*2.3. Microstructure*

Microstructure of the fabricated samples was observed by using a scanning electron microscope (JEOL JSM-5410) using an accelerating voltage of 20 kV. Prior to observation, the samples were gold sputter coated to improve the conductivity and prevent charging of the samples.

#### *2.4. Bulk Density*

Weight of the sample and its dimensions (width, length and thickness) were measured by a precision balance (Sartorious) and a vernier caliper (Mitutoyo), respectively. The bulk density was determined by dividing the weight by the calculated volume.
