Synthesis of Mesoporous Silica Derived from Geothermal Waste with Cetyl Trimethyl Ammonium Bromide (CTAB) Surfactant as Drug Delivery Carrier

Silica can be obtained from nature, such as generated from geothermal plant activity. Solid waste from Dieng geothermal contains silica with a huge amount of 84.4%. The silica can be investigated as drug delivery for its good biocompatibility. Preparation of geothermal solid waste into mesoporous silica involved several stages. The first stage followed purification to reduce the content of hazardous metals to the body, including arsenic, nickel, and lead. Purification was carried out using sulfuric acid with concentration of 20%, 30%, 40%, 50% and 60%. Optimum silica product was obtained at a silica purity of 98.2% and nickel content of 0.1% by using of 20% sulfuric acid. The silica was then synthesized into sodium silicate as a precursor using NaOH 4 N. Mesoporous silica was released from dropping the sodium silicate into a mixture of ammonia, ethanol, water and CTAB surfactant solutions. The addition of CTAB surfactant was carried out with mole variations of 0.015; 0.03; 0.075 and 0.1. Based on the BET analysis, the products with CTAB of 0.015 mol and 0.03 mol produced hysteresis most identical to mesoporous type. The optimum product was analyzed using XRF to comply quality standard for drug delivery carrier preparation.