Scientific Reports
·
2019
·Vol. 9
·期 1
·1-11
·
IF 4.011
Zhu Xiaowei,Yang Kuisuo,Wu Anping,Bai He,Bao Jinrong,Qiao Yan,Yang Yunjiang,Li Wenxian,Liu Ying
The novel submicro-spheres SiO 2 @LaPO 4 :Eu@SiO 2 with core-shell-shell structures were prepared by connecting the SiO 2 submicro-spheres and the rare earth ions through an organosilane HOOCC 6 H 4 N(CONH(CH 2 ) 3 Si(OCH 2 CH 3 ) 3 (MABA-Si). The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (IR). It is found that the intermediate shell of the submicro-spheres was composed by LaPO 4 :Eu nanoparticles with the size of about 4, 5–7, or 15–34 nm. A possible formation mechanism for the SiO 2 @LaPO 4 :Eu@SiO 2 submicro-spheres has been proposed. The dependence of the photoluminescence intensity on the size of the LaPO 4 :Eu nanoparticles has been investigated. The intensity ratios of electrical dipole transition 5 D 0 → 7 F 2 to magnetic dipole transition 5 D 0 → 7 F 1 of Eu 3+ ions were increased with decreasing the size of LaPO 4 :Eu nanoparticles. According to the Judd-Ofelt (J-O) theory, when the size of LaPO 4 :Eu nanoparticles was about 4, 5–7 and 15–34 nm, the calculated J-O parameter Ω 2 (optical transition intensity parameter) was 2.30 × 10 −20 , 1.80 × 10 −20 and 1.20 × 10 −20 , respectively. The increase of Ω 2 indicates that the symmetry of Eu 3+ in the LaPO 4 lattice was gradually reduced. The photoluminescence intensity of the SiO 2 @LaPO 4 :Eu@SiO 2 submicro-spheres was unquenched in aqueous solution even after 15 days.
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高影响因子
Journal of Coatings Technology and Research
·
2019
·Vol. 16
·期 3
·857-868
·
IF 1.584
Peng Mengke,Zhang Xiaodan,Xiao Xiao,Dong Mengjin,Zhao Guowei,Liu Peng,Chen Yashao,Wang Changhao
Abstract Magnesium alloy (MgA) was widely used in biomedical field owing to its good biocompatibility and degradability. The surface of MgA was usually modified to improve its corrosion resistance, biocompatibility, and biological properties. Herein, we employed a layer-by-layer assembly technique to assemble both polyanionic and polycationic electrolytes onto the microarc oxidation-treated MgA surface to yield MgA-MgO-PEI-[Ge(HANPs)/Lzm] 50 , where the gelatin-conjugated hydroxyapatite nanoparticles [Ge(HANPs)] are the polyanionic electrolyte, lysozyme (Lzm) is the polycationic electrolyte, and polyethyleneimine (PEI) is the transition layer. The morphology and chemical composition of MgA-MgO-PEI-[Ge(HANPs)/Lzm] 50 were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, indicating that [Ge(HANPs)/Lzm] 50 were successfully fabricated on the surface of MgA-MgO. The surface of MgA-MgO-PEI-[Ge(HANPs)/Lzm] 50 exhibited good hydrophilicity as evidenced by the low water contact angle of 24.5°. Excellent corrosion resistance of MgA-MgO-PEI-[Ge(HANPs)/Lzm] 50 was obtained since it can decrease about four orders of magnitude of corrosive current ( I corr ) compared to pristine MgA. The biological assay for MgA-MgO-PEI-[Ge(HANPs)/Lzm] 50 showed good antiplatelet adhesion and excellent antibacterial activities against both E. coli and S. aureus. Graphical abstract
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2022
·Vol. 48
·期 6
·2557-2573
·
IF 3.134
Liu Yueyu,Yin Zhili,Wang Ziqing,Mou Ronglin,Wei Zhong
High surface area ZrO 2 –KOH sample was prepared and used the catalyst for the synthesis of glycerol carbonate (GC) from dimethyl carbonate (DMC) and glycerol. The structure properties of ZrO 2 –KOH were characterized by XRD, BET, CO 2 -TPD, XPS, and ICP-OES. It was found that the strong basicity of ZrO 2 –KOH might be attributed to the oxygen vacancies as well as the big surface area. Experiments were developed to evaluate the effects of catalysis loading, proportion of reactants, temperature and reaction time on the conversion of glycerol to GC. The consequences showed that ZrO 2 –KOH was a highly efficient basic catalyst for synthesis of GC from glycerol. The catalytic performance of ZrO 2 –KOH is much better than that of ZrO 2 –KOH–CP, ZrO 2 –NH 4 OH, and some reported heterogeneous catalysts. And the higher performance of ZrO 2 –KOH was ascribed to the strong basicity. 99.43% conversion was obtained in a particular situation of catalyst/glycerol weight ratio of 3 wt%, DMC/glycerol molar ratio of 3:1, reaction temperature of 80 °C, and reaction time of 2 h. The plausible reaction mechanism for the transesterification on the strong basic active sites was discussed.
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高影响因子
CELLULOSE
·
2018
·Vol. 26
·期 2
·1195-1208
·
IF 3.809
Song Peng,Shen XiaoPing,He XiaoMei,Feng KaiHui,Kong LiRong,Ji ZhenYuan,Zhai LinZhi,Zhu GuoXing,Zhang DongYang
Abstract Heteroatom-doped porous carbon materials are one of the most promising electrodes for high-performance supercapacitors. However, the development of a simple, green and low-cost strategy for their preparation is still highly challenging. In this study, we reported a simple and sustainable preparation of nitrogen-doped hierarchically porous carbon (NHPC) by using cellulose as raw materials. A NaOH/urea (7:12) system acted as the solvent, activator, and dopant simultaneously. The resultant NHPC has a high BET specific surface area of 2245 m 2 g −1 , a typically porous architecture comprising of micro-, meso-, and macropores with an appropriate average pore size of 2.83 nm, as well as a suitable nitrogen-doping degree of 3 wt%. The unique features of NHPC afford an outstanding specific capacitance of 300 F g −1 at 0.5 A g −1 , representing a new capacitive record among the cellulose-derived carbon electrodes reported so far. The NHPC//NHPC supercapacitor cell displays a high energy density of 17.2 Wh kg −1 at 452 W kg −1 , and maintains 12.1 Wh kg −1 at 4500 W kg −1 . High rate capability (81% of capacitance retention from 0.5 to 10 A g −1 ) and excellent cycling stability (5% loss after 10,000 cycles) have been also demonstrated. The facile and affordable synthesis route together with outstanding energy storage behavior endows the cellulose-derived NHPC with promising application for supercapacitors.
Graphical abstract
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高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2022
·Vol. 30
·期 7
·2943-2954
·
IF 4.705
Lu Yanran,Zhang Wen,Wang Mei,Zhang Hua,Li Jiahui,Luo Wenhao
The adsorption is widely used to remove dyes from wastewater because of its low cost, simple preparation, and environmental friendliness. However, the existing adsorbents suffer from difficult recycling, inconvenient use, and a low regeneration rate. In this study, polyacrylonitrile (PAN) and graphene oxide (GO) was mixed for electrospinning GO/PAN nanofiber membrane and then chitosan (CS) was grafted to obtain CS-GO/PAN nanofiber membrane. CS-GO/PAN membranes were characterized with FE-SEM, EDX, FT-IR and, WCA. The effects of membrane types, dosage, solution pH on the removal of dye sunset yellow (SY) were systematically investigated. The results showed that more than 80% of SY were removed within 15 min at pH 2 using 100 mg CS-GO/PAN membrane. Adsorption kinetic data were fitted well with the pseudo-second-order model and adsorption achieved equilibrium within 240 min. The isotherm study followed the Langmuir model with the actual maximum adsorption capacity of 211.54 mg/g. After 5 adsorption–desorption cycles, the adsorption efficiency and the desorption efficiency of CS-GO/PAN were over 90% and 93%, respectively. Moreover, the membrane recovered easily from the water while its integrity was still maintained. The CS-GO/PAN membrane demonstrates the virtue of high adsorption capacity, easy operation, and good reusability, which could be considered as a promising material for adsorbing dyes in wastewater.
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高影响因子
CELLULOSE
·
2022
·Vol. 30
·期 3
·1517-1532
·
IF 6.123
Zhang Xuzhen,Zhou Jin,Huang Wenjian,Wu Canqing,Nan Jingwen
To prepare poly (butylene succinate) (PBS)/cellulose nanocrystals (CNCs) with high performance and investigate the relationship between microstructure and properties, in this work, CNCs were firstly treated with ethyl succinyl chloride to improve their interfacial compatibility with PBS. Then melt spun processing was adopted to obtain PBS/CNC fibers, which were followed by heat stretching to further improve the orientation and mechanical properties of as-spun PBS fibers. The effects of modification of CNCs on chemical structure, their wettability as well as dispersion, thermal properties and mechanical properties were systematically investigated for the composite fibers. The dispersion, alignment of the CNCs and crystalline thermal behavior, and PBS chain orientation in the composite fibers were significantly influenced by the stretching treatment. The possible formation of multidimensional oriented superstructure including regularly arranged PBS shish kebab crystals, modified CNCs and oriented PBS chains has been suggested via SEM and SAXS in the composite fibers prepared at the high draw ratio. Significant improvement in tensile strength has been realized at the high draw ratio due to the enhanced orientation and dispersion of CNCs as well as the formation of multidimensional oriented superstructure.
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高影响因子
FIBERS AND POLYMERS
·
2016
·Vol. 17
·期 11
·1741-1748
·
IF 1.022
Xu Bin,Li Qiaoping,Zhuang Linghua,Wang Qiang,Li Chao,Wang Guowei,Xie Fengwei,Halley Peter J.
3-methyl-1-(ethylacetyl)imidazolium chloride ([EtMIM]Cl), was synthesized for chitosan dissolution, and the dissolution and regeneration behaviors of chitosan in [EtMIM]Cl were thoroughly investigated. The solubility of chitosan in [EtMIM]Cl was measured at temperatures ranging from 40 °C to 110 °C, based on which the thermodynamic parameters of chitosan in [EtMIM]Cl were calculated. The polarizability and hydrogen bond accepting ability was determined by solvatochromic UV/vis spectroscopy. The regenerated chitosan from [EtMIM]Cl by adding methanol was characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Density functional theory (DFT) computations were performed to study the interactions between [EtMIM]Cl and chitobiose. Five kinds of hydrogen bonds, C-H/O, O-H/O, O-H/Cl, C-H/Cl, N-H/Cl were found, suggesting strong interactions between [EtMIM]Cl and chitobiose. In particular, the oxygen atom and the active methylene group of carboxylic ester in [EtMIM] + , formed strong hydrogen bonding with chitobiose. The molecular simulation results indicated that both the Cl − anions and [EtMIM] + cation played important roles in the chitosan dissolution process, by the disruption of native hydrogen bonds of chitosan.
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高影响因子
Journal of Ocean University of China
·
2014
·Vol. 13
·期 2
·236-242
·
IF 0.381
Lian Ziru,Wang Jiangtao
Molecularly imprinted polymers (MIPs) were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Systematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high affinity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction (MISPE) method followed by high-performance liquid chromatography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0–200 μg L −1 ( R
2 > 0.99). Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation ( n =3) being in the range of 2.89%–5.96%.
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高影响因子
Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-10
·
IF 3.125
Cao Hongyan,Guo Fenghao,Chen Zhiyong,Kong Xiang Zheng
Stimuli-responsive polymers have received growing attention in recent years owing to their wide applications in diverse fields. A novel stimuli-responsive polymer, based on oligo(ethylene glycol) diacrylate (OEGDA) and methacrylic acid (MAA), P(OEGDA-MAA), is prepared by precipitation polymerization and is shown to have a LCST-type VPTT (volume phase transition temperature) at 33 °C in water and a UCST-type VPTT at 43 °C in ethanol, all at concentration of 1 mg/mL. Both VPTTs are strongly concentration and pH dependent, providing an easy way to tune the phase transition temperature. The polymer is characterized with regard to its composition and its morphology in water and in ethanol at different concentration. The two transitions are studied and interpreted based on the results. This work provides a novel way for the preparation of a new type of stimuli-responsive polymer with great potential for different applications, particularly those in biomedical areas because PEG-based stimuli-responsive polymers are known to be nontoxic and non-immunogenic.
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高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2018
·Vol. 48
·期 3
·367-378
·
IF 1.401
Li Hongxia,Guo Lijiang,Li Jianqiang
The water activities of the MgCl 2 –RbCl–H 2 O ternary system and its sub-binary systems have been measured with the isopiestic method at 323.15 K. The measured water activities for the MgCl 2 –H 2 O and RbCl–H 2 O sub-binary systems agree well with the results reported in literature. The measured equal water activity lines of the MgCl 2 –RbCl–H 2 O ternary system are not straight lines, which means the mixing behavior of the solutions do not obey Zdanovskii’s rule. The solubility of the MgCl 2 –RbCl–H 2 O ternary system has been determined with the Flow-Cloud-Point method at 323.15 K, and the measured results are roughly consistent with values reported in the literature. The Pitzer model was selected to correlate the water activity and solubility data measured in this work. The predicted water activities and solubility isotherm for the MgCl 2 –RbCl–H 2 O ternary system at 323.15 K, with binary solution parameters only, both deviated from the experiment values. The ternary solution Pitzer model parameters were obtained by fitting the measured water activities in the ternary system. The water activities and solubility isotherms of the MgCl 2 –RbCl–H 2 O ternary system at 323.15 K were calculated including both binary and ternary solution parameters. The calculated water activities are consistent with the experimental values. The calculated solubility isotherms are roughly consistent with experiment values, except they deviate somewhat in the RbCl crystallization region.
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2014
·Vol. 293
·期 2
·441-451
·
IF 2.41
Cao Hongyan,Wang Qian,Li Min,Chen Zhiyong
A series of poly(ethylene glycol) diacrylate/methacrylic acid (PEGDA/MAA)-based nanogels showing multiresponsiveness toward temperature, salt concentration, and pH value were synthesized by aqueous precipitation polymerization. The effect of monomer loading amount, cross-linking degree, and cross-linker type on synthesis of hydrogels was investigated, and so were the influences of MAA content in the feed of synthesis of hydrogel, pH value, and NaCl concentration on the thermosensitivity of hydrogels. The lower critical solution temperature (LCST) of poly(PEGDA/MAA) hydrogels decreased with an increase of MAA content or NaCl concentration and a decrease of pH value. One of the resultant hydrogels (PEGDA575/MAA, 40/60 mol/mol) displayed a distinct LCST of 35 °C under a gastric liquid-like condition (pH 1.0, 150 mM NaCl). Such hydrogel showed a good potential in controlling the release of 5-fluorouracil (5-FU), an anticancer agents, under the above gastric liquid-like condition and also an intestinal liquid-like one.
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2022
·Vol. 48
·期 7
·2887-2901
·
IF 3.134
Huang Yan,Xing Wenxin,Zhou Liang,Tian Baozhu,Zhang Jinlong,Zhou Yi
Molybdenum oxide (MoO 3 ), as a transition metal oxide, has excellent catalytic activity, chemical stability, and high application value in the catalytic field. As a typical cocatalyst, noble metals, such as silver and gold, can be decorated with MoO 3 and improve their visible light absorption performance and photogenerated charge separation efficiency to achieve a higher light energy utilization rate. However, the high price of noble metals makes it challenging to realize large-scale industrial applications. Herein, a highly dispersed MoP quantum dot (QDs) decorated MoO 3 nanorods (PMO) was prepared by the co-calcination method to achieve efficient photocatalytic oxidation of target organic contaminants. Rhodamine B (RhB) and norfloxacin (NOR) were used as the model organic contaminants to evaluate the photocatalytic activity of the as-prepared composite photocatalysts. Based on the photoelectric performance and band structure analysis results, the enhancement mechanism of modification with MoP QDs in PMO was proposed. The introduction of MoP QDs in PMO can accelerate electron transfer and achieve a low recombination rate of photogenerated charges. Therefore, the photocatalytic degradation efficiency of RhB and NOR by PMO was higher than that of pristine MoO 3 nanorods and MoP QDs. The degradation efficiency of RhB and NOR could reach more than 97% and 100% within 40 min by PMO-5. Furthermore, photogenerated holes and hydroxyl free radical (·OH) as the primary active oxidants involved in the oxidation process of organic contaminants by PMO-5. PMO-5 still maintained vigorous catalytic activity after five cycles, indicating that it had good chemical stability. This work could provide a new strategy to construct a highly efficient photocatalyst for the efficient degradation of organic contaminants.
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高影响因子
危险品化学品经营许可证（带存储）