Fozia T. Minhas

Kinetic Study of an Effective Pb(II) Transport through a Bulk Liquid Membrane Containing Calix[6]arene Hexaester Derivative as a Carrier

The article describes transport of Pb(II) through bulk liquid membrane (BLM) containing calix[6]arene hexaester derivative (1) as a carrier. The effect of various parameters such as temperature, carrier concentration, stirring speed and type of solvent on the Pb(II) transport efficiency of the carrier through BLM was evaluated. The activation energy values for the extraction and re-extraction were found as 56.33 kJ mol−1 and 14.79 kJ mol−1, respectively. These values demonstrate that the process is diffusionally controlled by Pb(II). Observations indicate that the membrane entrance and exit rate constants (k1, k2) increase with increasing stirring speed as well as carrier concentration and decrease with increasing temperature. The effect of solvent on k1 and k2 was found to be in the order of CH2Cl2 > CHCl3 > CCl4.

Calix[4]arene Derivative as Copper(II) Carrier in a Bulk Liquid Membrane: A Kinetic Study

A bulk liquid membrane (BLM) experiment was carried out to check the Cu(II) transport efficiency of p-morpholinomethylcalix[4]arene (1) which was used as carrier. Liquid/liquid extraction experiments were also carried out to check the extraction and decomplexation efficiency of carrier 1. It has been observed that the maximum amount of Cu(II) was transported at pH = 12. The mass transfer of Cu(II) was analyzed on the basis of kinetic laws of two consecutive irreversible first order reactions. Thus, the kinetic parameters studied for the transport of Cu(II) were k1, k2, . BLM study revealed that Cu(II) transport increase with increase in concentration of carrier 1 from 1 × 10−5 to 1 × 10−4 M, rise in temperature from 298 to 308 K and at high stirring speed from 90 to 800 rpm. The effect of binary solvents on Cu(II) transport through BLM has also been studied. The values of k1, k2, decrease in the order of dichloromethane-hexane > dichloromethane-diethylether > dichloromethane > dichloromethane-ethylacetate > chloroform. However, dichloromethane was proved as a stable BLM solvent. The activation energy value for the extraction and re-extraction was found as 31.52 and 8.08 kJmol−1, respectively. These values demonstrate that Cu(II) transport is a diffusion controlled process. Thus, 1 was found to be an efficient carrier for Cu(II) transport through BLM.

Hg(II) Transport Through Modified Supported Liquid Membrane

In the present work, 5,11,17,23 tetrakis[(propylthio)methyl]-25,26,27,28-tetrahydroxycalix[4]arene (1) was utilized as Hg(II) selective carrier in supported liquid membrane (SLM) transport. For impregnation of carrier 1, Celgard 2500 and 2400 membranes were utilized as solid support. Influence of solvent type (chloroform, xylene, diphenyl ether, and toluene), as well as anion type (Cl−/NO− 3) was also explored on the transport of Hg(II). Danesi mass transfer model and Ficks first law of diffusion were followed for determining permeability (P) and flux (J) values. From the results of the solvents, it was revealed that permeability values increase in the order of diphenyl ether>chloroform>xylene>toluene. Moreover, Cl− was proved to be more effective co-anion for Hg(II) than NO− 3 due to lipophilicity in membrane phase. Efficient transport across SLM relies upon carrier specificity towards metal ion, appropriate solvent and co-anion. Hence, this study shows that Hg(II) transport is efficient and reproducible through SLM by using carrier 1.

Cellulose acetate/sericin blend membranes for use in dialysis

AbstractThe objective of this research is to synthesize cellulose acetate (CA) based membranes for hemodialysis. It is planned to blend sericin with CA to make CA/sericin blend membranes for examining the increment in dialysis efficiency of CA. Afterwards contact angle measurement, porosity, molecular weight cutoff, pure water flux and water uptake of blend membranes are determined to check the change in CA matrix after modification. Moreover, the surface morphology of CA/sericin blend membranes examined using SEM, AFM and FTIR analysis. These results reveal successful and homogenous blending of sericin in CA. The Bovine Serum Albumin (BSA) rejection and urea clearance of CA/sericin blend membranes were investigated to view their applicability in dialysis operation. Furthermore, concentration of sericin is varied in CA/sericin blend membranes and its impact was inspected on BSA rejection and Urea clearance. It is observable that M4 is showing best results among all prepared membranes. The increase of 7.5% sericin in CA matrix remarkably augments the BSA rejection and urea clearance up to 96 and 60%, respectively. Mainly protein nature of both sericin and BSA is responsible for the notable BSA rejection of CA/sericine blend membranes. Conclusively, the present study is novel and considerably applicable in wide range of dialysis procedure.