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In this study, the adsorption of NH3 gas on a bentonite from Ünye (Turkey) in its natural state and after acid treatments, was investigated experimentally at 298 K and up to 100 kPa. Bentonite was treated with HCl solutions of various concentrations (0.5–2.5 M) at 75°C for 4 h. X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption and thermogravimetric/differential thermal analysis (TG/DTA) were used to characterize the bentonite before and after acid treatment. The quantitative XRD analysis demonstrated that the bentonite sample was composed predominantly of smectite (75%), with abundant feldspar (20%) and minor opal-CT, analcime and quartz (5%). Increasing gas adsorption values of acid-treated bentonites were analysed depending on the structural changes of the clay. The NH3-adsorption capacities of the bentonite samples (3.801–5.068 mmol g–1) were also compared with previously studied clay-based materials (0.828–4.000 mmol g–1) in terms of their textural and structural differences.

Nonlinear optical materials have highly interesting photo-physical behaviors, which have a wide variety of applications, from optoelectronics to medicine. Nonlinear optical properties together with infrared and nuclear magnetic resonance analyses on the interaction between hydroquinone and pristine or boron and silicon doped C60 fullerene systems have been investigated by density functional theory. Hydroquinone@C60 systems in the cis and especially trans form have nonlinear optical applications. The obtained results related to optical properties such as polarizability and first hyperpolarizability may have useful predictive values which can be of interest.

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