Catalysis Science & Technology
·
2019
·Vol. 9
·期 12
·3270-3278
·
IF 5.726
Dan Liu,Chengwei Qiu,Minbo Li,Yanyu Xie,Lu Chen,Huaxiang Lin,Jinlin Long,Zizhong Zhang,Xuxu Wang
Kornblum oxidation (benzyl bromide to benzaldehyde) can be realized efficiently by NaOH-modified graphitic carbon nitride (g-C3N4). Different from the oxidation reaction carried out at high temperature using DMSO as an oxidant, our reaction is eco-friendly because it is carried out at room temperature under LED light irradiation using molecular oxygen as an oxidant, which avoids the problems of toxicity, pollution and purification. Alkali treatment leads to the surface deprotonation of g-C3N4 to form NaOH-modified g-C3N4 (Na/g-C3N4). The modifications of the electronic structure and surface chemical environment of g-C3N4 facilitate light absorption and formation of ˙O2− and therefore make the conversion of benzyl bromide reach up to 99%. This work demonstrates a green and sustainable route for benzaldehyde production and the superiority of g-C3N4 for organic syntheses.
研究领域:
有机化学
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环境科学
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DOI
高影响因子
Materials
·
2021
·Vol. 14
·期 11
·2741
·
IF 3.623
Pengcheng Lv,Ruihong Meng,Zhongyang Mao,Min Deng
In this study, the hydrated sodium aluminosilicate material was synthesized by one-step hydrothermal alkaline desilication using fly ash (FA) as raw material. The synthesized materials were characterized by XRD, XRF, FT-IR and SEM. The characterization results showed that the alkali-soluble desilication successfully had synthesized the sodium aluminosilicate crystalline (N-A-S-H) phase of sodalite-type (SOD), and the modified material had good ionic affinity and adsorption capacity. In order to figure out the suitability of SOD as an adsorbent for the removal of ammonium and phosphorus from wastewater, the effects of material dosing, contact time, ambient pH and initial solute concentration on the simultaneous removal of ammonium and phosphorus are investigated by intermittent adsorption tests. Under the optimal adsorption conditions, the removal rate of ammonium was 73.3%, the removal rate of phosphate was 85.8% and the unit adsorption capacity reached 9.15 mg/L and 2.14 mg/L, respectively. Adsorption kinetic studies showed that the adsorption of ammonium and phosphorus by SOD was consistent with a quasi-secondary kinetic model. The adsorption isotherm analysis showed that the equilibrium data were in good agreement with the Langmuir and Freundlich model. According to thermodynamic calculations, the adsorption of ammonium and phosphorus was found to be a heat-absorbing and spontaneous process. Therefore, the preparation of SOD by modified FA has good adsorption properties as adsorbent and has excellent potential for application in the removal of contaminants from wastewater.Keywords:N-A-S-H;sodalite;simultaneous removal;ammonium;phosphorus
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2022
·Vol. 10
·期 45
·9413-9423
·
IF 7.571
Yuxia Zhang,Xiaoyu Lu,Chongyi Chi,Yanyan Zheng,Qinhui Chen
It is of utmost importance that bleeding should be stopped and infection be prevented in people with trauma. In this study, an anisotropic Janus mesoporous silica nanosheet (MSNS) with different functional groups was designed and prepared. In order to endow both sides of the MSNS with independent fast hemostasis and effective antibacterial action, the MSNS was modified with cardanol (CA) and 2,3-epoxypropyltrimethylammonium (GTA). The addition of CA significantly improved the hemostatic property of the MSNS. In a SD rat femoral artery injury model, the hemostatic time of CA-MSNS-GTA was 47% shorter than that of the MSNS, attributed to the sealing of the hydrophobic alkyl side chain and the adhesion of phenolic hydroxyl groups in CA. CA-MSNS-GTA could form a three-dimensional network with fibrin to further accelerate the coagulation process. This Janus material exhibited excellent antibacterial effects (∼90%) against Gram-positive bacteria (S. pneumoniae) and Gram-negative bacteria (E. coli) due to the presence of GTA. The cytotoxicity test showed that CA-MSNS-GTA exhibited biosafety, which provided safety guarantee for clinical applications in the future. This Janus dressing with different functions on two opposite sides provides synergetic multifunctional effects during wound healing.
研究领域:
材料科学
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生物医学工程
·
创伤护理
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2025
·
IF 3.1
Cui Yuanlu,Yang Rongjie,Lan Yanhua,Zhai Jinxian
Ammonium dinitramide (ADN), an emerging green oxidizer for rocket propellants, faces application limitations due to its low-temperature thermal decomposition characteristics. This study investigates the impact of a small amount of ammonium nitrate (AN) doped into ADN crystal on the stability of ADN crystal. ADN crystal samples containing AN were prepared by solution evaporation method and solvent-antisolvent method, respectively. The results show that AN and ADN form solid solution crystal by solution evaporation method, while solvent-antisolvent method produces phase-separated AN/ADN mixture. Isothermal thermogravimetric analysis conducted at 318–333 K revealed significant decomposition mass loss (3.2–17.5%) exclusively in solid solution samples, whereas the samples of phase-separated AN/ADN crystals show good thermal stability. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), and ion chromatography (IC) were used to investigate the influence of different forms and contents of AN in ADN samples on the low-temperature thermal decomposition properties of ADN. The kinetic models in different decomposition stages were obtained by isothermal kinetic method. Molecular dynamics simulations revealed the decomposition mechanism that the doping of AN induced the elongation of N–N bonds in the surrounding ADN structure, leading to instability of the ADN structure. These findings provide a theoretical basis for improving the stability of ADN in storage and application. Graphical
研究领域:
材料科学
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化学工程
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物理化学
·
推进剂与炸药
✓ 已验证
DOI
高影响因子
Journal of Natural Gas Science and Engineering
·
2021
·
IF 4.965
Xuejian Liu,Quan Cao,Dongyan Xu,Shengjun Luo,Rongbo Guo
The maximum methane storage capacity (MSC) is of critical importance of methane hydrate to store methane. This paper reports the effects of vesicle solutions, formed through combination of carboxylate surfactants with cationic quaternary ammonium salt including hydroxypropyl trimethyl ammonium chloride chitosan (HACC) or dodecyl trimethyl ammonium chloride (DTAC), on the formation of methane hydrate. It was found that vesicles could raise the maximum MSC of hydrate by about 10 (V/V, the volume of methane stored by one volume of hydrate) at appropriate anion and cation concentrations. For example, at 800 ppm (parts per million) of sodium laurate (SL) and 600 ppm of HACC concentrations, the formed vesicles could elevate the maximum capacity to 151 V/V, 5.3% higher than that of sodium laurate alone. The vesicles formed could increase the maximum MSC, from 136 V/V to 147 V/V by sodium oleate (SO) and HACC, 145 V/V to 153 V/V by sodium decanoate (SD) and HACC and 137 V/V to 149 V/V by SO and DTAC. The reason for the enhancement is that the large hydrophobic space of the vesicles could solubilize methane molecules and facilitate them to contact with water molecules.
研究领域:
化学
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材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Le Zhang,Yong Liu,Jianlong Wang
The oxidation of ammonium (NH 4 + ) to dinitrogen (N 2 ) with high selectivity and high efficiency is still a challenge. Herein, a novel sunlight induced persulfate (PS)-based AOPs process (MgO/Na 2 SO 3 /PS/ hv ) was proposed by introducing solid base (MgO) and hydrated electron (e aq − ), to selectively oxidize NH 4 + to N 2 , with high selectivity and high efficiency at a wide range of pH value. The deprotonation of NH 4 + into NH 3 by MgO and the generation of •OH and SO 4 −• by PS activation were responsible for the high efficiency of NH 4 + oxidation. The buffering capacity provided by MgO to proton released from PS activation made the NH 4 + oxidation possible at a wide pH range. The e aq − from the Na 2 SO 3 / hv process was the main active specie to reduce NO 2 − and NO 3 − (NO x − ) into N 2 , responsible for high N 2 selectivity of NH 4 + oxidation. 100% NH 4 + could be oxidized within 30 min, and N 2 selectivity exceeded 96% at the initial pH range of 3–11 and the initial concentration of NH 4 + of 30 mg N/L. This work could offer an efficient AOPs process for selective NH 4 + oxidation, which is promising for the chemical denitrification of wastewater ….
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Sensors & Diagnostics
·
2023
·Vol. 3
·期 1
·79-86
·
IF 0
Min Shen,Tingting Pan,Yonghao Chen,Juewei Ning,Fengyu Su,Yanqing Tian
Ammonium ions (NH4+) are one of the important metabolic products and are closely related to human health. Currently, many NH4+ detection methods are inevitably disturbed by amino acids, K+, or other substituted amines (such as trimethylamine). To alleviate this problem, a new sensor was designed in this study, which consisted of the fluorescent indicator KS, hydrogel medium D4, and a hydrophobic membrane. In this sensing system, NH4+ and NH3 coexisted in equilibrium; NH3 could pass through a suitable hydrophobic film and transform into NH4+, which complexed with KS, resulting in a change of the probe's fluorescence intensity. By adjusting the internal composition of the sensing matrix, an excellent NH4+ sensor NS-1 was obtained; it demonstrated effective detection of NH4+ in the range 0.3–15.6 mM with a limit of detection (LOD) of 258 μM, and it was not disturbed by K+ or other substituting amines.
研究领域:
生物化学
·
分析化学
✓ 已验证
DOI
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Xudong Zhang,Wenbo Zhao,Jun Shen,Yugao Wang,Gang Liu,Yanxia Niu,Qingtao Sheng
Carbazole is an important organic chemical raw material with high added value, mainly derived from crude anthracene. In this research, three quaternary ammonium salts (QASs), containing triethylmethylammonium chloride (TEMAC), tetraethylammonium chloride (TEAC) and tetrapropylammonium chloride (TPAC), were innovatively used to separate carbazole from model anthracene oil by forming deep eutectic solvents (DESs). The results indicated that TEAC showed the highest separation ability among three QASs. Afterwards, the influences of mass ratio of TEAC to model anthracene oil (MO), stirring time, extraction temperature and initial concentration on the separation effect of carbazole were investigated. Under the optimized conditions (25℃, 25 min, mass ratio 1:5), the extraction efficiency (EE), distribution coefficient (DI) and selectivity (SE) of carbazole could reach up to 91.25 %, 24.26 and 66.09 %, respectively. The purity and yield of carbazole product separated from model anthracene oil were 91.02 % and 76.89 %, respectively. Moreover, carbazole with purity of 90.42 % could be separated from real crude anthracene with TEAC under the above optimized conditions. In addition, environment friendly water was used to regenerate the TEAC. After recycled for five times, the extraction ability of TEAC for carbazole did not change obviously. Finally, the hydrogen bond (N H…Cl) and van der Waals interaction (C H…π) existed between QASs and carbazole were revealed by FT-IR analysis and quantum calculations. The green and novel method presented in this work has implications for the separation of other high value-added products from coal tar.
研究领域:
化学工程
·
环境科学
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DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2022
·
IF 9.988
Lu Jiang,Pingxiao Wu,Yijing Xu,Yihao Li,Meiqing Chen,Zubair Ahmed,Nengwu Zhu
Triclinic birnessite (TB), a typical layered Mn oxide which is abundant naturally occurring minerals with a vital impact on the transformation of arsenite (As(III)) by adsorption and oxidation . As one of the most common critical metalloids , ammonium ion (NH 4 + ) universally coexists with birnessite in marine, sediments or groundwater where are contaminated with As(III). In this study, we investigated the impacts of NH 4 + on TB towards the transformation of As(III). Compared with the original TB (40.1%), the As(III) removal efficiencies of three different concentration (0.5 M, 1 M and 2 M) NH 4 + impressed triclinic birnessite (TB-0.5 N, TB-1N and TB-2N) are increased rapidly in the order of: TB-2N (80.4%) > TB-1N (75.8%) > TB-0.5 N (71.5%). In addition, TB-2N exhibited the highest initial oxidation rate of 0.0031 min −1 which exceeds twice as much as this of TB (0.0014 min −1 ). And TB-2N could reach the max oxidation efficiency when the As concentration is 0.08 mM. Due to two different mechanisms of As(III) oxidation on birnessites under acidic and alkaline conditions, TB-2N showed a higher removal efficiency than TB at pH 3.0, 5.0, 7.0 and 9.0. Hence, there are two main reasons for the advanced As(III) oxidation capacity of TB-2N. One is the improvement of the average oxidation state of Mn, the other is the increase of oxygen vacancy with the coexistence of NH 4 + . Moreover, the larger specific surface area of TB-2N also contribute to enhancing As(III) oxidation capacity. This study holds a fundamental understanding of the behavior of triclinic birnessite which is coexisted with ammonium ion towards the transformation of As(III) in the environment.
研究领域:
环境科学
·
矿物学
✓ 已验证
DOI
高影响因子
TALANTA
·
2018
·
IF 4.244
Zhongmin Feng,Ni Wang,Manli He,Lan Yang,Yun Wang,Ting Sun
A new diffusive gradients in thin films (DGT) technique with a micro-sized biochar-zeolite-zirconium oxide mixed binding phase is described for simultaneous sampling of dissolved orthophosphate and ammonium in freshwaters. The performance of mixed binding layer (MBL) DGT technique was characterized by evaluation of the following parameters: (1) the adsorption efficiency of phosphate and ammonium by the mixed binding phase, (2) the elution efficiency, (3) the time-series accumulation, and (4) the influences of pH, coexisting cations and DOC on DGT uptake. The mixed binding phase had high uptake for both phosphate and ammonium. The accumulated analyte mass increased linearly with time over 48 h ( Δ g = 1.3 mm) and 84 h ( Δ g = 1.9 mm), respectively. Simultaneous sampling of phosphate and ammonium using MBL-DGT was consistent over the 10–80 mg C L −1 DOC concentration range and the 3–8 pH range for a 24 h deployment. The coexisting cations (Na + , K + , Mg 2+ , and Ca 2+ ) were found to compete with the ammonium accumulation by MBL-DGT, but ammonium accumulation was consistent over concentration ranges typically found in most freshwaters (up to 0.01 mol L −1 Na + , 0.001 mol L −1 K + , 0.01 mol L −1 Mg 2+ , 0.03 mol L −1 Ca 2+ ). The MBL-DGT method also performed predictably in natural freshwaters containing different concentrations of metal ions and dissolved organic carbon. The results of this project have demonstrated that this new DGT method can offer a more cost-efficient method for simultaneously determining time-weighted average concentrations of ammonium and dissolved orthophosphate in most freshwaters, but inefficiently in high salinity waters because of its extremely high concentration of competing cations.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2024
·
IF 8.7
Haoran Xu,Guang Fu,Duclenh Phan,Liuxin Xiang,Thiquynhxuan Le,Libo Zhang
Ultrasound enhanced evaporating crystallization has been proposed to solve the problems of low crystallization yield and uneven particle size in the evaporating crystallization process of ammonium sulfate solution at atmospheric pressure. The effects of key operating parameters, including the ultrasound power, stirring speed, pH value, and ultrasound time, on the yield of ammonium sulfate product and the duration of solid–liquid transformation time are studied. The results show that the ultrasound crystallization can increase the ammonium sulfate yield by 52.9 %, reduce the solid–liquid transformation time of ammonium sulfate by 10 %, and obtain ammonium sulfate products with higher crystallinity and more uniform particle size. Ultrasound promotes the crystallization of ammonium sulfate by enhancing the transfer of heat in the solution and reducing the supersolubility of the ammonium sulfate solution from 937.5 g/L to 833.33 g/L. This study provides experimental justification for the use of ultrasound in atmospheric evaporative crystallization.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MINERALS ENGINEERING
·
2020
·
IF 3.795
Peilun Shen,Dianwen Liu,Xiaohui Xu,Xiaodong Jia,Xiaolin Zhang,Kaiwei Song,Jinpeng Cai
In this study, for the first time, we applied ammonium phosphate to pre-treat chrysocolla prior to sulfidization flotation. In addition, we investigated the structural characteristics of the copper sulfide film formed on the chrysocolla surfaces and its response to flotation. Micro-flotation experiments revealed that the addition of (NH 4 ) 3 PO 4 prior to sulfidization greatly improves the floatability of chrysocolla and its recovery increased from 8.71% to 87.97% with butyl xanthate as the collector. The results of the field emission scanning electron microscopy analysis showed that numerous regular fragments appeared on the chrysocolla surfaces after the addition of (NH 4 ) 3 PO 4 . The X-ray diffraction and X-ray photoelectron spectrometry analysis confirmed that these fragments were newly formed copper sulfide covering the chrysocolla surfaces, during this process a chemical reaction occurred in the slurry system, i.e. the Cu 2+ were reduced to Cu + , the S 2− were mainly oxidized to S − , (S 2 ) − , (S 2 ) 2− . The copper sulfide species primarily in the form of crystalline covellite (Cu + 3 (S 2 ) 2− S − ), which is the key to obtaining good flotation recovery. As a specific activator, (NH 4 ) 3 PO 4 participates in the liquid-solid phase chemical reaction between the sulfidizing reagent and the chrysocolla, which promotes the sulfidization reaction of chrysocolla.
研究领域:
矿物加工工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）