Environmental Earth Sciences
·
2022
·Vol. 81
·期 16
·1-12
·
IF 3.119
Feng Wenchao,Wu Jun,Lu Jian
The high concentration of manganese (Mn 2+ ) in geothermal water will seriously reduce its utilization rate. Manganese sand has been used to rapidly remove Mn 2+ from water. This study investigated the long-term removal of Mn 2+ from simulated geothermal water by manganese sand filtration column system. The average Mn 2+ removal rate from simulated water with the inlet water temperature of 25, 50, 70 °C were 87.4%, 96.2% and 99.0% during the operation of 90 days. The effluent pH did not change much compared with influent pH value (7.6–8.0). The Mn 2+ removal rates during the operation of 90 days with influent concentration of 1, 10, 20 and 50 mg/L were respectively 98.2%, 99.8%, 91.4% and 63.4%. The average removal rates of Mn 2+ were respectively 99.8% and 94.0% with the influent flow of 5.2 mL/min and 10.4 mL/min. The temperature change in the manganese sand filtration column was further explored in this paper. The experiment of filtration column heated/non-heated showed that the manganese sand filtration column heated had a better effect of removal which could run for 152 days. The dispersion coefficient ( D ) analysis derived from inverse modeling showed that a small temperature change in the filtration column system was conducive to the homogenization of manganese sand medium in the column. The Mn 2+ removal process of manganese sand filtration column heated was proposed. Surface characteristics analysis of manganese sand in the column after reaction showed that Mn 2+ removal mainly occurred in the upper part of the filter column. The surface material of manganese sand in the filtration column heated after operation was manganese oxide material mainly composed of Mn 2 O 3 and MnO 2 . These findings suggested the potential of manganese sand in the engineering application of removing Mn 2+ in geothermal water.
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JOM
·
2019
·Vol. 72
·期 4
·1687-1693
·
IF 2.305
Xia Yang,Zhao Jinlong,Dong Zhaowang,Guo Xueyi,Tian Qinghua,Zhang Siwen,Liu Yong
Ultra-high pure metallic zirconium powder was successfully obtained through a two-step gradient reduction of nano-ZrO 2 in Ar atmosphere. The first reduction by Mg was to remove ~ 85% oxygen, followed by a heat-treatment step to control the particle size and specific surface area of the powder, and the final reduction by calcium was to further purify the powder and decrease oxygen to an extremely low level (0.068 wt.%). The oxygen level in the final powder meets the standard specification of Zr sponge (ASTM B349/B349M-16). Processing parameters, including the reduction temperature, the amount of Mg and MgCl 2 and the heat treatment temperature, were investigated. Thermodynamic modeling with the assistance of HSC Chemistry software was carried out to understand the reduction reaction. This study offers a novel process for producing ultra-high pure metallic zirconium powder with the potential to replace the conventional Kroll process.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 6
·4649-4657
·
IF 2.019
Jiang Si,Wu Jihuai,Ye Beirong,Fan Yueyue,Ge Jinhua,Guo Qiyao,Huang Miaoliang
We present a facile one-step hydrothermal method to in situ grow nickel selenide (Ni 3 Se 2 ) nanosheets on nickel (Ni) foam (Ni 3 Se 2 /Ni) by using SeO 2 as selenide source, Ni foam as nickel source and NaBH 4 as reducing agent. The mole ratio of NaBH 4 /SeO 2 is optimized as 4:1. An asymmetric supercapacitor (ASC) is fabricated by using as synthesized Ni 3 Se 2 /Ni as positive electrode and activated carbon (AC) as negative electrode. The synthesized materials and assembled devices are measured and characterized by a field emission scanning electron microscopy, powder X-ray diffraction, cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The results shows that the as-synthesized Ni 3 Se 2 /Ni electrode possesses a high specific capacitance of 854 F g −1 at 1 A g −1 . The ASC can steadily operate with a high voltage of 1.6 V in 3 M KOH electrolytes, and possesses a superior energy density of 23.3 W h kg −1 at a power density of 398.1 W kg −1 . In addition, the Ni 3 Se 2 //AC ASC shows excellent charge/discharge stability, after 5000 cycles the capacitance retention reaches 91.11%. The excellent performance of Ni 3 Se 2 /Ni electrode is mainly due to the pseudo-capacitive by Ni 3 Se 2 and the 3D structure of Ni foam.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 5
·531-539
·
IF 1.42
Xing Xin-ming,Liu Guang-ming,Ding Yan-wei,Zhang Guang-zhao
The lower critical solution temperature (LCST) behavior of poly(acrylamide- co -diacetone acrylamide) (poly(AM- co -DAM)) copolymer in aqueous solutions was studied. The results demonstrate the LCST linearly decreases as the molar fraction of DAM ( f
DAM ) increases. In the range of f
DAM < 0.36, the transmittance increases as f
DAM decreases because the more hydrophilic copolymer chains can form looser aggregates with a lower refractive index. The transmittance exhibits a minimum when f
DAM is less than 0.28 as the chains form micelle-like structure with a size smaller than the wavelength. The LCST decreases with the initial polymer concentration, but it levels off when the polymer concentration is high enough. Moreover, no hysteresis can be observed in the change of transmittance during the heating-cooling process because no additional hydrogen bonds are formed in the collapsed state due to the steric hindrance of the large side groups in DAM units.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2021
·Vol. 39
·期 9
·1211-1216
·
IF 3.603
Xiang Ming-Yue,Lyu Dong,Liu Ling-Zhi,Men Yong-Feng
Crystallinity of bottlebrush polymers due to side chain crystallization has been considered to be related to the length of the side chains only under the assumption of complete participation of crystallization by all side chains. Recent experimental results revealed that in poly( n -alkyl methacrylate)s a fraction of side chains could not crystallize due to constraints imposed by the trapped main chain entanglements and required expansion of main chain-main chain distance. This result renders the original simplified consideration of the origin of crystallinity in bottlebrush polymers questionable. In this work, we introduce a new parameter f c , the fraction of crystallizable side chains, to better describe the crystallinity of bottlebrush polymers. A linear relationship between the melting enthalpy and the number of alkyl groups in side chains for bottlebrush polymers reported repeatedly indicates that f c remains essentially unchanged when bottlebrush polymers had the same main chain structure and grafting degree but different side chain lengths. The slope of the above-mentioned linear relationship is thus \(\Delta H_{\text{CH}_2}\times f_{c}\) , where \(\Delta H_{\text{CH}_2}\) stands for the melting enthalpy of one mole alkyl group packed into the crystal. With a known value of f c , it is possible to estimate the value of \(\Delta H_{\text{CH}_2}\) . In case of poly( n -alkyl methacrylate)s, we estimated \(\Delta H_{\text{CH}_2}\) of hexagonal crystal being at most 5.74 kJ/mol with the knowledge of possibly smallest f c of 0.67 obtained from small angle X-ray scattering data. Therefore, the crystallinity of bottlebrush polymer would be calculated based on the equation \(X_{\rm{c}}=f_{\rm{c}}\times\frac{N_{\rm{c}}}{N}\) with N and N c being the number of alkyl groups in a side chain and those packed in the crystalline structure, respectively. Both chemical structure and grafting degree of bottlebrush polymers affect f c .
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CELLULOSE
·
2021
·Vol. 28
·期 12
·7877-7891
·
IF 5.044
Ma Jianhua,Pu Haihong,He Pengxin,Zhao Qiangli,Pan Shaoxue,Wang Yaowu,Wang Chen
Multifunctional fibers have attracted widespread attention due to applications in flexible smart wearable devices. However, simultaneously obtaining a strong and functional woven fiber is still a great challenge owing to the conflict between the properties mentioned above. Herein, mechanically strong and highly conductive cellulose/carbon nanotube (CNT) composite fibers were spun using an aqueous alkaline/urea solution. The microstructure as well as physical properties of the resulting fibers were characterized via scanning electron microscopy, infrared spectroscopy, mechanical and electrical measurement. We demonstrated that carboxylic CNTs can be well dispersed in alkali/urea aqueous systems which also dissolved cellulose well. The subsequent wet spinning process aligned the CNTs and cellulose molecules inside the regenerated composite fiber well, enhancing the interaction between these two components and endowing the composite fiber having a 20% CNT loading with an excellent mechanical strength of 185 MPa. Benefiting from the formation of conductive paths, the composite fiber with the diameter of about 50 μm possessed an electrical conductivity value in the range of 64–1274 S/m for 5–20 wt% CNT loading. This excellent mechanical strength and high electrical conductivity enable the composite fiber to exhibit a great potential in joule heating; the heating temperature of cellulose/CNT-20 fiber reached more than 55 °C within 15 s at 9 V. In addition, the multifunctional filaments are further manufactured as a water sensor to measure humidity. This work provides a potential material that can be applied in the fields of wearable electronics and smart flexible fabrics. Graphic abstract
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MICROCHIMICA ACTA
·
2014
·Vol. 181
·期 9
·911-916
·
IF 3.719
Deng Hao-Hua,Li Guang-Wen,Liu Ai-Lin,Chen Wei,Lin Xin-Hua,Xia Xing-Hua
We demonstrate a sensitive and rapid colorimetric assay for selective detection of copper ions based on the strong coordination between Cu(II) ions and the tetrahydroxyaurate anions [Au(OH) 4 ] − on the surface of thermally treated bare gold nanoparticles (GNPs). The method for making the unmodified GNPs is simple and results in a nanomaterial with a highly specific response to Cu(II). The thermal treatment of the bare GNPs and the recognition of Cu(II) ions is accomplished in a single step within 5 min. The presence of Cu(II) causes the color to change from red to purple-blue. The limit of detection (LOD) is 0.04 μM of Cu(II) when using UV–vis spectrometry and ratioing the absorbances at 650 and 515 nm, respectively. The method also is amenable to bare eye (visual) inspection and in this case has an LOD of 2.0 μM of Cu(II).
Due to the strong coordination of Cu(II) ions with the tetrahydroxyaurate anions [Au(OH) 4 ] - on the thermally treated bare GNPs, Cu(II) can directly induce the aggregation of the GNPs, resulting in an obvious color change from wine-red to purple-blue.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 27
·期 2
·1966-1973
·
IF 1.569
Lu Changyu,Guan Weisheng,Hoang Tuan K. A.,Guo Jifeng,Gou Haigang,Yao Yiliang
In this work, Fe-series (Fe, Co, Ni) doped titanate nanotubes were synthesized via a simple, one pot hydrothermal process using commercial TiO 2 powder as the precursor. The samples were characterized by X-ray diffraction, nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, and UV–Vis. SEM and TEM results show that regularly uniform nanotubes were obtained and they possess homogeneous tubular structures with open ends. There is no significantly morphological and structural difference between TiNTs and Fe-series doped TiNTs. Furthermore, the photocatalytic properties of TiNTs and Fe-series doped TiNTs were studied using the degradation of ciprofloxacin. Fe-series doped TiNTs exhibit higher catalytic activities than those of TiNTs and commercial TiO 2 .
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 14
·12340-12350
·
IF 2.324
Zhou Jie,Bao Li,Wu Shengji,Yang Wei,Wang Hui
Rich nitrogen-doped porous carbon fiber (NC–NH 4 Cl) was successfully prepared from chitin via environmentally friendly simple pyrolysis supplemented with ammonium chloride as a recyclable porogen and nitrogen source. Compared with NH 4 HCO 3 and (NH 4 ) 2 SO 4 , NH 4 Cl proved to be the most effective porogen and nitrogen dopant for chitin. The as-made NC–NH 4 Cl exhibited a 3D architecture formed by numerous intertwined microfibrils with a hierarchical micro/mesoporous structure. Moreover, NC–NH 4 Cl possessed a high nitrogen content of 10.0 at.%, and about 70% of the nitrogen was in the form of pyridinic-N and pyrrolic-N. The NC–NH 4 Cl electrode could deliver superior specific capacitance of 284 F g −1 at a current density of 0.5 A g −1 , as well as favorable rate performance (ca. 66.3% retention as the current density rose from 0.5 to 20 A g −1 ) and long cycle life (ca. 96.9% maintained after 5000 cycles) in a three-electrode configuration. The assembled NC–NH 4 Cl-based symmetric capacitor presented a desirable energy density of 16.67 Wh kg −1 at 1 A g −1 . The results suggest that NC–NH 4 Cl is a promising candidate for supercapacitors.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 15
·20891-20902
·
IF 2.478
Peng Long-Gui,Ni Fu-Rong,Liu Jun,Sun Meng,Chang Meng-Jie,Xi Tong,Li Hui-Lu,Du Hui-Ling,Yang Jie,Li Ying
Bismuth vanadate (BiVO 4 ) is a promising photocatalyst material for photocatalytic degradation of organic pollutions. However, the fast recombination of photo-induced charge and insufficient light absorption often lead to poor photocatalytic performance. Herein, novel fibrous BiVO 4 /CdS (BVO/CdS) heterostructures are constructed by uniformly modifying caterpillar shaped electrospun BiVO 4 nanofibers with controllable quantity of CdS nanoparticles through hydrothermal reaction. The absorption of visible light and separation efficiency of photo-generated charge of BiVO 4 are significantly promoted after the decoration of CdS nanoparticles. As a result, the photocatalytic efficiency of the optimized BVO/CdS sample (BVO/CdS-2 stands for the sample synthesized with 0.05 mmol Cd(CH 3 COO) 2 and CH 4 N 2 S) is 90.43%, which is 3.3 times as high as that of pure BiVO 4 after 180 min irradiation under visible light, respectively. Moreover, the .O 2 − and .OH are the predominant active species for the degradation process indicated by scavengers added photocatalytic experiments. Due to the simple, low-cost and controllable synthetic process, the BVO/CdS heterojunctions are suitable for practical usage.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2014
·Vol. 30
·期 5
·863-867
·
IF 1.119
Wang Huan,Yao Yuan,Han Lu,Che Shun’ai
Self-assembled triblock terpolymers have attracted intense attention in recent years because of their abundant variety of assembly mesostructure. We reported the synthesis of mesoporous silica materials with the amphiphilic ABC triblock terpolymer polyethylene-poly(ethylene oxide)-polycaprolactone(PE-PEO-PCL) as a template and tetraethoxysilane(TEOS) as a silica source. Increasing the hydrophilic head group(PEO) led to the decrease of packing parameter g , which gave rise to the mesophase transformation from a cylindrical two-dimensional hexagonal P 6 mm structure to a cage-type face centered cubic closed-packing mesostructure. This new templating route provided a new insight into the template factor governed inorganic-organic self-assembly mesophases.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 26
·期 11
·8413-8420
·
IF 1.569
Tian Jiao,Ma Qianli,Dong Xiangting,Yang Ming,Yang Ying,Wang Jinxian,Yu Wensheng,Liu Guixia
The flexible color-tunable [Eu(BA) 3 phen + Tb(BA) 3 phen]/PMMA composite nanobelts have been fabricated by single axial electrospinning. Scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and fluorescence spectroscopy were used to characterize the final products. As-prepared nanobelts are almost uniform and the thickness and width of them are respectively ca. 890 nm and 16.6 ± 0.09 μm. The fluorescence intensity of Eu 3+ is increased with adding more Eu(BA) 3 phen into the composite nanobelts, and the fluorescence intensity of Tb 3+ is found to increase monotonically with introducing more Tb(BA) 3 phen into the composite nanobelts. By adjusting the ratio of Eu(BA) 3 phen to Tb(BA) 3 phen complexes, the fluorescence color of composite nanobelts can be tuned from red to yellow, yellow green, and green under the excitation of 290-nm single-wavelength ultraviolet light. Besides, the emission color could also be tuned easily from red to yellow, yellow to green via variation of excitation wavelengths. The novel color-tunable composite nanobelts have potential applications in the fields of color displays and sensor systems.
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危险品化学品经营许可证（带存储）