Networking and rheology of concentrated clay suspensions “matured” in mineral medicinal water
Metadatos
Mostrar el registro completo del ítemAutor
Aguzzi, Carola; Sánchez Espejo, Rita María; Cerezo González, María Pilar; Machado, José; Bonferoni, Cristina; Rossi, Silvia; Salcedo, Inmaculada; Viseras Iborra, César AntonioMateria
Clay pastes Rheology Pelotherapy Maturarion Mineral medicinal water
Fecha
2013Referencia bibliográfica
Aguzzi, C., Sánchez-Espejo, R., Cerezo, P., Machado, J., Bonferoni, C., Rossi, S., Salcedo, I., Viseras, C. (2013). Networking and rheology of concentrated clay suspensions "matured" in mineral medicinal water. International Journal of Pharmaceutics, 453:(2), 473-479
Resumen
This work studied the influence of “maturation” conditions (time and agitation) on aggregation states, gel
structure and rheological behaviour of a special kind of pharmaceutical semisolid products made of
concentrated clay suspensions in mineral medicinal water. Maturation of the samples was carried out in
distilled and sulphated mineral medicinal water, both in static conditions (without agitation) and with
manual stirring once a week, during a maximum period of three months. At the measured pH interval (7.5–8.0), three-dimensional band-type networks resulting from face/face contacts were predominant in the laminar (disc-like) clay suspensions, whereas the fibrous (rod-like) particles formed micro-aggregates by van der Waals attractions. The high concentration of solids in the studied systems greatly determined their behaviour. Rod-like sepiolite particles tend to align the major axis in aggregates promoted by low shearing maturation, whereas aggregates of disc-like smectite particles did not have a preferential orientation and their complete swelling required long maturation time, being independent of stirring. Maturation of both kinds of suspensions resulted in improved rheological properties. Laminar clay suspensions became more structured with time, independently from static or dynamic maturation conditions, whereas for fibrous clay periodic agitation was also required. Rheological properties of the studied systems have been related to aggregation states and networking mechanisms, depending on the type of clay minerals constituents. Physical stability of the suspensions was not impaired by the specific composition of the Graena medicinal water.