Nanoscale stereometric and fractal evaluation of clathrate formation at quartz surface by atomic force microscopy

Abstract

Abstract The clathrate formation on quartz crystal surface has been analyzed extensively by means of contact angle, Atomic Force Microscopy (AFM) measurements as well as by Fractal Theory (FT). Stereometric and fractal parameters were obtained from topographic maps by AFM and have extensively studied. The main goal was to study the influence of clathrate formation on the morphology and texture of quartz monocrystal conditioned with starch and mono ether amine acetate and the wetting characteristics of the quartz surface. The polished sections were initially conditioned in the isolated presence of each reagent and in the presence of their mixtures and at pH\xa0=\xa010.5. After a sequence of conditioning stages, the quartz surface analyses were carried out ex-situ obtaining the AFM images were by tapping mode. In the presence of a combination of flotation reagents under different conditions, 2D topographic maps, morphology photosimulations, and 3D topographic details revealed that there was formation of agglomerates on the surface of the monocrystal for quartz surface conditioned initially with starch (100\xa0mg L−1) and with addition of the mono ether amine acetate (50\xa0mg L−1). However, for the mixture containing higher concentrations of starch (1000\xa0mg L−1) was found a more organized structure, with the presence of smaller clusters. Thus, the increase in the concentration of starch promoted the formation of clathrate, indicating that mono ether amine acetate interacts more strongly with starch than with the surface of the monocrystal. This phenomenon also has decreased the quartz contact angle that changed from 62° to 24°, in the presence of mono ether amine (50\xa0mg L−1) and for the mixture containing higher concentrations of starch (1000\xa0mg L−1 corn starch\xa0+\xa050\xa0mg L−1 mono ether amine), respectively. Fractal theory proved to be an excellent tool for studying the complexity of surfaces and for improving processes for obtaining materials, in mineral processing and the other industries. Evidence has been provided indicating that co-adsorption through binary interactions between starch and amines by chemical complexation. Starch cages, that behaviour as a host guest molecule, leading to the amine molecules to penetrate them forming cluster.