Tecnai g2 f20 twin cryo tem instrument

The morphologies of OLA-ODTES-silica hybrids were investigated by transmission electron microscopy (TEM), employing a Tecnai™ G2 F20 TWIN Cryo-TEM instrument (FEI Company, Hillsboro, OR, USA) at 200 kV acceleration voltages. The samples were observed directly without further staining to improve contrast. The excess of the OLA/OLANa stabilizing complex was washed and removed via centrifugation as described in the sample preparation before calcination (see N₂ adsorption-desorption measurements). A droplet of diluted washed sample was poured on a carbon film coated copper grid and left to dry in air at room temperature.

Swelling tests were conducted using the lyophilized samples. The samples were placed in vials in deionized water at 37 °C the swollen samples being weighted at pre-settled times. The swelling degree (SD) was determined by the equation:
Wh is the weight of hydrated sample at the pre-established time and Wi the weight of the dried sample. Swelling degree was calculated as the average of three measurements.
FT-IR spectra were registered on powdered in the range 400–4000 cm⁻¹, with Tensor 37 from Bruker, Woodstock, NY, USA in ATR mode.
X-Ray diffractograms were obtained using Rigaku Ultima IV X-ray diffractometer, Tokyo, Japan. The measurements were performed on powdered samples at room temperature. The equipment was set in parallel beam geometry system in two specific configurations for the wide angle and low angle range.
Transmission electron microscopy images were obtained using Tecnai™ G2 F20 TWIN Cryo-TEM instrument from FEI Company™ (Eindhoven, The Netherlands) Thin slices (~100 nm) of epoxy included samples were examined from carbon film grids.