High Surface Area Silica Particles Using Anionic Surfactant Template Prepared by One-step Spray Drying System for Dye Removal Application

Abstract

This study reported the effect of sodium lauryl sulfate (SLS) as a template on silica morphology and its properties. The precursor was prepared by producing silica nanofluid by the sol-gel method and mixed with various SLS concentrations. After that, the precursor was spray-dried to generate silica powder. An increase in SLS concentration up to 2 critical micelle concentration (CMC) indicates an increase in the silica particle size from 2.12 μm in untemplated silica particles to 2.58 μm. On the other hand, when the SLS concentration increases to 3 CMC, the particle size decreases to 2.19 μm. A significant increase in total pore volume and surface area is obtained for silica particles synthesized at least at the SLS concentration of 2 CMC, around eight higher volumes than without SLS addition. In addition, they have a macropore compared to silica particles synthesized without SLS addition that only exhibits mesopore. The surface area was 1,011 m2/g for the SLS concentration at 3 CMC, whereas the silica without SLS has only a surface area of 131 m2/g. The SLS concentration at 2 CMC or higher leads to a significant increase in its physical properties because the micelle formation is enough for sacrificed template formation. Methylene blue solution was used as an adsorbate for evaluating the dye adsorption capacity that followed the Langmuir isothermal adsorption model. The highest theoretical maximum monolayer adsorption capacity was 142.9 mg/g, obtained by silica adsorbent with the SLS concentration at 3 CMC.

Antioxidant and Antimicrobial Agents from Avocado (Persea americana) Seed Extract Encapsulated in Gum Arabic through Spray Drying Method

“…For stiff materials such as silica, this phenomenon usually makes the particle in doughnut-like form. However, since the character of gum arabic is quite ductile, it only becomes a concave particle [12,24]. On the other hand, after the presence of avocado seed extract, the dopped liquid consists of not only gum arabic and water but also the extract that has a higher boiling point [6,7,25].…”

“…By doing so, the active compounds would be isolated from exposure to potential damage conditions, increasing their stability and prolonging active compound shelf life [9]. The most common method for microcapsule preparation is spray drying due to the predominance of high-speed particle production, low production cost, simple continuous process, and handily scale up to an industrial scale for mass production [8,[10][11][12]. With this drying method, the feed, consisting of active compounds dispersed in the selected encapsulation agent as an emulsion that would rapidly be converted into a stable microcapsule, provides a low temperature around the core [13].…”

Amine-functionalized porous silica production via ex- and in-situ method using silicate precursors as a selective adsorbent for CO2 capture applications

“…Silica is widely applied as an absorbent-adsorbent material, catalyst support, membrane, and slow-release drug delivery material. Besides having good mechanical properties and non-toxicity, silica-based functional materials can be modified to improve their performance in specific applications [ [1] , [2] , [3] , [4] , [5] , [6] , [7] ]. Modifying silica is carried out by grafting active functional groups on the surface of the support material either physically or chemically [ [8] , [9] , [10] , [11] ].…”

“…Using soft templates such as surfactants, which are soluble in polar and non-polar solvents, initiates the synthesis of porous silica in one step [ [28] , [29] , [30] ]. The formed surfactant molecule aggregation will evaporate with the solvent in the spray drying system, leaving a hollow structure on the particle surface [ 1 ]. Synthesis of porous silica using soft templates with the consecutive sol-gel spray drying method is a promising alternative for producing support materials in the ex-situ route.…”