Ethylene absorption in N-methyl-2-pyrrolidone/silver nano-solvent:Thermodynamics and kinetics study

The effect of presence of silver nanoparticles in pure N-methyl-2-pyrrolidone(NMP)solvent for ethylene gas absorption in an experimental pressure decaying setup has been investigated.All experiments were performed at temperatures of 278.15 K,298.15 K and 328.15 K and different pressures(up to ethylene dew point)as well as different concentrations of silver nanoparticles(0.05 g·L^(-1) and 0.1 g·L^(-1)).The kinetic data of absorption,Henry’s law constants,and heat of absorption were calculated.Comparison of the pure solvent and the nanofluids absorption results revealed that the presence of small amounts of nanoparticles could improve the absorption performance between 1.5%-18%.Finally,the effect of temperature,pressure,and nanoparticle concentration on the equilibrium results were investigated.

Dissolution and recrystallization of perovskite induced by N-methyl-2-pyrrolidone in a closed steam annealing method

High quality perovskite films with large columnar grains are greatly desired for efficient perovskite solar cells. Here, low volatility N-methyl-2-pyrrolidone(NMP) was added in MAI/IPA solution in a two-step spin-coating method, which promoted the conversion of lead iodide to perovskite. The perovskite films were annealed by a closed-steam annealing method to prolong the recrystallization process of perovskite films assisted by the residual NMP. It leaded to high quality CH_3NH_3PbI_3 perovskite films with large columnar grains due to its enhancement of the Oswald ripening. The large grain perovskite film leaded to efficient carrier transformation and injection, and low recombination. The photovoltaic performance of the perovskite solar cells was improved significantly.

Excess Molar Volumes and Viscosities of Binary Mixtures of p-Xylene with Cyclohexane, n-Heptane, n-Octane, Sulfolane, N-Methyl-2-pyrrolidone and Acetic Acid at 303.15 K and 323.15 K and Atmospheric Pressure

Experimental data on density and viscosity at 303.15K and 323.15K are presented for the binary mixtures of p-xylene with cyclohexane, n-heptane, n-octane, sulfolane, N-methyl-2-pyrrolidone and acetic acid.From these data, the excess molar volume and deviations in viscosity have been calculated. The computed quantities have been fitted to the Redlich-Kister Equation to derive coefficients and estimate the standard error values. Results are discussed in terms of intermolecular interactions.

Framework-solvent interactional mechanism and effect of NMP/DMF on solvothermal synthesis of [Zn_4O(BDC)_3]_8

In order to explore the effect mechanism of solvent on the synthesis of the metal organic framework materials, the microscopic interaction between solvent and framework and the effects of N,N-dimethyl-formamide(DMF) or N-methyl- 2-pyrrolidone(NMP) on solvothermal synthesis of [Zn4O(BDC)3]8 were investigated through a combined DFT and experimental study. XRD and SEM showed that the absorbability of NMP in the pore of [Zn4O(BDC)3]8 was weaker than that of DMF. The thermal decomposition temperature of [Zn4O(BDC)3]8 synthesized in DMF was higher than that in NMP according to TG and FT-IR. In addition, the nitrogen sorption isotherms indicated that NMP improved gas sorption property of [Zn4O(BDC)3]8. The COSMO optimized calculations indicated that the total energy of Zn4O(BDC)3 in NMP was higher than that in DMF, and compared with non-solvent system, the charge of zinc atoms decreased and the charge value was the smallest in NMP. Furthermore, the interaction of DMF, NMP or DEF in [Zn4O(BDC)3]8 crystal model was calculated by DFT method. The results suggested that NMP should be easier to be removed from pore of materials than DMF from the point of view of energy state. It can be concluded that NMP was a favorable solvent to synthesize [Zn4O(BDC)3]8 and the microscopic mechanism was that the binding force between Zn4O(BDC)3 and NMP molecule was weaker than DMF.

Effective N-methyl-2-pyrrolidone wet cleaning for fabricating highperformance monolayer MoS2 transistors

Two-dimensional semiconductors,such as MoS2 are known to be highly susceptible to diverse molecular adsorbates on the surface during fabrication,which could adversely affect device performance.To ensure high device yield,uniformity and performance,the semiconductor industry has long employed wet chemical cleaning strategies to remove undesirable surface contaminations,adsorbates,and native oxides from the surface of Si wafers.A similarly effective surface cleaning technique for two-dimensional materials has not yet been fully developed.In this study,we propose a wet chemical cleaning strategy for MoS2 by using N-methyl-2-pyrrolidone.The cleaning process not only preserves the intrinsic properties of monolayer MoS2,but also significantly improves the performance of monolayer MoS2 field-effect-transistors.Superior device on current of 12 μA·μm-1 for a channel length of 400 nm,contact resistance of 15 kΩ·μm,field-effect mobility of 15.5 cm^2·V^-1·s^-1,and the average on-off current ratio of 10^8 were successfully demonstrated.

High-performance PVDF-HFP based gel polymer electrolyte with a safe solvent in Li metal polymer battery

Poly(vinylidenefluoride-co-hexafluoropropylene)(PVDF-HFP)based gel polymer electrolytes are widely studied owing to their electrochemical stability and high dielectric constant.However,most gel polymer electrolytes show unsatisfied safety and interface compatibility due to excessive absorption of volatile and flammable liquid solvents.Herein,by using a safe solvent(N-methyl-2-pyrrolidone)with higher boiling(203℃)and flash points(95℃),we initiatively fabricate a flexible PVDF-HFP based gel polymer electrolyte.The obtained gel polymer electrolyte demonstrates a high ionic conductivity of 7.24×10^−4 S cm−1,an electrochemical window of 5.2 V,and a high lithium transference number of 0.57.As a result,the synthesized polymer electrolyte exhibits a capacity retention of 70%after 500 cycles at 0.5 C,and a discharge capacity of 86 mAh g−1 even at a high current rate of 10 C for LiFePO4 based Li metal batteries.Moreover,a stable Li plating/stripping for more than 500 h is achieved under 0.1 mAh at both room temperature and 70℃.Our results indicate that the PVDF-HFP polymer electrolyte is promising for manufacturing safe and high-performance Li metal polymer batteries.

A novel family of green ionic liquids with surface activities

Ionic liquids have many unique properties as a new and remarkable class of environmental benign solvents,which promises widespread applications in industry and other areas. However,the ionic liq-uids with surface activity are rarely reported. In this work,a series of novel ionic liquids was synthe-sized by using N-methyl-2-pyrrolidone and alkyl bromide. The physical properties of this family of ionic liquids have been characterized,which shows that these compounds have ionic liquids characteristics,surface activity and biocompatibility.