Submicrometer characterization of surfaces of epoxy‐based organic–inorganic nanocomposite coatings. A comparison of AFM study with currently used testing techniques

Abstract

Surface properties (morphology, hardness) of transparent colorless epoxy-based organic-inorganic nanocomposite coatings were investigated by atomic force microscopy, optical and scanning electron microscopy, nanoindentation, and the Persoz pendulum test. Friction and wear coefficients were obtained from tribological experiments. The influence of mechanical properties and the size, shape, and concentration of additives (colloidal silica particles and montmorillonite sheets) on the measured surface characteristics are discussed. It was found that the highest surface hardness (assigned by nanoindentation, pendulum test or expressed as the scratch resistance) exhibited materials with the glasstransition temperature close to 208C. Microcopy techniques revealed that surface morphology is influenced by both types of admixtures: on the nanometer scale by colloidal silica particles and on micrometer scale by montmorillonite platelets. Already 1 wt % of montmorillonite increased friction coefficients and wear resistance without distinctive changes of tensile properties. However, the addition of $ 20 wt. % of silica nanoparticles was necessary for the increase of wear and scratch resistances.

Thermal degradation and flammability of P/Si polysilsesquioxane epoxy nanocomposites

“…The characterization of the structure of nanocomposites Figure 2 illustrated that the solid-state 29 Si-NMR spectra of nanocomposite, which assigned to the T and Q groups of the silsesquioxane characteristic peak. The T and Q structures are shown in Scheme 3.…”

“…Solid-state 29 Si-NMR analysis was performed with a Bruker DSX 400WB (400 MHz) NMR spectrometer. TGA was conducted with a Thermal Analysis TGA-951 thermogravimetric analyzer at various heating rates (5, 10, 15, 20, and 30 C/min) under nitrogen atmosphere.…”

Effect of montmorillonite on properties of nanocomposite coatings

“…heterogeneities on nm size with roughness of units nm) were characteristics for O-I matrices without any nanoadditives. 12 The relief of the modified samples (2D and 3D images) shows MMT platelets rising from the O-I matrix (Fig. 5).…”

“…Colourless and transparent products can be prepared, which are in the glassy, main transition or rubbery state at 23uC (depending on the material and preparation technique used). [8][9][10][11][12] In this contribution, the influence of the concentration of two different commercial montmorillonite platelets, unmodified MMT (i.e. natural MMT containing Na z counter ions in the interlayer), and chemically modified MMT (i.e.…”

AFM Applications in Micro/Nanostructured Coatings

“…Spirkova et al applied several techniques to evaluate surface properties (morphology, hardness, wear) of organic-inorganic nanocomposite coatings prepared from silicon-containing precursors and Jeffamines (119). They indicated that the current AFM methods are applicable not only for the determination of surface topography, but also for the scratch resistance determination.…”