Yang,Mengjie Pu,Cao Yang,Qichun Zhang,Junfeng Niu
N,S-co-doped carbons were synthesized through the calcination of sulfur-modified chitosan for the first time, and utilized as persulfate activators for sulfamethoxazole (SMX) remediation in water. The chitosan and sulfonyl chloride underwent one-step sulfonylation reaction to generate S-modified chitosan. The catalyst NSC-3 showed both excellent adsorption and catalytic oxidation efficiency, corresponding 98.62% removal and 81.34% mineralization rate within 90 min. The rate constant ( k obs ) was up to 0.0578 min −1 , with 75.60-folders higher than that of sulfur-free catalyst NC (7.6580 ×10 −4 min −1 ). The synergy of N and S contributed to the improvement of removal efficiency. The adsorption and oxidation performance were highly depended on the S/N atomic ratio. At the S/N ratio of 0.18, the maximum adsorption and oxidation capability were obtained. The NSC-3/PS system exhibited outstanding adaptability at the wide pH range from 3.07 to 9.28, while the inhibitory effect occurred at strong basic conditions (pH = 11.01). The thiophene sulfur and structural defects were identified as the catalytic sites in activating PS. Both radical and non-radical pathways were responsible for degradation process, where 1 O 2 played a major role, SO 4 ·- exerted a minor contribution, and O 2 ·- acts as the precursor for the production of 1 O 2 . Another source of 1 O 2 was assigned to the activation of PS by structure defects . This work indicates that N,S-co-doped carbon at an optimal S/N atomic ratio effectively catalyzes persulfate, and provides an innovative method to construct bifunctional carbon materials of adsorption and oxidization.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·
IF 1.964
Pengfei Zhang,Jiang Deng,Jianyong Mao,Haoran Li,Yong Wang
By combination of photocatalysis and organocatalysis, a metal-free system composed of mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) and N -hydroxyphthalimide (NHPI) offers an efficient and environmentally friendly method for the oxidation of alcohols at room temperature. As a wide-band gap semiconductor, mpg-C 3 N 4 absorbs visible light and uses the energy to activate NHPI, resulting in high catalytic activity in the subsequent oxidation of alcohols. Interestingly, the main oxidation product of benzyl alcohol can be tuned from benzoic acid to benzaldehyde by increasing the ratio of mpg-C 3 N 4 in the catalyst system. To further understand the reaction route, electron spin resonance and Fourier transform infrared measurements were carried out, confirming that active oxygen and phthalimide N-oxyl radicals formed in the mpg-C 3 N 4 /NHPI system. Based on these results, a catalytic mechanism for the mpg-C 3 N 4 /NHPI system was proposed. Moreover, this metal-free system also works well for the oxidation of various aromatic alcohols with good selectivity for aldehydes or ketones.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 9
·2020-2030
·
IF 2.578
Shijun Long,Di Qiu,Ren Long,Xun Li,Hanyu Chen,Yiwan Huang,Xuefeng Li
In order to improve the performance of inorganic/organic composites, aluminum trihydroxide (ATH) core composites with a styrene-ethylene-butadiene-styrene block copolymer grafted with maleic anhydride (MAH- g -SEBS) shell phase, and P-N flame retardant as a synergistic agent, were prepared through an interface design. The effects of polyethylene glycol (PEG) content on the interfacial interaction, flame retardancy, thermal properties, and mechanical properties of high-density polyethylene (HDPE)/ATH composites were investigated by small angle X-ray diffraction, rotational rheometer, limiting oxygen index, thermogravimetric analysis (TGA), and tensile testing. The ATH synergistic effects of P-N flame-retardant improved the combustion performance of HDPE/ATH/PEG(3%)/MAH- g -SEBS/P-N (abbreviated as HDPE/MH3/M- g -S/P-N) composite by forming more carbon layer, increased the elongation at break from 21% to 558% compared to HDPE/ATH, and increased the interface thickness from 0.447 to 0.891 nm. SEM results support the compatibility of ATH with HDPE increased and the interfacial effect was enhanced. TGA showed the maximum decomposition temperature of the two stages and the yield of the residue at high temperature increased first and then decreased with the increase of PEG content. Rheological behavior showed the storage modulus, complex viscosity, and the relaxation time initially increased and then decreased with the increase of PEG content indicating PEG, M- g -S, and ATH powder gradually formed a partial coating, then a full coating, and finally an over-coated core-shell structured model.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 20
·期 26
·2310226
·
IF 13
Zhongwei Man,Zheng Lv,Yangyang Cao,Zhenzhen Xu,Qing Liao,Jiannian Yao,Feng Teng,Aiwei Tang,Hongbing Fu
Organic afterglow materials have significant applications in information security and flexible electronic devices with unique optical properties. It is vital but challenging to develop organic afterglow materials possessing controlled output with multi-stimuli-responsive capacity. Herein, dimethyl terephthalate (DTT) is introduced as a strong proton acceptor. The migration direction of N─H protons on two compounds Hs can be regulated by altering the excitation wavelength (Ex) or amine stimulation, thereby achieving dual-stimuli-responsive afterglow emission. When the Ex is below 300 nm, protons migrate to S 1-2 DTT , where strong interactions induce phosphorescent emission of Hs , resulting in afterglow behavior. Conversely, when the Ex is above 300 nm, protons interact with the S 0 DTT weakly and the afterglow disappears. In view of amine-based compounds with higher proton accepting capabilities, it can snatch proton from S 1-2 DTT and redirect the proton flow toward amine, effectively suppressing the afterglow but obtaining a new redshifted fluorescence emission with Δλ over 200 nm due to the high polarity of amine. Moreover, it is successfully demonstrated that the applications of dual-stimuli-responsive organic afterglow materials in information encryption based on the systematic excitation-wavelength-dependent (Ex-De) behavior and amine selectivity detection.
研究领域:
材料科学
·
光学材料
·
刺激响应材料
·
信息加密
·
物理化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Minzhe Chu,Yingying Zhai,Ningzhao Shang,Peijing Guo,Chun Wang,Yongjun Gao
The monomer of sustainable chitin, N-acetylglucosamine (NAG), is fabricated into a kind of N-doped carbon material (NC-HAP-700), with the template of hydroxyapatite (HAP). NC-HAP-700 exhibits excellent electrochemical capacitance of 346 F/g at the current density of 0.5 A/g and capacitance retention of 92% after 5000 times of charge-discharge cycles, which is superior to most reported functional carbon materials. Experiments and characterizations suggest that HAP is an ideal template to improve the surface area, create microporous structure and carbonyl groups for final carbon product. High percentage of pyridinic N, pyrrolic N and oxygen-containing groups are main contributions to the pseudo capacitance of NC-HAP-700. More important, the supercapacitors exhibit practical application in which solar energy can be stored and release to light up red LED.
研究领域:
材料科学
·
能源存储
·
电化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Zhaoxu Li,Xinyi Luo,Meifang Luo,Yuan Qin,Chaozhong Guo,Yao Liu,Zhongli Luo
To design inexpensive carbon catalysts and enhance their oxygen reduction reaction (ORR) activity is critical for developing efficient energy-conversion systems. In this work, a novel Fe-N-C hybrid electrocatalyst with carbon nanolayers-encapsulated Fe 3 O 4 nanoparticles is synthesized successfully by utilizing the molecular-level confinement of graphitic C 3 N 4 structures via hemin biomaterial. Benefiting from the Fe-N structure prevalent on the carbon nanosheets and large mesopore-dominated specific surface area, the synthesized catalyst under optimized conditions shows excellent electrocatalytic performance for ORR with an E ORR at 1.08 V versus reversible hydrogen electrode (RHE) and an E 1/2 at 0.87 V vs. RHE, and outstanding long-term stability, which is superior to commercial Pt/C catalysts (E ORR at 1.04 V versus RHE and E 1/2 at 0.84 V versus RHE). Moreover, the low hydrogen peroxide yield (<11%) and average electron transfer number (~3.8) indicate a four-electron ORR pathway. Besides, the maximum power density of the home-made Zn-air battery using the obtained catalyst is 97.6 mW cm −2 . This work provides a practical route for the synthesis of cheap and efficient ORR electrocatalysts in metal-air battery systems.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2020
·
IF 4.049
Di Zhou,Yunchao Zheng,Qiurong Luo,Die Gao,Qifeng Fu,Kailian Zhang,Zhining Xia,Lujun Wang
A novel multi-mode and chiral separation stationary phase co-modified with copolymer composed of N -isopropyl acrylamide (NIPAM) and aspartame was synthesized by atom transfer radical polymerization (ATRP) reaction. The synthetic material was evaluated using thermogravimetric analysis (TGA), Fourier transform infrared spectrometry (FT-IR) and elemental analysis (EA). Analytes including hydrophobic, hydrophilic, alkaline and acidic compounds were separated well using the prepared stationary phase named Sil-PPAM-NIPAM. Besides, the separation of chiral compounds proved that the developed column also has the potential of chiral separation ability. In summary, the prepared column possesses excellent hydrophilic interaction, ion exchange, reversed-phase and chiral separation modes during the separation of complex and chiral compounds.
研究领域:
化学
·
材料科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2024
·Vol. 59
·期 8
·3604-3623
·
IF 3.5
Wang Xintong,Yang Jiang,Chen Xu,Wang Yefei,Yang Zhen,Ding Wei
To mitigate CO 2 corrosion in the oil and gas industry, a green non-toxic β -N-butyl amino propionic acid (BAA) was synthesized using a low-energy and zero-waste one-pot method. The effectiveness of BAA as a corrosion inhibitor for N80 steel in CO 2 -saturated brine water was investigated through experimental measurements and theoretical modeling. The results demonstrate that BAA functions as an effective mixed-type corrosion inhibitor. BAA molecules interact with F (1 1 0) with the–COO– and–NH 2 + -moiety in the hydrophilic head group, and the hydrophobic groups are adsorbed on the steel surface in a configuration 45° away from the steel surface. The adsorption is a mixture of physical and chemical processes and is consistent with the Langmuir isothermal adsorption formula. When the concentration is greater than 50 ppm, a complete corrosion inhibitor film with high hydrophobicity can be adsorbed on the steel surface, which can effectively impede the diffusion of corrosive species from brine to the steel surface. Graphical abstract
研究领域:
腐蚀科学
·
材料工程
·
环境化学
·
石油天然气工业
✓ 已验证
DOI
高影响因子
SYNLETT
·
2018
·Vol. 29
·期 09
·1244-1248
·
IF 2.369
Xiangwen Kong,Lihua Liu,Siqin Luo,Shilu Fan,Haisheng Qian,Hua Xiao
A triphenylphosphine-promoted [3+2] cycloaddition of α,γ-bis-substituted allenoates and N-tosylaldimines followed by alkene isomerization was disclosed, affording a series of functionalized 2-pyrroline derivatives in moderate chemical yields with random diastereoselectivities.
研究领域:
有机化学
·
药物化学
·
合成方法学
·
杂环化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）