Synthesis of High Surface Area Mesoporous Silica Powder Using Anionic Surfactant

Over the past several years, synthesized mesoporous nanosilica (SiO2) powders have been developed by many different methods. The methods include precipitation and microemulsion, the St？ber method, chemistry, and technology. In this study, mesoporous silica powders are synthesized by the sol-gel method. The sol-gel method obtains a high purity silica powder; however, the process yields a low percentage. Past syntheses of SiO2 powder precursors are expensive, but this study needs to find a replacement precursor for low cost alternatives. A high surface area was used to form an anion surfactant sodium dodecyl sulfate, which regulates the molar concentration. The particles size variability was changed by the precursor molar ratio of the sodium silicate solution with hydrochloric acid. 1. Introduction The silica powders are considered competent materials because of their unique characteristics, such as low density, low thermal conductivity, high surface area, high thermal shock resistance, and high specific strength [1, 2]. They also have the potential to be used in a wide range of applications, including catalysts, thermal and electrical insulators, adsorbents, filters, light-weight structural materials, optoelectronic devices, humidity sensors, chemical polishing, and other fine precision equipments [3–6]. According to recent academic and technical reports, various chemical methods have been developed to control the particle shapes, size, and distribution of fine silica particles. In the conventional method, ammonia-catalyzed reactions of tetraethylorthosilicate with water in low-molecular-weight alcohols are synthesized by St？ber method. However, this method has to use a high cost alkoxide or organometallic compound. In this work, we demonstrate a sol-gel method that controls the sphere size, cubic shapes, and mesoporous silica using the low cost sodium silicate solution with surfactant sodium dodecyl sulfate (SDS). The pore size and surface area of the silica varied with pH and aging time. The characteristics of the silica varied with the change in surface area, pore volume, and particle shapes. 2. Experimental 2.1. Synthesis The flow chart in Figure 1 shows the experimental steps involved in the rapid processing of cubic silica powders. In a study on the typical synthesis, the water glass solution was prepared in a beaker and the 1？M？HCl solution dripped for 30 minutes. The mixture was stirred for 10 hours with a magnetic bar at 400？rpm using a churner [7]. The water glass solution was diluted with the desired weight percentage of silica in the starting