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The article examines the efficacy of okra pod extracts as a natural polymeric flocculant for kaolin suspension. The experiment measures the optimum flocculant dose for kaolin suspension, optimum potential of hydrogen (pH), viscosity, average molecular size and zeta potential of the flocculants. It examines the mechanism of the flocculation process using scanning electron microscope images and water entrapment values of the resultant flocculants, as well as the content of the okra pod extract.

Highlights: [•] First use of the exudate of Acacia nilotica as flocculant for kaolin suspension. [•] The exudate is predominantly carbohydrate having polyelectrolytic character. [•] Flocculation efficiency found to be function of zeta potential and molecular size. [•] Best results are obtained at 25ppm flocculant dose taken between pH 1.6 and 2.6. [Copyright &y& Elsevier]

ABSTRACT Hybrid membranes based on poly(vinyl alcohol) (PVA) of widely different molecular weights and ex situ nanosilica were synthesized and characterized as transdermal delivery device for Diltiazem hydrochloride. Investigations showed that change in PVA molecular weight strongly influenced physico-mechanicals of the hybrids especially at low nanosilica content than at higher levels. As for example at 1 wt %, low molecular weight PVA induced finer dispersion of silica nanoparticles resulting into higher dry state crystallinity and mechanical strength but slightly lower biocompatibility as compared to high molecular weight PVA. Those variations in physico-mechanicals finally affected Diltiazem retention and its elution from those membranes under physiological conditions. Low molecular weight PVA produced highest drug retention as well as slowest yet steady release than both high molecular weight PVA and neat PVA membranes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2076-2086, 2013 [ABSTRACT FROM AUTHOR]