Characterization of silica derived from Kelampayan (Neolamarckia cadamba) and rubber tree (Hevea brasiliensis)

Rubber wood and Kelampayan were treated with acid and base, namely, hydrochloric acid and sodium hydroxide to yield precipitates of silica. As most trees have only 0.01 per cent of silica when reduced to ash, other tropical species may have 1.0 per cent and a higher level of silica. It becomes important to extract it in order to prove the existence of silica in wood. A simple non-conventional method for extracting silica in the amorphous form is based on alkaline extraction followed by acid precipitation. Spectroscopic data from FTIR shows the main vibration number of the main functional group which is 0-H stretching group (alcohol) in peak 3297.48 cm-1 for rubberwood. While for Kelampayan shows the main functional group -OH at a peak of 3296.77 cm-1. Carboxylic acid salts which, from the CO2 group, also appeared in both silica at a peak of 1650-1550 cm-1. From the XRD results, the highest peak at an angle of 30-32° is shown for both silicas extracted from rubberwood and Kelampayan, which indicates that silica is in an amorphous state. Silica from rubberwood and Kelampayan have been tested for moisture absorption in order to determine whether it is safe for environmental use and whether it is usable to replace dehydrants that can be found on the market. It turns out that silica derived from rubber wood is better able to absorb moisture than silica derived from Kelampayan.