Octamethylcyclotetrasiloxane (D-4) can Chelate Lithium Ions from Aqueous Solutions

Lithium in seawater is a new reserve to supply lithium, which is used widely for battery manufacturing. We propose a method to extract lithium from ocean waters using a clear liquid, octamethylcyclotetrasiloxane (D-4). D-4 shows an exclusive affinity for lithium ions due to its crown ether-like structure, making it the ideal substance to use for lithium ion extractions from aqueous solutions. We used one milliliter of D-4 to fifty milliliters of a lithium chloride solution ( 1.0 x 10-5 M and 1.0X10-4 M) to perform the extractions using separatory funnels. Vacuum distillation was used to recycle and purify D-4 leaving lithium behind as the byproduct. We used our FTIR, AA and NMR instruments for analysis on the distilled D-4 and the extracted lithium chloride solutions. Results indicate that D-4 already contains lithium ions as a new store bought product; it attracts lithium ions when being synthesized. This new finding further signifies D-4’s potential for a lithium ion extraction