SYNTHESIS BICONTINUOUS CONCENTRIC LAMELLAR (BCL) SILICA USING SOLVOTHERMAL AND REFLUX METHODS

• Main Author: Hamdi, Rahmat
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/82878
• Institution: Institut Teknologi Bandung

Mesoporous silica is an oxide compound that has a pore size of 2–50 nm. The advantages of mesoporous silica include its large surface area, good thermal stability, high accessibility, and adjustable morphology. These properties can be controlled by varying the solvent, catalyst, surfactant, precursor, and synthesis stages. Mesoporous silica material is widely used as a catalyst support, adsorbent, CO2 capture, optical microreflector, and drug delivery agent. One group of mesoporous silica materials that has interesting properties is KCC-1 (KAUST Catalytic Center-1) because it has a bicontinuous concentric lamellar (bcl) structure. Silica bcl has a lamella structure that is interconnected and concentric. Silica bcl has higher accessibility than other silica groups. Silica bcl is generally synthesized using a reverse micelle emulsion system via a high-pressure solvothermal method using a Teflon-lined autoclave which has various limitations in being able to be produced on a large scale. Therefore, a method was developed with the same strategy at atmospheric pressure using the reflux method. Until now there are not many reports regarding the yield in the synthesis of silica bcl materials, whether using the solvothermal method or the reflux method. Therefore, this research focuses on analyzing the yield of silica bcl synthesized using the solvothermal and reflux methods. The solvothermal method produced a maximum yield of 72% at 12 hours of synthesis, which is the aggregation time limit. The reflux method was able to produce a yield of up to 94% after 24 hours of synthesis, which could be increased up to 72 hours while maintaining the morphology of the silica bcl based on SEM micrographs. From the results of the N2 physisorption test, variations of 8, 18, and 24 hour synthesis using the reflux method showed a hierarchical pore distribution and silica bcl pores were distributed in the micropore, mesopore, and macropore areas. The largest specific surface area and pore volume for the synthesis of bcl silica using the reflux method were obtained at a synthesis duration of 18 hours, namely 536 m2 /g and 2.36 cm3 /g. The isothermal types and hysteresis patterns of silica bcl synthesized for 18 and 24 hours using the reflux method were type IV and H3.