A polyelectrolyte-based system for separating charged particulates from aqueous biological suspensions

Recovery of high-value products from disintegrated cellular biomass such as microalgae is challenging due to the complex nature of the resulting multi-component multi-phase matrix. In this paper, we report a simple technique to separate a select component form such a mixture utilizing specific surface charges particles would carry. To demonstrate the process, negatively charged carboxylate-functionalized cellulose model particles (resembling algal cell surfaces) are used. The process involves addition of a water soluble cationic polyelectrolyte, Mono/Poly-(diallyldimethyleammonium chloride) (DADMAC/PolyDADMAC) to interact with the negatively charged beads and transpose the hydrophobicity of the beads which in turn mobilizes the bead-bound polyelectrolyte ensemble away from aqueous phase to an adjacently placed hydrophobic solvent, hexane. Results indicate that when the polymer is used at acidic pH conditions, the amount of surface-functionalized beads migrated more as compared to the monomer at basic conditions. It was also observed that the amount of beads migrated correlated positively with time. These results are interesting to the fact that such a technique can be developed to separate carbohydrate, protein and lipid-rich fractions from complex mixtures likely based on inherent charges these components carry in solution.

A polyelectrolyte-based system for separating charged particulates from aqueous biological suspensions Conference Paper