Factors influencing polybutadiene deposition within porous chromatographic zirconia

We have studied the effect of the conditions for the deposition of polymers in the preparation of polybutadiene-coated porous zirconia particles for reversed-phase chromatography. Chromatographic performance improves when the particle surface is pre-coated with elemental carbon by a chemical vapor deposition (CVD) process. Conversely, performance is significantly degraded when the solvent is removed very slowly during the deposition process. No improvement results when the particles are coated using small sequential loads of polymer. We hypothesize that the polymer deposition process is controlled by the rate at which the solvent meniscus recedes during solvent evaporation, by the affinity of the polymer for the zirconia surface, and by polymer-solvent and polymer-polymer interactions.