NOPR Collection:

Modification of polysulphone with cellulose acetate and application as membranes

1996-05-01T00:00:00Z

Title: Modification of polysulphone with cellulose acetate and application as membranes Authors: Sivakumar, M; Mohan, D; Mohan, V; Lakshmanan, C M Abstract: Ultrafiltration gains significance when certain chemical species present in low concentration have to be selectively removed from a multicomponent mixture containing certain heavy metal ions. Polysulphone is considered as the most promising candidate as ultrafiltration membrane. The use of polysulphonein aqueous separation is restricted due to its high hydrophobic nature. For aqueous separation, the blending of polysulphone with cellulose diacetate in solution medium using polar solvents was attempted. The effects of polymer and additive concentration have been studied. The modified membranes were subjected to pure water permeability and were applied for separation of metal ion in aqueous medium and the results are discussed. Page(s): 184-186

Mathematical modelling and computer simulation of molecular transport of benzene into tetrafluoroethylene/propylene copolymer membranes

1996-05-01T00:00:00Z

Title: Mathematical modelling and computer simulation of molecular transport of benzene into tetrafluoroethylene/propylene copolymer membranes Authors: Aminabhavi, Tejraj M; Phayde, Hemant T S Abstract: Kinetic curves for sorption/desorption cycles have been generated for tetrafluoroethylene/propylene copolymer membranes at 25, 40, 55 and 70⁰C by a gravimetric method. Diffusion coefficients have been obtained from the mathematical relations derived from Fick's relation. Numerical scheme based on the finite difference method has been used to describe the sorption/desorption processes. Theoretical kinetic curves have been compared well with the experimental values before 55% equilibrium saturation. Page(s): 178-183

Use of aromatic polyamide membranes in desalination

1996-05-01T00:00:00Z

Title: Use of aromatic polyamide membranes in desalination Authors: Biware, M V; Ghatge, N D Abstract: Piperazine containing polymers, having no 'H' atom at amide nitrogen have been prepared from diaminobenzanilides and diacid chlorides by low temperature polycondensation method. These polymers have been characterised by inherent viscosity, percent moisture regain, solubility, IR and thermal analysis. Amount of chlorine absorbed by the polyamides has been calculated by titrating polymer suspension with sodium thiosulphate. Membranes were cast from the polymer solution in dimethyl acetamide containing lithium chloride as an additive. These membranes' were studied for reverse osmosis (RO) performance in salt water with and without chlorine containing medium. Page(s): 173-177

An electro-membrane process for dibromopropanol epoxidation

1996-05-01T00:00:00Z

Title: An electro-membrane process for dibromopropanol epoxidation Authors: Manaf, A; Audinos, R Abstract: In this paper, an electro-membrane process has been described which allows to perform cyclodehydrohalogenation of dibromopropanols into epibromhydrin at room temperature. Epoxidation occurs in the stack fitted with ion exchange membranes when a constant direct current is applied on end electrodes. Hydroxyl ions are continuously fed into the reacting cell as bromide ions arelextracted, and it is not necessary with such a membrane reactor, to use a down-stream purification of the epibromhydrin produced. The mass yield in the, reacting cell was 70 ± 5%, due to diffusion of reactants and/or products through the membranes used. Page(s): 168-172