High-pressure spray microcapsules for the control of biofouling zebra mussels
Chemical Product Design and Engineering (CPD&E)
Chemical Product Design & Development - V (CPD&E - 5)
Keywords: Encapsulation, Particles from Gas-Saturated Solutions, Supercritical Spray Process, Zebra Mussel Control, Biofouling
The zebra mussel, Dreissena polymorpha, is an invasive species whose biofouling activity has major impacts on fresh water-dependent industries.
A new control strategy for this pest based on the encapsulation of biocides has been recently proposed. This approach, which exploits the great filtration capabilities of the species, may provide significant economic and environmental benefits over traditional physical and chemical control methods. Previous studies highlighted the potentialities of this strategy, showing that the entrapment of potassium chloride within a matrix of vegetable oil and vegetable wax enhances the toxicity of the salt. However, an economically viable formulation for the toxin-loaded microcapsules has not yet been found. Guaranteeing that the microcapsules have adequate size distribution and retardant power are the major challenges in developing such a method.
PGSS (Particles from Gas-Saturated Solutions) is an established high-pressure process using supercritical carbon dioxide and dissolving it in a melt of the later particle material. By atomization of this saturated melt, a fine powder with a narrow particle size distribution and a defined morphology is produced. A promising method for the encapsulation of chemical agents is adding non-melting particles to the melted material, which solidifies during the spray process covering the active agent. Using this method, the noted deficiencies in the entrapment of biocides for zebra mussel control may be reduced, and the retardant power of the particles may therefore be increased.
In this work, a new formulation of toxin-loaded microcapsules for zebra mussel control was designed, and the potentialities of PGSS in processing such a formulation were evaluated.
Varied spray parameters have been compared to show their effects on particle formation. Microcapsules produced by the PGSS process were then characterised in terms of their microstructure, size distribution and release characteristics and tested for their toxicity through laboratory renewal bioassays.
Preliminary results show that the formulation designed may constitute a competitive strategy for zebra mussel control. Furthermore, there are considerable opportunities to diversify the technology developed both in the control of other invasive species and in aquaculture applications (e.g. delivery of nutrients and antibiotics).
Presented Thursday 20, 15:40 to 16:00, in session Chemical Product Design & Development - V (CPD&E - 5).
