CONICET | Buscador de Institutos y Recursos Humanos

Two different approaches to predict the shape and size of polyvinyl alcohol beads are presented. Beads were obtained by extrusion-dripping of a boric acid-polyvinyl alcohol aqueous solution followed by sol-gel transition in a basic aqueous bath. The size and shape of green, matured and dried beads were measured by optical microscopy and image analysis. Statistical and fluid dynamical approaches were used to fit the experimental data. The shape of green and mature beads was found to depend on the viscosity of the dropping solution and the maturation time, respectively. The shape of dried beads was found to depend on the drying conditions and particle contraction. The size of mature and dried beads was correctly predicted from the operating conditions by means of a statistically developed model and from the ropping solution properties by means of a fluid dynamical approach. Optimal conditions for minimal dried particle size were obtained.