Filmes automontados de cera epicuticular

Abstract

Epicuticular wax (EW) films have a key role in cuticular water transport of plants, which is important to their survive. Self-assembled films from epicuticular wax were prepared to be used as model systems of epicuticular wax films found in plants. In these films were studied their growth uniformity, surface morphology, and hydrophobicity. The films revealed growth uniformity (linear growth) from fifth layer because of an influence of substrate. The surface morphology of the films were found be composed by pores formed by aggregates of EW molecules with fractal form. The increasing in number of film layers resulted in the increase of the number of pores up to a maximum value followed of a decreasing. Such increasing was assigned to the growth of aggregates whereas the decreasing was explained by the increasing of pore sizes, because during the growth of the aggregates the small pores are replaced by large ones. Hydrophobicity increased with the number of layers, which was associated with the increase of the irregularities on the surface produced by the pores and aggregates. In addition, it was noted that the number of pores increases with temperature. This was explained by the increasing in the mobility of EW molecules, which lead to a larger amount of EW molecules deposited on the films. Based on our results and advantages offered by self-assembled films–including control of thickness and structure – this type of film is feasible to be used as a model for studies of cuticular water transport in plants.