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Electrochemistry of Aluminosilicates
Published in Antonio Doménech-Carbó, Electrochemistry of Porous Materials, 2021
Currently, it is known that MB is a material resulting from the attachment of indigo, a blue dye extracted from leaves of añil or xiuquitlitl (Indigofera suffruticosa and other species) to the clay matrix of palygorskite, a fibrous phyllosilicate of ideal composition (Mg,Al)4Si8(O,OH,H2O)24 . nH2O, whose structure can be described as a continuous set of layers formed by two-dimensional tetrahedral and octahedral sheets. The tetrahedral and octahedral mesh gives rise to a series of rectangular tunnels of dimensions 6.4 × 3.7 Å. Palygorskite crystals are crossed by zeolite-like channels and permeated by weakly bound, non-structural (zeolitic) water. Magnesium and aluminum cations complete their coordination with tightly bound water molecules (structural water).
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Published in Eli Ruckenstein, Hangquan Li, Chong Cheng, Solution and Surface Polymerization, 2019
Junfeng Rong, Miao Sheng, Hangquan Li, Eli Ruckenstein
A novel methodology, in situ coordinated polymerization (18), was employed in this paper to prepare PE reinforced with nano-size palygorskite fibers. The major component of palygorskite is hydrous magnesium silicate, which is present as fibers with diameters less than 100 nm and lengths ranging from hundreds nm to several μm (Figure 6.2.1). Each Mg atom has two vacancies associated with it, which by reacting with TiCl4, generate bridges between Mg and TiCl4:
Application of the Scaling Method in Electro‐Optics
Published in Stoyl P. Stoylov, Maria V. Stoimenova, Molecular and Colloidal Electro-Optics, 2016
The clay mineral palygorskite (attapulgate) is an aqueous silicate of a shistous‐banded structure. The particles are rigid polydisperse rods of average length and diameter 500 nm and 20 nm, respectively. Particle refractive index is ca. 1.5, and particle surface charge in the aqueous suspensions is ca. 0.7 μC/cm2.
Stabilization of calcareous subgrade soils with polyelectrolytes: mechanisms and mechanical properties
Published in International Journal of Pavement Engineering, 2023
Jianxin Huang, Yosef Mohomad, Reginald B. Kogbara, Eyad Masad, Svetlana Sukhishvili, Dallas Little
More detailed images in Figure 12(b,c) and Figure 13(b,c) reveal these fibres are mostly likely palygorskite, as confirmed by the chemical analysis of these fibres from EDS. As shown in Figure 14, the fibrous mineral mainly comprised Si, Mg, Al, Fe, Ca, O with a Si: (Mg + Al) ratio of roughly 2:1, determined from the intensities of the peaks from the spectrum. It is known that palygorskite is a magnesium phyllosilicate with the ideal chemical formula of Mg5Si8O20(OH2)4·4(H2O) (Singer 2002). However, Al usually substitutes Si in the tetrahedra, or replaces Mg in the octahedra. Similarly, Fe and Ca could also replace Mg in the octahedra, but to a lesser extent (Singer 2002). Therefore, based on EDS chemical composition and the fibrous morphology of these minerals, it can be concluded that these fibres abundant in the stabilised soil were largely composed of palygorskite. Although these palygorskite fibres were formed by binding with polymer chains, the small polymer concentration was not detected by EDS. This is likely because the concentration of the elements was too low, below the detection limit of 0.1 wt.% for EDS (Goldstein et al. 2017). The dry polymer present in the soil was 0.4 wt.% (mass of dry polymer to mass of dry soil), the concentrations of the elements, such as sulphur (S) in PSS, was much lower, about 0.06 wt.% and nitrogen (N) in PDADMAC was 0.03%.
Effect of ultrasonic treatment of palygorskite on the catalytic performance of Pd-Cu/palygorskite catalyst for room temperature CO oxidation in humid circumstances
Published in Environmental Technology, 2018
Yongzhao Wang, Yongning Wang, Xiao Li, Zhaotie Liu, Yongxiang Zhao
Palygorskite (Pal) is a hydrated magnesium aluminum silicate clay mineral with a unique three-dimensional crystalline structure and has a lath or fibrous morphology. Pal has been widely used as an adsorbent, drilling fluid, catalyst and catalyst support owing to its unique structural and textural properties and low cost [29–36]. In our previous researches [29–32], the design and preparation of Pd-Cu/Pal catalyst with low precious metal content were studied by using Pal as the support, and the effects of the preparation method and calcination temperature on the catalytic performances for CO oxidation were also investigated. The Pd-Cu/Pal catalyst exhibited high CO catalytic oxidation performance at ambient temperature and in humid circumstances, but low catalytic activity and poor stability in the presence of moisture-rich content or at high space velocity. However, moisture is inevitable in practical application, and the moisture concentration in the feed gas is usually near-saturated.