Open Access. Powered by Scholars. Published by Universities.®

Membrane Science Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 7 of 7

Full-Text Articles in Membrane Science

Performance Evaluation On Vanadium Transport Through Supported Liquid Membrane By Tomac As Carrier, Somayyeh Nosrati Dr, N S. Jayakumar Dr, Mohd Ali Hashim Dr, Soumyadeep Mukhopadhyay Dr Jan 2013

Performance Evaluation On Vanadium Transport Through Supported Liquid Membrane By Tomac As Carrier, Somayyeh Nosrati Dr, N S. Jayakumar Dr, Mohd Ali Hashim Dr, Soumyadeep Mukhopadhyay Dr

Soumyadeep Mukhopadhyay Dr

Many industries use vanadium increasingly and as a consequence, the toxic effluents cause environmental concern. Here, we study the extraction of vanadium in supported ionic liquid membrane was studied. The effect of operational conditions on the process performance such as initial feed phase concentration, pH of the feed solution, pore size of the membrane support, type of ionic liquid charged on the support and stripping agent solution was investigated. Vanadium was effectively transported from the feed phase to the stripping phase of ammonia solution using the room temperature ionic liquid, tri-n-octyl methyl ammonium chloride (TOMAC) embedded in the support membrane. …


Behavior Of Hydrophobic Ionic Liquids As Liquid Membranes On Phenol Removal: Experimental Study And Optimization, Yee Sern Ng, Jayakumar Natesan Subramaniam, Mohd Ali Hashim Jan 2011

Behavior Of Hydrophobic Ionic Liquids As Liquid Membranes On Phenol Removal: Experimental Study And Optimization, Yee Sern Ng, Jayakumar Natesan Subramaniam, Mohd Ali Hashim

Ng Yee-Sern

Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also …


Performance Evaluation Of Organic Emulsion Liquid Membrane On Phenol Removal, Yee Sern Ng, Jayakumar Natesan Subramaniam, Mohd Ali Hashim Jan 2010

Performance Evaluation Of Organic Emulsion Liquid Membrane On Phenol Removal, Yee Sern Ng, Jayakumar Natesan Subramaniam, Mohd Ali Hashim

Ng Yee-Sern

The percentage removal of phenol from aqueous solution by emulsion liquid membrane and emulsion leakage was investigated experimentally for various parameters such as membrane:internal phase ratio, membrane:external phase ratio, emulsification speed, emulsification time, carrier concentration, surfactant concentration and internal agent concentration. These parameters strongly influence the percentage removal of phenol and emulsion leakage. Under optimum membrane properties, the percentage removal of phenol was as high as 98.33%, with emulsion leakage of 1.25%. It was also found that the necessity of carrier for enhancing phenol removal was strongly dependent on the internal agent concentration.


Dynamics Of Individual Molecules Of Linear Polyethylene Liquids Under Shear: Atomistic Simulation And Comparison With A Free-Draining Bead-Rod Chain, David Keffer, J. M. Kim, B. J. Edwards, B. Khomami Jan 2010

Dynamics Of Individual Molecules Of Linear Polyethylene Liquids Under Shear: Atomistic Simulation And Comparison With A Free-Draining Bead-Rod Chain, David Keffer, J. M. Kim, B. J. Edwards, B. Khomami

David Keffer

Nonequilibrium molecular dynamics (NEMD) simulations of a dense liquid composed of linear polyethylene chains were performed to investigate the chain dynamics under shear. Brownian dynamics (BD) simulations of a freely jointed chain with equivalent contour length were also performed in the case of a dilute solution. This allowed for a close comparison of the chain dynamics of similar molecules for two very different types of liquids. Both simulations exhibited a distribution of the end-to-end vector, |Rete|, with Gaussian behavior at low Weissenberg number (Wi). At high Wi, the NEMD distribution was bimodal, with two peaks …


Self-Consistent Multiscale Modeling In The Presence Of Inhomogeneous Fields, David Keffer Jan 2009

Self-Consistent Multiscale Modeling In The Presence Of Inhomogeneous Fields, David Keffer

David Keffer

Molecular dynamics (MD) simulations of a Lennard–Jones fluid in an inhomogeneous external field generate steady-state profiles of density and pressure with nanoscopic heterogeneities. The continuum level of mass, momentum, and energy transport balances is capable of reproducing the MD profiles only when the equation of state for pressure as a function of density is extracted directly from the molecular level of description. We show that the density profile resulting from simulation is consistent with both a molecular-level theoretical prediction from statistical mechanics as well as the solution of the continuum-level set of differential equations describing the conservation of mass and …


Atomistic Simulation Of Energetic And Entropic Elasticity In Short-Chain Polyethylenes, David Keffer, T. C. Ionescu, V. G. Mavrantzas, B. J. Edwards Jan 2008

Atomistic Simulation Of Energetic And Entropic Elasticity In Short-Chain Polyethylenes, David Keffer, T. C. Ionescu, V. G. Mavrantzas, B. J. Edwards

David Keffer

The thermodynamical aspects of polymeric liquids subjected to uniaxial elongational flow are examined using atomistically detailed nonequilibrium Monte Carlo simulations. In particular, attention is paid to the energetic effects, in addition to the entropic ones, which occur under conditions of extreme deformation. Atomistic nonequilibrium Monte Carlo simulations of linear polyethylene systems, ranging in molecular length from C24 to C78 and for temperatures from 300 to 450 K, demonstrate clear contributions of energetic effects to the elasticity of the system. These are manifested in a conformationally dependent heat capacity, which is significant under large deformations. Violations of the hypothesis …


Energetic And Entropic Elasticity Of Nonisothermal Flowing Polymers: Experiment, Theory, And Simulation, David Keffer, T. C. Ionescu, B. J. Edwards, V. G. Mavrantzas Jan 2008

Energetic And Entropic Elasticity Of Nonisothermal Flowing Polymers: Experiment, Theory, And Simulation, David Keffer, T. C. Ionescu, B. J. Edwards, V. G. Mavrantzas

David Keffer

The thermodynamical aspects of polymeric liquids subjected to nonisothermal flow are examined from the complementary perspectives of theory, experiment, and simulation. In particular, attention is paid to the energetic effects, in addition to the entropic ones, that occur under conditions of extreme deformation. Comparisons of experimental measurements of the temperature rise generated under elongational flow at high strain rates with macroscopic finite element simulations offer clear evidence of the persistence and importance of energetic effects under severe deformation. The performance of various forms of the temperature equation are evaluated with regard to experiment, and it is concluded that the standard …