Dense stable suspensions of medium-chain-length poly(3-hydroxyalkanoate) nanoparticles

作者：Peprah Benjamin A; Ramsay Juliana A; Ramsay Bruce A^*

来源：European Polymer Journal, 2016, 84: 137-146.

DOI：10.1016/j.eurpolymj.2016.09.015

• Suspension
• Medium-chain-length
• poly(3-hydroxyalkanoate)
• Mcl-PHA
• Nanoparticles
• Zeta potential
• Surfactant
• Latex

This is the first study to examine the formulation (selection of ionic and nonionic surfactants and their concentrations) and processing conditions (ultrasonication time and amplitude, and selection of solvent) to make dense suspensions (10 and 30% (w/v)) of medium-chain-length poly(3-hydroxyalkanoate) (mcl-PHA) with particles less than 300 nm. A two-stage emulsification-solvent evaporation process was used. Previous studies made suspensions at much lower solids content (up to 0.4% (w/v)). The dispersed phase was mcl-PHA initially dissolved in methylene chloride, while the continuous phase was water containing one or more surfactants. Water miscible solvents, such as acetone and tetrahydrofuran, could not make dense suspensions of PHA nanoparticles, while those with low water solubility were effective. Among the ionic surfactants, the anionic, sodium dodecyl sulfate (SDS), and the cationic, dodecyltrimethylammonium bromide, produced the smallest particle sizes (both similar to 100 nm). Nanoparticles were more stable when SDS was combined with any of the non-ionic surfactants tested. The zeta potential of nanoparticles stabilized with SDS and polyoxyethylene octyl phenyl ether (Triton X-100) or polyoxyethylene (20) sorbitan monooleate (Tween 80) increased slightly over 30 days, indicating that they may be more effective than the other non-ionic surfactants stabilizers where a decrease was observed. Using the same surfactant formulation, similar size mcl-PHA stable nanoparticle suspensions were produced using either an ultrasonic probe or a more scalable high-shear microfluidic device.

• 出版日期2016-11