The effect of hydrothermal processes on physical and biological properties of anionic nano clay calcium - aluminum type

Anionic nano clay or Layered double hydroxides are a class of nano structure materials with unique physico-chemical properties similar to natural hydrotalcite minerals with chemical formula ofMg6Al2 (OH) 16. CO3. 4H2O. these compounds can be composited with many organic species such as biomolecules، DNA and vitamins to form nanobiohybrids. In this study، Ca–Al–NO3 layered double hydroxide (LDH) nanoparticles of varying sizes weresynthesised by a process involving co-precipitation under hydrothermal condition. This methodproduces stable homogeneous LDH suspensions under variable hydrothermal treatmentconditions with particle size in the range of 7. 5nm–2. 5 μm. Layered double hydroxides werecharacterized by X-ray diffraction، Fourier transform infrared spectroscopy، thermal gravimetric/differential thermal analysis، scanning electron microscopy and transmission electron microscopy (TEM) and nanosizer analyses. By increasing the hydrothermal treatment time، the crystallinityand the particle size of obtained LDH increased. Scanning electron microscopy and TEMobservations showed uniform hexagonal flake-like particles with high aspect ratio. Finally، Ca–Al–NO3 LDH did not show any acute cytotoxic effect up to 100 mg/mLas measured by 3- (4،5-dimethylthiazol-2-yl) -2،5-diphenyltetrazolium bromide assay