title: Preparation of Mg-vermiculite nanoparticles using potassium persulfate treatment.
abstract: Delamination/exfoliation process of the Mg-vermiculite (Letovice, Czech Republic), particles with size less than 5 microm, was studied after potassium persulfate treatment and compared with known method utilized hydrogen peroxide treatment. X-ray powder diffraction (XRPD) patterns showed that treatment of Mg-vermiculite with different molar concentration of potassium persulfate: c = 0.02, 0.04, and 0.08 mol x dm(-3) at the temperature 60 degrees C for 2 hr caused reduction of relative intensity (I(rel.)) of the basal 001 diffraction to the 15%, 9%, and 4%, respectively, compared to intensity of 001 diffraction of untreated Mg-vermiculite (I(rel.) = 100%). On the other hand I(rel.) of the 001 diffraction of Mg-vermiculite after treatment with 30% and 50% (c = 9.8 and 17.4 mol x dm(-3)) hydrogen peroxide at the 60 degrees C for 2 hr decreased only to I(rel.) = 36% and 32%, respectively. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) verified effect of potassium persulfate treatment on structure degradation which is connected with higher degree of delamination/exfoliation of the particles and their cracking into nano-sized particles.
authors.affiliation: Institute of Material Chemistry, VSB - Technical University Ostrava, 17 Iistopadu 15/2172, 70833 Ostrava-Poruba, Czech Republic.
authors.forename: Vlastimil
authors.initials: V
authors.lastname: Matĕjka
authors.forename: Monika
authors.initials: M
authors.lastname: Supová-Krístková
authors.forename: Gabriela
authors.initials: G
authors.lastname: Kratosvá
authors.forename: Marta
authors.initials: M
authors.lastname: Valásková
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D017680:Potassium Compounds / Q000494:pharmacology*; D013431:Sulfates / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D017680:Potassium Compounds; D013431:Sulfates; C003760:vermiculite; C009007:potassium persulfate; D006861:Hydrogen Peroxide; D008274:Magnesium