Characterization of expansive soils for the foundation of an irrigation canal in the Peruvian Andes, Cabana-Mañazo case

Alterations in water content in swelling soils cause volume variation, which implies constructive, socioeconomic and environmental damage. This paper characterizes the swelling soil located in an irrigation canal of the Peruvian Altiplano and its behavior of the properties by addition of lime in 5, 10, 15 and 20% of the total weight. Finding that the sample of the station 6+575 has combined presence of montmorillonite clays in a percentage of 13.52% together with the group of kaolinites in a percentage of 1.31%, consequently, it makes expandable clay of high plasticity. The soils of the station 6+250 have the characteristics of kaolinite clay, which distinguishes it as having low plasticity. In the swelling tests the high expansiveness was found, in the station 6+575, which has decreased with the addition of lime. Considering that concrete canals are generally of small thickness it would be important to consider the slightly dangerous effects on irrigation infrastructure.

Determination of Surface Acidity on The Natural and Synthetic Montmorillonite Clays by Titration Method

Determination of surface acidity on the natural and synthetic montmorillonite clays has been carried out using the acid-base titration method to count the number of bound acid sites per gram of clay. The total acidity of natural and synthetic montmorillonite surfaces obtained was 4.67 and 5.33 mmol/g, respectively. FTIR analysis results indicate the presence of functional groups from the tetrahedral and octahedral constituents. Both samples have similar absorption patterns. The similarity of absorption patterns was followed by a decrease in intensity and shift in some absorption bands, and the appearance of new absorption bands.

Rheological modification of partially oxidised cellulose nanofibril gels with inorganic clays

This study aimed to quantify the influence of clays and partially oxidised cellulose nanofibrils (OCNF) on gelation as well as characterise their physical and chemical interactions. Mixtures of Laponite and montmorillonite clays with OCNF form shear-thinning gels that are more viscous across the entire shear range than OCNF on its own. Viscosity and other rheological properties can be fine-tuned using different types of clay at different concentrations (0.5–2 wt%). Laponite particles are an order of magnitude smaller than those of montmorillonite (radii of 150 Å compared to 2000 Å) and are therefore able to facilitate networking of the cellulose fibrils, resulting in stronger effects on rheological properties including greater viscosity. This work presents a mechanism for modifying rheological properties using renewable and environmentally-friendly nanocellulose and clays which could be used in a variety of industrial products including home and personal care formulations.

Addition of compatibilized nanoclay to GFRCs for improved izod impact strength and tensile properties

This research examines the effect of nanoclay silanization/compatibilization on the izod impact strength and tensile properties of epoxy-clay-based glass fiber reinforced composites (GFRCs). As per the existing literature, a key step in silanization of clay is washing of the silanized clay with acetone to remove the excess of silane molecules. However, contrary to this, the present research shows that acetone washing of the silanized clay lowers the tensile properties. GFRCs containing 2 phr nanoclay were processed. Three different montmorillonite clays were used in the initial investigations (two organically modified nanoclays designated as “CA” and “IE” and one unmodified nanoclay designated as “PG”). Silane concentration was varied in the range of 100–400% as proportion of nanoclay loading (i.e. 1X, 2X, 3X, and 4X). Silanization was validated by FTIR. XRD/TEM revealed increased d-spacing for silanized nanoclay and a partially exfoliated clay morphology in GFRCs. Highest izod impact strength (37% higher than the reference GFRC) without any loss in tensile properties was observed for GFRC reinforced with acetone washed 2X silanized “PG” nanoclay. GFRCs reinforced with silanized unwashed nanoclay (3X) showed 27% improvement in izod impact strength with significantly improved tensile strength (16% higher than the reference sample).

Nanocomposite Polymer Electrolytes of Sodium Alginate and Montmorillonite Clay

Nanocomposite polymer electrolytes (NPEs) were synthesized using sodium alginate (Alg) and either sodium (SCa-3-Na+)- or lithium (SCa-3-Li+)-modified montmorillonite clays. The samples were characterized by structural, optical, and electrical properties. SCa-3-Na+ and SCa-3-Li+ clays’ X-ray structural analyses revealed peaks at 2θ = 7.2° and 6.7° that corresponded to the interlamellar distances of 12.3 and 12.8 Å, respectively. Alg-based NPEs X-ray diffractograms showed exfoliated structures for samples with low clay percentages. The increase of clay content promoted the formation of intercalated structures. Electrochemical Impedance Spectroscopy revealed that Alg-based NPEs with 5 wt% of SCa-3-Na+ clay presented the highest conductivity of 1.96 × 10−2 S/cm2, and Alg with 10 wt% of SCa-3-Li+ showed conductivity of 1.30 × 10−2 S/cm2, both measured at 70 °C. From UV-Vis spectroscopy, it was possible to infer that increasing concentration of clay promoted a decrease of the samples’ transmittance and, consequently, an increase of their reflectance.

Synthesis, properties, and activity of MoVTeNbO catalysts modified by zirconia-pillared clays in oxidative dehydrogenation of ethane

Composites comprising MoVTeNbO mixed oxide and zirconia-pillared montmorillonite clays (PilCs) were prepared. XRD and TEM with EDX studies confirmed the preservation of M1 MoVTeNbO phase in these composites responsible for high activity and selectivity in ethane oxidative dehydrogenation into ethylene. For composites with PilC content of 10 wt%, the best ethylene yield exceeding that of bulk MoVTeNbO oxide was demonstrated for clays with zirconia pillars doped with Ce and Al possessing the highest specific surface area. This is explained by optimized chemical interaction of these clays with MoVTeNbO mixed oxide improving its bulk oxygen mobility and reactivity by structure disordering while blocking surface sites responsible for combustion due to the stabilization of the reactive terminal oxygen species.