E-beam deformation of ceramic particles

Electron irradiation may be a useful method for treating inorganic cosmetic powders such as talc for undesirablemicroorganisms if it can be established that no loss of quality or efficacy results as a consequence of the technique.A commercial electron accelerator was used to prepare bulk samples by exposure to electron irradiation under differentconditions.A morphological characterisation of the control talc was carried out using microscopy techniques and focused on theparticle size, shape and surface features of individual particles. Asperity dimensions vs. Roughness values were compared.Assessment of the bulk properties of the powders as a function of absorbed dose showed no serious impact on the qualityor efficacy of the powder for cosmetic applications. The particle size and the level of dust expelled during impact weremaintained. Changes to the surface chemistry of the irradiated powders were apparent from an increase in pH and waterretention with increasing dose. Improvements to the fragrance retention occurred for both irradiated powders tested.Importantly a satisfactory microorganism level was achieved with the lowest absorbed dose level tested i.e. 5 kGy.