Preparation, characterisation and application of thermally treated Algerian halloysite

Inner surface modification of halloysite nanotubes and its influence on morphology and thermal properties of polystyrene/polyamide‐11 blends

“…Figure displays the TGA and differential thermogravimetric (DTG) curves of Hal, Hal‐M and P(S‐ co ‐MAPC 1 (OH) 2 ) copolymer. The mass loss in the range 40–220 °C for both HNTs is due to the release of water adsorbed on the surface of the particles . The continuous mass drop up to 450 °C for Hal is attributed to the loss of intercalated water molecules in the interlayer space.…”

Nanoporous-walled silica and alumina nanotubes derived from halloysite: controllable preparation and their dye adsorption applications

“…A water monolayer also exists between the adjacent two layers. The general stoichiometry of halloysite is expressed as Al 2 O 3 ·2SiO 2 ·nH 2 O, where n equals 6 for 10 Å halloysite and 2 for 7 Å halloysite (Oya et al, 1987;Barrientos-Ramirez et al, 2009;Abdullayev et al, 2012;Kadi et al, 2012;Zhang et al, 2012;Kogure et al, 2013). The interlayer water in 10 Å halloysite evaporates easily in the dry air with the resultant generation of 7 Å halloysite (Yuan et al, 2012;Ouyang et al, 2014) (Reaction (1)).…”

“…In the past decade, there are many halloysite-related works, such as halloysite-based adsorbents (Viseras et al, 2008;Zhao and Liu, 2008;Kiani et al, 2011;Kadi et al, 2012;Kiani, 2014), catalysts (Barrientos-Ramirez et al, 2009;, advanced ceramics (Fu and Zhang, 2005), polymer nanocomposites Pasbakhsh et al, 2013;Carli et al, 2014;Sarifuddin et al, 2014;Yang et al, 2014), hard template (Zhou et al, 2011), and drug loading and releasing (Tan et al, 2014). Nonetheless, the halloysite nanotubes (abbreviated as Hal hereafter) feature a solid tube wall of tens of nanometers in thickness, which restricts the Hal with a confined specific surface area S BET of around 50 m 2 /g .…”

Thermal Dehydroxylation Kinetics of Algerian Halloysite by Differential Thermal Analysis

“…These experiments show that the decomposition process of the halloysite takes place in three major steps. The first endothermic peak in the range of 360-450 K corresponds to the liberation of water adsorbed on the surface of the particles (dehydration) [4]. The second step of structural decomposition of halloysite occurs in the endothermic peak between 700 and 950 K. The peak centered at about 863.3 K is assigned to the dehydroxylation of halloysite and the formation meta-halloysite.…”

“…An exothermic peak between 1200-1400 K, centered at about 1279.6 K (transformation from the amorphous metahalloysite into crystalline phases), could be explained by the formation of Si-Al spinel [4]. An exothermic peak between 1500-1650 K, centered at about 1586.3 K, corresponds to the formation of primary mullite and transformation of amorphous SiO 2 into a crystalline phase called cristobalite.…”