Modification to solution-diffusion model for performance prediction of nanofiltration of long-alkyl-chain ionic liquids aqueous solutions based on ion cluster

Mathematical modeling for nanofiltration of ionic liquids(ILs) solutions could assist to understand transfer mechanism and predict experimental values. In this work, modeling by solution-diffusion model for nanofiltration of long-alkyl-chain ILs aqueous solutions was proposed. Molecular simulations were performed to validate the existence of ion cluster in long-alkyl-chain ILs aqueous solution. Based on the results of simulations, parameters used in the solution-diffusion model were modified, such as concentration of ILs and diameter of ion cluster.The modeling process was developed for three long-alkyl-chain ILs aqueous solutions with different concentrations(1-alkyl-3-methylimidazolium chloride: [C6 mim]Cl, [C8 mim]Cl, [C10 mim]Cl). The calculated values obtained from modified solution-diffusion model could well match the experimental values.

Role of temperature gradient in liquid/solid phase solution-diffusion bonding

The liquid-film solution-diffusion bonding of ZCuBe2.5 alloys was conducted using Cu-based alloy powders. The tensile strength of the joint is up to 318 MPa. With the increase of temperature gradient, the bonding time decreases and the interface migration velocity increases remarkably. The appropriate temperature gradient is 5-40 K/cm. Under fixed bonding time, the thickness of diffusion layer increases with the increase of temperature gradient, and this tendency becomes more remarkable with the prolonging of bonding time.

Optimizing Reverse Osmosis Membrane Parameters through the Use of the Solution-Diffusion Model: A Review

When designing and building an optimal reverse osmosis (RO) desalination plant, it is important that engineers select effective membrane parameters for optimal application performance. The membrane selection can determine the success or failure of the entire desalination operation. The objective of this work is to review available membrane types and design parameters that can be selected for optimal application to yield the highest potential for plant operations. Factors such as osmotic pressure, water flux values, and membrane resistance will all be evaluated as functions of membrane parameters. The optimization of these parameters will be determined through the deployment of the solution-diffusion model devolved from the Maxwell Stephan Equation. When applying the solution-diffusion model to evaluate RO membranes, the Maxwell Stephan Equation provides mathematical analysis through which the steps for mass transfer through a RO membrane may be observed and calculated. A practical study of the use of the solution-diffusion model will be discussed. This study uses the diffusion-solution model to evaluate the effectiveness of a variety of Toray RO membranes. This practical application confirms two principal hypotheses when using the diffusion-solution model for membrane evaluation. First, there is an inverse relationship between membrane and water flux rate. Second, there is a proportional linear relationship between overall water flux rate and the applied pressure across a membrane.

Hierarchically microporous membranes for highly energy-efficient gas separations

The implementation of synthetic polymer membranes in gas separations,ranging from natural gas sweetening,hydrogen separation,helium recovery,carbon capture,oxygen/nitrogen enrichment,etc.,has stimulated the vigorous development of high-performance membrane materials.However,size-sieving types of synthetic polymer membranes are frequently subject to a trade-off between permeability and selectivity,primarily due to the lack of ability to boost fractional free volume while simultaneously controlling the micropore size distribution.Herein,we review recent research progress on microporosity manipulation in high-free-volume polymeric gas separation membranes and their gas separation performance,with an emphasis on membranes with hourglass-shaped or bimodally distributed microcavities.State-of-the-art strategies to construct tailorable and hierarchically microporous structures,microporosity characterization,and microcavity architecture that govern gas separation performance are systematically summarized.