Effect of montmorillonite on properties of nanocomposite coatings

Abstract

Unmodified or chemically modified montmorillonite (MMT) dispersed in water was added into the reaction mixture forming hybrid organic-inorganic (O-I) nanocomposite coating. Two basic systems made from functionalised trialkoxysilane and oligomeric diamine v. functionalised dialkoxysilane and triamine were prepared and compared. End properties depend not only on the concentration and kind of MMT used but also on the inner constitution of the O-I matrix. Already 1 wt-% of unmodified MMT influences considerably surface and mechanical properties, but the effect of chemically modified MMT is not so pronounced. This can be due to worse dispersion (scattering) of chemically modified MMT within the O-I matrix compared with unmodified one: while unmodified MMT is partially intercalated, partially exfoliated in the product, substantial amount of original, unaffected MMT clusters was found there. Solid state nuclear magnetic resonance spectroscopy confirmed the interaction of MMT platelets with the O-I matrix.

The influence of nanoadditives on surface, permeability and mechanical properties of self-organized organic–inorganic nanocomposite coatings

“…Even the small amounts (0.5 wt%) of the different nanoadditives studied in this work led to distinct differences in surface topography and roughness of the coating films prepared. In our previous work 15, [17][18][19] we have already shown that the relief of coatings without any additive or of such filled with varying contents of colloidal silica is very regular even in sub-micrometer scale. If any layered nanoadditive (LN) is used as an admixture, the relief becomes more rugged and the individual layers are typically clustered to self-assembled formations of different size and shape, depending on the type of LN used.…”

“…These effects were caused by incorporation of nanofillers, namely of 5-20 wt% SiO 2 15,17-19 or of 1-5 wt% of montmorillonites MNa or K30. [18][19][20] In the present work, the influence of silicate nanofillers at a much lower concentration, 0.5 wt%, was studied, with special interest on two newly tested montmorillonite nanofillers, bentonite for water systems (BW) and laponite (LX). The 13 C CP/MAS NMR spectra confirm the expected chemical composition and make possible to evaluate the conversion of epoxy-amine addition (step 2 of matrix synthesis).…”

“…9,10,[12][13][14] Recently we prepared and characterized series of O-I nanocomposite coatings with inorganic filler prepared by both above-mentioned methods, i.e., inorganic structure in situ built-up and nanofiller addition. As filler, colloidal silica was used in the concentration from 5 to 20 wt% [15][16][17][18][19] and montmorillonites at concentration from 1 to 5 wt%. [18][19][20] The present work is aimed at studying the effect of a really small inorganic nanofiller amount, 0.5 wt%, in composites with an organic inorganic hybrid matrix.…”

“…As filler, colloidal silica was used in the concentration from 5 to 20 wt% [15][16][17][18][19] and montmorillonites at concentration from 1 to 5 wt%. [18][19][20] The present work is aimed at studying the effect of a really small inorganic nanofiller amount, 0.5 wt%, in composites with an organic inorganic hybrid matrix. A set of nanofillers of the montmorillonite (layered silicates) family was compared, including unmodified and chemically modified montmorillonite, bentonite for water systems and laponite.…”

The role of organic modification of layered nanosilicates on mechanical and surface properties of organic–inorganic coatings

“…As nanofiller, colloidal silica (in concentrations from 0.5 to 20 wt% [24][25][26][27] ) and unmodified and several chemically modified montmorillonites at concentrations ranging from 0.5 to 5 wt% [26][27][28] were used. The previous study by the authors 27 was aimed at studying the effect of small amounts of inorganic nanofillers on the nanocomposite properties.…”