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Agradecimentos: The authors are grateful to FAPESP (Grant 2014/03691-7), CNPq (Grant 147530/2014), and CAPES for financial support and the Microfabrication Laboratory in the Brazilian Nanotechnology National Laboratory for the experimental support Abstract: The development of sensors based on nanostructures is an important task in fundamental and applied sciences to increase their sensitivity and selectivity. A better comprehension of materials aggregation at the nanoscale can provide insights and innovations for sensing and electronic appliances. We analyzed the electrical properties of polyelectrolytes assembled in a multilayered architecture with nanometric thickness control. We have fabricated layer-by-layer (LbL) thin films alternating positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged poly-(styrenesulfonate) (PSS) in a PDDA/PSS architecture. A homemade setup tracked the nanostructure growth by measuring the capacitance after each deposited layer onto gold interdigitated electrodes (IDEs). The capacitance increase linearly after each adsorbed bilayer, which is associated with the dielectric layer accumulated onto the IDEs. We interpreted such behavior in terms of the electrostatic potential on the IDEs, resulting in a dielectric constant of 21 +/- 3 for the PDDA/PSS film. Furthermore, we observed the capacitance changing in a zigzag-like behavior according to the outermost deposited layer due to the charge reversal process. Polycation surface charge density was estimated as (5.8 +/- 0.2) x 10(-20) c/mu m(2). We also analyzed the strong and weak character of PDDA and poly(allylamine hydrochloride) (PAH). The methodology proposed here allows for a better material choice that best suits a particular LbL application. Besides, the quantitative evaluation of the outermost layer charge density should enhance the adsorption of molecules that are routinely employed as active layers in (bio)sensing applications, contributing to improvements in (bio)sensor engineering FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES Fechado

Highly ordered AeBeA block copolymer arrangements in the submicrometric scale, resulting from dewetting and solvent evaporation of thin films, have inspired a variety of new applications in the nanometric world. Despite the progress observed in the control of such structures, the intricate scientific phenomena related to regular patterns formation are still not completely elucidated. SEBS is a standard example of a triblock copolymer that forms spontaneously impressive pattern arrangements. From macroscopic thin liquid films of SEBS solution, several physical effects and phenomena act synergisticallyto achieve well-arranged patterns of stripes and/or droplets. That is, concomitant with dewetting, solvent evaporation, and Marangoni effect, Rayleigh instability and phase separation also play important role in the pattern formation. These two last effects are difficult to be followed experimentally in the nanoscale, which render difficulties to the comprehension of the whole phenomenon. In this paper, we use computational methods for image analysis, which provide quantitative morphometric data of the patterns, specifically comprising stripes fragmentation into droplets. With the help of these computational techniques, we developed an explanation for the final part of the pattern formation, i.e. structural dynamics related to the stripes fragmentation.