Examining carbonate dissolution kinetics at mineral-water interface is crucial to understand numerous environmental and geochemical processes,including global carbon cycling,CO_(2)sequestration in deep geological rese...Examining carbonate dissolution kinetics at mineral-water interface is crucial to understand numerous environmental and geochemical processes,including global carbon cycling,CO_(2)sequestration in deep geological reservoirs,and trace elements release in terrestrial and aquatic environments.Here we explored the effect of circumneutral to alkaline pH solutions(pH 6-11)on dissolution kinetics of pure dolomite and Ca and Mg release stoichiometry in flow-through reactor experiments at 25±1℃.Results revealed that the dolomite dissolution rates obtained from effluent Ca and Mg concentrations(R_(Ca)and R_(Mg)in mol/cm^(2)/s)were dependent on input solution pH and HCO_(3)^(-)log activity.The pH dependence of dissolution rates showed two distinct trends,i.e.,at circumneutral pH ranging between 6 and 8,the dissolution rate decreased with increasing pH,with minimum rate at pH 8.While in the highly alkaline pH range(pH 9-11),the dolomite dissolution rate increased with an increasing pH.Irrespective of the input pH,the dolomite dissolution rates indicated a reverse relationship with HCO_(3)^(-)log activity,with the lowest dissolution rate(R Ca=3.80×10^(-12)mol/cm^(2)/s)at pH 8 where HCO_(3)^(-)log activity attained the highest value(-3.957).The lower R Ca and R Mg obtained at pH 8 compared to all the other pH could possibly be attributed to an inhibition caused by high HCO_(3)^(-)log activity in solution at this pH.Dolomite dissolution rates were non-stoichiometric at all the experimental pH values,showing higher preferential Ca over Mg release(R_(Ca)>R_(Mg))whereas an opposite trend was observed at pH 8,with R_(Ca)<R_(Mg)at the steady state.Saturation index values calculated using geochemical speciation modelling were positive for Mg-bearing minerals(brucite,dolomite,artinite)at alkaline pH of 10-11,indicating favourable conditions for their precipitation under studied conditions.This study provides insights on the significance of log ion activities of HCO_(3)^(-)and Me-OH^(+)under varying pH for elucidating the dissolution mechanism of dolomite in circumneutral to alkaline aqueous environments.展开更多
Nanofiltration(NF) technology,with its capacity for nanoscale filtration and controllable selectivity,holds significant promise in diverse applications.However,the current upper bound of permeance and selectivity of N...Nanofiltration(NF) technology,with its capacity for nanoscale filtration and controllable selectivity,holds significant promise in diverse applications.However,the current upper bound of permeance and selectivity of NF membranes is intrinsically constrained by the morphology and structure of the polyamide(PA) selective layer.This issue arises because NF membranes typically exhibit relatively smooth nodular structures,which theoretically impede efficient water transport.In this study,we enhanced the formation of nanobubbles by synergistically regulating with surfactant and low temperatures,resulting in the fabrication of PA NF membranes with a crumpled morphology.We observed that lower temperatures promote enhanced gas solubility in the aqueous phase,facilitating increased nanobubble formation through the foaming effect of surfactant sodium dodecylbenzene sulfonate(SDBS).Consequently,this resulted in the creation of PA NF membranes with more crumpled structures and superior performance,with pure water permeance reaching 36.25 ± 0.42 L m^(-2)h^(-1)bar^(-1),representing an improvement of 14.47 L m^(-2)h^(-1)bar^(-1)compared to the control group.Additionally,it maintains a high Na_(2)SO_(4) rejection rate of97.00 % ± 0.58 %.The PA NF membranes produced by eliminating nanobubbles and free interfaces exhibited a smooth structure,whereas introducing nanobubbles(through Na HCO_(3) addition,N_(2) pressurization,and ultrasonication) resulted in the formation of crumpled membranes.This emphasized that the large amount of nanobubbles generated by SDBS and low temperature in the interfacial process played a critical role in shaping crumpled PA NF membranes and enhancing membrane performance.This approach has the potential to provide valuable insights into customizing the structural design of TFC PA NF membranes,contributing to further advancements in this field.展开更多
In the present study, we investigated the complexation of risperidone with hydroxypropyl-β-cyclodextrin （HP-β-CD） in aqueous solution due to the poor water solubility and low oral bioavailability of risperidone in...In the present study, we investigated the complexation of risperidone with hydroxypropyl-β-cyclodextrin （HP-β-CD） in aqueous solution due to the poor water solubility and low oral bioavailability of risperidone in humans. The effect of temperature on the complexation was examined, and thermodynamic parameters of the complexation process, such as Gibbs free energy change （AG）, enthalpy change （AH） and entropy change （AS）, were also explored. Meantime, the solid dispersion of risperidone with HP-β-CD was prepared and confirmed by Fourier IR spectroscopy and X-ray diffractometry. The experimental results suggested that the complex of the drug with HP-β-CD at a molar ratio of 1：1 could form in aqueous solution, and the complexation was an endothermic and entropy-driven process. The risperidone-HP-β-CD solid dispersion exhibited a remarkable improvement in the dissolution rate of the drug. This might be attributed to the amorphous state, the enhanced wettability as well as the complex formation of the drug with HP-β-CD in aqueous solution.展开更多
AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid d...AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid dispersions, physical mixtures and as a pure drug) and investigate drug-polymer interactions in the solid state using X-ray powder d iffraction and fourier-transform infrared spectroscopy. Results The negative values of the Gibbs free energy and enthalpy of transfer explaine d the spontaneous transfer of daidzein from phosphate buffer solution (PBS) to a solution of PVP in PBS. X-ray powder diffraction patterns showed that the drug was in the amorphous state (ratio of the drug ∶ PVP<1∶5) when dispers ed i n PVP K30. The infrared spectra indicated there exist interactions between the O H of daidzein and the C=O of PVP K30. Conclusionthe dispersion of daidzein in PVP K30 considerably enhances the solubility and dissolution rat e.展开更多
Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral...Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral administration.The particle technology involves several approaches from the conventional size reduction processes to the newer,novel particle technologies that modify the solubility properties of the drugs and produce solid,powdered form of the drugs that are readily soluble in water and can be easily formulated into various dosage forms.This review highlights the solid particle technologies available for improving solubility,dissolution and bioavailability of drugs with poor aqueous solubility.展开更多
The aim of this work was to develop, optimize and characterize a silymarin-laden polyvinylpyrrolidone(PVP)-polyethylene glycol(PEG) polymeric composite to resolve low aqueous solubility and dissolution rate problem of...The aim of this work was to develop, optimize and characterize a silymarin-laden polyvinylpyrrolidone(PVP)-polyethylene glycol(PEG) polymeric composite to resolve low aqueous solubility and dissolution rate problem of the drug. A number of silymarin-laden polymeric formulations were fabricated with different quantities of PVP K-30 and PEG 6000 by the solvent-evaporation method. The effect of PVP K-30 and PEG 6000 on the aqueous solubility and dissolution rate was investigated. The optimized formulation and its constituents were characterized using powder X-ray diffraction(PXRD), differential scanning calorimetry(DSC), scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(FTIR) techniques. Both the PEG 6000 and PVP K-30 positively affected the aqueous solubility and dissolution rate of the drug. In particular, a formulation consisting of silymarin, PVP K-30 and PEG 6000(0.25/1.5/1.5, w/w/w) furnished the highest solubility(24.3972.95 mg/mL) and an excellent dissolution profile( $100% in 40 min). The solubility enhancement with this formulation was $ 1150-fold as compared to plain silymarin powder. Moreover, all the constituents existed in the amorphous state in this silymarin-laden PVP-PEG polymeric composite. Accordingly, this formulation might be a promising tool to administer silymarin with an enhanced effect via the oral route.展开更多
Soluble portions(SPs) 1-4(SP1-SP4) were afforded from sequentially dissolution and alkanolyses of Baiyinhua lignite(BL) in cyclohexane,CH3OH,CH3CH2OH,and(CH3)2CHOH at 300℃.They were analyzed with a gas chromatograph/...Soluble portions(SPs) 1-4(SP1-SP4) were afforded from sequentially dissolution and alkanolyses of Baiyinhua lignite(BL) in cyclohexane,CH3OH,CH3CH2OH,and(CH3)2CHOH at 300℃.They were analyzed with a gas chromatograph/mass spectrometer and quadrupole exactive orbitrap mass spectrometer(QEOTMS) with an atmosphere pressure chemical ionization source in positive-ion mode,while BL was characterized with an X-ray photoelectron spectrometer(XRPES).The results show that the yields of SP2 and SP3 are much higher than those of SP1 and SP4,and the total SP yield is ca.39.0%.According to the analysis with XRPES,pyrrolic nitrogen atoms are the most abundant nitrogen existing forms in BL.Thousands of nitrogen-containing aromatics(NCAs) were resolved with QEOTMS and their molecular masses are mainly in the range of 200-450 u.The main NCAs are N1O1 and N1O2 class species with double bond equivalent values of 4-18 and carbon numbers of 7-30.The nitrogen atoms appear in pyridine s,quinolines,benzoquinolines or acridine,and dibenzoquinolines or naphthoquinolines,while the oxygen atoms exist in methoxy and furan rings.展开更多
Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a ...Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a stable solid or aqueous preparation of PGE_1 formulatedwith HP-β-CD. Methods The effect of HP-β-CD on the solubility of PGE_1 was studied by phasesolubility method. The formation of inclusion complexes of PGE_1 with HP-β-CD in the aqueoussolution was confirmed by UV spectra, circular dichroism spectroscopy, and that in the solid stateby IR spectra and X-ray diffractome-try. An solid inclusion complex of PGE_1 with HP-β-CD wasprepared by lyophilization. The dissolution rate and stability of the inclusion complex weredetermined and compared with those of PGE_1 alone. Meanwhile, the stability of PGE_1 aqueoussolutions in the presence of HP-β-CD was studied under different pH conditions. Results Thesolubility of PGE_1 increased linearly with increasing HP-β-CD concentration in various pH bufferedsolutions, showing typical A_L-type phase solubility diagrams. The stability and dissolution rateof the solid inclusion complex of PGE_1 were significantly increased, compared with those of purePGE_1 . The stability of PGE_1 in HP-β-CD solutions was also obviously improved under acidic andbasic conditions, but the stabilizing effect was absent under neutral conditions. Conclusions Thesolubility,dissolution rate and chemical stability of PGE_1 are markedly improved by complexationwith HP-β-CD: It is quite possible to prepare a stable PGE_1 inclusion complex-containing soliddosage forms, but almost impossible to obtain a stable aqueous preparation of PGE_1 formulated withHP-β-CD.展开更多
The dominated contradiction in optimizing the performance of magnesium-air battery anode lies in the difficulty of achieving a good balance between activation and passivation during discharge process.To further reconci...The dominated contradiction in optimizing the performance of magnesium-air battery anode lies in the difficulty of achieving a good balance between activation and passivation during discharge process.To further reconcile this contradiction,two Mg-0.1Sc-0.1Y-0.1Ag anodes with different residual strain distribution through extrusion with/without annealing are fabricated.The results indicate that annealing can significantly lessen the“pseudo-anode”regions,thereby changing the dissolution mode of the matrix and achieving an effective dissolution during discharge.Additionally,p-type semiconductor characteristic of discharge productfilm could suppress the self-corrosion reaction without reducing the polarization of anode.The magnesium-air battery utilizing annealed Mg-0.1Sc-0.1Y-0.1Ag as anode achieves a synergistic improvement in specific capacity(1388.89 mA h g^(-1))and energy density(1960.42 mW h g^(-1)).This anode modification method accelerates the advancement of high efficiency and long lifespan magnesium-air batteries,offering renewable and cost-effective energy solutions for electronics and emergency equipment.展开更多
Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temper...Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.展开更多
The dissolution behavior of complex inclusions in refining slag was studied using confocal laser scanning microscope.Based on the dissolution curve of complex inclusions,the main rate-limiting link of CaO-SiO_(2)-Al_(...The dissolution behavior of complex inclusions in refining slag was studied using confocal laser scanning microscope.Based on the dissolution curve of complex inclusions,the main rate-limiting link of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was the diffusion in the molten slag.The dissolution rate of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was affected by the composition and size of inclusion.The functional relationship between the dimensionless inclusion capacity(Zh)and the dimensionless dissolution rate(Ry)of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was calculated as Ry=2.10×10^(-6)Zh^(0.160),while it was Ry=2.10×10^(-6)Zh^(0.0087)for Al_(2)O_(3)-CaO complex inclusions.On this basis,the complete dissolution time and rate of the complex inclusions were calculated by using the function relation between the Zh and Ry numbers.展开更多
The dissolution mechanism of hemimorphite in NH3-（NH4）2SO4-H2O system at 298.15 K was investigated by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy ...The dissolution mechanism of hemimorphite in NH3-（NH4）2SO4-H2O system at 298.15 K was investigated by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS） analysis. The results show that hemimorphite is soluble in NH3-（NH4）2SO4-H2O system and its residue exists in the form of an amorphous SiO2 layer on the hemimorphite surface. The XPS data also indicate that the Si 2p3/2 and O ls spectra of the hemimorphite are broadened and shift to higher binding energies and their binding energies are closer to silica with an increase of total ammonia and time. Solubility of hemimorphite in NH3-（NH4）2SO4-H2O system was measured by means of isothermal solution method at 298.15 K based on the study of the dissolution mechanism of hemimorphite. The results show that the solubility of zinc in solution increases firstly and then decreases with the increase of cr（NH3） （total ammonia concentration） at different NH3/NH4^＋ ratios. The solubility of silicon in solution decreases from 0.0334 mol/kg in ct（NH3）-4.1245 mol/kg NH3-（NH4）2SO4-H2O solution to 0.0046 mol/kg in cT（NH3）=7.6035 mol/kg NH3-（NH4）2SO4-H2O solution.展开更多
In a hydrogen-rich blast furnace,an increased coke load accentuates the support skeleton role of coke,particularly in the cohesive and dripping zones following partial dissolution with slag.To investigate the dissolut...In a hydrogen-rich blast furnace,an increased coke load accentuates the support skeleton role of coke,particularly in the cohesive and dripping zones following partial dissolution with slag.To investigate the dissolution behaviours of coke in these regions,coke samples were gasified in a N2-CO-CO_(2)-H_(2)-H_(2)O atmosphere,simulating hydrogen-rich blast furnace conditions.Subsequently,the dissolution of gasified coke with slag containing FeO was analysed.The influence of coke gasification degree and FeO concentration in slag on coke dissolution was examined.The results showed that both higher coke gasification degrees and increased FeO content accelerate coke mass loss and exacerbate surface degradation upon dissolution,while effects on the internal structure of coke remain relatively minor,especially regarding FeO concentration.Additionally,hydrogen-rich gasification raised the graphitisation level of coke,with dissolution further enhancing the graphitisation of gasified coke.展开更多
Global coral reef ecosystems have been severely degraded due to the combined effects of climate change and human activities.Changes in the seawater carbonate system of coral reef ecosystems can reflect their status an...Global coral reef ecosystems have been severely degraded due to the combined effects of climate change and human activities.Changes in the seawater carbonate system of coral reef ecosystems can reflect their status and their responses to the impacts of climate change and human activities.Winter and summer surveys in 2019 found that the ecological community of the Luhuitou coral reef flat was dominated by macroalgae and corals,respectively,contrasting with the conditions 10 years ago.The Luhuitou fringing reefs were sources of atmospheric CO_(2) in both seasons.In winter,the daily variation range of dissolved inorganic carbon(DIC)in Luhuitou coral reefs was up to 450μmol/kg,while that of total alkalinity(TA)was only 68μmol/kg.This indicated that the organic production was significantly higher than the calcification process during this period.The TA/DIC was approximately 0.15,which was less than half of that in healthy coral reefs;hence,photosynthesis-respiration processes were the most important factors controlling daily changes in the seawater carbonate system.The net community production(NCP)of the Luhuitou coral reef ecosystem in winter was as high as 47.65 mmol C/(m^(2)·h).While the net community calcification(NCC)was approximately 3.35 and-4.15 mmol CaCO_(3)/(m^(2)·h)during the daytime and nighttime respectively.Therefore,the NCC for the entire day was-21.9 mmol CaCO_(3)/(m^(2)·d),indicating a net autotrophic dissolved state.In summer,the acidification was enhanced by thunderstorms and heavy rain with the highest seawater partial pressure of CO_(2)(p CO_(2))and lowest pH T.Over the past 10 years,the increase rate of seawater p CO_(2) in Luhuitou reef was approximately 13.3μatm/a***,six times that of the open ocean,while the decrease rate of pH was approximately 0.0083/a,being five times that of the global ocean.These findings underscore the importance of protecting and restoring Luhuitou fringing reef,as well as similar reefs worldwide.展开更多
The deep layer has become an important replacement field for oil and gas exploration,but the formation mechanism of effective reservoirs is unknown,and the distribution of dessert reservoirs is difficult to predict,wh...The deep layer has become an important replacement field for oil and gas exploration,but the formation mechanism of effective reservoirs is unknown,and the distribution of dessert reservoirs is difficult to predict,which seriously affects the discovery of deep resources.In this paper,the reservoir of the first and second members of the Shahejie Formation in the Caofeidian 6-4S area of the Bozhong Depression is taken as an example.Through the comprehensive means such as well-seismic calibration,denudation recovery,source-sink quantitative coupling,basin simulation,microscopic observation,X-ray diffraction,inclusion and thermodynamic analysis,the reservoir formation mechanism of dissolution pores and the favorable area distribution of thermodynamic prediction of dissolution reaction in the study area are carried out.The results show that the dissolution pores are the dominant type,accounting for more than 80%of the total pores.The dissolution reaction between soluble minerals such as feldspar accumulated in the near source and acidic fluids such as organic acids formed in the adjacent strata is the main mechanism for the development of dissolution pores.The organic matter in the adjacent strata is controlled by temperature and pressure during the burial evolution process to form organic acids,and migrates to the adjacent reservoirs for selective dissolution under the action of pressure and other driving forces.The characteristics of thermodynamic parameters(ΔG,which can determine whether feldspar is dissolved)and kinetic parameters(R,indicating the degree of feldspar dissolution)of feldspar dissolution reaction show that the thermodynamic parameters of feldspar dissolution are positively correlated with temperature,and the kinetic parameters are correlated with the concentration of organic acid discharge.The results of thermodynamic and kinetic parameters are coupled with provenance-sedimentary facies-diagenetic facies,and it is predicted that the plane area of TypeⅠfavorable area is 50 km^(2),and the plane area of TypeⅡfavorable area is 62.4 km2.This method provides theoretical reference and method guidance for the prediction of favorable reservoir distribution of deep clastic rocks,and has a good application prospect.展开更多
The widespread use of plastic waste has caused significant environmental pollution,becoming a focal point of global concern,particularly the challenge of dechlorination in mixed plastic waste.Selective dissolution is ...The widespread use of plastic waste has caused significant environmental pollution,becoming a focal point of global concern,particularly the challenge of dechlorination in mixed plastic waste.Selective dissolution is a promising plastic chemical recycling technology that offers benefits such as simple processes,convenient operation,and recyclable solvents.However,selecting suitable solvents remains a challenge.This study establishes a virtual solvent database containing 530 common inorganic and organic solvents.By calculating theσ-profile of polyvinyl chloride(PVC)and polyethylene(PE)models using quantum mechanical calculations and employing the conductor-like screening model for real solvents(COSMO-RS)method,the solubility performance of these solvents for PVC and PE at different temperatures was predicted.The results demonstrate the high accuracy of the COSMO-RS method in predicting solubility.By comparing the solubility differences between PVC and PE in different solvents,a series of solvents suitable for selectively removing PVC from mixed plastics were identified,for example,N-methyl-2-pyrrolidone(NMP),dimethyl sulfoxide(DMSO),tetrahydrofuran(THF),and N,Ndimethylacetamide(DMAc).This method provides a novel solution to the solvent selection challenge in plastic chemical recycling,potentially shortening the research and development period,reducing experimental costs,and promoting the development of green and refined waste plastic recycling processes.展开更多
This work investigated the original microstructure of cold-worked alumina-forming austenitic steel,along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.%oxygen at 600...This work investigated the original microstructure of cold-worked alumina-forming austenitic steel,along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.%oxygen at 600℃,using solution-annealed steel for comparison.Anomalously,cold-worked steel presented milder corrosion compared to solution-annealed steel,with average corrosion depths of 314.3 and 401.0μm after 1700 h exposure.Cold working-induced de-twinning transformed the annealing twin boundaries into normal high-angle grain boundaries(NGBs),increasing NGBs proportion from 36%to 89%.The increased NGBs provided more nucleation sites for intergranular barriers composed of alternate NiAl and M23C6 precipitates,thus better obstructing the dissolution attack.展开更多
Polysaccharide-based polymers were used to produce nanoparticles of poorly soluble antiviral drugs using a rapid precipitation process. The structure-property relationships of four novel cellulose acetate-based polyme...Polysaccharide-based polymers were used to produce nanoparticles of poorly soluble antiviral drugs using a rapid precipitation process. The structure-property relationships of four novel cellulose acetate-based polymers were studied for their solubility enhancement of poorly soluble drugs. Particles were purified by dialysis, and dried powders were recovered after freeze-drying. The particle diameters were 150–200 nm. The target drug loading in the particles was 25 wt%, and the drug loading efficiencies were 80–96%. The effects of the formulation process and nanoparticle properties on drug solubility were investigated. All nanoparticles afforded increased solubility and faster release compared to pure drugs. Drug release was a function of the relative hydrophobicity (or solubility parameters) of the polymers.Production and hosting by Elsevier B.V. on behalf of Shenyang Pharmaceutical University.展开更多
Magnesium implants have received widespread attention in orthopaedic surgery.However,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their applications.In this study,a...Magnesium implants have received widespread attention in orthopaedic surgery.However,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their applications.In this study,a kind of unique core-shell heterojunction CuS@PPy nanostructures was synthesized and then incorporated in polycaprolactone(PCL)to construct an intelligent coating(CuS@PPy/PCL)on micro-arc-oxidized Mg implants.The PCL-based coating can realize near-infrared(NIR)-driven antibacterial and controllable Mg dissolution according to different bone healing stages.At the beginning of bone remodelling,the coating exhibits promising antibacterial properties with 99.67%and 99.17%efficacy against S.aureus and E.coli,respectively,thanks to the singlet oxygen(^(1)O_(2))and alkoxyl radicals(RO·)generated by the photodynamic effect of CuS@PPy heterojunction under low-power NIR light(1.5 W/cm^(2)).In the bone reparative stage,the PCL-based coating can maintain high corrosion resistance to meet the mechanical requirements of Mg implants in human body fluid.However,after the complete rehabilitation of bones,through a high-power(2 W/cm^(2))NIR light,the PCL-based coating changed from an elastic to a viscous flow state(44.7℃)under the photothermal effects of CuS@PPy,leading to quick degradation of the PCL-based coating and following accelerating dissolution of the Mg implant(avoiding secondary surgery).Hopefully,this NIR-responsive coating may provide an innovative method for the antibacterial and controllable dissolution of Mg implants.展开更多
This study investigates the anodic dissolution and electrochemical behavior of molybdenum in a NaCl-KCl molten salt system at 1023 K.The anodic dissolution process was systematically analyzed,revealing a sequential ox...This study investigates the anodic dissolution and electrochemical behavior of molybdenum in a NaCl-KCl molten salt system at 1023 K.The anodic dissolution process was systematically analyzed,revealing a sequential oxidation pathway of molybdenum into high-valence ions(Mo^(6+),Mo^(5+),Mo^(4+))under vary-ing electrolysis potentials.Electrochemical Impedance Spectroscopy(EIS)demonstrated that the dissolu-tion is governed by both charge transfer and diffusion mechanisms,with reduced impedance at higher potentials facilitating molybdenum dissolution.The reduction behavior of dissolved molybdenum ions was further explored using cyclic voltammetry(CV)and square wave voltammetry(SWV),confirming a multi-step reduction process controlled by diffusion and high reversibility.Nucleation studies using chronoamperometry established that molybdenum deposition follows an instantaneous nucleation mech-anism.Morphological analysis of cathodic deposits revealed that current density significantly influences particle size,transitioning from nano-sized spherical particles to larger equiaxed crystals with increasing current density.These findings provide a comprehensive understanding of molybdenum’s electrochemical properties in molten salts,offering valuable insights for optimizing electrolysis processes and advancing molybdenum-based material production.展开更多
基金funding enabled and organized by CAUL and its Member Institutionsby COMSTEQ-TWAS research grant 2018(18-268 RG/EAS/AS_C)。
文摘Examining carbonate dissolution kinetics at mineral-water interface is crucial to understand numerous environmental and geochemical processes,including global carbon cycling,CO_(2)sequestration in deep geological reservoirs,and trace elements release in terrestrial and aquatic environments.Here we explored the effect of circumneutral to alkaline pH solutions(pH 6-11)on dissolution kinetics of pure dolomite and Ca and Mg release stoichiometry in flow-through reactor experiments at 25±1℃.Results revealed that the dolomite dissolution rates obtained from effluent Ca and Mg concentrations(R_(Ca)and R_(Mg)in mol/cm^(2)/s)were dependent on input solution pH and HCO_(3)^(-)log activity.The pH dependence of dissolution rates showed two distinct trends,i.e.,at circumneutral pH ranging between 6 and 8,the dissolution rate decreased with increasing pH,with minimum rate at pH 8.While in the highly alkaline pH range(pH 9-11),the dolomite dissolution rate increased with an increasing pH.Irrespective of the input pH,the dolomite dissolution rates indicated a reverse relationship with HCO_(3)^(-)log activity,with the lowest dissolution rate(R Ca=3.80×10^(-12)mol/cm^(2)/s)at pH 8 where HCO_(3)^(-)log activity attained the highest value(-3.957).The lower R Ca and R Mg obtained at pH 8 compared to all the other pH could possibly be attributed to an inhibition caused by high HCO_(3)^(-)log activity in solution at this pH.Dolomite dissolution rates were non-stoichiometric at all the experimental pH values,showing higher preferential Ca over Mg release(R_(Ca)>R_(Mg))whereas an opposite trend was observed at pH 8,with R_(Ca)<R_(Mg)at the steady state.Saturation index values calculated using geochemical speciation modelling were positive for Mg-bearing minerals(brucite,dolomite,artinite)at alkaline pH of 10-11,indicating favourable conditions for their precipitation under studied conditions.This study provides insights on the significance of log ion activities of HCO_(3)^(-)and Me-OH^(+)under varying pH for elucidating the dissolution mechanism of dolomite in circumneutral to alkaline aqueous environments.
基金the National Natural Science Foundation of China (Nos.52430001,52470091,52200108) for the financial support。
文摘Nanofiltration(NF) technology,with its capacity for nanoscale filtration and controllable selectivity,holds significant promise in diverse applications.However,the current upper bound of permeance and selectivity of NF membranes is intrinsically constrained by the morphology and structure of the polyamide(PA) selective layer.This issue arises because NF membranes typically exhibit relatively smooth nodular structures,which theoretically impede efficient water transport.In this study,we enhanced the formation of nanobubbles by synergistically regulating with surfactant and low temperatures,resulting in the fabrication of PA NF membranes with a crumpled morphology.We observed that lower temperatures promote enhanced gas solubility in the aqueous phase,facilitating increased nanobubble formation through the foaming effect of surfactant sodium dodecylbenzene sulfonate(SDBS).Consequently,this resulted in the creation of PA NF membranes with more crumpled structures and superior performance,with pure water permeance reaching 36.25 ± 0.42 L m^(-2)h^(-1)bar^(-1),representing an improvement of 14.47 L m^(-2)h^(-1)bar^(-1)compared to the control group.Additionally,it maintains a high Na_(2)SO_(4) rejection rate of97.00 % ± 0.58 %.The PA NF membranes produced by eliminating nanobubbles and free interfaces exhibited a smooth structure,whereas introducing nanobubbles(through Na HCO_(3) addition,N_(2) pressurization,and ultrasonication) resulted in the formation of crumpled membranes.This emphasized that the large amount of nanobubbles generated by SDBS and low temperature in the interfacial process played a critical role in shaping crumpled PA NF membranes and enhancing membrane performance.This approach has the potential to provide valuable insights into customizing the structural design of TFC PA NF membranes,contributing to further advancements in this field.
基金Science and Technology Million Project of Inner Mongolia Medical University(Grant No.YKD2014KJBW012)
文摘In the present study, we investigated the complexation of risperidone with hydroxypropyl-β-cyclodextrin （HP-β-CD） in aqueous solution due to the poor water solubility and low oral bioavailability of risperidone in humans. The effect of temperature on the complexation was examined, and thermodynamic parameters of the complexation process, such as Gibbs free energy change （AG）, enthalpy change （AH） and entropy change （AS）, were also explored. Meantime, the solid dispersion of risperidone with HP-β-CD was prepared and confirmed by Fourier IR spectroscopy and X-ray diffractometry. The experimental results suggested that the complex of the drug with HP-β-CD at a molar ratio of 1：1 could form in aqueous solution, and the complexation was an endothermic and entropy-driven process. The risperidone-HP-β-CD solid dispersion exhibited a remarkable improvement in the dissolution rate of the drug. This might be attributed to the amorphous state, the enhanced wettability as well as the complex formation of the drug with HP-β-CD in aqueous solution.
文摘AimTo study effects of PVP K30 on the aque ou s solubility and dissolution properties of daidzein. Methods To measure the aqueous solubility and dissolution rates of daidzein in three diffe rent states (within solid dispersions, physical mixtures and as a pure drug) and investigate drug-polymer interactions in the solid state using X-ray powder d iffraction and fourier-transform infrared spectroscopy. Results The negative values of the Gibbs free energy and enthalpy of transfer explaine d the spontaneous transfer of daidzein from phosphate buffer solution (PBS) to a solution of PVP in PBS. X-ray powder diffraction patterns showed that the drug was in the amorphous state (ratio of the drug ∶ PVP<1∶5) when dispers ed i n PVP K30. The infrared spectra indicated there exist interactions between the O H of daidzein and the C=O of PVP K30. Conclusionthe dispersion of daidzein in PVP K30 considerably enhances the solubility and dissolution rat e.
基金This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology(2012-0001499).
文摘Pharmaceutical particle technology is employed to improve poor aqueous solubility of drug compounds that limits in vivo bioavailability owing to their low dissolution rate in the gastrointestinal fluids following oral administration.The particle technology involves several approaches from the conventional size reduction processes to the newer,novel particle technologies that modify the solubility properties of the drugs and produce solid,powdered form of the drugs that are readily soluble in water and can be easily formulated into various dosage forms.This review highlights the solid particle technologies available for improving solubility,dissolution and bioavailability of drugs with poor aqueous solubility.
文摘The aim of this work was to develop, optimize and characterize a silymarin-laden polyvinylpyrrolidone(PVP)-polyethylene glycol(PEG) polymeric composite to resolve low aqueous solubility and dissolution rate problem of the drug. A number of silymarin-laden polymeric formulations were fabricated with different quantities of PVP K-30 and PEG 6000 by the solvent-evaporation method. The effect of PVP K-30 and PEG 6000 on the aqueous solubility and dissolution rate was investigated. The optimized formulation and its constituents were characterized using powder X-ray diffraction(PXRD), differential scanning calorimetry(DSC), scanning electron microscopy(SEM) and Fourier transform infrared spectroscopy(FTIR) techniques. Both the PEG 6000 and PVP K-30 positively affected the aqueous solubility and dissolution rate of the drug. In particular, a formulation consisting of silymarin, PVP K-30 and PEG 6000(0.25/1.5/1.5, w/w/w) furnished the highest solubility(24.3972.95 mg/mL) and an excellent dissolution profile( $100% in 40 min). The solubility enhancement with this formulation was $ 1150-fold as compared to plain silymarin powder. Moreover, all the constituents existed in the amorphous state in this silymarin-laden PVP-PEG polymeric composite. Accordingly, this formulation might be a promising tool to administer silymarin with an enhanced effect via the oral route.
基金Supported by the Key Project of Joint Fund from National Natural Science Foundation of China and the Government of Xinjiang Uygur Autonomous Region(U1503293)the National Key Research and Development Program of China(2018YFB0604602)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Soluble portions(SPs) 1-4(SP1-SP4) were afforded from sequentially dissolution and alkanolyses of Baiyinhua lignite(BL) in cyclohexane,CH3OH,CH3CH2OH,and(CH3)2CHOH at 300℃.They were analyzed with a gas chromatograph/mass spectrometer and quadrupole exactive orbitrap mass spectrometer(QEOTMS) with an atmosphere pressure chemical ionization source in positive-ion mode,while BL was characterized with an X-ray photoelectron spectrometer(XRPES).The results show that the yields of SP2 and SP3 are much higher than those of SP1 and SP4,and the total SP yield is ca.39.0%.According to the analysis with XRPES,pyrrolic nitrogen atoms are the most abundant nitrogen existing forms in BL.Thousands of nitrogen-containing aromatics(NCAs) were resolved with QEOTMS and their molecular masses are mainly in the range of 200-450 u.The main NCAs are N1O1 and N1O2 class species with double bond equivalent values of 4-18 and carbon numbers of 7-30.The nitrogen atoms appear in pyridine s,quinolines,benzoquinolines or acridine,and dibenzoquinolines or naphthoquinolines,while the oxygen atoms exist in methoxy and furan rings.
文摘Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a stable solid or aqueous preparation of PGE_1 formulatedwith HP-β-CD. Methods The effect of HP-β-CD on the solubility of PGE_1 was studied by phasesolubility method. The formation of inclusion complexes of PGE_1 with HP-β-CD in the aqueoussolution was confirmed by UV spectra, circular dichroism spectroscopy, and that in the solid stateby IR spectra and X-ray diffractome-try. An solid inclusion complex of PGE_1 with HP-β-CD wasprepared by lyophilization. The dissolution rate and stability of the inclusion complex weredetermined and compared with those of PGE_1 alone. Meanwhile, the stability of PGE_1 aqueoussolutions in the presence of HP-β-CD was studied under different pH conditions. Results Thesolubility of PGE_1 increased linearly with increasing HP-β-CD concentration in various pH bufferedsolutions, showing typical A_L-type phase solubility diagrams. The stability and dissolution rateof the solid inclusion complex of PGE_1 were significantly increased, compared with those of purePGE_1 . The stability of PGE_1 in HP-β-CD solutions was also obviously improved under acidic andbasic conditions, but the stabilizing effect was absent under neutral conditions. Conclusions Thesolubility,dissolution rate and chemical stability of PGE_1 are markedly improved by complexationwith HP-β-CD: It is quite possible to prepare a stable PGE_1 inclusion complex-containing soliddosage forms, but almost impossible to obtain a stable aqueous preparation of PGE_1 formulated withHP-β-CD.
基金the National Natural Science:Foundation of China(52375370)the Open Project of Salt Lake Chemical Engineering Research Complex,Qinghai University(2023-DXSSKF-Z02)+2 种基金the Nat-ural Science Foundation of Shanxi(202103021224049)GDAS Projects of International cooperation platform of Sci-ence and Technology(2022GDASZH-2022010203-003)Guangdong province Science and Technology Plan Projects(2023B1212060045).
文摘The dominated contradiction in optimizing the performance of magnesium-air battery anode lies in the difficulty of achieving a good balance between activation and passivation during discharge process.To further reconcile this contradiction,two Mg-0.1Sc-0.1Y-0.1Ag anodes with different residual strain distribution through extrusion with/without annealing are fabricated.The results indicate that annealing can significantly lessen the“pseudo-anode”regions,thereby changing the dissolution mode of the matrix and achieving an effective dissolution during discharge.Additionally,p-type semiconductor characteristic of discharge productfilm could suppress the self-corrosion reaction without reducing the polarization of anode.The magnesium-air battery utilizing annealed Mg-0.1Sc-0.1Y-0.1Ag as anode achieves a synergistic improvement in specific capacity(1388.89 mA h g^(-1))and energy density(1960.42 mW h g^(-1)).This anode modification method accelerates the advancement of high efficiency and long lifespan magnesium-air batteries,offering renewable and cost-effective energy solutions for electronics and emergency equipment.
基金supported by the National Natural Science Foundation of China(Grant No.U21B2062)supported by the Key Laboratory for Carbonate Reservoirs of China National Petroleum Corporation。
文摘Burial dissolution is a critical diagenetic process influencing ultra-deep carbonate reservoir development and preservation.Artificial carbonate samples with different internal structures were prepared,and high-temperature and highpressure dissolution kinetic simulations were conducted.The results demonstrate that the intensity of burial dissolution is controlled by temperature and pressure,while tectonic-fluid activity influences the development pattern of burial dissolution,ultimately determining the direction of its differential modification.Extensive burial dissolution is likely to occur primarily at relatively shallow depths,significantly influencing reservoir formation,preservation,modification,and adjustment.The development of faults facilitates the maintenance of the intensity of burial dissolution.The maximum intensity of burial dissolution occurs at the tips and overlap zones of faults and intersections of multiple faults.The larger the scale of the faults,the more conducive it is to the development of burial dissolution.Burial dissolution fosters the formation of fault networks characterized by enhanced reservoir capacity and permeability.Burial dissolution controlled by episodic tectonic-fluid activity is a plausible explanation for forming the Tarim Basin's ultra-deep fault-controlled“stringbead-like”reservoirs.
基金support from the National Key R&D Program(No.2023YFB3709900)the National Natural Science Foundation of China(Grant No.U22A20171)+1 种基金the High Steel Center at the North China University of Technologythe University of Science and Technology Beijing,China.
文摘The dissolution behavior of complex inclusions in refining slag was studied using confocal laser scanning microscope.Based on the dissolution curve of complex inclusions,the main rate-limiting link of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was the diffusion in the molten slag.The dissolution rate of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was affected by the composition and size of inclusion.The functional relationship between the dimensionless inclusion capacity(Zh)and the dimensionless dissolution rate(Ry)of CaO-SiO_(2)-Al_(2)O_(3)complex inclusions was calculated as Ry=2.10×10^(-6)Zh^(0.160),while it was Ry=2.10×10^(-6)Zh^(0.0087)for Al_(2)O_(3)-CaO complex inclusions.On this basis,the complete dissolution time and rate of the complex inclusions were calculated by using the function relation between the Zh and Ry numbers.
基金Projects(511340071) supported by the National Natural Science Foundation of China
文摘The dissolution mechanism of hemimorphite in NH3-（NH4）2SO4-H2O system at 298.15 K was investigated by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS） analysis. The results show that hemimorphite is soluble in NH3-（NH4）2SO4-H2O system and its residue exists in the form of an amorphous SiO2 layer on the hemimorphite surface. The XPS data also indicate that the Si 2p3/2 and O ls spectra of the hemimorphite are broadened and shift to higher binding energies and their binding energies are closer to silica with an increase of total ammonia and time. Solubility of hemimorphite in NH3-（NH4）2SO4-H2O system was measured by means of isothermal solution method at 298.15 K based on the study of the dissolution mechanism of hemimorphite. The results show that the solubility of zinc in solution increases firstly and then decreases with the increase of cr（NH3） （total ammonia concentration） at different NH3/NH4^＋ ratios. The solubility of silicon in solution decreases from 0.0334 mol/kg in ct（NH3）-4.1245 mol/kg NH3-（NH4）2SO4-H2O solution to 0.0046 mol/kg in cT（NH3）=7.6035 mol/kg NH3-（NH4）2SO4-H2O solution.
基金the financial support provided by the National Natural Science Foundation of China(Nos.52174300 and 52404340)Science and Technology Innovation Key R&D Program of Chongqing,China(No.CSTB2024TIAD-STX0009)+3 种基金The Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN202401507)Chongqing Talent Plan Project(cstc2021ycjh-bgzxm0211)Natural Science Foundation of Chongqing,China(No.CSTB2024NSCQ-LZX0052)Chongqing Doctoral“Through Train”Project(No.sl202100000343).
文摘In a hydrogen-rich blast furnace,an increased coke load accentuates the support skeleton role of coke,particularly in the cohesive and dripping zones following partial dissolution with slag.To investigate the dissolution behaviours of coke in these regions,coke samples were gasified in a N2-CO-CO_(2)-H_(2)-H_(2)O atmosphere,simulating hydrogen-rich blast furnace conditions.Subsequently,the dissolution of gasified coke with slag containing FeO was analysed.The influence of coke gasification degree and FeO concentration in slag on coke dissolution was examined.The results showed that both higher coke gasification degrees and increased FeO content accelerate coke mass loss and exacerbate surface degradation upon dissolution,while effects on the internal structure of coke remain relatively minor,especially regarding FeO concentration.Additionally,hydrogen-rich gasification raised the graphitisation level of coke,with dissolution further enhancing the graphitisation of gasified coke.
基金Supported by the National Key Research and Development Program of China(Nos.2021YFC3100500,2022YFC3103602,2021YFF0502800)the National Natural Science Foundation of China(No.U23A2035)+3 种基金the Science and Technology Planning Project of Guangdong Province,China(No.2023B1212060047)the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LTO1919)the Visiting Fellowship Program of the State Key Laboratory of Marine Environmental Science,Xiamen University(No.MELRS1914)the Hainan Province Key R&D Program(No.ZDYF2023SHFZ131)。
文摘Global coral reef ecosystems have been severely degraded due to the combined effects of climate change and human activities.Changes in the seawater carbonate system of coral reef ecosystems can reflect their status and their responses to the impacts of climate change and human activities.Winter and summer surveys in 2019 found that the ecological community of the Luhuitou coral reef flat was dominated by macroalgae and corals,respectively,contrasting with the conditions 10 years ago.The Luhuitou fringing reefs were sources of atmospheric CO_(2) in both seasons.In winter,the daily variation range of dissolved inorganic carbon(DIC)in Luhuitou coral reefs was up to 450μmol/kg,while that of total alkalinity(TA)was only 68μmol/kg.This indicated that the organic production was significantly higher than the calcification process during this period.The TA/DIC was approximately 0.15,which was less than half of that in healthy coral reefs;hence,photosynthesis-respiration processes were the most important factors controlling daily changes in the seawater carbonate system.The net community production(NCP)of the Luhuitou coral reef ecosystem in winter was as high as 47.65 mmol C/(m^(2)·h).While the net community calcification(NCC)was approximately 3.35 and-4.15 mmol CaCO_(3)/(m^(2)·h)during the daytime and nighttime respectively.Therefore,the NCC for the entire day was-21.9 mmol CaCO_(3)/(m^(2)·d),indicating a net autotrophic dissolved state.In summer,the acidification was enhanced by thunderstorms and heavy rain with the highest seawater partial pressure of CO_(2)(p CO_(2))and lowest pH T.Over the past 10 years,the increase rate of seawater p CO_(2) in Luhuitou reef was approximately 13.3μatm/a***,six times that of the open ocean,while the decrease rate of pH was approximately 0.0083/a,being five times that of the global ocean.These findings underscore the importance of protecting and restoring Luhuitou fringing reef,as well as similar reefs worldwide.
基金The National Natural Science Foundation of China under contract Nos U24B2016 and 42202157the National Basic Research Program of China under contract No. KJGG2022-0101+1 种基金the Key Laboratory of Tectonics and Petroleum Resources under contract No. TPR-2023-04CNOOC Technology Project under contract No. KJZH-2023-2105
文摘The deep layer has become an important replacement field for oil and gas exploration,but the formation mechanism of effective reservoirs is unknown,and the distribution of dessert reservoirs is difficult to predict,which seriously affects the discovery of deep resources.In this paper,the reservoir of the first and second members of the Shahejie Formation in the Caofeidian 6-4S area of the Bozhong Depression is taken as an example.Through the comprehensive means such as well-seismic calibration,denudation recovery,source-sink quantitative coupling,basin simulation,microscopic observation,X-ray diffraction,inclusion and thermodynamic analysis,the reservoir formation mechanism of dissolution pores and the favorable area distribution of thermodynamic prediction of dissolution reaction in the study area are carried out.The results show that the dissolution pores are the dominant type,accounting for more than 80%of the total pores.The dissolution reaction between soluble minerals such as feldspar accumulated in the near source and acidic fluids such as organic acids formed in the adjacent strata is the main mechanism for the development of dissolution pores.The organic matter in the adjacent strata is controlled by temperature and pressure during the burial evolution process to form organic acids,and migrates to the adjacent reservoirs for selective dissolution under the action of pressure and other driving forces.The characteristics of thermodynamic parameters(ΔG,which can determine whether feldspar is dissolved)and kinetic parameters(R,indicating the degree of feldspar dissolution)of feldspar dissolution reaction show that the thermodynamic parameters of feldspar dissolution are positively correlated with temperature,and the kinetic parameters are correlated with the concentration of organic acid discharge.The results of thermodynamic and kinetic parameters are coupled with provenance-sedimentary facies-diagenetic facies,and it is predicted that the plane area of TypeⅠfavorable area is 50 km^(2),and the plane area of TypeⅡfavorable area is 62.4 km2.This method provides theoretical reference and method guidance for the prediction of favorable reservoir distribution of deep clastic rocks,and has a good application prospect.
基金financially supported by SINOPEC Research Institute of Petroleum Processing Co.,Ltd.the National Natural Science Foundation of China(22302220)+2 种基金the Shanxi Province Science Foundation for Youth(202203021222403)Funding support was also received from the Synfuels China Co.,Ltd.the Institute of Coal Chemistry,Chinese Academy of Sciences。
文摘The widespread use of plastic waste has caused significant environmental pollution,becoming a focal point of global concern,particularly the challenge of dechlorination in mixed plastic waste.Selective dissolution is a promising plastic chemical recycling technology that offers benefits such as simple processes,convenient operation,and recyclable solvents.However,selecting suitable solvents remains a challenge.This study establishes a virtual solvent database containing 530 common inorganic and organic solvents.By calculating theσ-profile of polyvinyl chloride(PVC)and polyethylene(PE)models using quantum mechanical calculations and employing the conductor-like screening model for real solvents(COSMO-RS)method,the solubility performance of these solvents for PVC and PE at different temperatures was predicted.The results demonstrate the high accuracy of the COSMO-RS method in predicting solubility.By comparing the solubility differences between PVC and PE in different solvents,a series of solvents suitable for selectively removing PVC from mixed plastics were identified,for example,N-methyl-2-pyrrolidone(NMP),dimethyl sulfoxide(DMSO),tetrahydrofuran(THF),and N,Ndimethylacetamide(DMAc).This method provides a novel solution to the solvent selection challenge in plastic chemical recycling,potentially shortening the research and development period,reducing experimental costs,and promoting the development of green and refined waste plastic recycling processes.
基金supported by the Nuclear Technology R&D Program.
文摘This work investigated the original microstructure of cold-worked alumina-forming austenitic steel,along with its precipitation and dissolution corrosion behaviors in lead-bismuth eutectic with 10-8 wt.%oxygen at 600℃,using solution-annealed steel for comparison.Anomalously,cold-worked steel presented milder corrosion compared to solution-annealed steel,with average corrosion depths of 314.3 and 401.0μm after 1700 h exposure.Cold working-induced de-twinning transformed the annealing twin boundaries into normal high-angle grain boundaries(NGBs),increasing NGBs proportion from 36%to 89%.The increased NGBs provided more nucleation sites for intergranular barriers composed of alternate NiAl and M23C6 precipitates,thus better obstructing the dissolution attack.
基金supported by Research Initiation Grant,BITS Pilani,Pilani campus,India
文摘Polysaccharide-based polymers were used to produce nanoparticles of poorly soluble antiviral drugs using a rapid precipitation process. The structure-property relationships of four novel cellulose acetate-based polymers were studied for their solubility enhancement of poorly soluble drugs. Particles were purified by dialysis, and dried powders were recovered after freeze-drying. The particle diameters were 150–200 nm. The target drug loading in the particles was 25 wt%, and the drug loading efficiencies were 80–96%. The effects of the formulation process and nanoparticle properties on drug solubility were investigated. All nanoparticles afforded increased solubility and faster release compared to pure drugs. Drug release was a function of the relative hydrophobicity (or solubility parameters) of the polymers.Production and hosting by Elsevier B.V. on behalf of Shenyang Pharmaceutical University.
基金support to this work:the National Natural Science Foundation of China(grant No.50971064,No.51361004)the Innovative Foundation of HUST(grant 2017KFYXJJ164).
文摘Magnesium implants have received widespread attention in orthopaedic surgery.However,the mechanical degradation and concurrent inflammation caused by the rapid corrosion of Mg limits their applications.In this study,a kind of unique core-shell heterojunction CuS@PPy nanostructures was synthesized and then incorporated in polycaprolactone(PCL)to construct an intelligent coating(CuS@PPy/PCL)on micro-arc-oxidized Mg implants.The PCL-based coating can realize near-infrared(NIR)-driven antibacterial and controllable Mg dissolution according to different bone healing stages.At the beginning of bone remodelling,the coating exhibits promising antibacterial properties with 99.67%and 99.17%efficacy against S.aureus and E.coli,respectively,thanks to the singlet oxygen(^(1)O_(2))and alkoxyl radicals(RO·)generated by the photodynamic effect of CuS@PPy heterojunction under low-power NIR light(1.5 W/cm^(2)).In the bone reparative stage,the PCL-based coating can maintain high corrosion resistance to meet the mechanical requirements of Mg implants in human body fluid.However,after the complete rehabilitation of bones,through a high-power(2 W/cm^(2))NIR light,the PCL-based coating changed from an elastic to a viscous flow state(44.7℃)under the photothermal effects of CuS@PPy,leading to quick degradation of the PCL-based coating and following accelerating dissolution of the Mg implant(avoiding secondary surgery).Hopefully,this NIR-responsive coating may provide an innovative method for the antibacterial and controllable dissolution of Mg implants.
基金financially supported by the National Natural Science Foundation of China for Distinguished Young Scholar(No.52025042)the Open Fund of State Key Laboratory of Advanced Metallurgy(No.KF24-12)。
文摘This study investigates the anodic dissolution and electrochemical behavior of molybdenum in a NaCl-KCl molten salt system at 1023 K.The anodic dissolution process was systematically analyzed,revealing a sequential oxidation pathway of molybdenum into high-valence ions(Mo^(6+),Mo^(5+),Mo^(4+))under vary-ing electrolysis potentials.Electrochemical Impedance Spectroscopy(EIS)demonstrated that the dissolu-tion is governed by both charge transfer and diffusion mechanisms,with reduced impedance at higher potentials facilitating molybdenum dissolution.The reduction behavior of dissolved molybdenum ions was further explored using cyclic voltammetry(CV)and square wave voltammetry(SWV),confirming a multi-step reduction process controlled by diffusion and high reversibility.Nucleation studies using chronoamperometry established that molybdenum deposition follows an instantaneous nucleation mech-anism.Morphological analysis of cathodic deposits revealed that current density significantly influences particle size,transitioning from nano-sized spherical particles to larger equiaxed crystals with increasing current density.These findings provide a comprehensive understanding of molybdenum’s electrochemical properties in molten salts,offering valuable insights for optimizing electrolysis processes and advancing molybdenum-based material production.
