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Nucleation of the Electroactive γ Phase and Enhancement of the Optical Transparency in Low Filler Content Poly(vinylidene)/Clay Nanocomposites

“…After this process the nanocomposite is typically melted at 210 °C and recrystallized to room temperature . Since the clay can suffer structural modifications at this temperature, , six films with a clay concentration of 0.50 wt % were prepared at temperatures between 170 and 220 °C in order to study the effect of the polymer melting temperature during nanocomposite preparation. The effect of clay concentration on the electroactive phase content was further studied in films with 0.10, 0.25, and 0.50 wt % of montmorillonite.…”

“…15 The stabilization of either γ or β phase is not understood and depends on factors such as cooling rate and surface modification of the clays. 14,15 On the other hand, by increasing meting temperature, the reduction of the interlayer spacing of the clays at temperatures above 200 °C due the elimination of interlayer water 25 prevents the exfoliation of montmorillonite which in turn reduces the contact area between the negatively charged delaminated clays and the dipolar moments of PVDF, preventing its crystallization of the electroactive phases. The interlayer water elimination and the collapse of the interlayer distance is confirmed by the disappearance of the d (001) diffraction peak, 29 attributed to the interlayer distance, at 2θ ≈ 9°, in the XRD patterns for samples prepared at temperatures above the 200 °C (Figure 2, panels a and b, inset).…”

Aerobic oxidation of biomass derived 5-hydroxymethylfurfural into 5-hydroxymethyl-2-furancarboxylic acid catalyzed by a montmorillonite K-10 clay immobilized molybdenum acetylacetonate complex

“…110), ( 105), ( 210) and ( 300) reflections, respectively. 21 In addition, a sharp peak at 2θ = 26.5 belongs to quartz. 22 On comparison of the XRD pattern of the K-10 clay with that of the K-10 clay-Mo, there is no difference between them, which indicated that the clay structure is retained after the immobilization of MoO 2 (acac) 2 .…”

Synthesis of high surface area Al-containing mesoporous silica from calcined and acid leached kaolinites as the precursors

“…Mesoporous aluminosilicates can be prepared by controlled acid extraction of aluminum from calcium bentonite clay but their specific surface areas are only about 300-400 m 2 /g, much lower than ordinary mesoporous silica [22]. Surfactant-treated K10 montmorillonite with added amorphous silica showed a specific surface area of 736 m 2 /g [23,24]. The preparation of microporous silica with a specific surface area of about 350 m 2 /g has been reported by Okada et al using selectively acid-leached metakaolinite (dehydroxylated kaolinite) [25].…”