JOURNAL OF HAZARDOUS MATERIALS
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2015
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IF 4.529
Lijuan Feng,Shuang Zhao,Shenglei Sun,Wenyu Wang,Baoyu Gao,Qinyan Yue
The influences of solution pH on coagulation/ultrafiltration (C–UF) process were investigated by using three purified Al species of polyaluminium chloride (PACl). A series of online-simulation experiments were developed to assess the coagulation removal efficiencies (turbidity, UV 254 ), floc properties and membrane fouling in this paper. The results showed that change of pH had a significant impact on coagulation efficiencies, floc properties, membrane flux as well as the whole process. Under acidic condition, the hydrolysis action of aluminum salts was restrained which is bad for charge neutralization. While under alkaline region, absorption was the dominant mechanism to combine HA–Kaolin. Meanwhile, HA is apt to soluble by deprotonating under alkaline region which is hard to remove. These common effects made the experiment results complex. HA removal efficiency of Al a and Al b were higher than that of Al c , but the turbidity removal by Al c was slightly higher under the same pH condition. Flocs generated by Al a at pH 6 had advantages such as larger size and the most loosely structure which contributed the most to alleviating membrane fouling. Membrane fouling with Al b and Al c in alkaline range was more serious than that in acidic range.
研究领域:
环境科学
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水处理工程
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产品关联
DOI
PubMed
高影响因子
Materials
·
2015
·Vol. 8
·期 8
·5363-5375
·
IF 2.651
Liangjie Pan,Benxue Jiang,Jintai Fan,Qiuhong Yang,Chunlin Zhou,Pande Zhang,Xiaojian Mao,Long Zhang
The synthesis of pure and well dispersed lutetium aluminum garnet (LuAG) powder is crucial and important for the preparation of LuAG transparent ceramics. In this paper, high purity and well dispersed LuAG powders have been synthesized via co-precipitation method with lutetium nitrate and aluminum nitrate as raw materials. Ammonium hydrogen carbonate (AHC) was used as the precipitant. The influence of aging time, pH value, and dripping speed on the prepared LuAG powders were investigated. It showed that long aging duration (>15 h) with high terminal pH value (>7.80) resulted in segregation of rhombus Lu precipitate and Al precipitate. By decreasing the initial pH value or accelerating the dripping speed, rhombus Lu precipitate was eliminated and pure LuAG nano powders were synthesized. High quality LuAG transparent ceramics with transmission >75% at 1064 nm were fabricated using these well dispersed nano LuAG powders.Keywords:co-precipitation method;single phase;pH values;LuAG powder;transparent ceramics
研究领域:
材料科学
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无机化学
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产品关联
DOI
PubMed
高影响因子
TETRAHEDRON
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2014
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IF 2.817
Shouhai Yang,Wenge Yang,Qirun Guo,Tuan Zhang,Keyi Wu,Yonghong Hu
A simple but highly selective coumarin-based fluorescence probe 1 , 8-(1,3-dithiane)-7-hydroxycoumarin was designed and synthesized for both the ratiometric detection of Hg 2+ and the on–off response to pH change in aqueous solution. The sensor detected Hg 2+ selectively via Hg 2+ -promoted thioacetal deprotection reaction within five minutes and reflected pH in the range from 7.8 to 11.9 as a result of the equilibrium between weak-fluorescent acid form and strong-fluorescent base form. In addition, the probe has an excellent selectivity towards Hg 2+ over other competitive metal ions for biomedical and environmental applications. The sensing behavior of our probe was studied by UV–visible absorption spectra and fluorescence spectra .
研究领域:
分析化学
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环境科学
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生物医学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING COMMUNICATIONS
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2017
·
IF 1.297
Heng Zhang,Guoxiang Zhou,Junliang Wu,Jing Zhong,Jianlin Wu,Xianming Shi
Electroosmosis has been extensively employed as an effective method for the dewatering treatment of soils and thus the reinforcement of weak soils. At the microscopic level, this treatment process is inherently complex due to in situ chemical and electrochemical reactions, migration of ions and particles, and the dependence of zeta potential of various particles on the local pH value in the soil. This complexity has hindered further understanding of mechanisms underlying the electroosmosis technology. Here, we design an external electric field in which alternating pulse wave potentials were partially used to adjust the pH value of the soil and manipulate the dynamics of in situ formed nanoparticles and their interconnectivity. The experimental results reveal that the in situ formation of Ca-rich particles, instead of water drainage, may serve as the main mechanism underlying the observed soil reinforcement when using calcium chloride as the treatment electrolyte. The interconnectivity of such particles may be the key for the shear strength improvement without significant settlement of the soil.
研究领域:
土力学
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环境工程
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2022
·Vol. 24
·期 17
·10394-10407
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IF 3.945
Jing Xiao,Cong Wang,Bai-Qi Feng,Tian-Yu Liu,Shao-Yi Jia,Hai-Tao Ren,Yong Liu,Song-Hai Wu,Xu Han
Although synthesis of oligoaniline (OANI) by persulfate and aniline has been investigated in the recent years, the impact of phenol on the synthesized soluble OANI is still not clear. In this study, our results indicate that phenol and pH mediate the production of the blue water-soluble OANI (OANIblue) in the reaction between sodium persulfate (SPS) and aniline under alkaline conditions, and the yields of OANIblue increase with increasing concentrations of phenol and pH values. Quenching experiments rule out the contributions of SO4˙− and ˙OH to aniline oxidation and imply that the non-radical activation of SPS is an important pathway in the formation of OANIblue. MALDI-TOF-MS analysis indicates that phenol apparently inhibits the polymerization degree of aniline in that the molecular weights of OANIblue gradually decrease from 1586.4 to 684.6 when phenol is increased from 0 to 2.0 mM. FTIR and Raman analyses confirm the structure of aniline oligomers in OANIblue and indicate that phenol inhibits the phenazine-like structure in OANIblue and facilitates the transformation of benzenoid rings to quinoid rings in the oxidation products. However, simultaneous activation of SPS by phenol and aniline is likely to occur in the reaction system with the formation of PhNH˙, as indicated by DFT calculations. The high scavenging reactivity of phenol towards both PhNH2˙+ and PhNH˙ implies that PhNH2˙+ and PhNH˙ are not the intermediates in the formation of OANIblue. DFT calculations also reveal that apart from the one-electron transfer pathway between aniline and SPS, the two-electron transfer pathway is also likely to occur in the presence of phenol, resulting in the formation of PhNH+/PhN˙˙ without producing PhNH2˙+ and PhNH˙. The produced PhNH+/PhN˙˙ intermediates then couple with aniline, PhNH+, aminophenyl sulfate and its hydrolysate to form dimers, trimers, oligomers, and eventually OANIblue. This study not only describes a novel method to prepare water-soluble OANI, but also gives new insight on the importance of phenol in the production of OANIblue.
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2023
·
IF 3.9
Guangyuan Chen,Meng Zhang,Tong Zhou,Zhongxiang Ding,Haiying Tang,Yuanhui Ji,Changsong Wang
Struvite (MgNH 4 PO 4 ·6 H 2 O，MAP), a type of high-quality, slow-release fertilizer, is the main component of urinary stones in animals and humans and causes scale formation in industrial pipes. Therefore, MAP dissolution is an important research topic. Herein, MAP dissolution experiments are performed and a thermodynamic model is developed to evaluate the influences of pH, temperature ( T ), and particle size ( P s ) on surface reaction resistance ( 1/k s ) and diffusion resistance ( 1/k d ). The results show that MAP solubility decreases with an increase in pH and the effects of pH change are more obvious than those of T or P s . The total resistance ( 1/k T ) of MAP dissolution increases with pH increase, P s growth, or T reduction. The comparison of 1/k s and 1/k d reveals surface reaction as the MAP dissolution control step and indicates a linear relation among 1/k s , 1/k d , and the natural logarithm of P s at pH 7.0.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
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2015
·
IF 2.467
Honghai Wu,Hanrui Xie,Guangping He,Yufeng Guan,Yanlin Zhang
Tetracycline frequently needs to be detected in the environment; therefore, iron-intercalated montmorillonite (Fe-Mt) was evaluated as a model adsorbent to evaluate tetracycline adsorption behavior . The Fe-Mt sample derived from Na + -montmorillonite (Mt) by the introduction of iron-(hydr)oxides was fully characterized using the techniques of XRD , FTIR , TEM, and SEM as well as N 2 -adsorption/desorption methods. The delaminated structure of Fe-Mt could cause remarkable increases in both the surface area and pore volume. Fe-Mt also showed remarkably distinct behavior from Mt for TC adsorption. The TC adsorption by Fe-Mt was found to be highly influenced by the pH as well as the types and concentrations of background electrolytes. The positive effect of anions on the TC adsorption by Fe-Mt at acidic pH values follows the following adsorption maximum order: PO 4 3 − > SO 4 2 − » NO 3 − > Cl − > ClO 4 − . The solution pH affects the TC adsorption, and the adsorption maximum occurs at a pH around 5.0. The Langmuir and Freundlich equations were shown to fit well to the TC adsorption isotherms on Fe-Mt, and the former equation was a better fit. These adsorption-related performances could be ascribed to Fe-Mt having formed characteristic bulk/surface/pore structures. The multiple potential coexisting efficient mechanisms or pathways responsible for the TC adsorption by Fe-Mt were finally proposed and discussed in comparison with Mt and ferrihydrite .
研究领域:
环境科学
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化学
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材料科学
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产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
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2012
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IF 0
Yang Hou,Ping Hu,Wen Bo Han
The dispersion of SiC nanopowders in ethanol solution was studied by sedimentation test, particle size measurement and TEM analysis. The dispersion behavior of SiC nanopowders in ethanol solution was strongly dependent on the pH values, types and amounts of dispersant. PEI was found to be effective for the dispersion of SiC nanopowders in ethanol solution. With the addition of PEI, the isoelectric points of SiC nanopowders in ethanol solution were at pH 9.5, and shift to pH 12.3. The stability of SiC suspension increased with the dispersant content increasing until reached 2.5 wt% PEI. The suitable pH value for the dispersion of SiC nanopowders should lower than 10.
研究领域:
材料科学
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化学工程
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DOI
ANALYTICAL CHEMISTRY
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2017
·
IF 6.32
Shuai Li,Anwei Zhu,Tong Zhu,John Z. H. Zhang,Yang Tian
Glucose and pH are two important indicators of diabetes mellitus. However, their dynamic changes at the same time in brain are still not clear, mainly due to a lack of a single biosensor capable of simultaneous quantification of two species in a live rat brain. In this work, a selective and sensitive ratiometric electrochemical biosensor was developed for simultaneously quantifying glucose and pH using both current and potential outputs in a rat brain of diabetic model. Here, glucose oxidase was first employed as a specific recognition element for both glucose and pH because the active center (FAD) could undergo a 2H+/2e– process. Moreover, an insensitive molecule toward pH and glucose was used as an inner-reference element to provide a built-in correction to improve the accuracy. The ratio between the oxidation peak current density of glucose and that of ABTS gradually increased with increasing concentration of glucose, and showed a good linearity in the range of 0.3–8.2 mM. Meanwhile, the midpotential difference between glucose oxidase and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) positively shifted with pH decreasing, leading to accurate determination of pH in the linear range of 5.67–7.65. Thus, combined with the unique properties of carbon fiber microelectrode, including easy to insert and good biocompatibility, the developed single biosensor was successfully applied to detect pH and glucose at the same time in hippocampus, striatum, and cortex in a live rat brain of diabetic model.
研究领域:
生物医学工程
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神经科学
·
代谢研究
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yongxin Zheng,Hengkai Gao,Ziyao Liu,Cenhao Li,Xianchao Feng,Lin Chen
This study aimed to develop an ammonia and pH super-sensitive label by incorporating methyl red and bromothymol blue (MR-BTB, MB) into gellan gum/sodium carboxymethyl cellulose (GG/CMC-Na, GC). Furthermore, E-nose as an auxiliary tool combined with the labels to monitor meat freshness. Results showed that MB had more color change than pure MR or BTB, and the detection limit of ammonia about the MR-BTB (1:2) group was only 2.82 ppm. The addition of MB significantly increased tensile strength, moisture content, and water solubility, but decreased elongation at break and transmittance of the GC label ( p < 0.05). The result of FTIR and SEM indicated the formation of hydrogen bonds and well compatibility between MB and GC. Furthermore, the color of the GC-10.0MB label was constantly obviously changing during meat storage, indicating that the GC-10.0MB label had great potential for monitoring the freshness of the lamb meat. A high correlation was found between ΔE of GC-10.0MB label and TVB-N (R 2 = 0.9092) and pH (R 2 = 0.9114) of meat. Interestingly, the high correlation between ΔE of GC-10.0 MB label and the response value of S2 (R 2 = 0.7531), S6 (R 2 = 0.9921), and S7 sensor (R 2 = 0.8325) of E-nose was also found.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
·
IF 4.539
Zewei Zhao,Zhiguang Wu,Sven Rutkowski,Sergei I. Tverdokhlebov,Johannes Frueh
Micropumps are in animal and human bodies and on cellular levels vital for the life functions. In case of critical problems like diseases, artificial micropumps are candidates to take over important functions. These functions are ranging from release of substances over removing toxics to stirring stomach fluids, helping to disperse medicine. We hereby present a Janus micropump, powered by hydrogen bubbles, which is able to operate in a gastric pH environment. This Janus micropump consumes hydrochloric acid as an external fuel and releases magnesium ions , which act as micronutrients . The presented Janus micropumps do display significant pumping power by moving external tracer particles and stop after exhausting their magnesium or alternatively acid fuel. The pumping properties depend significantly on the surrounding pH environment and the amount of external surfactant added. Analysis of tracer particle motion shows, that the cause of this movement are the bubbles generated that drag the liquid along after bubble release.
研究领域:
生物医学工程
·
材料科学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Fan Yang,Xiaojiao Yu,Zongbin Liu,Kai Wang,Yuduo Liang,Juan Qiu,Ting Zhang,Jinfen Niu,Jie Zhao,Binghua Yao
BiPO 4 with a prismatic morphology is successfully prepared using a hydrothermal method . The phase of the as-prepared BiPO 4 is a monazite monoclinic phase. The pH of the zero point of charge is approximately 5 for the BiPO 4 . The effects of the catalyst dosage, initial concentration of moxifloxacin, and initial pH of the moxifloxacin solution on the photocatalytic degradation of moxifloxacin over the as-prepared BiPO 4 are first studied. In addition, cations such as K + , Zn 2+ , and Al 3+ and anions such as CO 3 2− , HPO 4 2− , SO 4 2− , F − , and Cl − are introduced into the photocatalytic system to investigate their effects. Furthermore, through reactive species trapping, it is proven that ⋅O 2 − can be converted to ⋅OH and N 2 can be reduced to NH 3 in acidic solution. This work provides an essential study of BiPO 4 for its application in photocatalytic fields.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）