Myrciaria floribunda is a species native to the restinga areas of the Atlantic Forest that presents great phenotypic variation in fruits, great socioeconomic importance in regions of natural occurrence and high productive potential. The characterization of heterogeneous populations is crucial for plant selection and breeding programs, since it allows the distinction of superior individuals. The aim of this study was to characterize the reproductive structure of M. floribunda accessions, and to observe the influence of climate and environment on its reproductive process, through floral biology, floral morphoanatomy and reproductive phenology. Apis mellifera and Trigona spinipes are the main floral visitors of cambui. Stigma receptivity lasts up to 5 hours after flower opening and pollen viability was above 90%. Regarding the flower structure, the female sexual organ is monocarpic, the ovary is efferent, bilocular, with two ovules per locule, the inflorescence is fascicle-like and consists of small white flowers, actinomorph symmetry, heteroclamid and monoclines. Plants bloomed irregularly throughout the year, concentrating flowering in two periods of the year with the greatest peaks in March and August, while the greatest fruiting peaks were observed in April and September.

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Morphoanatomy, floral biology and reproductive phenology of Cambuí ( Myrciaria floribunda (H. West ex willd.) O. Berg.)

This article deals with the synthesis and formation of mesoporous titania films by latex beads templating The infiltration of latex template by titanium precursor solution resulted in compact films that generated an inverted pore network resulting from the latex removal as it was observed by Scanning Electron Microscopy (SEM) measurements The goal of this work is to analyze the deposition of latex beads on glassy substrates and eventual infiltration by precursor solution of mesoporous titania The final product was bulky films with porosity in the micrometric scale defined by latex beads The synthesis of latex beads was carried out in the absence of N2 and the titania precursor solution was obtained from the ternary system: HCl/P-123/1 Butanol The characterization of films by SEM was carried out after the removal of latex template by calcination in a tubular oven The appearance of films was compact for 30% V/Vo  dispersion concentration and there was a well-defined pore network observed in the SEM characterization associated with the presence of latex beads that assembles by Solvent Controlled Evaporation (SCE) technique SEM characterization showed that latex beads coated on glass substrates and formed a network structure that could be applied to functional devices like solar cells, catalizers and batteries  It is necessary to decrease the concentration of the dispersion to form films with homogeneous monolayers that become transparent to visible light
KEYWORDS: Nanotechnology, semiconductor oxide, self-structured materials

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Geração de Filmes de Titânia meso-macroporosa por Modelagem de Esferas de Látex

Improvement of porous materials has been one of the goals of nanotechnology. There is an increasingly real need to understand the mechanisms that generate self-structured materials specifically those that originate from colloidal particle templates such as: polymers, silica, titania and silicon. These templates are important to produce devices with industrial applications such as: solar cells, desalinizers, batteries and photonic crystals. One of the main difficulties encountered in the application of colloidal particles is to produce them on a large scale with uniform size and deposit them on flat surfaces so that they can homogeneously cover a substrate forming crystallographic domains on a micrometric scale. The objective of this work is to analyze the formation of nanocrystalline films of titania on metallic surfaces that were characterized by scanning electron microscopy (SEM). The metallic substrates were commercial steel plates found in hardware stores. The substrate was covered with latex beads infiltrated by a precursor solution of titania and subsequently heat treated in a tubular oven at 600 oC for one hour. It is observed that the metallic substrate influences the topography of the mesoporous titania film resulting in a lamellar structure in which  interaction with the external environment is suitable. These results show that the nature of the substrate directly influences the topography of the mesoporous titania, which is no longer hexagonal with ordered pores but lamellar allowing the production of self-cleaning membranes with direct application in civil construction.
KEYWORDS: Colloidal particles, Metallic substrates, Lamelar structure.

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Recobrimento de Superfícies metálicas por Filmes de Titânia meso-macroporosa

The conditions of chemical synthesis can be crucial for polymerization of styrene in such a way that it can be produced latex beads at nanometric range (ϕ < 400nm). In this work, it will be analyzed how the absence of N2 and surfactant will result in colloidal particles with high affinity to agglomerate forming two kinds of nanostructured assemblies: colloidal crystals and nanowires. Four syntheses were realized and four parameters were changed: temperature, impeller speed, and initiator and styrene concentrations. The dispersion was filtered and coated on glass slides by evaporation induced self-assembly (EISA) process. Morphology and topography were observed at Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM) respectively. They show how the synthesis conditions play a vital a role on the formation of self assembly nanostructures that can be applied as templates for sensors and biomaterials devices.

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Walker de Lima Cordeiro

Papers

Analysis of Styrene Polymerization Without Surfactant and N2 Gas in Cylindrical Flask.