Avaliação da dispersão de nanomateriais em cuba de ultrassom e análise de seu potencial fitotóxico

Abstract

Due to their reduced size, nanoparticles (NP) present a high reactivity that could bring toxicity risks. The cellulose nanofiber (CNF) and the multiwall carbon nanotubes functionalized with carboxyl (MWCNT-COOH) are examples of nanomaterials (NMs) and possess size-dependent chemical and physical characteristics. Dispersion is an important process for the NMs suspension s and the most common method that is used for the nanoparticles dispersion is the ultrasonic. However, there are different dispositives to do that. This study has the objective to evaluate the dispersion of NMs, MWCNT-COOH and CNF, in an ultrasonic bath dispersion and analyze the phytotoxicity effects using Lactuca sativa as a vegetal model. We performed the DLS technique to knowledge Hydrodynamic Diameter (HD), Polydispersity Index (PDI) and Zeta Potential (ZP) values. Most of all the concentrations dispersed better in M199+FBS; PDI was variable independent of dispersion medium and ZP was negative in all the groups with a variability between them. We also exposed the seeds of L.sativa to the NMs and we observed a high influence of them in the germination, root size and hypocotyl size. As a conclusion, the ultrasonic bath dispersion presented a great potential of dispersion and the NMs did not present toxicity, however, they had an influence on the evaluated parameters to the L. sativa.