In this paper,the effect of sodium laurate(SL)on the properties of sodium lauroyl glutamate(SLG),such as surface activity,foam,wetting,emulsification,and resistance to hard water,has been systematically investigated.T...In this paper,the effect of sodium laurate(SL)on the properties of sodium lauroyl glutamate(SLG),such as surface activity,foam,wetting,emulsification,and resistance to hard water,has been systematically investigated.The results showed that the critical micelle concentration(cmc)of SLG was 0.30 mmol/L,and the surface tension at the cmc(γcmc)was 34.95 mN/m.With the increase of SL content,the efficiency of SLG solution in reducing the surface tension was decreased.When the SL content was increased,there was no significant change in the foaming ability and foam stability of SLG solutions.The increase of SL content improved both the emulsification and wettability of SLG,but reduced its water resistance.展开更多
The sodium-iodine(Na-I)battery exhibits significant potential as an alternative energy storage device to the lithium-ion battery.However,its development is hindered by inadequate electrical and thermal stability,as we...The sodium-iodine(Na-I)battery exhibits significant potential as an alternative energy storage device to the lithium-ion battery.However,its development is hindered by inadequate electrical and thermal stability,as well as the dissolution and shuttling of polyiodide.In this study,we report a preparation method for melamine carbon sponge(MC)via carbonizing a commercially available kitchen sponge.It was revealed that the as-prepared MC,composed of unique self-growing carbon nanotubes,could provide both physical and chemical adsorption capabilities for intermediate polyiodides to improve the electrochemical performance of NaI.Consequently,the NaI/MC electrode effectively minimized polyiodide dissolution and reduced the electrochemical impedance.The NaI/MC cathode demonstrated a high average discharge capacity of 92.75 mAh·g^(–1)over 200 cycles while maintaining a coulombic efficiency of 94%.The research findings from our study have promising applications in Na-I batteries.展开更多
Sodium-ion batteries(SIBs)have emerged as a promising alternative to commercial lithium-ion batteries be-cause of the similar properties of Li and Na as well as the abundance and accessibility of sodium resources.The ...Sodium-ion batteries(SIBs)have emerged as a promising alternative to commercial lithium-ion batteries be-cause of the similar properties of Li and Na as well as the abundance and accessibility of sodium resources.The devel-opment of anode materials with a high capacity,excellent rate performance,and long cycle life is the key to the indus-trialization of SIBs.Biomass-derived carbon(BDC)anode materials synthesized from resource-rich,low-cost,and re-newable biomass have been extensively researched and their excellent sodium storage performance has been proven,making them the most promising new low-cost and high-performance anode material for SIBs.This review first intro-duces the sources of BDCs,including waste biomass such as plants,animals,and microorganisms,and then describes sev-eral methods for preparing BDC anode materials,including carbonization,chemical activation,and template methods.The storage mechanism and kinetic process of Na^(+)in BDCs are then considered as well as their structure control.The electrochemical properties of sodium-ion storage in BDCs with different structures are examined,and suggestions for future re-search are made.展开更多
Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated wi...Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated with sodium halides(NaBr and NaI)are presented to capture elemental mercury(Hg^(0))from flue gas.The modified RM underwent comprehensive characterization,including analysis of its textural qualities,crystal structure,chemical composition,and thermal properties.The results indicate that the halide impregnation substantially impacts the surface area and pore size of the RM.Hg^(0) removal performance was evaluated on a fixed-bed reactor in simulated flue gas(consisting of N_(2),O_(2),CO_(2),NO and SO_(2),etc.)on a modified RM.At an optimal adsorption temperature of 160℃,NaI-modified sorbent(RMI5)offers a removal efficiency of 98%in a mixture of gas,including O_(2),NO and HCl.Furthermore,pseudo-second-order model fitting results demonstrate the chemisorption mechanism for the adsorption of Hg^(0) in kinetic investigations.展开更多
Sodium cocoyl glycinate(SCG),an environmentally friendly anionic amino acid surfactant,is widely used in daily chemical products as an upgraded alternative to traditional surfactants.In this study,crude Camellia oleif...Sodium cocoyl glycinate(SCG),an environmentally friendly anionic amino acid surfactant,is widely used in daily chemical products as an upgraded alternative to traditional surfactants.In this study,crude Camellia oleifera saponin(COS)was purified using AB-8 macroporous adsorption resin,and its composition and structure were analyzed.The effects of different mole fractions of COS(αCOS)on surface tension(γ),oil-water interfacial tension(IFT),emulsification,and foam properties of COS-SCG binary mixed systems were investigated in mixtures of SCG with purified COS.The stability ofγand foamability under diverse environmental conditions were also discussed.The results indicated that the COS-SCG system exhibited remarkable surface-active synergism.The minimum critical micelle concentration(cmc)of the mixed system was lower than that of SCG,and adding a small mole fraction of COS(1%-2%)induced a synergistic reduction ofγ.Specifically,the cmc andγwere 2.50×10-4 mol/L and 23.1 mN/m forαCOS=1%,respectively.The system exhibited exceptional IFT reduction capacity,achieving a minimum value of 1.42 mN/m atαCOS=10%.The mixed system reached a foaming volume(atαCOS=50%)and foam stability(atαCOS=75%)were 51.0 mL and 97.37%,respectively.Microscopic analysis further confirmed these outstanding foam properties.Moreover,the COS-SCG system displayed reducedγwith enhanced foaming volume under elevated temperatures(35-75℃)and salinity(0-20 g/L).However,acidic conditions and hard water compromised bothγstability and foamability.展开更多
Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)are two typical titanate-based sodium-storage materials,featuring the high theoretical capacity and favorable structure stability,respectively.Regulating the ratio of them in the...Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)are two typical titanate-based sodium-storage materials,featuring the high theoretical capacity and favorable structure stability,respectively.Regulating the ratio of them in the composite material is the key to strengthen its electrochemical characteristics.Herein,based on the high specific surface area and abundant surface functional groups of carbon dots(CDs),sodium titanate precursors containing CDs were in situ prepared by one-step hydrothermal method.After the thermal conversion of the precursors,a composite material(NNTO/C)of Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)was obtained,containing conductive carbon derived from CDs.The introduc⁃tion of conductive carbon not only adjusts the composition ratio of the mixed phases,but also provides a small charge transfer impedance(Rct,7.48Ω)and a big specific surface area(100.8 m^(2)/g).As a result,NNTO/C composites exhibit better sodium storage behavior while playing the synergistic interaction of mixed phases.When employed as the anode,after 200 cycles at 0.05 A/g,NNTO/C still maintains a specific capacity of 143.8 mA‧h/g.After 400 cycles at 1.00 A/g,the specific capacity remains as high as 108 mA‧h/g.This study suggests an innovative thinking for designing two-phase structures of electrode materials and the greater use of CDs in electrochemical energy storage.展开更多
The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitat...The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitation process were systematically investigated by physicochemical properties test,using SEM and Raman spectra.As the concentration of sodium oxalate increases,both the precipitation rate and particle size of gibbsite decrease.The presence of sodium oxalate not only increases the viscosity of sodium aluminate solution,but also promotes the transformation of Al(OH)4^? to Al2O(OH)6^2?.The overall reaction rate constant decreases and the apparent activation energy of gibbsite increases with the increasing sodium oxalate concentration,the rate controlling step of which is chemical reaction.The needle-like sodium oxalate precipitates on the gibbsite crystals and covers the active Al(OH)3 seed sites,which leads to the lower precipitation rate and the finer particle size of gibbsite during the seed precipitation process.展开更多
The wettability,surfactivity and the correlation between wettability and surfactivity of sodium diethylhexylphosphate,sodium diethylhexyl polyoxyethylene phosphate and their complex in NaOH solutions were studied.A co...The wettability,surfactivity and the correlation between wettability and surfactivity of sodium diethylhexylphosphate,sodium diethylhexyl polyoxyethylene phosphate and their complex in NaOH solutions were studied.A complex alkali resistant phosphate surfactant with good permeability was prepared.The wettability of surfactants was investigated by measuring the immersion time,sinking time and capillary effects of nature cotton grey fabric in NaOH solutions.The surfactivity of the surfactants was characterized by measuring the surface tension.The effect of the complex on the surface appearance of cotton grey fabric was also investigated with a scanning electron microscope(SEM) .The results show that all the surfactants exhibit good wettability for cotton grey fabric in 0.5-5.0 mol/L of NaOH solutions,the complex system exhibits better wettability in 5.0-7.0 mol/L of NaOH solutions,in comparison with either corresponding single surfactant component employed,and wettability is well correlative with the surfactivities of the surfactant.SEM images indicate that the cotton grey fabric is well wetted by the alkaline surfactant solution and the quality of fabric is improved.展开更多
Two finite element(FE) models were built up for analysis of stress field in the lining of aluminum electrolysis cells.Distribution of sodium concentration in cathode carbon blocks was calculated by one FE model of a c...Two finite element(FE) models were built up for analysis of stress field in the lining of aluminum electrolysis cells.Distribution of sodium concentration in cathode carbon blocks was calculated by one FE model of a cathode block.Thermal stress field was calculated by the other slice model of the cell at the end of the heating-up.Then stresses coupling thermal and sodium expansion were considered after 30 d start-up.The results indicate that sodium penetrates to the bottom of the cathode block after 30 d start-up.The semi-graphitic carbon block has the largest stress at the thermal stage.After 30 d start-up the anthracitic carbon has the greatest sodium expansion stress and the graphitized carbon has the lowest sodium expansion stress.Sodium penetration can cause larger deformation and stress in the cathode carbon block than thermal expansion.展开更多
All-solid-state lithium-ion batteries(LIBs)using ceramic electrolytes are considered the ideal form of rechargeable batteries due to their high energy density and safety.However,in the pursuit of all-solid-state LIBs,...All-solid-state lithium-ion batteries(LIBs)using ceramic electrolytes are considered the ideal form of rechargeable batteries due to their high energy density and safety.However,in the pursuit of all-solid-state LIBs,the issue of lithium resource availability is selectively overlooked.Considering that the amount of lithium required for all-solidstate LIBs is not sustainable with current lithium resources,another system that also offers the dual advantages of high energy density and safetydall-solid-state sodium-ion batteries(SIBs)dholds significant sustainable advantages and is likely to be the strong contender in the competition for developing next-generation high-energy-density batteries.This article briefly introduces the research status of all-solid-state SIBs,explains the sources of their advantages,and discusses potential approaches to the development of solid sodium-ion conductors,aiming to spark the interest of researchers and attract more attention to the field of all-solid-state SIBs.展开更多
High-voltage sodium-ion batteries(SIBs)are emerging as promising candidates for large-scale energy storage systems due to their abundant sodium source and high energy density.However,the instability of the electrode e...High-voltage sodium-ion batteries(SIBs)are emerging as promising candidates for large-scale energy storage systems due to their abundant sodium source and high energy density.However,the instability of the electrode electrolyte interphase remains a critical barrier to the potential use of high-voltage SIBs.Herein,sodium difluorophosphate(NaDFP)and fluoroethylene carbonate(FEC)serve as functional electrolyte additives to stabilize the interface of the high-voltage cathode.The oxidative competition between FEC and NaDFP facilitates the robust formation of the cathode-electrolyte interface(CEI)layer,enriched with inorganic components such as NaF/NaPO_(x)F_(y).The highly conductive NaF/NaPO_(x)F_(y)and inorganics provide fast ion transport pathways and mechanical strength,thereby mitigating the decomposition of carbonates and NaPF_(6).The half-cell equipped with BE 2 F+0.5 DFP demonstrates 93.9%capacity retention at 4.3 V across 600 cycles,showcasing excellent cycling capability.Full HC||NVOPF cells exhibit sustained performance with 91.69%capacity retention and a capacity of 91.57 mA·h/g over 1000 cycles at a 5 C rate.This study is poised to garner increased scholarly interest in the domain of rational electrolyte formulation for practical applications.展开更多
The main objective of this paper focuses on the changes that occur in the strength and microstructural properties of sodium silicate activated fly ash based geopolymer due to varying the sulfate salt and water content...The main objective of this paper focuses on the changes that occur in the strength and microstructural properties of sodium silicate activated fly ash based geopolymer due to varying the sulfate salt and water content.A series of tests including X-ray diffraction,Fourier transform infrared spectroscopy,scanning electron microscopy,physical adsorption and unconfined compressive strength were used to investigate this effect.The results indicate that the higher water content has an adverse effect on the alkali activation and microstructural properties of geopolymer,so the optimum mass ratio of sodium sulfate in alkali-activated geopolymer under different water-to-binder ratios shows a“peak shifting”phenomenon,i.e.,the higher the water-to-binder ratio,the higher the optimum mass ratio.Lower presence of sodium sulfate has no significant effect on the alkali-activated geopolymer systems;higher addition of sodium sulfate,however,could cause the symmetrical stretching vibration of Si—O and the symmetrical stretching vibration of Si—O—Si and Al—O—Si,and promote the formation of N-A-S-H gels.Furthermore,the cement effect of the gel and sodium sulfate aggregate could improve the integrity of pore structure obviously.The maximum strength of geopolymer curing at ambient temperature was 52 MPa.This study obtains the rule that the strength properties of alkali-activated geopolymers vary with the water-to-binder ratio and sodium sulfate content.The feasibility of geopolymer co-activated by sodium sulfate and sodium silicate was investigated,and reference for engineering application of alkali-activated geopolymer in salt-bearing areas was provided.展开更多
BACKGROUND New therapies are urgently needed for Alzheimer disease(AD). Sodium oligomannate(GV-971) is a marine-derived oligosaccharide that has been shown to decrease amyloid deposition, reduce neuroinflammation, rec...BACKGROUND New therapies are urgently needed for Alzheimer disease(AD). Sodium oligomannate(GV-971) is a marine-derived oligosaccharide that has been shown to decrease amyloid deposition, reduce neuroinflammation, reconstitute gut microbiota, and improve cognition in animal models of AD. A Phase 3 trial was conducted to assess efficacy and safety of GV-971. METHODS We conducted a Phase 3, double-blind placebo-controlled trial in patients with mild-to-moderate AD. Participants were randomized to receive placebo or GV-971(900 mg) for 36 weeks. The primary outcome was the drug-placebo difference in change from baseline on the 12-item cognitive subscale of the Alzheimer′s Disease Assessment Scale(ADAS-cog12). Secondary endpoints were drug-placebo differences on the Clinician′s Interview-Based Impression of Change(CIBIC+), Alzheimer′s Disease Cooperative Study-Activities of Daily Living(ADCS-ADL) scale, and Neuropsychiatric Inventory(NPI). The effect of GV-971 on the cerebral glucose metabolic rate was examined by 18 Fluorine-FDG PET in a subgroup. Safety and tolerability were monitored. RESULTS 818 participants were randomized, of which 408 were assigned to GV-971 and 410 to placebo. A significant drug-placebo difference in favor of GV-971 was present at each measurement time-point on the ADAS-Cog12. The difference between groups with regard to the change from baseline was-2.15 points(95% confidence interval,-3.07 to-1.23;P<0.0001;effect size 0.531) after 36 weeks treatment. There was a trend towards benefit on CIBIC+(P=0.0588) but not on the ADCS-ADL(P=0.5712), NPI(P=0.8004), or the CMRglu. TEAE incidence77% and 76%, comparable between the two groups. Two deaths occurred in the GV-971 group;these were determined not to be related to GV-971. CONCLUSION GV-971 demonstrated significant efficacy in improving cognition and showed sustained improvement across al observation periods. GV-971 was safe and well tolerated.展开更多
The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-so...The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-sodium acetate(SMMZ)has a high sorption efficiency and removal performance.The ammonia-nitrogen removal rate of SMMZ reaches 92.90%.The surface of SMMZ becomes loose and some pores appear,the specific surface area,total pore volume and average pore diameter increase after modification.Compared to the natural zeolite,SMMZ has a more concentrated pore size distribution in the range of 0-10 nm.The cation exchange capacity(CEC)of SMMZ is higher than that of the natural zeolite.And the ammonia nitrogen removal rate is consistent with the change of CEC.The SMMZ possesses rapid sorption and slow balance characteristics and ammonia-nitrogen sorption is consistent with both Langmuir adsorption isotherm model and Freundlich adsorption isotherm model.The adsorption kinetics of ammonia-nitrogen follows the pseudo-second order kinetic model.展开更多
A novel process was proposed for the utilization of potash feldspar by roasting in the presence of sodium carbonate. The effects of roasting temperature, granularity, molar ratio of sodium carbonate to potash feldspar...A novel process was proposed for the utilization of potash feldspar by roasting in the presence of sodium carbonate. The effects of roasting temperature, granularity, molar ratio of sodium carbonate to potash feldspar and roasting time on the silica extraction rate were investigated. Under the optimal roasting conditions, the silica extraction rate was 98%. The optimal conditions, determined using an orthogonal experiment, were found to be roasting temperature of 875 A degrees C, potash feldspar granularity of 74-89 mu m, molar ratio of sodium carbonate to potash feldspar of 1.2:1, and roasting time of 80 min. The kinetics of potash feldspar roasting in the presence of sodium carbonate was described by the shrinking core model and the reaction rate was found to be controlled by the chemical reaction at the particle surface. According to the Arrhenius expression, the activation energy was 164.99 kJ/mol, and the process could be expressed as [1-(1-alpha)(1/3)]=2.66x10(5) exp[-164990/(RT)] t.展开更多
The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigat...The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigated by means of solution chemistry, ultraviolet spectrophotometry(UV), inductively coupled plasma atomic emission spectrometry(ICP-AES) and X-ray photoelectron spectroscopy(XPS). It is observed that dolomite with different size fractions has depressing effect on hematite flotation using sodium oleate as collector, and dolomite could be the "mineral depressant" of hematite using sodium oleate as collector. The reasons for that are concerned with sodium oleate consumption and the adsorption onto hematite of dissolved species of dolomite.展开更多
The influence of pulp temperature on the floatability and adsorption behavior of fine wolframite with sodium oleate was investigated by microflotation experiments, electric conductivity tests, adsorption measurements,...The influence of pulp temperature on the floatability and adsorption behavior of fine wolframite with sodium oleate was investigated by microflotation experiments, electric conductivity tests, adsorption measurements, and FT-IR analysis. Microflotation results show that fine wolframite with sodium oleate exhibits a good floatability at pH 8–9. Electric conductivity tests indicate that the high temperature enhances the ionization degree and electric mobility of oleate species, then the flotation recovery of fine wolframite and the adsorption amount of sodium oleate are observed to increase with the rise in pulp temperature. The results of adsorption experiments are found to meet Freundlich isotherms successfully, and the isosteric enthalpy （ΔH^Θ） is in conformity with the chemical bonding. The changes in FT-IR analysis provide sufficient evidence that sodium oleate interacts with the metal cations of wolframite surface, and the increase in pulp temperature clearly promotes the chemisorption intensity. These findings will be beneficial to strengthen the flotation behavior of fine wolframite.展开更多
In order to offer high grade concentrate to produce alumina by Bayer, the reverse-flotation technology of bauxite was investigated. The results show that sodium hexmetaphosphate has different depression on the flotati...In order to offer high grade concentrate to produce alumina by Bayer, the reverse-flotation technology of bauxite was investigated. The results show that sodium hexmetaphosphate has different depression on the flotation of diaspore and kaolinite. The recoveries of diaspore decrease markedly with the increase of the concentration of sodium hexmetaphosphate with dodecyl-amine as collector. Fourier transform infrared spectra indicate that the absorbance band 875cm -1 of the asymmetric stretching vibration of bridge oxygen P—O—P shifts to 880cm -1 , and the 1264cm -1 of the asymmetric stretching vibration of the bridge PO2 shifts to 1267cm -1 in the diaspore’s spectra. This demonstrates that sodium hexmetaphosphate interacts through bridging PO2 groups with the Al atoms exposed on the diaspore and kaolinite surfaces to form P—O—Al bond. Adsorption measurements also testify that sodium hexmetaphosphate adsorbs easily on the surface of diaspore. The adsorption density of PO-3 on the surface of diaspore is about 4.7×10 -6 mol/m2, while that on the kaolinite is only about 3.5×10 -7 mol/m2 when pH value is 6.展开更多
The sodium expansion curves of semi-graphitic cathode measured with the improved Rapoport-Samoilenko apparatus. The and TiB2/C composite cathode with different TiB2 contents were mathematic model of the sodium expansi...The sodium expansion curves of semi-graphitic cathode measured with the improved Rapoport-Samoilenko apparatus. The and TiB2/C composite cathode with different TiB2 contents were mathematic model of the sodium expansion was deduced on the basis of the experimental results. The sodium expansion parameter （a） and penetration rate factor （Q）, were introduced into the model The model was validated with the experimental sodium expansion curves self-measured and reported. The results show that the variation tendency of the sodium expansion parameter （a） and penetration rate factor （Q） is consistent with that of the experimental curves. The model is capable of not only conveniently judging the cathode quality, but also favorably establishing a unified standard of the resistance to sodium penetration of cathode.展开更多
In this paper,the effect of sodium butyl xanthate(NaBX)adsorption on the surface of bornite at different pH on flotation was studied by adsorption kinetic and thermodynamic.The flotation results demonstrated that the ...In this paper,the effect of sodium butyl xanthate(NaBX)adsorption on the surface of bornite at different pH on flotation was studied by adsorption kinetic and thermodynamic.The flotation results demonstrated that the recovery was the highest when pH was 9 in NaBX solution(4×10^?5 mol/L).The adsorption kinetics showed the reaction of NaBX on the bornite conformed to the second order kinetic equation;it belonged to the multimolecular layer adsorption of Freundlich model;the maximum adsorption rate constant was 0.30 g/(10^?6 mol·min),and the equilibrium adsorption capacity was 2.70×10^?6 mol/g.Thermodynamic calculation results indicated that the adsorption process was spontaneous chemisorption,and the adsorption products of NaBX on bornite surface were cupric butyl xanthate,ferric butyl xanthate and dixanthogen,which were confirmed by infrared spectrum measurements.展开更多
文摘In this paper,the effect of sodium laurate(SL)on the properties of sodium lauroyl glutamate(SLG),such as surface activity,foam,wetting,emulsification,and resistance to hard water,has been systematically investigated.The results showed that the critical micelle concentration(cmc)of SLG was 0.30 mmol/L,and the surface tension at the cmc(γcmc)was 34.95 mN/m.With the increase of SL content,the efficiency of SLG solution in reducing the surface tension was decreased.When the SL content was increased,there was no significant change in the foaming ability and foam stability of SLG solutions.The increase of SL content improved both the emulsification and wettability of SLG,but reduced its water resistance.
基金supported by Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive Application(Grant No.ZDSYS20220527171407017).
文摘The sodium-iodine(Na-I)battery exhibits significant potential as an alternative energy storage device to the lithium-ion battery.However,its development is hindered by inadequate electrical and thermal stability,as well as the dissolution and shuttling of polyiodide.In this study,we report a preparation method for melamine carbon sponge(MC)via carbonizing a commercially available kitchen sponge.It was revealed that the as-prepared MC,composed of unique self-growing carbon nanotubes,could provide both physical and chemical adsorption capabilities for intermediate polyiodides to improve the electrochemical performance of NaI.Consequently,the NaI/MC electrode effectively minimized polyiodide dissolution and reduced the electrochemical impedance.The NaI/MC cathode demonstrated a high average discharge capacity of 92.75 mAh·g^(–1)over 200 cycles while maintaining a coulombic efficiency of 94%.The research findings from our study have promising applications in Na-I batteries.
文摘Sodium-ion batteries(SIBs)have emerged as a promising alternative to commercial lithium-ion batteries be-cause of the similar properties of Li and Na as well as the abundance and accessibility of sodium resources.The devel-opment of anode materials with a high capacity,excellent rate performance,and long cycle life is the key to the indus-trialization of SIBs.Biomass-derived carbon(BDC)anode materials synthesized from resource-rich,low-cost,and re-newable biomass have been extensively researched and their excellent sodium storage performance has been proven,making them the most promising new low-cost and high-performance anode material for SIBs.This review first intro-duces the sources of BDCs,including waste biomass such as plants,animals,and microorganisms,and then describes sev-eral methods for preparing BDC anode materials,including carbonization,chemical activation,and template methods.The storage mechanism and kinetic process of Na^(+)in BDCs are then considered as well as their structure control.The electrochemical properties of sodium-ion storage in BDCs with different structures are examined,and suggestions for future re-search are made.
基金supported by the National Natural Science Foundation of China(22278066,21776039)the National Key R&D Program of China(2023YFB4103001)The Fundamental Research Funds for the Central Universities(DUT2021TB03).
文摘Mercury removal from coal combustion flue gas remains a significant challenge for environmental protection due to the lack of cost-effective sorbents.In this study,a series of red mud(RM)-based sorbents impregnated with sodium halides(NaBr and NaI)are presented to capture elemental mercury(Hg^(0))from flue gas.The modified RM underwent comprehensive characterization,including analysis of its textural qualities,crystal structure,chemical composition,and thermal properties.The results indicate that the halide impregnation substantially impacts the surface area and pore size of the RM.Hg^(0) removal performance was evaluated on a fixed-bed reactor in simulated flue gas(consisting of N_(2),O_(2),CO_(2),NO and SO_(2),etc.)on a modified RM.At an optimal adsorption temperature of 160℃,NaI-modified sorbent(RMI5)offers a removal efficiency of 98%in a mixture of gas,including O_(2),NO and HCl.Furthermore,pseudo-second-order model fitting results demonstrate the chemisorption mechanism for the adsorption of Hg^(0) in kinetic investigations.
文摘Sodium cocoyl glycinate(SCG),an environmentally friendly anionic amino acid surfactant,is widely used in daily chemical products as an upgraded alternative to traditional surfactants.In this study,crude Camellia oleifera saponin(COS)was purified using AB-8 macroporous adsorption resin,and its composition and structure were analyzed.The effects of different mole fractions of COS(αCOS)on surface tension(γ),oil-water interfacial tension(IFT),emulsification,and foam properties of COS-SCG binary mixed systems were investigated in mixtures of SCG with purified COS.The stability ofγand foamability under diverse environmental conditions were also discussed.The results indicated that the COS-SCG system exhibited remarkable surface-active synergism.The minimum critical micelle concentration(cmc)of the mixed system was lower than that of SCG,and adding a small mole fraction of COS(1%-2%)induced a synergistic reduction ofγ.Specifically,the cmc andγwere 2.50×10-4 mol/L and 23.1 mN/m forαCOS=1%,respectively.The system exhibited exceptional IFT reduction capacity,achieving a minimum value of 1.42 mN/m atαCOS=10%.The mixed system reached a foaming volume(atαCOS=50%)and foam stability(atαCOS=75%)were 51.0 mL and 97.37%,respectively.Microscopic analysis further confirmed these outstanding foam properties.Moreover,the COS-SCG system displayed reducedγwith enhanced foaming volume under elevated temperatures(35-75℃)and salinity(0-20 g/L).However,acidic conditions and hard water compromised bothγstability and foamability.
文摘Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)are two typical titanate-based sodium-storage materials,featuring the high theoretical capacity and favorable structure stability,respectively.Regulating the ratio of them in the composite material is the key to strengthen its electrochemical characteristics.Herein,based on the high specific surface area and abundant surface functional groups of carbon dots(CDs),sodium titanate precursors containing CDs were in situ prepared by one-step hydrothermal method.After the thermal conversion of the precursors,a composite material(NNTO/C)of Na_(2)Ti_(3)O_(7)and Na_(2)Ti_(6)O_(13)was obtained,containing conductive carbon derived from CDs.The introduc⁃tion of conductive carbon not only adjusts the composition ratio of the mixed phases,but also provides a small charge transfer impedance(Rct,7.48Ω)and a big specific surface area(100.8 m^(2)/g).As a result,NNTO/C composites exhibit better sodium storage behavior while playing the synergistic interaction of mixed phases.When employed as the anode,after 200 cycles at 0.05 A/g,NNTO/C still maintains a specific capacity of 143.8 mA‧h/g.After 400 cycles at 1.00 A/g,the specific capacity remains as high as 108 mA‧h/g.This study suggests an innovative thinking for designing two-phase structures of electrode materials and the greater use of CDs in electrochemical energy storage.
基金Projects(51774079,51674075)supported by the National Natural Science Foundation of ChinaProject(N182508026)supported by the Fundamental Research Funds for the Central Universities,China。
文摘The precipitation performance and kinetics of gibbsite from sodium aluminate solution with different sodium oxalate concentrations as well as the corresponding influence mechanism of oxalate during the seed precipitation process were systematically investigated by physicochemical properties test,using SEM and Raman spectra.As the concentration of sodium oxalate increases,both the precipitation rate and particle size of gibbsite decrease.The presence of sodium oxalate not only increases the viscosity of sodium aluminate solution,but also promotes the transformation of Al(OH)4^? to Al2O(OH)6^2?.The overall reaction rate constant decreases and the apparent activation energy of gibbsite increases with the increasing sodium oxalate concentration,the rate controlling step of which is chemical reaction.The needle-like sodium oxalate precipitates on the gibbsite crystals and covers the active Al(OH)3 seed sites,which leads to the lower precipitation rate and the finer particle size of gibbsite during the seed precipitation process.
基金Project(20573079) supported by the National Natural Science Foundation of China
文摘The wettability,surfactivity and the correlation between wettability and surfactivity of sodium diethylhexylphosphate,sodium diethylhexyl polyoxyethylene phosphate and their complex in NaOH solutions were studied.A complex alkali resistant phosphate surfactant with good permeability was prepared.The wettability of surfactants was investigated by measuring the immersion time,sinking time and capillary effects of nature cotton grey fabric in NaOH solutions.The surfactivity of the surfactants was characterized by measuring the surface tension.The effect of the complex on the surface appearance of cotton grey fabric was also investigated with a scanning electron microscope(SEM) .The results show that all the surfactants exhibit good wettability for cotton grey fabric in 0.5-5.0 mol/L of NaOH solutions,the complex system exhibits better wettability in 5.0-7.0 mol/L of NaOH solutions,in comparison with either corresponding single surfactant component employed,and wettability is well correlative with the surfactivities of the surfactant.SEM images indicate that the cotton grey fabric is well wetted by the alkaline surfactant solution and the quality of fabric is improved.
基金Project(50374081) supported by the National Natural Science Foundation of China
文摘Two finite element(FE) models were built up for analysis of stress field in the lining of aluminum electrolysis cells.Distribution of sodium concentration in cathode carbon blocks was calculated by one FE model of a cathode block.Thermal stress field was calculated by the other slice model of the cell at the end of the heating-up.Then stresses coupling thermal and sodium expansion were considered after 30 d start-up.The results indicate that sodium penetrates to the bottom of the cathode block after 30 d start-up.The semi-graphitic carbon block has the largest stress at the thermal stage.After 30 d start-up the anthracitic carbon has the greatest sodium expansion stress and the graphitized carbon has the lowest sodium expansion stress.Sodium penetration can cause larger deformation and stress in the cathode carbon block than thermal expansion.
基金the support of the Grant-in-Aid for JSPS Research Fellow.
文摘All-solid-state lithium-ion batteries(LIBs)using ceramic electrolytes are considered the ideal form of rechargeable batteries due to their high energy density and safety.However,in the pursuit of all-solid-state LIBs,the issue of lithium resource availability is selectively overlooked.Considering that the amount of lithium required for all-solidstate LIBs is not sustainable with current lithium resources,another system that also offers the dual advantages of high energy density and safetydall-solid-state sodium-ion batteries(SIBs)dholds significant sustainable advantages and is likely to be the strong contender in the competition for developing next-generation high-energy-density batteries.This article briefly introduces the research status of all-solid-state SIBs,explains the sources of their advantages,and discusses potential approaches to the development of solid sodium-ion conductors,aiming to spark the interest of researchers and attract more attention to the field of all-solid-state SIBs.
基金Project(2023QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,ChinaProject(51932011)supported by the National Natural Science Foundation of China+1 种基金Project(2023JJ10060)supported by the Natural Science Foundation of Hunan Province,ChinaProject(23A0003)supported by the Scientific Research Fund of Hunan Provincial Education Department,China。
文摘High-voltage sodium-ion batteries(SIBs)are emerging as promising candidates for large-scale energy storage systems due to their abundant sodium source and high energy density.However,the instability of the electrode electrolyte interphase remains a critical barrier to the potential use of high-voltage SIBs.Herein,sodium difluorophosphate(NaDFP)and fluoroethylene carbonate(FEC)serve as functional electrolyte additives to stabilize the interface of the high-voltage cathode.The oxidative competition between FEC and NaDFP facilitates the robust formation of the cathode-electrolyte interface(CEI)layer,enriched with inorganic components such as NaF/NaPO_(x)F_(y).The highly conductive NaF/NaPO_(x)F_(y)and inorganics provide fast ion transport pathways and mechanical strength,thereby mitigating the decomposition of carbonates and NaPF_(6).The half-cell equipped with BE 2 F+0.5 DFP demonstrates 93.9%capacity retention at 4.3 V across 600 cycles,showcasing excellent cycling capability.Full HC||NVOPF cells exhibit sustained performance with 91.69%capacity retention and a capacity of 91.57 mA·h/g over 1000 cycles at a 5 C rate.This study is poised to garner increased scholarly interest in the domain of rational electrolyte formulation for practical applications.
基金Project(51878322)supported by the National Natural Science Foundation of ChinaProject(18YF1FA112)supported by Key Research and Development Program of Gansu Province,China。
文摘The main objective of this paper focuses on the changes that occur in the strength and microstructural properties of sodium silicate activated fly ash based geopolymer due to varying the sulfate salt and water content.A series of tests including X-ray diffraction,Fourier transform infrared spectroscopy,scanning electron microscopy,physical adsorption and unconfined compressive strength were used to investigate this effect.The results indicate that the higher water content has an adverse effect on the alkali activation and microstructural properties of geopolymer,so the optimum mass ratio of sodium sulfate in alkali-activated geopolymer under different water-to-binder ratios shows a“peak shifting”phenomenon,i.e.,the higher the water-to-binder ratio,the higher the optimum mass ratio.Lower presence of sodium sulfate has no significant effect on the alkali-activated geopolymer systems;higher addition of sodium sulfate,however,could cause the symmetrical stretching vibration of Si—O and the symmetrical stretching vibration of Si—O—Si and Al—O—Si,and promote the formation of N-A-S-H gels.Furthermore,the cement effect of the gel and sodium sulfate aggregate could improve the integrity of pore structure obviously.The maximum strength of geopolymer curing at ambient temperature was 52 MPa.This study obtains the rule that the strength properties of alkali-activated geopolymers vary with the water-to-binder ratio and sodium sulfate content.The feasibility of geopolymer co-activated by sodium sulfate and sodium silicate was investigated,and reference for engineering application of alkali-activated geopolymer in salt-bearing areas was provided.
文摘BACKGROUND New therapies are urgently needed for Alzheimer disease(AD). Sodium oligomannate(GV-971) is a marine-derived oligosaccharide that has been shown to decrease amyloid deposition, reduce neuroinflammation, reconstitute gut microbiota, and improve cognition in animal models of AD. A Phase 3 trial was conducted to assess efficacy and safety of GV-971. METHODS We conducted a Phase 3, double-blind placebo-controlled trial in patients with mild-to-moderate AD. Participants were randomized to receive placebo or GV-971(900 mg) for 36 weeks. The primary outcome was the drug-placebo difference in change from baseline on the 12-item cognitive subscale of the Alzheimer′s Disease Assessment Scale(ADAS-cog12). Secondary endpoints were drug-placebo differences on the Clinician′s Interview-Based Impression of Change(CIBIC+), Alzheimer′s Disease Cooperative Study-Activities of Daily Living(ADCS-ADL) scale, and Neuropsychiatric Inventory(NPI). The effect of GV-971 on the cerebral glucose metabolic rate was examined by 18 Fluorine-FDG PET in a subgroup. Safety and tolerability were monitored. RESULTS 818 participants were randomized, of which 408 were assigned to GV-971 and 410 to placebo. A significant drug-placebo difference in favor of GV-971 was present at each measurement time-point on the ADAS-Cog12. The difference between groups with regard to the change from baseline was-2.15 points(95% confidence interval,-3.07 to-1.23;P<0.0001;effect size 0.531) after 36 weeks treatment. There was a trend towards benefit on CIBIC+(P=0.0588) but not on the ADCS-ADL(P=0.5712), NPI(P=0.8004), or the CMRglu. TEAE incidence77% and 76%, comparable between the two groups. Two deaths occurred in the GV-971 group;these were determined not to be related to GV-971. CONCLUSION GV-971 demonstrated significant efficacy in improving cognition and showed sustained improvement across al observation periods. GV-971 was safe and well tolerated.
基金Project(51174017) supported by the National Natural Science Foundation of China
文摘The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were investigated.The results show that the modified zeolite by microwave-sodium acetate(SMMZ)has a high sorption efficiency and removal performance.The ammonia-nitrogen removal rate of SMMZ reaches 92.90%.The surface of SMMZ becomes loose and some pores appear,the specific surface area,total pore volume and average pore diameter increase after modification.Compared to the natural zeolite,SMMZ has a more concentrated pore size distribution in the range of 0-10 nm.The cation exchange capacity(CEC)of SMMZ is higher than that of the natural zeolite.And the ammonia nitrogen removal rate is consistent with the change of CEC.The SMMZ possesses rapid sorption and slow balance characteristics and ammonia-nitrogen sorption is consistent with both Langmuir adsorption isotherm model and Freundlich adsorption isotherm model.The adsorption kinetics of ammonia-nitrogen follows the pseudo-second order kinetic model.
基金Project(51204054)supported by the National Natural Science Foundation of ChinaProject(2007CB613603)supported by the National Basic Research Program of ChinaProject(N140204011)supported by the Ministry of Education Basic Scientific Research Business Expenses,China
文摘A novel process was proposed for the utilization of potash feldspar by roasting in the presence of sodium carbonate. The effects of roasting temperature, granularity, molar ratio of sodium carbonate to potash feldspar and roasting time on the silica extraction rate were investigated. Under the optimal roasting conditions, the silica extraction rate was 98%. The optimal conditions, determined using an orthogonal experiment, were found to be roasting temperature of 875 A degrees C, potash feldspar granularity of 74-89 mu m, molar ratio of sodium carbonate to potash feldspar of 1.2:1, and roasting time of 80 min. The kinetics of potash feldspar roasting in the presence of sodium carbonate was described by the shrinking core model and the reaction rate was found to be controlled by the chemical reaction at the particle surface. According to the Arrhenius expression, the activation energy was 164.99 kJ/mol, and the process could be expressed as [1-(1-alpha)(1/3)]=2.66x10(5) exp[-164990/(RT)] t.
基金Project(51374079)supported by the National Natural Science Foundation of ChinaProject(KKSY201521031)supported by Talent Cultivation Foundation of Kunming University of Science and Technology,ChinaProject(2015Y067)supported by Foundation of Yunnan Educational Committee,China
文摘The effect of dolomite with different particle size fractions on hematite flotation was studied using sodium oleate as collector at p H of about 9. The effect mechanism of dolomite on hematite flotation was investigated by means of solution chemistry, ultraviolet spectrophotometry(UV), inductively coupled plasma atomic emission spectrometry(ICP-AES) and X-ray photoelectron spectroscopy(XPS). It is observed that dolomite with different size fractions has depressing effect on hematite flotation using sodium oleate as collector, and dolomite could be the "mineral depressant" of hematite using sodium oleate as collector. The reasons for that are concerned with sodium oleate consumption and the adsorption onto hematite of dissolved species of dolomite.
基金Project(51704058)supported by the National Natural Science Foundation of China
文摘The influence of pulp temperature on the floatability and adsorption behavior of fine wolframite with sodium oleate was investigated by microflotation experiments, electric conductivity tests, adsorption measurements, and FT-IR analysis. Microflotation results show that fine wolframite with sodium oleate exhibits a good floatability at pH 8–9. Electric conductivity tests indicate that the high temperature enhances the ionization degree and electric mobility of oleate species, then the flotation recovery of fine wolframite and the adsorption amount of sodium oleate are observed to increase with the rise in pulp temperature. The results of adsorption experiments are found to meet Freundlich isotherms successfully, and the isosteric enthalpy （ΔH^Θ） is in conformity with the chemical bonding. The changes in FT-IR analysis provide sufficient evidence that sodium oleate interacts with the metal cations of wolframite surface, and the increase in pulp temperature clearly promotes the chemisorption intensity. These findings will be beneficial to strengthen the flotation behavior of fine wolframite.
文摘In order to offer high grade concentrate to produce alumina by Bayer, the reverse-flotation technology of bauxite was investigated. The results show that sodium hexmetaphosphate has different depression on the flotation of diaspore and kaolinite. The recoveries of diaspore decrease markedly with the increase of the concentration of sodium hexmetaphosphate with dodecyl-amine as collector. Fourier transform infrared spectra indicate that the absorbance band 875cm -1 of the asymmetric stretching vibration of bridge oxygen P—O—P shifts to 880cm -1 , and the 1264cm -1 of the asymmetric stretching vibration of the bridge PO2 shifts to 1267cm -1 in the diaspore’s spectra. This demonstrates that sodium hexmetaphosphate interacts through bridging PO2 groups with the Al atoms exposed on the diaspore and kaolinite surfaces to form P—O—Al bond. Adsorption measurements also testify that sodium hexmetaphosphate adsorbs easily on the surface of diaspore. The adsorption density of PO-3 on the surface of diaspore is about 4.7×10 -6 mol/m2, while that on the kaolinite is only about 3.5×10 -7 mol/m2 when pH value is 6.
基金Project(2005CB623703) supported by the Major State Basic Research and Development Program of ChinaProject(2008AA030502) supported by the National High-Tech Research and Development Program of ChinaProject(GUIKEJI0639032) supported by the Science Fund Project of Guangxi Province, China
文摘The sodium expansion curves of semi-graphitic cathode measured with the improved Rapoport-Samoilenko apparatus. The and TiB2/C composite cathode with different TiB2 contents were mathematic model of the sodium expansion was deduced on the basis of the experimental results. The sodium expansion parameter （a） and penetration rate factor （Q）, were introduced into the model The model was validated with the experimental sodium expansion curves self-measured and reported. The results show that the variation tendency of the sodium expansion parameter （a） and penetration rate factor （Q） is consistent with that of the experimental curves. The model is capable of not only conveniently judging the cathode quality, but also favorably establishing a unified standard of the resistance to sodium penetration of cathode.
基金Projects(51504053,51374079)supported by the National Natural Science Foundation of ChinaProject(2015M571324)supported by the Postdoctoral Science Foundation of China
文摘In this paper,the effect of sodium butyl xanthate(NaBX)adsorption on the surface of bornite at different pH on flotation was studied by adsorption kinetic and thermodynamic.The flotation results demonstrated that the recovery was the highest when pH was 9 in NaBX solution(4×10^?5 mol/L).The adsorption kinetics showed the reaction of NaBX on the bornite conformed to the second order kinetic equation;it belonged to the multimolecular layer adsorption of Freundlich model;the maximum adsorption rate constant was 0.30 g/(10^?6 mol·min),and the equilibrium adsorption capacity was 2.70×10^?6 mol/g.Thermodynamic calculation results indicated that the adsorption process was spontaneous chemisorption,and the adsorption products of NaBX on bornite surface were cupric butyl xanthate,ferric butyl xanthate and dixanthogen,which were confirmed by infrared spectrum measurements.
