The aim of this study is to determine the adsorption properties of microwave synthesized inorgano-organo montmorillonites. Microwave irradiation is preferred because of its low time and energy consumption properties, forming an advantage in industrial applications. In addition to the intercalation of Keggin and hexadecyltrimethylammonium (HDTMA + ) cations, the aging process of pillaring solution was also carried out through the microwave irradiation. Both inorgano clays, namely the parents, and their inorgano-organo derivatives, were prepared by using the same amounts of aluminum by keeping the OH − /Al 3+ and Al 3+ /clay ratios constant. The HDTMA + /clay ratio was changed in inorgano-organo clays (IOCs) during the preparation. The effects of these parameters on the surface properties and adsorption behaviors of the samples were investigated by conducting X-ray diffraction (XRD), Fourier transform infrared (FTIR) and simultaneous thermal analyses (STA), as well as batch adsorption experiments, in which phenol was used as a model pollutant. The results of XRD analyses reveal that the intercalation is successfully achieved. The existence of the Keggin and HDTMA + cations was observed in FTIR spectra of the samples. Through the STA, it was determined that the existence of organic layer increases the dehydroxylation temperature and the thermal behavior of inorgano-organo montmorillonites strongly depends on the structure of the parent clay. An increase in the adsorption efficiencies with increasing HDTMA + /clay ratio was observed, except with the highest ratio. The behavior of this sample was explained by the formation of the second HDTMA + layer leading to the hydrophilic surface formation. 

AB ST R ACT : In this study, a new procedure for the synthesis of pillared clays is proposed. Ageing processes and intercalation reactions were carried out using microwave irradiation in order to decrease the consumption of three industrially-important parameters; time, water consumption and energy. The effects of microwave irradiation, the amount of Al and the Al 3+ /clay ratio on the physicochemical properties of Al-pillared montmorillonites were investigated. The structural changes, depending on the intercalation and microwave irradiation, were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and scanning electron microscopy (SEM) analyses and by measuring the specific surface area and pore-size distribution. Additionally, simultaneous thermal analyses (STA) and zeta potential measurements were carried out to determine physicochemical properties. According to the XRD measurements, the d 001 value of microwaveirradiated samples is not affected by the amount of Al and the Al 3+ /clay ratio; microwave irradiation causes a 0.20 nm contraction in the d 001 value in comparison to that of a conventionally pillared sample. The results of FTIR analyses reveal that the intensity of peaks assigned to Keggin-OH and Keggin-H 2 O stretches is diminished in the case of microwave-irradiated samples. The STA analyses indicate that the amount of water released during dehydroxylation is decreased in the case of microwave-irradiated samples. By considering the contraction in d 001 values and the decreases in Keggin-stretching bands and also in the amount of dehydroxylation water, it was concluded that microwave irradiation has a calcination effect.