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Ultrafast electronic relaxation of nucleobases from ¹ππ* states to the ground state (S0) is considered essential for the photostability of DNA. However, transient absorption spectroscopy (TAS) has indicated that some nucleobases in aqueous solutions create long-lived ¹nπ*/³ππ* dark states from the ¹ππ* states with a high quantum yield of 0.4–0.5. We investigated electronic relaxation in pyrimidine nucleobases in both aqueous solutions and the gas phase using extreme ultraviolet (EUV) time-resolved photoelectron spectroscopy. Femtosecond EUV probe pulses cause ionization from all electronic states involved in the relaxation process, providing a clear overview of the electronic dynamics. The ¹nπ* quantum yields for aqueous cytidine and uracil (Ura) derivatives were found to be considerably lower (

Triiodide (I3−) is a species well-known to influence the nature of perovskite materials. Here, we highlight possible and unexpected sources of I3−, i.e. the iodide (I−) salt solutions used for the synthesis of metal-halide perovskites.

This paper reviews the properties of methanesulfonic acid (MSA) and its potential for use in hydrometallurgy. Although MSA is much less known than sulfuric, hydrochloric or nitric acid, it has several appealing properties that makes it very attractive for the development of new circular flowsheets in hydrometallurgy. Unlike other organic acids such as acetic acid, MSA is a very strong acid (pKa = − 1.9). In addition, it is very stable against chemical oxidation and reduction, and has no tendency to hydrolyze in water. In terms of its environmental impact, MSA has low toxicity and is biodegradable. In nature, it is part of the geochemical sulfur cycle. A useful property is the high solubility of its salts in water: methanesulfonate salts have a much higher solubility in water than sulfate salts. Additionally, MSA and its salts are compatible with the electrowinning of metals because the anode reaction involves the formation of oxygen gas (unlike chlorine gas formation in chloride electrolytes) and no cathodic reduction of the anion occurs (unlike nitrate reduction in nitrate electrolytes). MSA is particularly interesting for lead hydrometallurgy, where it offers more environment-friendly alternatives to HBF4 and H2SiF6. However, MSA can also be adopted in all hydrometallurgical processes that require strong Brønsted acids. It can be used in the metallurgy of copper, zinc, cobalt, nickel, and rare earths, as well as in the recycling of metals from end-of-life products. Although MSA itself is a non-oxidizing acid, in combination with hydrogen peroxide it yields strongly oxidizing lixiviants that can leach copper from chalcopyrite or dissolve metallic silver. The global production of MSA is expected to increase rapidly in the near future thanks to both the industrialization of a new sustainable synthesis process and its many applications (cleaning fluids, electrolytes for electroplating, redox-flow batteries, catalysts in organic synthesis, and as a solvent for high-molecular-weight polymers). As a result, MSA will become more widely available and a lower price will make it an increasingly attractive option. Graphical Abstract

In this academic position paper, we propose the 12 Principles of a novel and more sustainable approach to hydrometallurgy that we call “circular hydrometallurgy.” The paper intends to set a basis for identifying future areas of research in the field of hydrometallurgy, while providing a “sustainability” benchmark for assessing existing processes and technological developments. Circular hydrometallurgy refers to the designing of energy-efficient and resource-efficient flowsheets or unit processes that consume the minimum quantities of reagents and result in minimum waste. The application of a circular approach involves new ways of thinking about how hydrometallurgy is applied for both primary and secondary resources. In either case, the emphasis must be on the regeneration and reuse of every reagent in the process. This refers not only to the acids and bases employed for leaching or pH control, but also any reducing agents, oxidizing agents, and other auxiliary reagents. Likewise, the consumption of water and energy must be reduced to an absolute minimum. To consolidate the concept of circular hydrometallurgical flowsheets, we present the 12 Principles that will boost sustainability: (1) regenerate reagents, (2) close water loops, (3) prevent waste, (4) maximize mass, energy, space, and time efficiency, (5) integrate materials and energy flows, (6) safely dispose of potentially harmful elements, (7) decrease activation energy, (8) electrify processes wherever possible, (9) use benign chemicals, (10) reduce chemical diversity, (11) implement real-time analysis and digital process control, and (12) combine circular hydrometallurgy with zero-waste mining. Although we realize that the choice of these principles is somewhat arbitrary and that other principles could be imagined or some principles could be merged, we are nevertheless convinced that the present framework of these 12 Principles, as put forward in this position paper, provides a powerful tool to show the direction of future research and innovation in hydrometallurgy, both in industry and in academia. Graphical Abstract

The thermophysical properties of aqueous electrolyte solutions are of interest for applications such as water electrolyzers and fuel cells. Molecular dynamics (MD) and continuous fractional component Monte Carlo (CFCMC) simulations are used to calculate densities, transport properties (i.e., self-diffusivities and dynamic viscosities), and solubilities of H2 and O2 in aqueous sodium and potassium hydroxide (NaOH and KOH) solutions for a wide electrolyte concentration range (0-8 mol/kg). Simulations are carried out for a temperature and pressure range of 298-353 K and 1-100 bar, respectively. The TIP4P/2005 water model is used in combination with a newly parametrized OH- force field for NaOH and KOH. The computed dynamic viscosities at 298 K for NaOH and KOH solutions are within 5% from the reported experimental data up to an electrolyte concentration of 6 mol/kg. For most of the thermodynamic conditions (especially at high concentrations, pressures, and temperatures) experimental data are largely lacking. We present an extensive collection of new data and engineering equations for H2 and O2 self-diffusivities and solubilities in NaOH and KOH solutions, which can be used for process design and optimization of efficient alkaline electrolyzers and fuel cells.

The past 10–20 years have seen numerous academic papers describing the benefits of ionic liquids (ILs) and deep-eutectic solvents (DESs) for leaching, solvent extraction and electrowinning. The scientific community—including the authors of this opinion article—have frequently proclaimed these neoteric solvents as game-changers in extractive metallurgy. Despite this, there have been no commercial breakthroughs. In this paper we reflect on the reasons why ILs and DESs seem to have failed to impact on the metallurgical industry. These include: (1) issues with high viscosity; (2) limited chemical stability under the conditions of metallurgical processes; (3) difficulties with recycling and reuse; (4) a lack of demonstrated unit processes and flowsheets on the pilot scale; (5) insufficient material-property data available for engineering purposes; (6) the administrative burden of obtaining licenses and safety permits; (7) very high costs for large-scale operations; and (8) minimal added value compared to state-of-the-art hydrometallurgical processes. Our belief is that innovations in hydrometallurgy based on ILs or DESs are unlikely. Instead, we should be aiming for a deeper understanding of hydrometallurgical processes at the molecular level. This is because advances are more likely to derive from the refocused efforts of experienced IL/DES researchers investigating the speciation and chemical thermodynamics of hydrometallurgical solutions, which will then hasten the transition from linear to low-energy-input, circular hydrometallurgy. Graphical Abstract

International audience; Bolaamphiphilic-type structures can be effective substitutes to conventional surfactants for the interaction and stabilization of colloidal interfaces in water. Different families of bolaamphiphiles were used as a growth control and stabilizing agent for the formation of gold nanoparticles (AuNPs). The nature of polar heads and the length of hydrophobic chain are key parameters for modulating the interaction with gold surfaces. In particular, interactions between hydrophobic chains dramatically strengthen the interactions with NP surfaces leading to a reversible aggregation process. This affects not only the gold nanoparticle growth mechanism and stabilization properties but also the catalytic properties of the modified gold nanoparticles.

Biochar nanoparticles (BC-NP) have attracted significant attention because of their unique environmental behavior, some of which could potentially limit large-scale field application of biochar. Accurate prediction of the fate and transportability of BC-NP in soil matrix is the key to evaluating their environmental influence. This study investigated the effects of soil grain size and environmentally relevant solution chemistry, such as ionic strength (cation concentration, 0.1 mM–50 mM; cation type, Na+, and Ca2+), and humic acid (HA; 0–10 mg/L), on the transport behavior of BC-NP via systematic column experiments. The transportability of BC-NP in the soil-packed column decreased with decreasing soil grain size and was inversely proportional to soil clay content. At low cation concentrations (0.1–1.0 mM), a considerable proportion of BC-NP (15.95%–67.17%) penetrated the soil columns. Compared with Na+, Ca2+ inhibited the transportability of BC-NP in the soil through a charge shielding effect. With increasing HA concentration, the transportability of BC-NP increased, likely due to an enhanced repulsion force between BC-NP and soil particles. However, at a high HA concentration (10 mg/L), Ca2+ bridging reduced the transportability of BC-NP in the soil. Breakthrough curves of BC-NP were explained by the two-site kinetic retention model. The antagonistic effects of ionic strength and HA indicated that the transport behavior of BC-NP in the soil was governed by competitive effects of some environmental factors, including soil grain size, environmental solution chemistry, and natural organic matter content.

Summary Ever since the first reports on metal halide perovskite solar cells, a fundamental claim regarded a straightforward solution processability of the material, allowing for affordable and scalable processing. Therefore, understanding perovskite ink properties is a fundamental requirement toward industrialization. However, the evolution over time of these inks, which has a tremendous impact on the final performances of devices, is not yet extensively addressed. Any minute change in the ink composition can result in large variations in the photovoltaic performances, because these directly influence crystallization dynamics and final material composition. This is particularly important for the recent complex ink formulations, where the presence of numerous chemical species implies the existence of diverse interconnected equilibria. In this perspective, recent discoveries on the perovskite ink modifications over time are critically discussed, and directions for future research are proposed, including a survey of the most effective diagnostic tools used so far to investigate such inks.

This short overview describes the historical development of the physics and chemistry of organic solvents and solutions from the alchemist era until the present time based on some carefully selected examples that can be considered landmarks in the history of solution chemistry.

Doping chemistry has become one of the most effective means of tuning materials' properties for diverse applications. In particular for scheelite-type CaWO4, high-oxidation-state doping is extremely important, since one may expand the scheelite family and further create prospective candidates for novel applications and/or useful spectral signatures for nuclear forensics. However, the chemistry associated with high-valence doping in scheelite-type CaWO4 is far from understanding. In this work, a series of scheelite-based materials (Ca1-x-y-zEuxKy□z)WO4 (□ represents the cation vacancy of the Ca2+ site) were synthesized by hydrothermal conditions and solid-state methods and comparatively studied. For the bulk prepared by the solid-state method, occupation of high-oxidation-state Eu3+ at the Ca2+ sites of CaWO4 is followed by doping of the low-oxidation-state K+ at a nearly equivalent molar amount. The Eu3+ local symmetry is thus varied from the original S4 point group symmetry to C2v point group symmetry. Surprisingly different from the cases in bulk, for the nanoscale counterparts prepared by hydrothermal conditions, the high-oxidation-state Eu3+ was incorporated in CaWO4 at two distinct sites, and its amount is higher than that of the low-oxidation-state K+ even though KOH was used as a mineralizer, creating a certain amount of cation vacancies. Consequently, an apparent split emission of 5D0 → 7F0 was first demonstrated for (Ca1-x-y-zEuxKy□z)WO4. The doping chemistry of high oxidation states uncovered in this work not only provides an explanation for the commonly observed spectral changes in rare-earth-ion-modified scheelite structures, but also points out an advanced direction that can guide the design and synthesis of novel functional oxides by solution chemistry routes.

Supplementary cementitious materials (SCMs) are usually employed to replace partial cement and the pore-solution chemistry of blended cements is extremely essential for their cement hydration and d...

Radial distribution functions are commonly used to represent the structures of solutions, which represent the probability of finding another atom in the shell at a distance r from the atom of inter...

The adsorption characteristics of Eu(III) on colloidal bentonite particles were investigated by batch experiments as functions of colloid concentration, pH, foreign ions, and temperature. Bentonite colloids displayed remarkable adsorption ability to Eu(III), the Eu(III) adsorption was significantly affected by solution chemistry. The Eu(III) adsorption increased with colloids concentration and pH increasing. Divalent cations (Ca2+, Mg2+ and Sr2+) and anions (Cl− and SO42−) inhibited Eu(III) adsorption, whereas PO43− greatly enhanced Eu(III) adsorption. High temperature was beneficial for Eu(III) adsorption, the adsorption process was a spontaneous endothermic process. The results suggested that colloids could acted as an efficient carrier for Eu(III) transport.

Recently dolomite analogs, including norsethite, kutnahorite, and PbMg(CO3)2, etc., have attracted much attention due to their dolomite-like crystallographic structure and the resulting potential in solving “dolomite problem.” Previous studies indicate that mechanisms that underlie the formation of norsethite exhibit some similarities to pathways of dolomite crystallization. However, the crystallization behavior of norsethite is still poorly understood, and the physicochemical factors regulating the process are not yet fully established. Herein, to determine the relationships between solution chemistry and formation pathway of norsethite, a series of experiments for the synthesis of norsethite from the solutions with different concentrations of Mg2+ and Ba2+ by a CO2 gas-diffusion method was carried out under ambient conditions. The morphology and phase composition of the products were investigated by a range of techniques, including XRD, FESEM, micro-Raman, and FTIR techniques. ICP-AES was used to monitor the evolution of the concentrations of Mg2+ and Ba2+ in the mineralization solutions. Our observations suggest that the formation pathway of norsethite strongly depends on Mg/Ba ratio in solution, and pure norsethite can directly crystallize from the solutions with Mg/Ba ratio ranging in 20–40. This is the first time to report the direct precipitation of dolomite analogs at ambient temperatures. It suggests that direct precipitation is a feasible pathway for cation ordering structure formation under ambient conditions.

In flotation, metal ions possess significant roles that are usually fulfilled by either selectively activating or depressing the target minerals. Despite that tremendous efforts have been made to address the roles of metal ions in flotation, it still lacks a comprehensive review, especially to compare various ions instead of focusing on a specific one. This review begins by elaborately categorizing the factors involved in affecting the roles of metal ions in flotation. After that, well-accepted mechanisms are updated and discussed from the ore type. Furthermore, typical approaches to explore the underlying mechanisms are emphasized, including traditional techniques such as micro-flotation, contact angle measurement, zeta potential measurement, and other recent prevailing methodologies, like computational method, solution chemistry calculation, and cyclic voltammetry. This work will pave the way to promote flotations via activities like selectively adding/reducing metal ions, choosing reagents, and regulating the slurry chemistry.

High-entropy ceramics is a new class of materials having a great potential and wide application. The carbide of Ti, Zr, Hf, Ta, Nb is a typical member of this group. It has been synthesized mostly through blending, milling, and high-temperature solid-state reaction of metal carbide precursors for each metal. This route needs extremely high temperature (2300 °C), which makes it energy and technology demanding. We have developed a chemical route for high-entropy carbide powder that needs a synthetic temperature that is several hundred degrees Celsius lower. A solution of desired metal citrates with an excess of citric acid was converted into a metal oxide/active carbon nanocomposite. Starting from a solution enabled ideal mixing of precursors on a molecular level, allowing us to skip any milling and blending steps. The nanocomposite was treated in vacuum at 1600 °C, giving a phase-pure high-entropy carbide. The intermediate compounds and products were characterized by means of solid-state analysis.

In this paper electrical discharge plasma in liquid was used for synthesis of carbon nanoparticles (NPs). In addition, targeted changes of the NPs surface properties were selectively achieved via treatment of as-prepared NPs by a gas-liquid interfacial discharge produced in contact with the colloidal solution. The results of the solution chemistry induced at the plasma-liquid interface for surface engineering of NPs are discussed.

Soft X-ray absorption spectroscopy (XAS) observes element-specific intermolecular interactions of light elements in liquid phase through the core-to-valence excitation. We have newly developed liqu...

An in-house designed membrane process suitable for subsea natural gas dehydration was studied. The use of a membrane absorber together with a thermopervaporation (TPV) unit for solvent regeneration in a closed loop enables the effective and clean production of high-pressure natural gas close to the wellhead. This process avoids the continuous chemical injection for preventing hydrate formation in natural gas pipelines. The regeneration of the absorbent agent (triethylene glycol (TEG)) by TPV in the closed loop is highly energy-efficient, owing to the unlimited free cooling energy from the cold subsea water. In this work, the performance of membranes in TPV for TEG regeneration was evaluated experimentally for the first time. Morphological and permeation characterizations of an AF2400 thin-film composite membrane were carried out, and high separation factors outperforming the vapor–liquid equilibrium (VLE) were obtained for the solutions containing various water contents at feed temperatures ranging from 30 to 70 °C. The highest values of a separation factor (128,000) and a permeability (2380 (Barrer)) were obtained for the TEG solution containing 30 wt % water at 30 °C, while the highest water flux (468 (g/m2·h)) was reached at 70 °C. Moreover, the concentration polarization phenomenon induced by the temperature gradient was revealed in the membrane’s vicinity of the feed channel. A 3D computational fluid dynamics simulation was performed over the entire module to correct the driving force for a more precise assessment of the membrane permeance. The temperature and concentration profiles in the membrane module domains were explored, and a good agreement with experimental data was obtained.

Water-lean solvents have been proposed as a possible alternative to aqueous amine systems in postcombustion carbon capture. There is however little data available on how amine degradation is affected by different solvents. This study presents new insights on the effect of solvent on thermal degradation of alkanolamines from laboratory-scale degradation experiments. Replacing the water in aqueous monoethanolamine (MEA) solutions with organic diluents resulted in varying thermal degradation rates. Overall, all tested organic diluents (triethylene glycol, diethylene glycol, mono ethylene glycol, tetrahydrofurfuryl alcohol, N-formyl morpholine/water, and N-methyl-2-pyrrolidone) resulted in higher thermal degradation rates for loaded MEA. None of the proposed parameters, such as acid–base behavior, polarity, or relative permittivities, stood out as single contributing factors for the variation in degradation rates. The typical degradation compounds observed for an aqueous MEA solvent were also observed for MEA in various concentrations and with various organic diluents.

HO radicals are the most important reactive species generated during water treatment by non-thermal plasma devices. In this letter, we report the first quantification of the steady-state concentration and lifetime of plasma-produced hydroxyl radicals in water solutions at pH 3 and 7, and we discuss the differences based on their reactivity with other plasma-generated species. Finally, we show to what extent the use of chemical probes to quantify short-lived reactive species has an influence on the results and that it should be taken into account.

This work is focused on studying the chemical equilibrium phenomena of precursor solutions used to growth hybrid inorganic–organic MAPbI3 perovskite films. Special emphasis was made on the effect of important variables such as solvents type, ligands, temperature, and concentration on the chemical equilibrium and subsequent effect on film morphology. These results provided important information to develop a novel synthesis route based on chemical bath deposition (CBD) method that allowed to grow thin films of MAPbI3 with grain sizes greater than 10 μm and high degree of crystalline ordering, features that led to getting MAPbI3 films with improved stability. The proposed CBD method, in addition to being novel for the growth in solution of MAPbI3 thin films, is scalable, low cost, and promising, since it offers great prospects for the manufacture of highly stable perovskite hybrid solar cells.

Oxidative etching possesses an enriched flexibility and atomic-level accuracy in tailoring the size, morphology, surface structure, and composition of colloidal nanocrystals toward their catalytic ...

The chemical compositions of the aqueous phases in alkali-activated slag (AAS) paste and Portland cement (PC) paste were determined up to 28 d with the aim of obtaining a better understanding of the stability of the hydration products in the two binder systems. The saturation levels with respect to the hydration products of PC and AAS were obtained by thermodynamic modelling. The main findings of this study were: the effective saturation index for portlandite in the AAS system was always below zero and the sulfate-bearing phases were not stable in the AAS system compared with those in the PC; strätlingite and hydrotalcite phases were stable in the AAS paste due to the high magnesium and silicon concentrations in the pore solution; both the ionic strength and alkalinity of the AAS pore solution were higher than those of the PC pore solution, which were responsible for more severe efflorescence in the AAS paste and the higher conductivity of the AAS pore solution. According to thermodynamic estimations, tobermorite-based C–S–H was dominant in the AAS system after 7 d, while jennite-based and tobermorite-based C–S–H gels were present in the PC system up to 28 d. The results suggest that in PC and AAS pastes, different solid phases are formed during the hydration, which change with time, and the reactions and equilibria in both binders are completely different.

Direct delivery of enzymes into intact plants using cell-penetrating peptides (CPPs) is an attractive approach for modifying plant functions without genetic modification. However, by conventional methods, it is difficult to maintain the enzyme activity for a long time because of proteolysis of the enzymes under physiological conditions. Here, we developed a novel enzyme delivery system using polyion complex vesicles (PICsomes) to protect the enzyme from proteases. We created PICsome-bearing reactive groups at the surface by mixing an anionic block copolymer, alkyne-TEG-P(Lys-COOH), and a cationic peptide, P(Lys). The PICsome encapsulated neomycin phosphotransferase II (NPTII), a kanamycin resistance enzyme, and protected NPTII from proteases in vitro. A CPP-modified PICsome delivered NPTII into the root hair cells of Arabidopsis thaliana seedlings and provided kanamycin resistance in the seedlings that lasted for 7 days. Thus, the PICsome-mediated enzyme delivery system is a promising method for imparting long-term transient traits to plants without genetic modification.

Densities of up to 16 aqueous solutions of zinc sulfate have been measured at 5 K intervals over the temperature range of 293.15 ≤ T/K ≤ 353.15 at concentrations 0.004 ≤ m/mol·kg-1 ≤ 2.5 and 0.1 MPa pressure using a commercial glass vibrating tube densimeter (vtd). Particular attention was paid to establishing the concentrations and pH values of the solutions. Densities of the same solutions were also measured at 343.15 and 373.15 K at 0.3 MPa pressure in a purpose-built high-temperature Pt/Rh-vtd. The two sets of densities at 343.15 K were in excellent agreement, with an average difference of 0.01%. Apparent molar volumes, Vφ, calculated from the densities were fitted with an extended Redlich-Rosenfeld-Meyer equation. However, the standard (infinite dilution) molar volumes, Vo(ZnSO4, aq), derived via this equation differed significantly (by up to 2 cm3·mol-1) from the values obtained by ionic additivity using literature data. This difference is probably mostly due to ion-pairing effects.

Surface functionalization of metallic nanoparticles is an attractive route to tailor the ensemble geometry and redox properties of active sites in heterogeneous catalysts. However, it is challenging to generate well-defined interfaces through conventional impregnation and one-pot colloidal synthesis methods. In this work, we utilize ligand exchange reactions for post synthetic surface modification of colloidal nanoparticles to generate unique core-shell and surface alloy structures. We use halometallate and metal chalcogenide complexes to create surface sites that are active for electrocatalytic hydrogen evolution reaction (HER). We synthesize a self-limiting monolayer of metal chalcogenides on colloidal Au nanoparticles through biphasic ligand exchange reaction between ammonium tetrathiomolybdate (NH4)2MoS4 complex and Au nanoparticles. Through a combination of spectroscopy techniques and computational methods, we show that strong Au-S interactions introduce electronic and geometric distortion to the geometry and bond metrics of MoS42- complex. Moreover, proximal MoS4 units adsorbed on the Au surface interlink to form small MoSx oligomers with highly active bridging disulfide sites. Consequently, these core-shell AuMoS4 nanoparticles exhibit significantly higher HER activity than MoS42- supported on non-interacting carbon supports under highly acidic electrolyte conditions. Although post catalysis characterization reveals partial hydrolysis of surface adsorbed MoSx species, stable HER activity under bulk electrolysis condition indicates that active sites remain persistent. In an effort to extend these ligand exchange reactions to create metal/metal interfaces on other coinage metal nanoparticles such as Ag, we design metal-ligand coordination complexes to mitigate undesired galvanic replacement reactions. By varying the strength and number of coordinating ligands, we fine-tune the redox potential of oxidized noble metal precursors and confine the deposition of noble metals to a few surface layers of the Ag nanoparticles. We utilize organic amine and phosphine ligands to generate Ag@AgM core-shell nanoparticles, where M = Pd, Pt, and Au. Surface alloy or pure metal shells of Pd and Pt on Ag nanoparticles generated through this ligand-based strategy exhibited high precious metal atom utilization in electrocatalytic hydrogen evolution reaction.

Delayed fracture healing is a major health issue involved with aging. Therefore, strategies to improve the pace of repair and prevent non-union are needed in order to improve patient outcomes and lower healthcare costs. In order to accelerate bone fracture healing noninvasively, we sought to develop a drug delivery system that could safely and effectively be used to deliver therapeutics to the site of a bone fracture. We elected to pursue the promising strategy of using small-molecule drug conjugates that deliver therapeutics to bone in an attempt to increase the efficacy and safety of drugs for treating bone-related diseases.This strategy also opened the door for new methods of administering drugs. Traditionally, administering bone anabolic agents to treat bone fractures has relied entirely on local surgical application. However, because it is so invasive, this method’s use and development has been limited. By conjugating bone anabolic agents to bone-homing molecules, bone fracture treatment can be performed through minimally invasive subcutaneous administration. The exposure of raw hydroxyapatite that occurs with a bone fracture allows these high-affinity molecules to chelate the calcium component of hydroxyapatite and localize primarily to the fracture site.Many bone-homing molecules (such as bisphosphonates and tetracycline targeting) have been developed to treat osteoporosis. However, many of these molecules have toxicity associated with them. We have found that short oligopeptides of acidic amino acids can localize to bone fractures with high selectivity and with very low toxicity compared to bisphosphonates and tetracyclines.We have also demonstrated that these molecules can be used to target peptides of all chemical classes: hydrophobic, neutral, cationic, anionic, short, and long. This ability is particularly useful because many bone anabolics are peptidic in nature. We have found that acidic oligopeptides have better persistence at the site of the fracture than bisphosphonate-targeted therapeutics. This method allows for a systemic administration of bone anabolics to treat bone fractures, which it achieves by accumulating the bone anabolic at the fracture site. It also opens the door for a new way of treating the prevalent afflictions of broken bones and the deaths associated with them.We further developed this technology by using it to deliver anabolic peptides derived from growth factors, angiogenic agents, neuropeptides, and extracellular matrix fragments. We found several promising therapeutics that accelerated the healing of bone fractures by improving the mineralization of the callus and improving the overall strength. We optimized the performance of these molecules by improving their stability, targeting ligands, linkers, dose, and dosing frequency.We also found that these therapeutics could be used to accelerate bone fracture repair even in the presence of severe comorbidities (such as diabetes and osteoporosis) that typically slow the repair process. We found that, unlike the currently approved therapeutic for fracture healing (BMP2), our therapeutics improved functionality and reduced pain in addition to strengthening the bone. These optimized targeted bone anabolics were not only effective at healing bone fractures but they also demonstrated that they could be used to speed up spinal fusion. Additionally, we demonstrated that acidic oligopeptides have potential to be used to treat other bone diseases with damaged bone.With these targeted therapeutics, we no longer have to limit bone fracture healing to casts or invasive surgeries. Rather, we can apply these promising therapeutics that can be administered non-invasively to augment existing orthopedic practices. As these therapeutics move into clinical development, we anticipate that they will be able to reduce the immobilization time that is the source of so many of the deadly complications associated with bone fracture healing, particularly in the elderly.

We employ a fine-tuned theoretical framework, combiningab initiomolecular dynamics (AIMD), density functional theory (DFT), and time-dependent (TD) DFT methods, to investigate the interactions and optical properties of the iodoplumbates within the low coordinative γ-butyrolactone (GBL) solvent environment, widely employed in the perovskite synthesis. We uncover the extent of GBL coordination to PbI2investigating its relation to the solvated PbI2optical properties. The employed approach has been further validated by comparison with the experimental UV–vis absorption spectrum of PbI2in GBL solvent. A comparison with other solvents, commonly employed in the perovskite synthesis, such asN,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) is also reported. The methodology developed in this work can be reasonably extended to the investigation of similar systems.

International audience; Water, being the universal solvent, acts as a competing agent in fundamental processes, such as folding, aggregation or biomolecular recognition. A molecular understanding of hydrophobic hydration is of central importance to understanding the subtle free energy differences, which dictate function. Ab initio and classical molecular dynamics simulations yield two distinct hydration water populations in the hydration shell of solvated tert-butanol noted as “HB-wrap” and “HB-hydration2bulk”. The experimentally observed hydration water spectrum can be dissected into two modes, centered at 164 and 195 cm–1. By comparison to the simulations, these two bands are attributed to the “HB-wrap” and “HB-hydration2bulk” populations, respectively. We derive a quantitative correlation between the population in each of these two local water coordination motifs and the temperature dependence of the solvation entropy. The crossover from entropy to enthalpy dominated solvation at elevated temperatures, as predicted by theory and observed experimentally, can be rationalized in terms of the distinct temperature stability and thermodynamic signatures of “HB-wrap” and “HB-hydration2bulk”.

In this paper, a comprehensive study of the solid and solution chemistry of etoricoxib (ETR) was conducted through the combined experimental identification and theoretical calculation. Six new solv...

Porous carbons have shown considerable potential in catalysis as either as supports or metal-free catalysts. Various methods based on solution chemistry have been intensively developed for the preparation of porous carbon-based catalysts with controllable morphology, pore structure, surface chemical property as well as the desired active sites. Nowadays, mechanochemical synthesis, a re-emerging strategy, has become more and more popular in the synthesis of porous carbons, due to its feasibility and high synthetic efficiency under solvent-free condition. This Minireview presents recent advances in the mechanochemical synthesis of porous carbons by ball milling, and their applications in catalysis. It starts a brief introduction of the characteristics and work mechanism of ball milling, and then discuss the preparation of porous carbons as metal-free catalysts and carbon-supported metal catalysts. Finally, some issues and further opportunities for the mechanochemical synthesis of porous carbon-based catalysts are proposed and discussed.

Recent developments in high- and middle-income countries have exhibited a shift from conventional urban water systems to alternative solutions that are more diverse in source separation, decentralization, and modularization. These solutions include nongrid, small-grid, and hybrid systems to address such pressing global challenges as climate change, eutrophication, and rapid urbanization. They close loops, recover valuable resources, and adapt quickly to changing boundary conditions such as population size. Moving to such alternative solutions requires both technical and social innovations to coevolve over time into integrated socio-technical urban water systems. Current implementations of alternative systems in high- and middle-income countries are promising, but they also underline the need for research questions to be addressed from technical, social, and transformative perspectives. Future research should pursue a transdisciplinary research approach to generating evidence through socio-technical "lighthouse" projects that apply alternative urban water systems at scale. Such research should leverage experiences from these projects in diverse socio-economic contexts, identify their potentials and limitations from an integrated perspective, and share their successes and failures across the urban water sector.

Contrary to expectations based on solution chemistry, scanning tunneling microscopy results show that, on a Ag(111) surface, the formation of a TTF-TCNE charge transfer complex is favored over an a...

Characterization of structural heterogeneity of liquid solutions and the pursuit of its nature have been challenging tasks to solution chemists. In the last decade, an emerging method called excess spectroscopy has found applications in this area. The method, combining the merits of molecular spectroscopy and excess thermodynamic functions, shows the ability to enhance the apparent resolution of spectra, provides abundant information concerning solution structures and intermolecular interactions. In this review, the thinking and mathematics of the method, as well as its developments, are presented first. Then, research progress related to the exploration of the method is thoroughly reviewed. The materials are classified into two parts, small-molecular solutions and ionic liquid solutions. Finally, potential challenges and the perspective for further development of the method are discussed.

Advanced reduction processes (ARPs) have emerged as a promising method for destruction of persistent per- and polyfluoroalkyl substances (PFAS) in water due to the generation of short-lived and highly reductive hydrated electrons (eaq-). This study provides a critical review on the mechanisms and performance of reductive destruction of PFAS with eaq-. Unique properties of eaq- and its generation in different ARP systems, particularly UV/sulfite and UV/iodide, are overviewed. Different degradation mechanisms of PFAS chemicals, such as perfluorooctanoic acid (PFOA), perfluorooctanesulfonate (PFOS), and others (e.g., short chain perfluorocarboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs), per- and polyfluoro dicarboxylic acids, and fluorotelomer carboxylic acids), are reviewed, discussed, and compared. The degradation pathways of these PFAS chemicals rely heavily upon their head groups. For specific PFAS types, fluoroalkyl chain lengths may also affect their reductive degradation patterns. Degradation and defluorination efficiencies of PFAS are considerably influenced by solution chemistry parameters and operating factors, such as pH, dose of chemical solute (i.e., sulfite or iodide) for eaq- photoproduction, dissolved oxygen, humic acid, nitrate, and temperature. Furthermore, implications of the state-of-the-art knowledge on practical PFAS control actions in water industries are discussed and the priority research needs are identified.

The iron selenide (Fe–Se) family of nanoparticles (FexSey—where x/y ranges from 1:2 to 1:1) has been fabricated by a thermal decomposition method. The control over solution chemistry has been devel...

The US plan for high-level nuclear waste includes the immobilization of long-lived radionuclides in glass or ceramic waste forms in stainless-steel canisters for disposal in deep geological repositories. Here we report that, under simulated repository conditions, corrosion could be significantly accelerated at the interfaces of different barrier materials, which has not been considered in the current safety and performance assessment models. Severe localized corrosion was found at the interfaces between stainless steel and a model nuclear waste glass and between stainless steel and a ceramic waste form. The accelerated corrosion can be attributed to changes of solution chemistry and local acidity/alkalinity within a confined space, which significantly alter the corrosion of both the waste-form materials and the metallic canisters. The corrosion that is accelerated by the interface interaction between dissimilar materials could profoundly impact the service life of the nuclear waste packages, which, therefore, should be carefully considered when evaluating the performance of waste forms and their packages. Moreover, compatible barriers should be selected to further optimize the performance of the geological repository system. Immobilization of radionuclides in glass or ceramic forms in stainless steel in deep geological repositories is planned in the US for disposal of nuclear waste. Under simulated repository conditions, corrosion could be significantly accelerated at the interfaces of different barrier materials.

The solubility behavior and solution chemistry of CL-20/MTNP (2,4,6,8,10,12-hexanitro-hexaaza-isowurtzitane/1-methyl-3,4,5-trinitropyrazole) energetic cocrystals in organic solvents were first investigated to offer some important information on thermodynamics. The phase solubility diagram (PSD) and eutectic point (Keu1) of three solvents were also determined. Moreover, the solubility behavior of CL-20/MTNP energetic cocrystals was explained using the solubility product and solution complexation theories. The solution complexation results indicated that the CL-20/MTNP cocrystal has the strongest complexation effect in ethanol. The Keu1 values were all below 1 in three studied solvents, suggesting that the CL-20/MTNP cocrystal was less soluble than the other two pure components. Furthermore, studying the solubility behavior and solution chemistry of the CL-20/MTNP cocrystals has provided further insights into the screening, preparation and scaling-up of energetic cocrystals.

The effects of model proteins (OVA: ovalbumin and BSA: bovine serum albumin) on the colloidal stability of graphene oxide (GO) with different lateral sizes (around 1000, 500, 350 and 200 nm, respectively) were investigated. At low salt concentrations, the aggregation rate (k) of GO displayed a parabolic relationship: it increased until kfast (regime I), remained at kfast (regime II), and then decreased gradually to zero (regime III), with the increase of protein concentrations at environmental pH (4, 6 and 9). Compared to BSA, much higher concentrations of OVA were needed to achieve similar effects on GO stability induced by BSA, since OVA has a smaller molecular size and fewer positively charged groups. In regime I, the k of GO increased with the increase of lateral size at the same concentration of proteins, and a higher dosage of proteins was needed to drive k to kfast for smaller sized GO. However, there was no such lateral size dependent effect in regime III, which was attributed to the predominance of steric repulsion caused by the large amount of proteins. In regime I, GO displayed higher stability at higher pH, and thus more proteins were required to drive k to kfast. In regime III, the proteins were more effective in stabilizing GO under higher pH conditions due to the enhanced electrostatic and steric repulsion. This study highlights the crucial effects of the GO lateral size, protein properties and concentrations, as well as solution chemistry, on GO stability in aquatic environments.

To compare photodegradation processes in single- and binary-contaminant systems, a representative antibiotic (tetracycline) and insecticide (imidacloprid) were employed as two contaminants of emerging concern. Ag/AgBr modified BiOBr was synthesized hydrothermally in an ionic-liquid/water medium and characterized via various techniques to support mechanistic studies. As-prepared flower-shaped Ag/AgBr/BiOBr exhibits superior photocatalytic activity to Ag/AgBr and BiOBr. Parallel experiments were conducted in single-contaminant systems to optimize the solution chemistry for comparison studies; these suggested that the photodegradation rate (DR) is highest at 1.0 g L−1 at catalyst dosages ranging from 0.6 to 1.4 g L−1, while raising the initial concentration reduces the DR. Additionally, electrostatic interactions between the reactants and photocatalyst cause DR fluctuations at different pH values. In the mechanistic studies, the contributions of the dominant active species (˙O2− and h+) were analysed quantitatively through quenching tests with scavengers. Furthermore, electrostatic interactions between the reactants and the active species result in non-equilibrated contributions from ˙O2− and h+ in single-contaminant systems. Comparison studies distinctly demonstrated a synergistic effect in binary-contaminant systems, which is caused by the mutually complementary utilization of h+ and ˙O2− during the photodegradation of tetracycline and imidacloprid.

The V-Cr-Fe ternary slime is an emerging heavy metal waste after a series of pyro- and hydro-metallurgical processes (so called “slime of the slag”), usually containing considerable metal resources and nearly 70 wt% H2O inside. In this study, a facile leaching-complexation method is proposed for the cleaner, efficient and selective recovery of V, Cr and Fe. After efficient leaching procedure in the H2SO4 solution, 94% V and 97% Fe were selectively precipitated out via the complexation with C5H10NNaS2. Subsequently, the V and Fe could be further separated through the dissociation in alkaline solution, in which the Fe(OH)3 solid and Ca2V2O7 (with the addition of CaO) were generated, respectively. Furthermore, the complexing agent could be regenerated for next cycles, minimizing the potential secondary wastewater or solid waste formation . As a result, a cleaner and sustainable metal recovery method was developed, providing further understanding of the solution chemistry and separation technologies.

With the special focus to obtain a new tridentate ligand able to coordinate Fe(III), 3-hydroxy-2-(5'-hydroxypentyl)-4H-pyran-4-one (5-H) has been synthesized. Iron/ligand solution chemistry has been investigated in aqueous solution by ESI-MS and cyclic voltammetric measurements. The physiologic predominant specie is the tris-chelate complex as Job test attested. The electrode potential of the [FeIII(5)3]/[FeII(5)3]– couple was evaluated to be –0.54 V vs. SCE, pH 7.4.

The intramolecular dehalogenation reaction as an essential step is generally involved in the deprotection of carbon–carbon double bonds in solution chemistry. However, harsh reaction conditions oft...

Mg-Al layered double hydroxides (LDHs) were synthesized and applied to soils to control phosphorus (P) loss. Saturated soil column experiments and numerical modeling were conducted to investigate the transport, retention, and release behavior of P in natural soil with and without mixing LDHs under various solution chemistries. Retention of P in the soil increased with the addition of 0.5% LDHs and in the presence of Ca2+ in comparison to K+. The simulated results showed that irreversible retention of P is greater in the presence of Ca2+ than K+ in soil without LDHs and in the presence of 0.5% LDHs in comparison to the absence. The increase of ionic strength (IS) for K+ from 1 to 100 mM resulted in increased P retention in LDH-soil system due to more inner-sphere complexes and increased adhesive force. Near equilibrium retention on the reversible site occurred for all these experiments. The P was desorbed and the transport of dissolved P was improved with the reduction of IS in the presence of K+. On the other side, larger ion exchange and reduction of IS in the presence of Ca2+ induced the release of Fe/Al oxides which brought transport of P absorbed on those minerals, suggesting the potential for Fe/Al oxides-facilitated transport of P under the change of soil solution chemistry. Additionally, the transport and stability of LDHs in soil column were also investigated. The dissolution and transport of LDHs could be impeded in presence of high cation valence and IS.