M. Göktuğ Ahunbay

Highly CO2 Selective Microporous Metal-Imidazolate Framework-Based Mixed Matrix Membranes

Microporous metal-imidazolate framework (MMIF), a highly CO2 selective MOF, was incoporated into a polymeric membrane for separation of CO2 from CH4 and N2 for the first time. MMIF nanoparticles of 50-200 nm were synthesized using the sonication method and dispersed into Matrimid, a commercial polyimide, with MOF loading of 10% and 20% by weight to fabricate mixed matrix membranes (MMMs). Morphology, thermal behavior, and glass transition temperature of the membranes were characterized, and single and mixed gas permeation measurements at 35 °C and 4 bar feed pressure were carried out to reveal their separation performance. Both 10% and 20% MMIF containing Matrimid membranes exhibited enhanced gas permeabilities for all three gases. Contrary to expectations, ideal selectivity of membranes was not improved possibly due to the flexible framework of MMIF. On the other hand, mixed gas permeability measurements showed significant improvement in CO2/CH4 separation factor by 130% and CO2/N2 separation factor by 79% due to competitive adsorption favoring CO2.

Adsorption of perfluorohexane in BAM-P109 type activated carbon via molecular simulation

Perfluorohexane adsorption on porous activated carbon was studied via Monte Carlo methods. In order to estimate the microporous adsorption capacity at relative pressures (P/P0) 0.1, 0.3, and 0.6, microporous structures were generated by simply packing corannulene and oxygenated corannulene fragments together into a simulation box and the benchmark data were validated by calculating CO2 and Ar adsorption isotherms prior to estimating the perfluorohexane adsorption capacity of the candidate material BAM-P109. Since ∼50% of the total pore volume of this material is mesoporous, the mesoporous adsorption capacity was also estimated using a slit-pore model with varying pore widths at P/P0 = 0.3 and 0.6. Prior to the adsorption simulations, the saturation pressure of perfluorohexane at 273 K was estimated as 8.13 kPa through a series of Monte Carlo simulations, which is in good agreement with the experimental data of 8.55 kPa.

RETRACTED ARTICLE: Molecular simulation of Zn2+, Cu2+, Pb2+, and NH4+ ion-exchange in clinoptilolite

The following article has been retracted from publication in the Taylor & Francis journalDesalination and Water Treatment:BarisDemir, M. GoktugAhunbay,Molecular simulation of Zn2+, Cu2+, Pb2+, NH+4...