Preparation and characterization of “green” hybrid clay-dye nanopigments

• The modification is necessary for making clays suitable for specific application.
• This study focused on developing Rhodamine B/Unye bentonite (Rh-B/UB) nanopigment.
• The spectroscopic data of his nanopigment revealed that the Rh-B dye molecules migrate into the interlayer spacing of the Unyebentonite as the cationic species and monolayer form.

We obtained a low cost and abundant nanopigment material composed of Rhodamine B (Rh-B) organic dye compound and Unye bentonite (UB) clay from Turkey. The characterization of the nanopigment was investigated using scanning electron microscopy (SEM), particle size distribution, powder X-ray diffraction (PXRD), Fourier transformed infra-red spectroscopy (FT-IR) and thermal analysis techniques. According to the result of texture analyses, we showed that the particle size distribution (d: 0.5-mean distribution) of Rh-B/UB nanopigment material was around 100 nm diameter. It was also demonstrated that the samples had a particle size around nm diameter in SEM images. As seen in the PXRD and thermal analysis, there is a difference in basal spacing by 1.46° (2θ) and a higher mass loss by 7.80% in the temperature range 200–500 °C compared to the raw bentonite.