Effect of Polyvinylpyrrolidone and Sodium Lauroyl Isethionate on Kaolinite Suspension in an Aqueous Phase

Abstract

Kaolinite is a very useful raw material in industries, such as paints, paper, plastics, cosmetics, pharmaceuticals, and ceramics. Rheological properties and/or suspension stability of kaolinite are crucial factors in these products. The rheology and suspension of kaolinite has been studied intensively so far.1-8) Nakagaki M., et al. [3][4][5] provided evidences that the divalent cations exert stronger effect than monovalent cations on a reduced viscosity and Bingham yield value of the suspension. In an aqueous suspension of kaolinite, the -NH group of urea, hydrazine and formamide, and the -OH group of alcohols form the hydrogen bonding with an -SiO group on kaolinite surface to alter fluidity of a suspension. 10,11) In this situation divalent cations manifest stronger effect than monovalent ones on the Bingham yield value.3-6) The edge(ϩ)/face(Ϫ) inter-particle interactions promote aggregation and increase the viscosity of a suspension. On the other hand, adsorption of multivalent anions decreases charge density on the edge, diminishing edge(ϩ)/face(Ϫ) interparticle interaction, which results in reduction of the viscosity. 7)Johnson indicated that the kaolinite edge contains both silica-and alumina-like sites positively charged at low pH, but bears a negative charge at high pH. Kaolinite face contains by contrast only silica-like charge sites and remains negatively charged within a wide pH range. 12,13) Heath and Todros 14) derived both a Bingham yield value and viscosity of kaolin suspension as a function of pH and electrolyte concentration. Their results showed a minimum viscosity around pH 7 and they assumed that the isoelectric point of particle's edges was around pH 7. Adsorption of polyacrylic acid (PAA) on kaolinite particles affected flocculation/dispersion of a suspension solution. PAA proved a higher suspension stability at low or high concentration than at a medium concentration.1,2) The sodium salt of polyacrylic acid (Na-PAA) is adsorbed by alumina sites on the edge of kaolinite particles but not on the site of silica on basal plane of particles.15) The acid form of carboxylic acid of PAA can be adsorbed via hydrogen bonding between the carbonyl group of carboxylic acid and the hydroxyl group on a surface of the kaolinite basal plane.16) Gebhardt and Fuerstenau 17) measured the adsorption amount of PAA by silica. Conceicao et al. 18) probed influence of carboxymethylcellulose on rheological behavior of kaolinite suspension in the presence of ammonium polycarbonate as a dispersant. The presence of carboxymethylcellulose in kaolinite suspension conferred a shear thinning behavior, especially in the low shear rate range, followed by a trend to Newtonian fluid behavior. Na kagaki M., et al. 3,4) pointed out that polyvinylpyrrolidone (PVP) acts on kaolinite suspension as a flocculating agent at concentration lower than 2ϫ10 Ϫ3 %, but as a dispersing agent above that point. Yalcin et al. 19) studied the influence of surfactants (sodium or ammonium dodecyl sulfate, SDS or ADS) on flow behavior of ben...

The Properties of the Ulcinj Peloid make it Unique Biochemical Laboratory Required for the Treatment of Problematic Skin and Health Care

“…Kaolin, or hydrated aluminum silicate was known for thousands of years and is used in making plastics, ceramics, cement and paints. It is increasingly used in the pharmaceutical and cosmetics industry as an emollient agent, desiccant and adsorbent [16,17]. Peloid sample from the area of Ulcinj coast showed significant antimicrobial activity with the strain Candida albicans 24433, whereas the mean zone of inhibition for concentration of 200mg/ml is 26.0 mm, while for concentration of 100 mg/ml it is 23.0 mm.…”

“…Kaolin, or hydrated aluminum silicate was known for thousands of years and is used in making plastics, ceramics, cement and paints. It is increasingly used in the pharmaceutical and cosmetics industry as an emollient agent, desiccant and adsorbent[16,17].…”

Experimental studies on the desorption of adsorbed sodium poly(acrylic acid) from crude kaolin particles

“…The studies have usually focused on the achievement of rheologically stable dispersion (Husband, 1998;Mpofu et al, 2003;Ma, 2011;Rao et al, 2011), the electrokinetic properties of the system (Braggs et al 1994;Alkan et al, 2005;Lagaly, 2006;Chassagne et al, 2009;Amorós et al, 2010;Duman et al, 2012;Leong et al, 2012), the adsorption isotherms (Backfolk et al, 2001;Marco and Llorens, 2005;Hoch and Bandara, 2005;Backfolk et al, 2006;Kwan et al, 2006Kwan et al, , 2011Totland et al, 2011), and the identification of the reaction mechanism causing the dissolution of metal ions from the particles (Huertas et al, 1998(Huertas et al, , 1999Yuan et al, 1998;Zaman et al, 2003). Dodson and Somasundaran (1983) studied the desorption of polyacrylamide and hydrolyzed polyacrylamide from the kaolinite surface.…”