The Effect of Hydrothermal Curing on the Efflorescence of Micro/Nanometric Size Jordanian Aluminosilicate Inorganic Polymers.

This study investigates the possibility of reducing the efflorescence (excess or non-reactive salts) effect of inorganic polymers based on aluminosilicate materials from Jordan. This was achieved by minimizing the particle size of the raw materials, and using hydrothermal curing at 80° C, 120° C and 150° C, then comparing the results with other different curing conditions; ambient and humid. Kaolinite (K), volcanic tuff (Vt), and silica sand (Ss) raw materials were used. The raw materials were ground to the average particle sizes (d₅₀) of: <10µm, <200nm, and <100nm. Three different mixing ratios of Vt, K, and Ss were used to study their dissolution behavior and to prepare inorganic polymers. X-ray diffraction (XRD), X-ray fluorescence (XRF), and inductively coupled plasma (ICP) techniques were used to identify the mineralogical and chemical composition of the raw and processed materials. The samples of <10µm were successful to be molded and analyzed for compressive strength. The average compressive strength was about 65 Mpa under hydrothermal condition cured at 150°C. The samples of nanometric size failed because the material in this range of size behaves and exhibits one or more nanoscale phenomena. Qualitative and quantitative measurements of efflorescence formation were also determined. The average alkali leaching was reduced from 3.14% of ambient cured samples to 0.83% of hydrothermally cured ones. This highest strength result indicates that the alkaline solution has reacted with the majority of Al³⁺ and Si⁴⁺ of silicates raw material. [ABSTRACT FROM AUTHOR]