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A Study of the Anomalous Kerr Effect on Dispersions of Clays in the Presence of Excess Salt and Water‐Soluble Amphiphilic Additives
Published in Stoyl P. Stoylov, Maria V. Stoimenova, Molecular and Colloidal Electro-Optics, 2016
P. Schmiedel, S. Holzheu, H. Hoffmann
Our saponite samples are a gift from the Hoechst AG. Saponite is a synthetic layered silicate with the formula [Mg3(Si3.7,Al0.3)O10(OH)2]Na0.3. In solution it disperses into disklike particles with a diameter of ca. 500 Å and a thickness of 10 Å. Due to the dissociation of the Na+ ions the particles are negatively charged with a surface charge density of e/150 Å2. We investigated solutions with two different concentrations: a dilute one with 0.01 wt% and a semidilute one with 0.7 wt%. At these concentrations the rotational volumes of the particles begin to overlap. To study the dependence of the ionic strength on the signals different amounts of NaBr were added.
Removal of emerging pollutants by clay and clay-nZVI nanocomposites-A review
Published in Environmental Technology Reviews, 2023
Geetha Gopal, Amitava Mukherjee
Clay minerals and clays with fine particulate sizes and a porous structure with a large surface area can have excellent physical and chemical interactions with dissolved species. Electrostatic repulsion, crystallinity and adsorption, and complex cation exchange are some of the factors that can impact such interactions. The high bonding strength is shown by highly porous surface areas with good attractive force. Clays are hydrous aluminosilicates consisting of mixtures of minerals of fine-grained clay, other mineral crystals, and metal oxides. Kaolinite is the major component; however, it is also made up of a variety of minerals such as quartz, mica, feldspar, illite, and montmorillonite. Bentonite is predominantly made up of montmorillonite, a smectite-group clay mineral with hydrous magnesium–calcium aluminium silicate structure. It is very colloidal and plastic clay made up of very small particles that are created by in situ devitrification of volcanic ashes. Smectite is the mineral name assigned to the group of silicates, including Na, Ca, Mg, Fe, and Li–Al. The most widely used minerals within the smectite group are Na-montmorillonite, Ca-montmorillonite, saponite (Mg), nontronite (Fe), and hectorite (Li). Ball clay, sedimentary clay that is fine-grained and highly porous, consists primarily of kaolinite, mica, and quartz with minimal quantities of organic matter and other minerals.
Mechanical, thermal, and morphological properties of low-density polyethylene nanocomposites reinforced with montmorillonite: Fabrication and characterizations
Published in Cogent Engineering, 2023
Safaa Kh. Al-Jumaili, Wasan A. Alkaron, Maithem Y. Atshan
The best way to enhance polymer’s properties is by adding reinforcement materials (Alhazmi et al., 2021; Althahban et al., 2023; Hiremath et al., 2021). Although many works and studies were carried out on polymer reinforcement, the mechanical and thermal properties of polymers are not sufficiently developed. Clay is one of the most frequently used reinforcement materials due to its availability, and it also causes remarkable reinforcement to the polymers (G. -M. Kim et al., 2001; Liu et al., 2015; McNally et al., 2003). Adding modest amounts of clay (natural or modified) to the polymers is highly interesting as they offer improved polymer matrix properties, such as strength, toughness, and thermal. Natural clay is an inorganic layered silicate and belongs to the smectite group of minerals. Smectite is mainly used as a group of layered silicate nanoclays in polymer nanocomposites due to its possibility of intercalating process of polymers between the clay layers (Ray & Okamoto, 2003). Even though there are various types of smectite, for example, sodium montmorillonite, hectorite, and saponite, montmorillonite (MMT) still remains to be the most popular in comparison to others because of its acceptability of employing in polymers. However, the reason behind this is the high surface area which Na+ MMT has, aspect ratio, and the availability of MMT.
Adsorption of nickel from aqueous solutions by natural and acid-activated nano-structured bentonite
Published in Particulate Science and Technology, 2022
Zahra Ashouri Mehranjani, Majid Hayati-Ashtiani, Mehran Rezaei
Bentonite is a clay with a major component of smectite minerals, such as montmorillonite, beidellite, nontronite, hectorite, and saponite. Montmorillonite, the dominant phase of bentonites, comprises one octahedral sheet sandwiched between two tetrahedral ones (Ghazizahedi and Hayati-Ashtiani 2018). The porous structures of montmorillonites mainly consist of micropores (smaller than 2 nm), mesopores (between 2 and 50 nm), and macropores (larger than 50 nm) (Mouzon, Bhuiyan, and Hedlund 2016). Bentonites are generally known for some of their outstanding properties, such as relatively high specific surface area, high cation exchange capacity, swelling, adsorption capacity, chemical, and mechanical stability. Bentonites are mainly used in bleaching earth, catalysts, drilling mud, foundry bounds, palletizing iron ore, nano clays, and adsorption (Ostovaritalab and Hayati-Ashtiani 2019). Some properties of bentonite can be improved through acid activation, ion exchange, cationic surfactants treating, polymer modification, and heating in which acid activation is the most commonly used method (Leroy et al. 2017).