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Adding gentamicin to silk fibroin enhances both the antibacterial performance and degradation rate of silk-based materials. The increased material degradation rate can affect the strength of early internal fixation, resulting in internal fixation failure. This study sought to adjust the gentamicin concentration to control the material degradation rate, thereby better meeting clinical application requirements. The in vitro degradation, water absorption rate, and expansion rate of silk-based materials containing different gentamicin concentrations were studied. A gentamicin-loaded silk-based screw was implanted into the femurs of New Zealand rabbits. Micro-computed tomography was used to measure the screw diameter, which was then used to calculate the degradation rate. The specimens were stained with hematoxylin and eosin and Masson’s trichrome. The in vitro results revealed increasing material degradation rates with increasing gentamicin concentration but no significant differences in water absorption rates with different gentamicin concentrations. The degradation rates of gentamicin-loaded (4 mg/g) silk-based rod-like materials were approximately 11.08% at three months in vitro and 9.4% in the animal experiment. The time for complete degradation was predicted from the fitting curve to be approximately 16 months. No inflammatory hyperplasia was observed in bone or soft tissue. The degradation and biocompatibility of the material containing 4 mg/g gentamicin meet clinical application requirements, and previous experimental results demonstrate good antibacterial performance of materials containing this gentamicin concentration.

CuAgSe has been considered as a promising thermoelectric material because of its high mobility and low thermal conductivity. The superior performance of CuAgSe is closely related to its crystal structure and electric properties. In this work, the stabilities and electronic structures of different three CuAgSe subcells have been theoretically investigated using Vienna Ab initio Simulation Package (VASP) with DFT calculations. We found that the different occupations of copper atoms would affect the stability and electronic structures of CuAgSe subcells. The various directions of Cu-Se chain in neighbor layers will result in different stabilities and electronic properties.

In order to have a better understanding of the electronic structures and physical properties of Cu2-δX (X = Se, S, Te) copper chalcogenides. First principles were performed to calculate the chemical shift, band structure, and electron density of states of Cu2-δX (X = Se, S, Te). By comparing our calculation results with previous experimental works, we found that the predicted electronic structures of Cu2Se, Cu2Te and Cu2S transform from semimetal to semiconductor after adding on-site Coulomb U, which reflects the real properties of the materials. By using (Density Functional Theory) DFT + U method, the calculation result is close to the real electronic structure. The calculation result of chemical shift of adding U does not reach the ideal expectation, and the reason is not clear at present. In this paper, the theoretical electronic structures of Cu2Se, Cu2Te and Cu2S are better calculated by DFT + U method and compared with the actual properties. The effect of Cu-s electron on the chemical shift is understood, and a theoretical result of the chemical shift is calculated, which provides a powerful reference for the subsequent research and understanding of the electronic structure and physical properties of the compounds with S groups of Cu.

Characterizing atom/ion mobility in superionic materials is one of the most essential topics. In this work, we show that the copper ion mobility in a promising thermoelectric material Cu x AgSe y (x, y = 0.98, 1.02), can be significantly changed by modulating the element ratio, x/y. With 63 Cu NMR linewidth as a direct measure of the copper ion mobility, we observed distinguishable Cu ion mobility in the samples with different ratios even under ambient temperatures. This distinction was further evaluated in terms of correlation times and activation energy of copper diffusion. The contrast in ion mobility could be understood from the point of view of vacancy mediation. This work gives fruitful information for understanding ion dynamics and related topics.

Room-temperature ionic liquids based on the bis ((trifluoromethyl)sulfonyl)-imide anion with the tributyl phosphate (TBP) system employed to extract lithium ion from salt lake brine with a high Mg/Li ratio. The influences of cation structure, concentration of ionic liquid and phase ratio on extraction efficiency were investigated. Results indicated that N-butyl pyridinium bis((trifluoromethyl)sulfonyl)imide (BD) has high extraction efficiency for lithium; tributylmethylammomium bis((trifluoromethyl)sulfonyl)imide (JA) has lower extraction efficiency for lithium and impurity ions but exhibits better selectivity; when cation exchange mechanism occurs during solvent extraction by using ionic liquids as a synergistic extraction agent, the cation more hydrophobic was, the more difficult for it to enter the solution exchange process.

A green and efficient liquid–liquid extraction system was developed for the separation of lithium isotopes by using hydrophobic ionic liquids (ILs = [C4,6,8,10mim]+[NTf2]−) as extraction organic phase and benzo-15-crown-5 (B15C5) as complexing agent. The maximum single-stage separation factor α of 6Li/7Li obtained in this study was 1.029 ± 0.001, indicating 6Li was enriched in ionic liquid phase while 7Li was concentrated in the aqueous phase. The lithium ion was extracted into the ionic liquid in the formation of 1:2 complex [Li+(B15C5)2]. The negative data of thermodynamic parameters (∆ H0 and ∆ G0) suggest that the extraction system was a spontaneous exothermic process. In addition, effective lithium isotopes separation factor and the extraction efficiency of lithium ions can be gained in the condition of lower temperature with softer counter anions in the novel extraction system.

A novel phosphonium ionic liquid (IL), tetrabutylphosphonium bis(2,4,4-trimethylpentyl)phosphinate([P 4444 ][BTMPP]), was prepared and characterized by NMR spectroscopy. The solvent extraction behavior of lithium from aqueous solution by this IL in toluene was investigated. The extraction behavior was carried out as a function of various parameters such as aqueous acidity, temperature and extractant concentration. The extraction efficiencies obtained in [P 4444 ][BTMPP] were compared with those observed in molecular extractant bis(2,4,4-trimethylpentyl) phosphinic acid (HBTMPP), from which the anion of the ionic liquid extractant was prepared. The extraction efficiency for extraction of lithium by [P 4444 ][BTMPP] was much higher than that for extraction by HBTMPP. The extracted species were ascertained from slop analysis method which indicated 1:1 (metal:ligand) ratio in the complex. In addition, the effects of thermodynamic parameters, the stripping of lithium from the ionic liquid, and the reusability of the phosphonium ionic liquid were studied in detail.

Extraction of Li+ ions from salt lake brine into an ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) mixed with tri-n-butyl was investigated. The extraction mechanism was been studied using UV–Vis spectroscopy From the temperature dependence data, the thermodynamic functions values (ΔG°, ΔH°, and ΔS°) were calculated. Furthermore, stripping of metals from ionic liquid phase to an aqueous phase by hydrochloric acid was accomplished.

Atomic-scale dynamics of a representative noble metal chalcogenide superionic conductor, stromeyerite (CuAgS), were examined by nuclear magnetic resonance (NMR) spectroscopy at various temperatures. Motional narrowing of 63 Cu NMR line width was found in its cubic phase, demonstrating copper ions start diffusing via a hopping process. Moreover, the absence of 63 Cu NMR signal in its orthorhombic or hexagonal phases was discussed, which could be well explained by copper ordering and reduced local symmetry at copper sites. The above NMR results are relevant for understanding its electron-crystal phonon-liquid behaviors and transient structure-transformation, which are associated with extremely low thermal conductivities and abnormal change of thermal power during superionic phase transition in this material.

Two non-fluorinated ionic liquids (ILs), namely tetrabutylammonium bis(2-ethylhexyl)-phosphate, [N4444][DEHP], and tetraoctylammonium bis(2-ethylhexyl)-phosphate, [N8888][DEHP], were synthesized and fully characterized by 1H and 13C NMR spectroscopy. These functionalized ILs were subsequently evaluated in terms of their ability to extract lithium ions from aqueous solution. The extraction efficiencies of these functionalized ILs for lithium ions were measured as a function of various extraction parameters, including aqueous acidity, temperature and extractant concentration. The extracted species were determined using a slope analysis method, which indicated that the ILs formed a 1:1 (metal:ligand) complex. Fourier transform infrared spectroscopy studies were conducted to better understand the nature of the extracted species. We also investigated the stripping of the lithium ions from the organic phase and the re-use of the ionic liquid in a subsequent extraction step.

In this paper, a novel liquid-liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquid (IL) and dichloroethane as extraction solvent and dibenzo-14-crown-4 (DB14C4) as extractant. Results showed that the separation performance of DB14C4 has been improved after the ILs were involved in the extraction process. The maximum single stage separation factor α for 6Li/7Li obtained in the present study was 1.021. The light lithium isotope 6Li and the heavy lithium isotope 7Li were concentrated in organic phase and solution phase, respectively. The order of the single stage separation factor obtained in different lithium salts was LiI > LiBr > LiClO4 > LiCl. From the temperature dependence data, the thermodynamic functions values of the lithium isotope exchange reaction were calculated.

A novel liquid–liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquids (ILs = [C 6,8,10,12 mim] + [PF 6 ] － ) as extraction solvent and benzo-15-crown-5 (B15C5) as extractant. The effects of the concentration of lithium salt, counter anion of lithium salt, initial pH of aqueous phase, and extraction temperature on the lithium isotopes separation were studied. The maximum single-stage separation factor α of 6 Li/ 7 Li obtained in the present study was 1.038 ± 0.002, indicating the lighter isotope 6 Li was enriched in organic phase while the heavier isotope 7 Li was concentrated in the aqueous phase. The formation of 2:1 complex Li(B15C5) 2 + in the IL phase was determined on the basis of slope analysis method. The large value of the free energy change (− G 0 = 77.87 J mol −1 ) indicated the high separation capability of the lithium isotopes by B15C5/30%CH 3 Cl-70% C 6 mimPF 6 mixture extraction system. Lithium in Li(B15C5) 2 + complex was stripped by 0.5 mol·L −1 HCl solution. The extraction system offers high efficiency, simplicity application prospect to separation lithium isotope separation from LiCl solution.

Herein, the amine-functionalized MCM-41 mesoporous silica (denoted as MCM-41-NH2) was synthesized and applied to adsorption and recovery U(VI) ions from aqueous solutions. The results showed that the sorption of U(VI) on MCM-41-NH2 was strongly dependent on pH and ionic strength. The sorption was mainly dominated by outer-sphere surface complexation and the sorption equilibrium can be reached within 60 min. The maximum sorption capacity of MCM-41-NH2 for U(VI) was calculated to be 386.98 mg g−1 at pH 5.60, much higher than that of the other reported materials.

Separation among lithium ion and magnesium ion remains challenging. In this work, solvent extraction of lithium ions from the Mg(II)-containing salt lake brine into a commonly used ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C 4 mim][NTf 2 ]) using the neutral phosphorus compound tri-n-butyl phosphate (TBP) as the extractant was investigated. The extraction behavior of lithium ions was investigated as a function of various parameters: acidity of the salt lake brine, dosage of ionic liquid and phase ratio. Under the optimal conditions, the single extraction efficiency of lithium was 92.37%, which indicated that it was an efficient extraction system for the recovery of lithium ions. Based on the study of thermodynamics, thermodynamic parameters of the lithium ion extraction reaction were obtained. The extracted species were ascertained from slope analysis method which indicated 1:1 (metal:ligand) ratio in the complex. UV–visible and Fourier transform infrared spectroscopy (FTIR) studies were also carried out to understand the nature of the extracted species.

Water molecules have been reported to cause the degradation of perovskite crystals by forming a hydrated intermediate structure and then lead iodide irreversibly. Here, the quality of fully crystallized perovskite films is found to be improved by spraying water vapor with an appropriate time. Moreover, this healing effect was found to be reversible and would disappear when the water molecules escaped. Through measuring the steady-state and time-resolved photoluminescence of perovskite film before and after water vapor spray, we found that water molecules can deactivate the nonradiative recombination centers due to hydrogen bonding with uncoordinated ions on the surface of perovskite film. Furthermore, by analyzing the capacitance of devices without and with water vapor spray, the healing or deactivation effect was clearly seen in the significantly decreased density of defect states. This work emphasized the effectiveness of hydroxyl to heal the defects due to dangling bonds on the material surface, and cl...

To examine the ionic migrations on atomic level in metal chalcogenide phonon glasses, 63Cu solid state nuclear magnetic resonance (NMR) spectroscopy was performed in an archetype CuAgSe compound. The observed characteristic motional narrowing effect in the superionic state provide clear evidence for the model of single ion-hopping instead of free-ion-like motion. We further find, for the first time, that thermal conductivity is strongly correlated with cation dynamics revealed by NMR within the range of temperatures investigated. This investigation provides better understanding how microscopic structure affects thermal transport properties which is of current interest in transition-metal chalcogenide based fast ion conductors.

Lithium is known as the energy metal and it is a key raw material for preparing lithium isotopes which have important applications in nuclear energy source. In this work, a typical room temperature ionic liquid (RTILs), 1-butyl-3-methyl-imidazolium hexafluorophosphate ([C4mim][PF6]), was used as an alternative solvent to study liquid/liquid extraction of lithium from salt lake brine. In this system, the ionic liquid, NaClO4 and tributyl phosphate (TBP) were used as extraction medium, co-extraction reagent and extractant respectively. The effects of solution pH value, phase ratio, ClO4− amount and other factors on lithium extraction efficiency had been investigated. Optimal extraction conditions of this system include the ratio of TBP/IL at 4/1 (v/v), O/A at 2:1, n(ClO4−)/n(Li+) at 2:1, the equilibration time of 10 min and unadjusted pH. Under the optimal conditions, the single extraction efficiency of lithium was 87.28% which was much higher than the conventional extraction system. Total extraction efficiency of 99.12% was obtained by triple-stage countercurrent extraction. Study on the mechanism revealed that the use of ionic liquid increased the extraction yield of lithium through cation exchange in this system. Preliminary results indicated that the use of [C4mim][PF6] as an alternate solvent to replace traditional organic solvents (VOCs) in liquid/liquid extraction was very promising.

Application of a room temperature ionic liquid (RTILs), 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim][PF 6 ]), in the extraction of lithium ion from salt lake brine using tributyl phosphate (TBP) as extractant was investigated. The effects of temperature, pH value of solution, phase ratio and other factors on the extraction were studied in detail. The preliminary experimental results had demonstrated that, compared with using conventional extraction system, the extraction efficiency had been increased greatly in this ionic liquid system. Study on the mechanism revealed that the extraction most likely occurred by a cation exchange mode in this system. This work highlights the vast opportunities in separation applications for ionic liquid.

The Huajian gold deposit is one of the largest hydrothermal intrusion-related gold deposits in eastern Hebei Province, located in the northern margin of the North China Craton (NCC). The mineralization in this district displays a close spatial association with the shoshonitic Niuxinshan intrusive complex (NIC), which contributes to the characterization of the metallogeny associated with convergent margin magmatism. In the current study, new geochronological and geochemical data are combined with previously published isotopic data, obtained from the granitic rocks in the NIC, to constrain the timing of the district's tectonic setting transformation and determine its bearing on regional metallogeny. The new geochronological data constrain the timing of the tectonic transformation between 155 and 185 Ma. The NIC's granitic rocks can be geochemically subdivided into two groups. One group's geochemical signature exhibits steep rare earth element (REE) patterns with negligible Eu anomalies, lower Yb, higher Sr, and negative Nb-Ta-Ti (NTT) anomalies, which indicate a volcanic-arc environment with a thickened crust in a convergent setting. The other group exhibits flat REE patterns with obvious negative Eu anomalies, higher Yb, lower Sr, and weak NTT anomalies, which indicate an intra-plate extensional environment with a thinning crust. Combining geochronologic and isotopic data, the mineralization is Late Jurassic (~155 Ma). This is interpreted to be genetically related to the crystallization of the shallow crustal-sourced portions of this complex. Additionally, a tectonic model is presented that provides a plausible explanation for the abundant polymetallic mineralization that occurs in the northern margin of the NCC after 155 Ma.

Implant-associated infections and non-absorbing materials are two important reasons for a second surgical procedure to remove internal fixation devices after an orthopedic internal fixation surgery. The objective of this study was to produce an antibacterial and absorbable fixation screw by adding gentamicin to silk-based materials. The antibacterial activity was assessed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in vitro by plate cultivation and scanning electron microscopy (SEM). We also investigated the properties, such as the mechanical features, swelling properties, biocompatibility and degradation, of gentamicin-loaded silk-based screws (GSS) in vitro. The GSS showed significant bactericidal effects against S. aureus and E. coli. The antibacterial activity remained high even after 4 weeks of immersion in protease solution. In addition, the GSS maintained the remarkable mechanical properties and excellent biocompatibility of pure silk-based screws (PSS). Interestingly, after gentamicin incorporation, the degradation rate and water-absorbing capacity increased and decreased, respectively. These GSS provide both impressive material properties and antibacterial activity and have great potential for use in orthopedic implants to reduce the incidence of second surgeries.