Derrick S. Dlamini

Effect of Cross-Linking Agent Chemistry and Coating Conditions on Physical, Chemical, and Separation Properties of PVA-Psf Composite Membranes

Composite nanofiltration membranes were formed by depositing ultra-thin, cross-linked polyvinyl alcohol (PVA) film on porous polysulfone (PSf) support membranes following a three step dip-coating procedure. The PVA coating films were cross-linked with aliphatic tricarboxylic acids (cis-/trans-aconitic) and aromatic dicarboxylic acids (phthalic, isophthalic, and terephthalic). Tricarboxylic acid cross-linked PVA was less crystalline and slightly more hydrophilic relative to PVA films cross-linked by aromatic dicarboxylic acids suggesting that the tricarboxylic acids are more effective is disrupting PVA crystallinity than the dicarboxylic acids. Cross-linked PVA-PSf composite membranes rejected NaCl and MgSO4 in the order: trans-aconitic acid < cis-aconitic acid < terephthalic acid < isophthalic acid < phthalic acid.

Comparative studies of the morphological and thermal properties of clay/polymer nanocomposites synthesized via melt blending and modified solution blending methods

In this study, EVA/clay nanocomposites were prepared by two different methodologies i.e. melt blend technique and solution blend technique. Comparative analyzes of morphological and thermal properties of the nanocomposites fabricated by two different methods were done. The modified solution method was found to be an efficient method to obtain nanocomposite strips with uniform dispersion of the clay at organoclay loading of 8% and crystallinity by extrusion. The melt blending method produced nanocomposites with high porosity, intercalation, and thermal stability, whereas solution blending technique resulted in composites with more intercalated-exfoliated morphology, and less porosity and thermal stability.