Physical properties of natural deep eutectic solvent and its application in remediation of heavy metal lead in soil.

At present, solvent extraction is an effective method to remove heavy metals from soil, which has certain practical significance. The physical properties such as density, viscosity and conductivity of NADESs with different proportions synthesized based on the double solid components of glycolic acid (GA) and L-proline (L-PRO) and the physical properties of NADESs aqueous solution at the lowest eutectic point (3:1) were studied. The extraction effect of NADESs on soil heavy metal Pb2+ under different conditions was studied. The results showed that under the conditions of atmospheric pressure of 101.33 kPa, the lowest eutectic melting point, DESs concentration of 0.6 mol·L-1, extraction temperature of 313.15 K and extraction time of 4 h, the extraction rate of Pb2+ by NADESs was 95.28%. In addition, the internal structure of DESs was characterized by IR and NMR, which indicated that intermolecular hydrogen bonds were formed. and the interaction between DESs and Pb2+ was analyzed by quantum chemical calculation, which showed that the hydroxyl group of GA was more likely to form coordination bond with Pb2+, and chelation occurred between them. This kind of DESs provides a new idea for the removal of heavy metals in soil.

Hotspots analysis and perspectives of Prussian blue analogues (PBAs) in environment and energy in recent 20 years by CiteSpace.

Prussian blue analogs (PBAs), a type of metal-organic frameworks (MOFs), have attracted much attention because of their large specific surface area, high porosity, easy synthesis, and low cost. This paper presents the first review of PBAs by applying the bibliometric visualization software CiteSpace. The co-occurrence, co-citation, and clustering analysis of 2214 articles in the Web of Science database on the topic of "Prussian blue analogs" over the past 20 years were performed. The results provide a comprehensive overview of the evolution of the research hotspots for this material, and most importantly, it is identified that the research hotspots and trends for PBAs materials are concentrated in the environmental and energy fields. For example, the material is used as an adsorbent or catalyst to reduce pollutants, produce clean energy, or for energy storage applications such as batteries or supercapacitors. Finally, some outlooks are provided on the future research trends of this material in the environmental and energy fields, presenting the challenges faced by this material. For instance, the conductivity and corrosion resistance of the material needs to be improved and secondary contamination should be decreased or even avoided. It is believed that this paper would provide a comprehensive, systematic, and dynamic overview of the research of PBAs, and promote the future research of PBAs in the fields of environment and energy.

Facile synthesis of a hollow Ni-Fe-B nanochain and its enhanced catalytic activity for hydrogen generation from NaBH4 hydrolysis.

A hollow Ni-Fe-B nanochain is successfully synthesized by a galvanic replacement method using a Fe-B nanocomposite and a NiCl2 solution as the template and additional reagent, respectively. Both the concentration of Ni and the morphology of the resulting Ni-Fe-B alloy are controlled by varying the duration of the replacement process during the synthesis. The Ni-Fe-B sample synthesized for 60 min (Ni-Fe-B-60) shows the best catalytic activity at 313 K, with a hydrogen production rate of 4320 mL min-1 gcat -1 and an activation energy for the NaBH4 hydrolysis reaction of 33.7 kJ mol-1. The good performance of Ni-Fe-B-60 towards the hydrolysis of NaBH4 can be ascribed to both hollow nanochain structural and electronic effects. Furthermore, the effects of temperature, catalyst amount, and concentration of NaOH and NaBH4 on the hydrolysis process are systematically studied, and an overall kinetic rate equation is obtained. The hollow Ni-Fe-B nanochain catalyst also shows good reusability characteristics and maintained its initial activity after 5 consecutive cycles.

Nanoscale Ni-B electrocatalyst prepared from nickel ethylenediamine complex for direct ethanol electrocatalytic oxidation.

Ni-B/Cu electrode prepared by the electroless deposition technique of chemical reduction of nickel ethylenediamine complex with BH4- was characterized by SEM, XRD and XPS techniques, respectively, and evaluated using ethanol electrocatalytic oxidation by the method of cyclic voltammetry. The as-prepared Ni-B/Cu electrode exhibited much higher electrocatalytic activity than the Ni-B/Cu electrode obtained via direct reduction of nickel metallic ions. The effects of the nickel ethylenediamine complex can be attributed to both the structural effect and electronic effect. The nickel ethylenediamine complex can not only make an electroless deposition stable and highly dispersed, but also facilitate the formation of more nanoscale microcrystalline Ni on the electrode surface, which increased the electrochemical oxidation activity. Moreover, ethylenediamine influenced the electronic states of Ni and B on the electrode surface, more electrons transfer from the B to Ni that the Ni active sites became more highly unsaturated, which could promote the form of adsorbed active ethanol.

1'-Benzyl-4,4''-bis-(4-chloro-phen-yl)-3-(2,6-dichloro-phen-yl)-1''-methyl-4,5-dihydro-isoxazole-5-spiro-3'-piperidine-5'-spiro-3''-pyrrolidine-2''-spiro-3'''-indoline-2''',4'-dione.

The asymmetric unit of the title compound, C(43)H(34)Cl(4)N(4)O(3), contains two crystallographically independent mol-ecules. In both mol-ecules, the pyrrolidine ring adopts a twist conformation, the oxindole units are slightly distorted from planarity and the isoxazoline ring adopts an envelope conformation. The crystal structure is stabilized by N-H⋯O hydrogen-bonding inter-actions giving one-dimensional chain structures.

(5''E)-1''-Benzyl-1'-methyl-5''-[4-(methyl-sulfan-yl)benzyl-idene]-4'-[4-(methyl-sulfan-yl)phen-yl]dispiro-[indoline-3,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione dichloro-methane solvate.

In the title compound, C(38)H(36)N(3)O(2)S(2)·CH(2)Cl(2), the 2-oxindole ring is almost planar (r.m.s. deviation = 0.032 Å), the pyrrolidine ring adopts a twist conformation and the piperidone ring exists as a chair. Three short C-H⋯O intra-molecular contacts occur. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯N inter-actions. The dichloro-methane solvent mol-ecule is disordered over two orientations in a 0.765 (11):0.235 (11) ratio.

Improvement of the functions of osteoblasts seeded on modified poly(D,L-lactic acid) with poly(aspartic acid).

One of the challenges in the field of tissue engineering is the development of biomaterial/cell interactions. For the purposes of the present study, two molecular weights of poly(aspartic acid) (PASP) were used to modify poly(D,L-lactic acid) (PDLLA) films in order to enhance their cell affinity. The properties of the PDLLA-modified surfaces and the controls were investigated by water contact angle measurement and electron spectroscopy for chemical analysis (ESCA). These data reflect the change in the biocompatibility of modified PDLLA surfaces. Then rat osteoblasts were seeded onto these modified surfaces and on controls to examine their effects on cell adhesion and proliferation. Cell morphologies on these surfaces were studied by scanning electron microscopy (SEM), and cell viability was evaluated with a MTT assay. In addition, differentiated cell function was assessed by measuring alkaline phosphatase (ALP) activity. The results suggest that PASP-modified surfaces may enhance the interactions between osteoblasts and PDLLA films.