CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Wenxin Zhu,Wei Huang,Wenhua Zhou,Zhe Qiu,Zheng Wang,Haojun Li,Yonggui Wang,Jian Li,Yanjun Xie
Bio-based membranes for emulsion separation are sustainable, low-cost, renewable, biodegradable, and nontoxic. Herein, an antibacterial sandwich-like composite paper was fabricated by a facile process using Ag nanoparticles (Ag NPs)-coated pulp fibers and cellulose nanofibrils (CNFs). The obtained Ag-Pulp/CNF composite paper was superhydrophilic, allowing a 96 % separation efficiency for various oil-in-water emulsions. This outstanding separation efficiency was maintained over 20 separation cycles. The composite paper also showed satisfactory separation performance for water-in-oil emulsions after modification to render the surface hydrophobic. The CNFs provided the composite a nanoscale pore, which rejected nearly 100 % of bacteria when used to filter bacteria-contaminated emulsions due to a physical barrier effect. Attributed to the intrinsic antibacterial capability of Ag NPs, the composite paper exhibited strong antibacterial performance against Escherichia coli . Thus, the composite paper that was mainly derived from sustainable pulp fibers exhibited potential performance for oil/water separation and water purification.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2020
·
IF 2.463
Zhengjun Fang,Shengqiong Tan,Feng Wu,Yinchun Jiao,Chaktong Au,Yuting Wang,Jing Shen,Bing Yi
Solvent and substituent effects on the ultraviolet absorption properties of Schiff bases were targeted both experimentally and computationally. A wide set of X-PhCH = NPhCH = CHPh-Y were prepared for this study, and their maximum absorption wavelength ( λ max ) and the corresponding energy (υ max ) in thirteen solvents were measured. The results show that the λ max of the compounds ranges from 347 to 388 nm. With increase of electron withdrawing or electron donating ability of X or Y, a bathochromic shift is observed. Furthermore, the λ max values are sensitive to the properties of solvents, while the polarity of solvents alone fails to account for the trends of solvatochromism . Computational analyses based on density functional theory were conducted to elucidate the phenomena. The polarization effect of solvent on solute can be used to measure the effect of solvent, and polarizability parameter Δη is proved to be more effective to scale the solvent effects on UV absorption of the compounds. Finally, a quantitative model has been developed to express the effects of substituent and solvent on υ max . The derived model enables practical expression of the relationship between substituents, solvents and UV absorption.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Rongrong Li,Wei Wang,Xianlang Chen,Hong Chen,Huanhuan Bao,Yuwei Zhu,Jia Zhao,Deman Han
This study reports the equilibrium solubility for monobenzone in methanol, ethanol, n-propanol, isopropanol, n-butanol, acetonitrile, ethyl acetate, acetone, 1,4-dioxane, cyclohexane, N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), n-hexane, n-octanol, and water that was determined by means of the isothermal method between 283.15 and 313.15 K under p = 101.1 kPa. The maximum value of monobenzone solubility was 0.6316 in mole fraction at 313.15 K dissolved in ethyl acetate, but the least data was achieved in water. The solubility of monobenzone increased with the rising temperature and the order followed in the 15 pure solvents was ethyl acetate (0.6316, 313.15 K) > 1,4-dioxane (0.4350, 313.15 K) > methanol (0.1356, 313.15 K) > acetonitrile (0.1247, 313.15 K) > (ethanol, isopropanol) > n-propanol (0.09942, 313.15 K) > n-butanol (0.08346, 313.15 K) > n-octanol (0.03546, 313.15 K) > cyclohexane (8.020×10–3, 313.15 K) > n-hexane (3.133 × 10–3, 313.15 K) > NMP (2.372 × 10–4, 313.15 K) > DMF (1.145 × 10–4, 313.15 K) > acetone (4.032 × 10–5, 313.15 K) > water (3.019 × 10–5, 313.15 K). There was no existence of processes such as solvation or polymorphic transformation during the entire experiment. Several models covering the modified Apelblat, λh, Wilson, and non-random two-liquid models were applied to correlate and calculate monobenzone solubility data in fifteen monosolvents. Results showed that the modified Apelblat equation provided the best results with the experimental ones. The largest relative average deviation and root-mean-square deviation were no more than 4.74 × 10–2 and 1.81 × 10–3, respectively.
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Iranian Chemical Society
·
2020
·Vol. 17
·期 8
·2095-2103
·
IF 1.552
Cao Jiangping,Xie Qilong,Liang Yongfeng,Di Hongwei,Yi Zonghui,Ma Gui,Zhang Ping
Abstract A rapid and simultaneous method for the determination of naphthol isomers in human urine has been developed and validated by using molecular complex-based dispersive liquid–liquid microextraction followed by high-performance liquid chromatography. This method worked by the formation of hydrogen bond interaction between the extractant (1-octanol, Lewis base) and the analytes (naphthols, Lewis acid). Experimental parameters, including the type and volume of the extractant and disperser, pH, addition of salt, extraction time, were examined and optimized. Additionally, the proposed method was applied to human urine samples collected from six volunteer donors of the chemical laboratory. Under the optimum conditions, average recovery rates for the real samples varied from 78.5 to 98.2%, with the relative standard deviations less than 7.6%. The method offered excellent linearity over a range of 5–5000 ng/mL with correlation coefficient ( r < 0.999). The detection limit ( S / N = 3) was 0.61–0.69 ng/mL. The developed method was successfully applied to the determination of naphthol isomers in human urine. Compared with the previous DLLME methods, the feature of the new procedure lies in simpler sample preparation, higher sensitivity and lower cost of the extraction device. Also, theoretical calculations were conducted to understand the molecular interaction mechanism between 1-octanol and naphthols. Graphic abstract
✓ 已验证
产品关联
DOI
高影响因子
ATMOSPHERIC ENVIRONMENT
·
2020
·
IF 4.039
Fenghua Li,Shanshan Tang,Narcisse T. Tsona,Lin Du
Kinetics and mechanism of α-terpineol oxidation by OH radicals were studied in the aqueous phase under acidic condition, and the optical properties of the reaction products were examined. Using the relative rate method, the rate constant of α-terpineol reaction with OH radicals was determined to be (1.3 ± 0.3) × 10 10 M −1 s −1 . The reaction products were analyzed by gas chromatography-mass spectrometry (GC-MS) and the reaction mechanism was proposed. The absorbance changes of the products were monitored by a UV–vis spectrophotometer, and α,β-unsaturated ketone compounds were observed. A certain distribution of α-terpineol in the aqueous phase has the potential to be conducive to the formation of aqueous secondary organic aerosols. At the same time, in order to investigate the persistence of α-terpineol in the atmosphere, its lifetime towards reaction with OH in atmospheric water was determined to be 6.2 h and 1.0 h in urban and remote area, respectively.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Jiangping Cao,Qilong Xie,Hongwei Di,Yongfeng Liang,Gui Ma,Zonghui Yi,Ping Zhang,Peng Fu,Jikai Li
A method for the simultaneous determination of eight phenolic compounds (PCs) with a wide polarity range in water samples has been developed and validated using molecular complex based dispersive liquid–liquid microextraction (MC-DLLME) followed by high-performance liquid chromatography. In this process, the molecular complex acted as the extractant, which was formed by tributyl phosphate (TBP) and 1-octanol through hydrogen bond interaction in situ, using a disposable polyethylene pipette for the extraction. The extraction mechanism was investigated by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), which demonstrated that a TBP-1-octanol complex formed via P O HO hydrogen bonding . Furthermore, the extraction mechanism in the dual extraction solvent system involves hydrogen bonding for polar PCs and physical extraction for weak polar and apolar ones. Under the optimum conditions, detection limits were in the range 0.4–5.51 ng/mL and recoveries for the real samples varied from 82.0% to 104.7%, with a relative standard deviation (RSD) of <9.1%. The developed method is simple, inexpensive and sensitive and was successfully applied to the extraction and determination of phenolic compounds in water samples.
✓ 已验证
产品关联
DOI
高影响因子
Microfluidics and Nanofluidics
·
2020
·Vol. 24
·期 6
·1-11
·
IF 2.489
Du Yuhan,Mo Liangji,Wang Xiaoda,Wang Hongxing,Ge Xue-hui,Qiu Ting
Mint oil is a complex mixture of comparatively volatile and labile components, making it challenging to be efficiently encapsulated and retained in microcapsules using traditional approaches. Microencapsulation, by encapsulating the substance with certain shells, can effectively reduce the diffusion, evaporation and the reactions of the inside actives with the external environment. The microencapsulation of mint oil and other aromatic actives have been a prevailing method to improve the stability, prolong the storage time, and enhance the controllability of the actives. Monodisperse core–shell microcapsules based on double emulsions prepared by microfluidic technology with controllable structure, pH-responsive ability, and adjustable release properties are successfully developed. Different flow rates, glutaraldehyde concentration, solidification time and pH have been used to adjust the core sizes, the shell thickness, the crosslinking density and the shrinkage degree of the shell. By monitoring their mint oil sustained release ability through an ultraviolet spectrophotometer, appropriate conditions to form the mint oil microcapsules with high encapsulation efficiency and controllability in release properties are achieved, building the foundation for better mint oil storage, transportation, and their applications.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 17
·9985-9995
·
IF 3.119
Xiaomin Li,Zhengjiang Du,Yi Wu,Yadong Zhen,Rixin Shao,Bingqi Li,Chengmeng Chen,Quansheng Liu,Huacong Zhou
Construction and application of novel hydrogenation catalysts is important for the conversion of carbonyl or aldehyde compounds into alcohols in the field of biomass utilization. In this work, a novel, efficient, and easily prepared hafnium–graphite oxide (Hf–GO) catalyst was constructed via the coordination between Hf4+ and the carboxylic groups in GO. The catalyst was applied into the hydrogenation of biomass derived carbonyl compounds via the Meerwein–Ponndorf–Verley (MPV) reaction. The catalyst gave high efficiency under mild conditions. An interesting phenomenon was found whereby the activity of the catalyst increased gradually in the initial stage during reaction. The solvent, isopropanol, was proved to have an activation effect on the catalyst, and the activation effect varied with different alcohols and temperatures. Further characterizations showed that isopropanol played the activation effect via replacing the residual solvent (DMF) in micro- and mesopores during the preparation process, which was hard to be completely removed by common drying process.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Meng Chen,Wei Lu,Hejun Zhu,Leifeng Gong,Ziang Zhao,Yunjie Ding
Linear α-olefins (C8–C12 α-olefin, LAOs) are acknowledged as high-value-added chemicals in both lubricant production and the polyolefin industry. An alternative route to the synthesis of high-purity LAOs is the dehydration of linear long-chain n-alcohols, whereas elevating the activity and selectivity of catalysts remains a challenge. Herein, we presented that on using sodium-modified γ-Al2O3 as the catalyst, a high selectivity (up to 96.87%) to 1-decene was achieved, and an optimized experimental condition (329 °C and 0.25 h–1) was found using the response surface method. Characterization results including X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), pyrolysis (Py)-IR, NH3-temperature-programmed desorption (TPD), and CO2-TPD showed that a suitable ratio (∼0.4 wt %) of sodium impregnation could inhibit the strong acid sites of the catalyst, and sodium impregnation led to the formation of additional base sites, which accounted for the synergistic effect with other acid sites to promote further conversion of ethers to olefins. This work is of significance for the synthesis of LAOs from long-chain n-alcohols.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Jiao Sha,Teng Ma,Rui Zhao,Pengshuai Zhang,Renren Sun,Gaoliang Jiang,Yameng Wan,Haixia He,Xinding Yao,Yu Li,Tao Li,Baozeng Ren
In this work, the solubility of doxifluridine in methanol, ethanol, n-propanol, n-butanol, isobutanol, n-Pentanol, n-hexanol, n-octanol, (±)-2-ethyl-1-hexanol, acetone, dimethyl formamide (DMF), dimethyl sulfoxide (DMSO) were experimentally determined by a laser dynamic method within the temperature range from 278.15 K to 333.15 K at 101.3 kPa. The measured results demonstrated that the experimental solubility of doxifluridine in all selected pure solvents increased with the rise of temperature. It was also found that the order of the mole fraction solubility of doxifluridine in the twelve mono-solvents was: DMSO > DMF > methanol > acetone > ethanol > n-propanol > n-butanol > n-pentanol > n-hexanol ≈ isobutanol > n-octanol > (±)-2-ethyl-1-hexanol. In order to facilitate the industrial application and other studies, the experimental data of solubility were fitted well using the λh equation, the van't Hoff equation, the modified Apelblat equation, the NRTL model and the UNIQUAC model. Moreover, the apparent thermodynamic properties of doxifluridine in all mono-solvents were investigated by the famous modified Van't Hoff equation from the solubility data.
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 25
·10621-10627
·
IF 3.288
Xue Xiong,Meiling Qi
This work presents a novel column fabrication approach for capillary gas chromatography (CGC) through the condensation reaction of a hydroxyl-terminated polymer with a cross-linker inside a capillary column. In this work, polypropylene glycol (PPG 4000) and tris[3-(trimethoxysilyl)propyl]isocyanurate (ICS) were employed to fabricate the PPG-gel capillary column for GC analyses. Inside the column, a 3D cross-linked organogel network forms on the capillary inner surface by condensation of PPG 4000 with ICS under the given mild conditions. As a result, the PPG-gel column exhibited moderate polarity and showed distinctly advantageous resolving performance and inertness for carboxylic acids over the PPG column by the conventional static coating method. Also, it achieved high-resolution separations of the isomer mixtures of alkanes, alkylbenzenes and halobenzenes. Moreover, the PPG-gel column exhibited dramatically improved solvent stability because of its cross-linked organogel network. The organogel column displayed excellent column repeatability and reproducibility with the RSD% values in the range of 0.01–0.04% for run-to-run, 0.71–0.84% for day-to-day and 2.4–3.1% for column-to-column. The proposed organogel approach is facile and applicable to other analogous materials and has a promising future for wide applications.
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Xiao Li,Jia Chen,Heng Wang,Xuanxuan Wang,Yuxiu Xiao
Hexafluoroisopropanol-alkanol (C 6 –C 12 ) supramolecular solvents were proposed and their application potential as restricted access extraction solvents was assessed. Hexafluoroisopropanol acts as alkanol reverse micelle-forming agent and density-regulating agent for the supramolecular solvent synthesis. The formation of supramolecular solvent only needs a small percentage of hexafluoroisopropanol (<10% v/v for alkanol <5% v/v) and is almost not affected by the pH (2-11) and low ionic strength (NaCl <3%, w/v) of aqueous medium. The supramolecular solvents have higher density than water and consist of reversed micellar aggregates with irregular mesh structures and hydrophilic inner cavities, and the hydrophilic cavity size is obviously dependent on the hexafluoroisopropanol amount in the bulk system but almost not relevant to the alkanol amount. The hydrogen-bond and hydrophobic interactions of hexafluoroisopropanol with alkanol and the hydrogen-bond force between hexafluoroisopropanol and water play crucial roles in the formation of supramolecular solvent. The supramolecular solvents not only do not or slightly dissolve macromolecules (proteins, polysaccharides , and humic acid sodium), but also can effectively exclude them in extraction procedure ; meanwhile, they can extract small molecules from complex samples with high extraction rate (even near 100% through optimization). The extraction mechanism involves the hydrophilic inner cavity size of supramolecular aggregates and the interactions (hydrogen-bond, hydrophobic) between supramolecular solvent and analytes. The suitability of supramolecular solvents as extractants was evaluated by extracting and determining chlorophenols in real water samples, coupled with high performance liquid chromatography-ultraviolet detector. The enrichment factors of 72–147 were obtained. Limits of detection were from 0.38 to 0.57 ng mL −1 . The recoveries ranged from 96.0 to 107.9%, and intra-day and inter-day precisions were less than 4.0%. The novel hexafluoroisopropanol-alkanol supramolecular solvents have promising potential as restricted access extractants.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）