Colloid Chemistry of Clays.

Nuclear Magnetic Resonance and Rheological Studies on the Thixotropic Properties of Montmorillonite-Water Systems

“…Freundlich (3), von Engelhardt (4), and Hause ( 5 ) assume that there are long-range electrical forces which permit the indivigual particles to act over distances of the order of lo3 A. This would be similar to the type of structure found in a magnet where all the free electrons of the iron are lined up in the same direction.…”

Isotropic/nematic and sol/gel transitions in aqueous suspensions of size selected nontronite NAu1

“…Such a view was also shared by Van Olphen (1951) and from that time on, this interpretation of the gel structure has been referred to as the ''house of cards'' structure and is still often presented in clay chemistry textbooks. Opposite views were presented by Hauser and Reed (Hauser & Reed, 1937;Hauser, 1945) and Norrish (1954) who viewed the gel as an oriented network stabilized by repulsive interactions between the electrical double layers of the clay platelets. Various subsequent rheological analyses of the properties of natural swelling clay gels (Na-montmorillonite mainly) have favoured either the ''house of cards'' (Van Olphen, 1964;Khandal & Tadros, 1988;Miano & Rabaioli, 1994) or repulsive gel model (Weiss & Frank, 1961;Callaghan & Ottewill, 1974;Rand et al, 1980;Ramsay, 1986;Vali & Bachmann, 1988;Bradenburg & Lagaly, 1988;Lagaly, 1989;Abend & Lagaly, 2000;Ten Brinke et al, 2007).…”

Colloid Properties of Some Western Clays

“…Early in the 1920's, howe\rer, it was shown that the clay particle was crystalline (6,27). Since that time the crystalline nature of the clay minerals has been demonstrated by many investigators (3,5,7,8,9,12,13,14,19,20,21). The x-ray studies were followed by those made with the electron microscope (1,7,8,17,21,22) and the shapes of the clay minerals were also ascertained.…”