Microscopia de varredura por sonda mecânica: uma introdução

Abstract

A análise estrutural de materiais experimentou um grande avanço nos últimos anos, associado ao desenvolvimento das técnicas de Microscopia de Varredura por Sonda Mecânica, surgidas na década passada e consolidadas nos anos 90. Trata-se de um enfoque analítico inteiramente original, envolvendo conhecimento e tecnologia multidisciplinar, de amplo espectro de aplicação, devido, principalmente, à resolução em escala nanométrica, à facilidade de operação ao ar, em meio líquido e em vácuo e à possibilidade de grandes ampliações na direção z. Neste artigo, são descritos os princípios básicos das técnicas mais utilizadas, ilustrados através de exemplos de trabalhos realizados pelo grupo do Laboratório de Nanoscopia da Fundação Centro Tecnológico de Minas Gerais - CETEC. São apresentados exemplos obtidos em diversas tipos de materiais, visando mostrar a potencialidade destas novas técnicas de análise nanoestrutural.

Biocompatible oil core nanocapsules as potential co-carriers of paclitaxel and fluorescent markers: preparation, characterization, and bioimaging

“…The appropriate morphology of nanocarriers is crucial in the designing of drug delivery systems used in diagnosis and therapy. AFM is a technique, with dimensional resolutions from 0.1 up to 10 nm, that offers a unique chance for visualizing nanoparticles in natural surroundings [ 35 ]. Furthermore, it allows direct measurement of size in dried state of probes, which lets contemporary characterization of nanoconstructs’ shape and structure.…”

The use of atomic force microscopy as an important technique to analyze the dispersion of nanometric fillers and morphology in nanocomposites and polymer blends based on elastomers

“…When the tip passes through a sample, the oscillation phase can change according to the different interaction conditions between the tip and the sample, resulting in phase image contrast [70] , and it is commonly used to distinguish different domains or different blend components [18] . According to Bokobza et al [71] , phase imaging provides variation of surface stiffness arising from differences in moduli between the components of a given system.…”

PLA-PEG nanocapsules radiolabeled with 99mTechnetium-HMPAO: Release properties and physicochemical characterization by atomic force microscopy and photon correlation spectroscopy

“…AFM is a powerful technique, with dimensional resolutions from 1 up to 100 Å, that provides a unique possibility for visualizing nanoparticles in a natural environment, without sample manipulation (Neves et al, 1998). While PCS measures hydrodynamic radius, the AFM technique allows direct measurement of size in samples in a partially dried state, deposited on freshly cleaved mica plates, which permits simultaneous characterization of particle shape and structure.…”