PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 20
·14223-14233
·
IF 3.906
Yang Wang,Lijuan Liu,Pan Chen,Lina Zhang,Ang Lu
The physical dissolution of cellulose in aqueous solutions of tetramethyl ammonium hydroxide, triethylmethyl ammonium hydroxide, tetraethyl ammonium hydroxide, benzyltrimethyl ammonium hydroxide, benzyltriethyl ammonium hydroxide, NaOH and LiOH via freezing–thawing was investigated. Increasing the hydrophobicity of the cation greatly improved its dissolution capacity, leading to significant enhancement of cellulose solubility and stability against chain aggregation and gelation. The hydrophobic cations accumulated at the cellulose interface and decreased the surface tension, favouring dispersion of the disintegrated cellulose due to its amphiphilicity; this was consistent with molecular dynamics simulations. On the other hand, the solubility of cellulose followed the Hofmeister series, and cations with greater kosmotropicity originating from their greater hydrophobicity exhibited stronger dissolution power; this observed interaction pattern may be useful for further exploration and designation of novel solvents of cellulose. These aqueous quaternary ammonium hydroxides can be readily recycled and reused, which presents great potential in the green chemistry field.
研究领域:
材料科学
·
化学工程
·
绿色化学
·
物理化学
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产品关联
DOI
PubMed
高影响因子
Metabolites
·
2022
·Vol. 12
·期 5
·444
·
IF 5.581
Muhammad Khalid Hameed,Wajid Umar,Ali Razzaq,Tariq Aziz,Muhammad Aamer Maqsood,Shiwei Wei,Qingliang Niu,Danfeng Huang,Liying Chang
Nitrogen (N) is an essential element for plant growth and development. The application of a balanced and optimal amount of N is required for sustainable plant yield. For this, different N sources and forms are used, that including ammonium (NH4+) and nitrate (NO3−). These are the main sources for N uptake by plants where NH4+/NO3−ratios have a significant effect on the biomass, quality and metabolites composition of lettuce grown in soil, substrate and hydroponic cultivation systems. A limited supply of N resulted in the reduction in the biomass, quality and overall yield of lettuce. Additionally, different types of metabolites were produced with varying concentrations of N sources and can be used as metabolic markers to improve the N use efficiency. To investigate the differential metabolic activity, we planted lettuce with different NH4+/NO3−ratios (100:0, 75:25, 50:50, 25:75 and 0:100%) and a control (no additional N applied) in soil, substrate and hydroponic cultivation systems. The results revealed that the 25% NH4+/75% NO3−ratio increased the relative chlorophyll contents as well as the biomass of lettuce in all cultivation systems. However, lettuce grown in the hydroponic cultivation system showed the best results. The concentration of essential amino acids including alanine, valine, leucine, lysine, proline and serine increased in soil and hydroponically grown lettuce treated with the 25% NH4+/75% NO3−ratio. The taste and quality-related compounds in lettuce showed maximum relative abundance with the 25% NH4+/75% NO3−ratio, except ascorbate (grown in soil) and lactupicrin (grown in substrate), which showed maximum relative abundance in the 50% NH4+/50% NO3−ratio and control treatments, respectively. Moreover, 1-O-caffeoylglucose, 1,3-dicaffeoylquinic acid, aesculetin and quercetin-3-galactoside were increased by the application of the 100% NH4+/0% NO3−ratio in soil-grown lettuce. The 25% NH4+/75% NO3−ratio was more suitable in the hydroponic cultivation system to obtain increased lettuce biomass. The metabolic profiling of lettuce showed different behaviors when applying different NH4+/NO3−ratios. Therefore, the majority of the parameters were largely influenced by the 25% NH4+/75% NO3−ratio, which resulted in the hyper-accumulation of health-promoting compounds in lettuce. In conclusion, the optimal N applications improve the quality of lettuce grown in soil, substrate and hydroponic cultivation systems which ultimately boost the nutritional value of lettuce.Keywords:ammonium;lettuce;metabolites;nitrogen;nitrate
研究领域:
农业
·
植物科学
·
代谢组学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2019
·
IF 3.073
Meng Li,Mengjie Sun,Wenya Liu,Xu Zhang,Cuiming Wu,Yonghui Wu
Composite anion exchanges membranes are prepared by incorporating quaternized graphene oxide (QGO) within poly(vinyl alcohol) (PVA) or the mixture of PVA and quaternized polyethyleneimine (QPEI), followed by cross-linking with formaldehyde. The PVA-QGO series of membranes have low ion exchange capacities (IECs) of 0.10–0.37 mmol/g and low water uptakes ( W R ) of 16.1%–22.0%, leading to high area resistances (>60 Ω cm 2 ). The PVA-QPEI-QGO series of membranes show much lower area resistances of 2.47–6.04 Ω cm 2 , which is ascribed to the improved IECs (0.86–1.37 mmol/g) and W R (46.8%–71.4%). Both series of membranes show higher alkali resistance than commercial membrane AMV. Their weight losses are in the range of 0.5%–8.9% after immersion in 60 °C 2 mol/L NaOH alkaline solution for 32 days, while the value of AMV membrane is 19.2%. When utilized for electrodialysis (ED) application to recover NaOH from NaOH/Na 2 WO 4 mixture, the prepared membranes exhibit high selectivity, as evidenced by the low leakage ratio of Na 2 WO 4 . The leakage ratio of the optimized composite membrane to WO 4 2− is only 5.1%, while the leakage ratio of AMV membrane is up to 61.4%. To explore this reason, the composite membranes are selected for the ED separation of monovalent ions. The separation efficiency ( S ) of the optimized membrane is 83.9%, which is similar to the value of commercial anion selective membrane NEOSEPTA® ACS (88.7%), confirming further the selectivity of the composite membranes.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2023
·Vol. 11
·期 2
·564
·
IF 3.5
Shuai Li,Shenghai Yang,Pengfei Zhao,Yongming Chen,Chaobo Tang,Yanqing Lai,Chaoyong Deng,Changhong Wang
The electrodissolution-coupled hafnium alkoxide (Hf(OR)4, R is alkyl) synthesis (EHS) system, which has significant environmental and economic advantages over conventional thermal methods, serves as a promising system for green and efficient Hf(OR)4electro-synthesis. The EHS system is operated based on the simultaneous heterogeneous reactions of hafnium dissolution and ethanol dehydrogenation, as well as the spontaneous solution-based reaction of Hf4+and OR−. Employing green ethanol and Hf as feedstocks, the anodic hafnium corrosion/dissolution electrochemical behavior of the Et4NCl or Et4NHSO4based anhydrous system was investigated through electrochemical measurements combined with SEM observations. The results demonstrated that the Et4NCl-based anhydrous ethanol system exhibited an efficient mechanism of passive film pitting corrosion breakdown and metal hafnium dissolution, while the Et4NHSO4-based anhydrous ethanol system reflected the weak corrosion mechanism of the anodic hafnium under the passive film. The polarization resistance of the Et4NCl system was dramatically lower than that of the Et4NHSO4system, which indicated that the Et4NCl system had superior anodic hafnium corrosion performance compared to the Et4NHSO4system. Overall, the investigation of the electrochemical behaviors of anodic hafnium corrosion/dissolution provides theoretical guidance for the efficient operation of EHS electrolysis.Keywords:hafnium;anhydrous ethanol;tetraethylammonium chloride;tetraethylammonium bisulfate;electrocatalytic corrosion;mechanism;polarization resistance
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Danzhang Liu,Xiaoqing Weng,Yanfeng Jin,Richard M. Kasomo,Shunfu Ao,Hongqiang Li
Feldspar is a typical sesquioxide which is associated with phosphate ore. It can greatly prevent the formation of calcium sulfate crystals during the wet process of phosphoric acid production, resulting in the loss of P 2 O 5 , and therefore lowering the phosphoric acid recovery. To achieve the selective separation of feldspar from phosphate ore, we first tried using a new Gemini quaternary ammonium salt as the collector in conjunction with a reverse flotation approach. The flotation tests of single minerals and artificially mixed minerals were employed to investigate the collecting ability and selectivity of the collector, the adsorption mechanism was also evaluated by means of zeta potential measurements and molecular dynamic calculations. The flotation results demonstrate that the collector showed a strong harvesting effect and selectivity on feldspar rather than fluorapatite . When the Gemini concentration was set at 7.5 × 10 −6 mol/L, the P 2 O 5 grade could reach 31.69% with a corresponding recovery of 77.57%, indicating that Gemini collector could suitably be used as a potential chemical to achieve the effective removal of feldspar from phosphate ore. The results obtained from zeta potential measurements and molecular dynamics simulations indicate that the adsorption of Gemini collector on feldspar was more pronounced compared to that on fluorapatite surface and the interaction between Gemini and both minerals was mainly ascribed to electrostatic interaction . This work aims to provide a reference for using Gemini as collector combined with reverse flotation approach to achieve the effective removal of sesquioxide from phosphate ore and further enhance the quality of phosphate fertilizers .
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
DOI
高影响因子
Molecular Plant
·
2021
·
IF 13.164
Wen Hao Tian,Jia Yuan Ye,Meng Qi Cui,Jun Bo Chang,Yu Liu,Gui Xin Li,Yun Rong Wu,Ji Ming Xu,Nicholas P. Harberd,Chuan Zao Mao,Chong Wei Jin,Zhong Jie Ding,Shao Jian Zheng
Phosphorus (P) is an indispensable macronutrient required for plant growth and development. Natural phosphate (Pi) reserves are finite, and a better understanding of Pi utilization by crops is therefore vital for worldwide food security. Ammonium has long been known to enhance Pi acquisition efficiency in agriculture; however, the molecular mechanisms coordinating Pi nutrition and ammonium remains unclear. Here, we reveal that ammonium is a novel initiator that stimulates the accumulation of a key regulatory protein, STOP1, in the nuclei of Arabidopsis root cells under Pi deficiency. We show that Pi deficiency promotes ammonium uptake mediated by AMT1 transporters and causes rapid acidification of the root surface. Rhizosphere acidification-triggered STOP1 accumulation activates the excretion of organic acids, which help to solubilize Pi from insoluble iron or calcium phosphates. Ammonium uptake by AMT1 transporters is downregulated by a CIPK23 protein kinase whose expression is directly modulated by STOP1 when ammonium reaches toxic levels. Taken together, we have identified a STOP1-centered regulatory network that links external ammonium with efficient Pi acquisition from insoluble phosphate sources. These findings provide a framework for developing possible strategies to improve crop production by enhancing the utilization of non-bioavailable nutrients in soil.
研究领域:
植物学
·
分子生物学
·
农业科学
✓ 已验证
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2012
·
IF 0.826
Jianxian ZENG,Xiahui SUN,Lifeng ZHENG,Qincheng HE,Shu LI
Polyquaternium-6 (PQ6) as the water-soluble polymer was used for complexing the anion forms of tungsten (VI) before ultrafiltration. Tungsten (VI)-PQ6 complex was retained by polysulfone hollow fiber ultrafiltration membrane in the complexation-ultrafiltration process. Effects of various operating parameters such as polymer metal ratio(PMR), pH and chloride ion concentration on permeate flux ( J ) and tungsten rejection coefficient ( R ) were investigated. The integration of four experiments including concentration, decomplexation, diafiltration and reuse of regenerated polymer was carried out. In the process of concentration, J declines slowly and R is about 1 at PMR of 3 and pH of 7. Tungsten concentration in the retentate increases linearly with volume concentration factor. Tungsten is concentrated efficiently with the membrane. The concentrated retentate was used further for the decomplexation. It takes about 6 min to reach the decomplexation equilibrium at chloride ion concentration of 50 mgL −1 . The decomplexation percentage of tungsten (VI)-PQ6 complex reaches 56.1%. In the diafiltration process, tungsten (VI) can be extracted effectively by using 50 mgL −1 chloride ion solution, and the purification of the regenerated PQ6 is acceptably satisfactory. The regenerated PQ6 was used to bind tungsten (VI) at various pH values. The binding capacity of the regenerated PQ6 is close to that of fresh PQ6, and the recovery percentage of binding capacity is higher than 90%.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 15
·4748
·
IF 4.927
Qing Zhang,Huiyuan Liu,Junxia Guan,Xiaochun Yang,Baojing Luo
Phosphating sesbania gum (DESG) was obtained by modifying sesbania gum (SG) with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and endic anhydride (EA). The structure of DESG was determined using Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance spectroscopy (1H-NMR). Flame-retardant polylactic acid (PLA) composites were prepared by melt-blending PLA with DESG, which acted as a carbon source, and ammonium polyphosphate (APP), which acted as an acid source and a gas source. The flame retardancy of the PLA composite was investigated using vertical combustion (UL-94), the limiting oxygen index (LOI) and the cone calorimeter (CONE) test. Thermal properties and morphology were characterized via thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM), respectively. Experimental results indicated that when the mass ratio of DESG/APP was equal to 12/8 the LOI value was 32.2%; a vertical burning test (UL-94) V-0 rating was achieved. Meanwhile, the sample showed a lowest total heat release (THR) value of 52.7 MJ/m2, which is a 32.5% reduction compared to that of neat PLA. Using FESEM, the uniform distribution of DESG and APP in the PLA matrix was observed. The synergistic effect of DESG and APP effectively enhanced the flame retardancy of PLA. Additionally, the synergistic mechanism of DESG and APP in PLA was proposed.Keywords:polylactic acid;sesbania gum;ammonium polyphosphate;flame retardancy
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganics
·
2025
·Vol. 13
·期 8
·272
·
IF 3
Juan Du,Xiang Wan,Caixiong Song,Kangsheng Wu,Wenbing Yang,Beiye Liu,Qi Yang,Jingjing Fang,Ayesha Razzaq
Crystal twinning, a common growth phenomenon, can substantially affect material performance in fields such as semiconductors, nonlinear optics, and drug development, yet its elimination during crystallization is challenging. This study presents a method for the controlled synthesis of ZSM-5 zeolite as either single crystals or twinned crystals using kaolin as the primary raw material. The method leverages the etching effect of ammonium fluoride (NH4F) on the aluminosilicate structure derived from pre-treated kaolin. By adjusting the concentrations of NH4F and the structure-directing agent tetrapropylammonium bromide (TPABr), pure ZSM-5 single crystals and twinned crystals were selectively synthesized. Conventionally, NH4F is employed to introduce defects into zeolite structures. In contrast, this work demonstrates its utility in controlling crystal habit. The synthesis utilizes kaolin, an abundant and low-cost aluminosilicate mineral, to provide the entire aluminum source and a portion of the silicon source, offering an economical alternative to expensive precursors like aluminum isopropoxide. The resulting single and twinned crystals exhibited high crystallinity, demonstrating the viability of using natural minerals to produce high-quality zeolites. The physical and chemical properties of the kaolin-derived ZSM-5 were characterized and compared to those of ZSM-5 synthesized from conventional chemical reagents. A growth mechanism for the formation of single and twinned crystals is also proposed.
研究领域:
材料科学
·
晶体学
·
无机化学
·
纳米技术
·
化学合成
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2021
·Vol. 67
·期 6
·e17184
·
IF 3.993
Jiancheng Lan,Linzhe Li,Wensen Song,Hammad Saulat,Haowen Wu,Jianhua Yang,Chengmin Yang,Yang Li,Jinming Lu,Yan Zhang
Pure-silica MFI zeolite membrane composed of intergrown four prism crystals was fabricated by using tetrabutylammonium (TBA + ) and tetraethylammonium (TEA + ) as cooperating templates and the induced function of MFI seeds under synthesis solution with molar composition of 1TEOS:0.2TBAOH:0.2TEABr:180H 2 O. The ethanol/water separation factor was 64 with a flux of 1.40 kg m −2 hr −1 for 5 wt% ethanol/water mixture at 60°C. In contrast, single TBAOH and TEAOH template led to formation of uncontinuous MEL and MFI membrane respectively, without ethanol-selectivity. The behavior of quaternary ammonium (TBA + and TEA + ) varied in different system: (a) In “TBA + + TEA + ” system, TBA + and TEA + were incorporated into MFI zeolite channel simultaneously; (b) In “TPA + + M + ” system (M = TEA or TBA), either TEA + or TBA + could not be occluded into channel, however, appropriate amount of TBA + could accelerate membrane crystallization, meanwhile increase in TEA + slowed down crystallization rate of MFI membrane. This work extends the alternative preparation approaches of ethanol perm-selective MFI membrane.
研究领域:
材料科学
·
化学工程
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2016
·
IF 1.846
Hua Sun,Lu Wang,Baoshu Liu
The solubility of α-glycine in water with different additives (sodium nitrate, ammonium nitrate , ammonium sulfate , and ammonium chloride) was measured under atmospheric pressure across the temperature range of (293.15–343.15) K at intervals of 10.00 K using a dynamic laser method. Solubility was found to increase with increasing temperature and additive level. The experimental data were correlated with the modified Apelblat model, nonrandom two-liquid model (NRTL), and λh model. The R 2 of the fitting regression indicated good applicability of these models to the glycine solubility data in the studied systems ( R 2 > 0.99). Apparent standard enthalpy, entropy, and Gibbs free energy changes of the solution were calculated based on the van't Hoff equation to elucidate the dissolution mechanism. The results showed that the dissolving process of glycine was endothermic, and the main dissolution driving force contributor was enthalpy in all the additive + water systems studied. By means of enthalpy-entropy compensation analysis, a non linear Δ H sol Θ versus Δ G sol Θ enthalpy-entropy compensation plot with positive and negative slopes was obtained for the systems studied. The evaluated values of H E showed that the mixing process of α-glycine in all the systems studied was exothermic.
研究领域:
物理化学
·
热力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Haosong Liu,Xuyang Liu,Fangbo Zhao,Yang Liu,Lijia Liu,Lihong Wang,Chengbao Geng,Pei Huang
In order to improve the anti-biofouling performance of ultrafiltration membrane, quaternized graphene oxide (QGO) was synthesized as a membrane modifier by in-situ growth of quaternary ammonium salt on the graphene oxide surface. A hydrophilic and antibacterial dual functional membrane was prepared with this kind of modifiers by immersion phase inversion method. The modified membrane obviously exhibits enhanced hydrophilicity, antibacterial and mechanical properties than the unmodified Polyvinylidene fluoride (PVDF) membranes. At the same time, it is proved that graphene oxide, as a carrier of quaternary ammonium salt, can significantly reduce the loss of antibacterial substances from the membranes.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 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）