Crystal Morphology and Differential Meso–Micro Pore-Volume Distribution Patterns of Clinoptilolite Fractions

Analysis of scanning electron microscope (SEM) morphology and pore-volume distribution of commercial clinoptilolite fractions have been conducted experimentally using an analyzer by measuring the N2adsorption isotherm. The commercial material was fractionated by sieving through different sieves viz., <125 μ (Z1; fine fraction), 125–250 μ (Z2; medium fraction) and >250 μ (Z3; coarse fraction). All three fractions exhibited type IV isotherm of IUPAC. Adsorption hysteresis (H3) suggested that the pores are slit-shaped even though the pores are multi-shaped in reality. SEM results have shown, the morphology of clinoptilolite having particle size grains of 396 nm (fine fraction, 125 μ sieve), 488 nm (medium fraction, 125–250 μ sieve) and 541 nm (coarse fraction, >250 μ sieve) with layered structure. However, medium fraction has exhibited incomplete hexagonal structure too. The meso–micro pore-volume distribution of the fractions were calculated from the hysteresis loop according to the adsorption curves of Barret, Joyner and Halenda. There was only a minor change in pore volume to each incremental pore volume for the coarse clinoptilolite fraction. © 2014, The National Academy of Sciences, India.