SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2020
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IF 3.232
Angxin Tong,Xiaojun Tang,Feng Zhang,Bin Wang
In this study, we mainly focused on predictable regularities of the red shift of ultraviolet spectra for β-phenylethylamine (PEA), NaCl and NaOH in aqueous solution. The absorption peaks of the UV spectra near 191 nm of NaCl, NaOH and PEA in aqueous solution moved in the direction of a red shift while the molar absorption coefficient at the peak increased regularly with the increasing solution concentration. These shifts were obtained for solutions with concentrations ranging from 3.68 to 1000 mmol/L for NaCl, from 0.762 to 2000 mmol/L for NaOH, and from 0.0515 to 8.91 mmol/L for PEA. The plots of the logarithm of the solution concentration for NaCl and PEA versus the absorbance at 191 nm and at the peak were linear, and the plots of the logarithm of the solution concentration for NaCl and PEA versus the wavelength at the peak (shifted from 191 nm) were also linear. In addition, the plots of the logarithm of the solution concentration for NaOH that ranged from 0.762 to 1.96 mmol/L versus the absorbance at 191 nm and at the peak were linear as well as the plots of the logarithm of the solution concentration for NaOH that ranged from 1.96 to 2000 mmol/L versus the wavelength at the peak. The slopes of the absorbance at 191 nm of PEA, NaCl and NaOH were somewhat similar to the absorbance at the peak separately, whereas the slopes of the wavelengths at the peak were different from them. Finally, in order to obtain the predictable regularity of the red shift of the UV spectrum for the mixture, 22 ternary mixtures were prepared. The results indicate that the inhibiting effect of hydroxide ions (OH-) caused the wavelength near 206 nm to remain unchanged when the solution concentration of NaOH in the mixture was more than 0.762 mmol/L.
研究领域:
化学
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光谱学
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分析化学
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DOI
高影响因子
Processes
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2018
·Vol. 6
·期 4
·35
·
IF 1.279
Pingping He,Xingchi Qian,Zhaoyang Fei,Qing Liu,Zhuxiu Zhang,Xian Chen,Jihai Tang,Mifen Cui,Xu Qiao
A series of carbon aerogels were synthesized by polycondensation of resorcinol and formaldehyde, and their structure was adjusted by managing solution concentration of precursors. Carbon aerogels were characterized by X-ray diffraction (XRD), Raman, Fourier transform infrared spectroscopy (FTIR), N2adsorption/desorption and scanning electron microscope (SEM) technologies. It was found that the pore structure and morphology of carbon aerogels can be efficiently manipulated by managing solution concentration. The relative micropore volume of carbon aerogels, defined by Vmicro/Vtol, first increased and then decreased with the increase of solution concentration, leading to the same trend of CO2adsorption capacity. Specifically, the CA-45 (the solution concentration of precursors is 45 wt%) sample had the highest CO2adsorption capacity (83.71 cm3/g) and the highest selectivity of CO2/N2(53) at 1 bar and 0 °C.Keywords:carbon aerogels;concentration;structure manipulation;CO2capture
研究领域:
材料科学
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环境工程
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产品关联
DOI
高影响因子
Crystals
·
2023
·Vol. 13
·期 4
·607
·
IF 2.7
Dongyang Wang,Qiang Wang,Zongqiong Lin,Tiantian Pang,Ning Ding
In this study, according to the acquired polydopamine deposition rates, polydopamine films with equal thickness were prepared under different conditions on SiO2substrates. Subsequently, we investigated the influence of dopamine solution pH and concentration on the formation of surface aggregates of the deposited polydopamine films. Assumptions were made to explain how pH and concentration execute their effects. Based on the optimized parameters, a continuous and smooth polydopamine film with a thickness of about 14 nm and a roughness of 1.76 nm was fabricated on a silicon dioxide substrate, through the deposition for 20 minutes in a dopamine solution with a concentration of 1.5 mg/mL and a pH of 8.2. The prepared polydopamine film was then employed as a precursor and subjected to a high-temperature process for the carbonization and graphitization of the film. Raman spectroscopy analysis indicated that the resulting graphene-like film had fewer structural defects in comparison with previous works and the results of XPS indicated that most of the carbon atoms were bound into the cross-linked honeycomb lattice structure. The prepared graphene-like material also exhibited high electrical conductivity and satisfying mechanical elasticity.Keywords:polydopamine;pH;concentration of dopamine solution;graphene-like film
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
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Xinrui Zhao,Yu Xiang,Aihui Zhou,Jiugang Yuan,Jin Xu
Keratin molecules contain many hydrophobic amino acids and disulfide bonds that render them poorly soluble in water, thus greatly limiting their properties and applications as biomaterials. Improving the solubility of keratin and the stability of highly concentrated solutions is the key to solving this. In this paper, wool keratin was first dissolved and then PEGylated in a novel reduced deep eutectic solvent (DES) to obtain a stable keratin solution with a concentration of 300 g/L. The hydrophobicity, particle size distribution, conformation, and rheological properties of this high-concentration keratin solution were investigated. The results showed that a thiol–ene click reaction reduced the thiol content by up to 60% and inhibited thiol–thiol cross-linking. PEGylation also reduced the hydrophobic areas on the keratin surface, thus improving its stability in an aqueous solution. In the highly concentrated PEGylated keratin solution, the secondary conformation changed from α-helix to β-sheet. Polarized light microscopy indicated the formation of liquid crystals after applying friction. Rheological tests showed that the solution had a shear-thinning behavior at high shear rates, indicating that molecular chain reorientation was induced under the action of shear forces, which may help to strengthen the materials.
研究领域:
生物材料学
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化学工程
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分子生物学
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产品关联
DOI
高影响因子
JOURNAL OF CRYSTAL GROWTH
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2022
·
IF 1.83
ShuTian XuanYuan,Hongxun Hao,Cuihong Hu,Jinqi Lan,Tong Song,Chuang Xie
Quantitative analysis of crystallization processes remains challenging due to the complicated relationships among the multiple phases and their spectra. In this work, in situ Raman spectroscopy was chosen to quantitatively analyze the solution concentration and suspension density simultaneously in a crystallization process . A model based on support vector regression (SVR) was developed to separate the information of solution and solid from the Raman spectra. The simultaneous correlations of the spectra with solution concentration and suspension density were achieved and the results were evaluated. It demonstrated that the SVR-based method proposed in this work gave satisfactory fitting and prediction performance. Furthermore, the model was validated in the reactive crystallization of the ternary NaHCO 3 -Na 2 CO 3 -H 2 O system. It suggested that baseline removal is not necessary when using this model. The effect of bubbles should be included for the clear solution but could be neglected in solid suspensions. The results of this work provide a simple and rapid option for the quantitative analysis of crystallization processes and similar suspension systems.
研究领域:
化学工程
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分析化学
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DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2025
·Vol. 40
·期 3
·682-692
·
IF 1.1
Wu Jun,Zhao Lei,Yang Cuina,Zhang Yuhua,Sun Shengfei,Yao Lu
This paper adopted the hydrothermal method to prepare tungsten oxide (WO 3 ) nanorod films and studied the effects of precursor solution concentration (0.02, 0.03, 0.06 mol/L peroxytungstic acid) and annealing temperature (200, 300, 400 °C) on their electrochromic properties. The microstructure characterization of WO 3 films were performed using scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM), and their electrochromic properties were tested by combining an electrochemical workstation with an ultraviolet-visible spectrophotometer. The results showed that the precursor solution concentration directly affected the thickness (290, 560, 990 nm) and microstructure of WO 3 films, significantly impacting their electrochromic properties. However, the annealing temperature had a negligible effect. As the precursor solution concentration increased, the optical modulation of WO 3 films gradually decreased, reaching 51.1%, 43.8%, and 35.1%, respectively. The switching time first increased and then stabilized, with coloring times of 7.3, 7.7, and 7.7 s, respectively, and bleaching times of 3.8, 6.5, and 6.5 s, respectively. The coloration efficiency gradually increased but the increase was relatively small, reaching 41.8, 44.4, and 44.8 cm 2 /C, respectively. Moreover, the cycling stability of WO 3 films was poor, with the ratios of the final value of optical modulation to the initial value 0.33, 0.26, and 0.34, respectively. Additionally, there were bigger differences in the bleached state transmittance, while the colored state transmittance showed smaller variations. However, the former has better cycling stability than the latter. In summary, to obtain better electrochromic properties, the thickness of WO 3 films should not exceed 290 nm.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
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2020
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IF 2.365
Zibin Gao,Xiaoqian Lv,Yufei Fu,Xianghuan Zang,Yongjun Sun,Shuo Li,Huimin Zhang,Shanlin Qiao,Long Wang,Yanping Sun
Most of the mesoporous chiral mesoporous silica (CMS) was synthesized by the chiral surfactant-directing method. In this study, a facile method was designed to synthesize CMS. In this method, achiral amphiphile was used as templating agents, and dilute ammonia solution was applied to induce the chirality of the CMS. Meanwhile, its morphology can be controlled by changing the concentration of the aqueous ammonia solution. The obtained CMS was characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results showed that all of the CMS possessed highly ordered mesostructures, and as the concentration of ammonia decreases, the chirality of the CMS becomes more obvious. Water-insoluble drug curcumin (Cur) was used as a model drug. The characteristics of CMS before and after drug loading were further detected by Fourier transform infrared spectrometer (FT-IR), N2 adsorption–desorption and differential scanning calorimetry (DSC). The result showed that Cur was successfully loaded inside the pores of the CMS and remained an amorphous state due to steric inhibition. Additionally, CMS could significantly increase the release rate of Cur under different pH conditions.
研究领域:
材料科学
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药学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2023
·
IF 2.6
Weijie Jia,Yuqi Su,Songtao Cao,Ao Dong,Ying Zhang,Maogang He
Mutual diffusion coefficients of three alkanes (n-heptane, n-octane and isooctane) in cyclohexane were measured by digital holographic interferometry under atmospheric pressure. The measured temperature points were 288.15 K, 298.15 K and 308.15 K, respectively and the mass fraction of the measured solution range was from 0.05 to 0.95. The extended relative uncertainty of the measurement system was estimated to be less than 2.4%. The dependence of mutual diffusion coefficient on temperature and solution concentration was studied. The mutual diffusion coefficients of these three binary mixtures increase with the increase of temperature and have a nearly linear relationship with the solution concentration. And the image processing process of holographic interference image is introduced in detail. Zhang et al .’s model, Darken model and Vignes model were used to predict the mutual diffusion coefficients of the three binary mixtures, the absolute average of relative deviations (AARDs) are 2.97%, 3.89% and 6.18%, respectively and Zhang et al .’s model is the one with the best agreement among the three models.
研究领域:
化学工程
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物理化学
·
热力学
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产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Mei Dong,Kuilong Liu,Guoqiang Song,Guiping Ma
In this study, MOF-on-MOF hybrids were successfully synthesized by interfacial growth method using CoZn-ZIF as guest MOF and MIL-101(Fe) as host MOF, and then employed as heterogeneous catalysts to activate peroxymonosulfate (PMS) in the degradation of dyes. The hybrids exhibited different morphologies depending on the Co/Zn ratios (10/0, 10/2, 10/10, and 2/10), all of which displayed exceptional catalytic performance. Notably, the hybrid with a Co/Zn ratio of 10/2 showed the highest degradation rate of MB, reaching 100 % removal within 3 min with a k obs value of 452.75 Lg −1 min −1 based on the pseudo-second-order kinetic model. Through EPR characterization and scavenging experiments, it was determined that the degradation of dyes occurred through a combination of radical (SO 4 •-, •OH)and non-radical ( 1 O 2 ) pathways, with 1 O 2 and SO 4 •- playing prominent roles. Various factors such as Co/Zn ratio, catalyst dosage, PMS concentration, initial pH, temperature, and MB solution concentration were systematically investigated to understand their influence on the catalytic performance. Furthermore, the influence of inorganic ions, humic acid (HA), and the reusability and stability of the catalyst was evaluated, demonstrating its potential for practical applications. Overall, this research provides valuable insights into the design and application of MOF-based catalysts for environmental remediation processes.
研究领域:
环境科学
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催化
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材料科学
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化学工程
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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）