This work is an investigation of the effect of different nanofillers: organically modified montmorillonite (MMT), sepiolite (SEP) and nano titanium dioxide (nTiO2) and combination of them in poly(butylene adipate‐co‐terephthalate) (PBAT) films. Thermal morphological and rheological analyses were conducted to explain the behavior of this nanoparticles on O2 and water vapor permeability coefficients, light transmission, and mechanical properties presented in previous study. Thermal stability of the nanocomposites was slightly decreased by the nanofillers presence. Differential scanning calorimetry and X‐ray analyses were carried out to investigate the crystallization behavior of nanocomposites. Transmission electron microscopic analysis showed regular and homogeneous dispersion of the nanoparticles, but scanning electron microscopy showed lack of adhesion in the sepiolite‐PBAT interface. Rheological measurements showed significant increase in both complex viscosity and storage modulus due to interactions between clays and PBAT and the effect of sepiolite and nTiO2 on improving the exfoliation of montmorillonite as synergism between the nanofillers.

The bacteria of the genus Curtobacterium are usually seen as plant pathogen, but some species have been identified as endophytes of different crops and could as such present a potential for disease control and plant growth promotion. We have therefore applied the desorption electrospray ionization mass spectrometry imaging (DESI-MSI) in the direct analysis of living Curtobacterium sp. strain ER1/6 colonies to map the surface metabolites, and electrospray ionization tandem mass spectrometry (ESI-MS/MS) for characterization of these compounds. Several colony-associated metabolites were detected. The ESI-MS/MS showed characteristic fragmentations for phospholipids including the classes of glycerophosphocholine, glycerophosphoglycerol, and glycerophosphoinositol as well as several fatty acids. Although a secure identification was not obtained, many other metabolites were also detected for this bacteria species. Principal component analysis showed that fatty acids were discriminatory for Curtobacterium sp. ER1/6 during inoculation on periwinkle wilt (PW) medium, whereas phospholipids characterize the bacterium when grown on the tryptic soy agar (TSA) medium. Recently, the fast characterization of microbial secondary metabolite biomarkers by desorption electrospray ionization mass spectrometry (DESI-MS) has rapidly increased. 14-17 The DESI-MS is the combination of electrospray ionization mass spectrometry (ESI-MS) and direct sample desorption using a flow of electrosprayed charged droplets bombarding a surface to be analyzed; therefore, it is also applicable to solid samples such as complex biological materials. allowing the determination of the nature of antibiotics and their localizations at the surface of the colonies. 16,26,28,29 In this report, we have used DESI-MSI, allied to the electrospray ionization tandem mass

The image of Transmission Electron Microscopy Micrographs by Mayara Pollyane Calderaro and colleagues shows the morphology of nanobiocomposites: PBAT/hybrid nanofiller‐montmorilonitte, sepiolite, and nanoTiO2. The nanocomposites with isolated nanoclays present tactoids and some agglomerates, while good dispersion of the nanoTiO2 particle is observed in the polymeric matrix. The hybrid nanocomposites show synergism on mechanical and barrier properties due to the dispersion of nanofillers, mainly for the montmorillonite that presented intercalated and exfoliated structures. Doi: https://doi.org/10.1002/app.50414

Neste trabalho foram estudados nanocompósitos de PBAT com TiO2, montimorilonita (MMT) e sepiolita (SEP). Para a avaliação da influência destas nanocargas nas propriedades mecânicas e térmicas do material, foram realizadas análises de resistência à tração, Calorimetria Exploratória Diferencial (DSC) e Análise Termogravimétrica (TGA). Através destas análises foi possível observar que a adição de MMT ocasionou em um aumento do módulo de elasticidade das amostras e que a adição de SEP causou um aumento nas temperaturas de cristalização e fusão (Tc e Tf) e uma diminuição na cristalinidade e nas entalpias de cristalização e de fusão (ΔHc e ΔHf) do nanocompósito em relação ao PBAT puro.