Formation of a 10 A phase with halloysite structure under hydrothermal conditions with varying initial chemical composition

We studied the process of obtaining nanostructured halloysite by varying the parameters for cre-ating the initial composition. The initial composition was synthesized by co-hydrolysis of (C3H7O)3Al , (C2H5O)4Si in the C6H14-NH3 center dot H2O system. Aluminum hydrosilicate with the composition Al2Si2O5(OH)4 was synthesized under hydrothermal conditions (220 degrees C, 2 MPa, 96 h). Particles of plate-like morphology with av-erage length 100 - 200 nm and 60 nm thickness were obtained. The PXRD patterns revealed the presence of two phases. Plate-like kaolinites are found. Also we observed the formation of a halloysite-like phase. Studies of synthesized samples by IR spectroscopy and thermal analysis revealed the presence of organic-modified hydrosilicate with phase transition around 412 degrees C. The resulting phase is promising for studying the processes of adsorption and further exfoliation.

Automated summary

We investigated the process of obtaining nanostructured halloysite by adjusting the parameters of the initial composition synthesis. Aluminum hydrosilicate with Al2Si2O5(OH)4 composition was synthesized under hydrothermal conditions. The resulting particles had a plate-like morphology with an average length of 100-200 nm and a thickness of 60 nm. Two phases, plate-like kaolinites and a halloysite-like phase, were identified. The synthesized samples also revealed the presence of organic-modified hydrosilicate with a phase transition temperature of approximately 412 degrees C, which holds promise for adsorption and exfoliation studies.