Superhydrophobic Coating Derived from Geothermal Silica to Enhance Material Durability of Bamboo Using Hexadimethylsilazane (HMDS) and Trimethylchlorosilane (TMCS)

Abstract

Bamboo, a fast-growing plant from Asia, is used as building material with unique properties, while exhibiting fast degradation due to its hydrophobicity. Therefore, many attempts have been implemented using several technologies for bamboo modification to alter the hydrophobicity. Most previous studies producing superhydrophobic properties are conducted by using tetraethoxysilane (TEOS) as a precursor agent. However, this method, using TEOS with harmful properties and unaffordable compounds, requires many steps to accomplish the experimental method. Therefore, this paper employed geothermal solid waste as a silica source of the precursor. Thus, an effective and efficient method was applied to prepare superhydrophobic coating by using a precursor of geothermal silica and further modification using hexamethyldisilazane (HMDS) and trimethylchlorosilane (TMCS). The research was executed by the full factorial statistical method using two numerical variables (HMDS/TMCS concentration and silica concentration) and one categorical variable (solvent types). The uncoated material revealed higher weight gain in mass and moisture content than that of the coated bamboo after the soil burial test to assess the durability of the bamboo. However, the durability of superhydrophobic coating realized hydrophobic performance for both agents during sand abrasion for a total of 120 s at an angle of 45°. Statistical results showed the optimum contact angle (CA) achieved in superhydrophobic performance with lower silica concentration for HMDS concentration and the appropriate solvent of n-hexane for HMDS and iso-octane for TMCS. All results were supported using many instruments of analysis to confirm the step-by-step alteration of geothermal silica to be used as a superhydrophobic coating, such as XRF, XRD, FTIR, SEM, and SEM EDX.

Optimization of the Sound Absorption Coefficient (SAC) from Cellulose–Silica Aerogel Using the Box–Behnken Design

“…44 The geothermal silica is widely used in various applications, such as an adsorbent, 45 chitosan coating, 46 preparation of silicon, 47 synthesis of silica xerogel, 48 synthesis of silica aerogel, 49 synthesis of mesoporous silica, 50,51 and superhydrophobic coating. 52 Meanwhile, fly ash, 53 bamboo leaves, 54,55 rice husks, 24,56,57 and bagasse were extensively studied for their silica content. The initial method for preparing cellulose−silica aerogel is dissolution that is performed using cellulose solvents, such as calcium thiocyanate, 58 ammonium thiocyanate, 59 liquid ammonia/ammonium thiocyanate (NH 3 /NH 4 SCN), 60 and N,N-dimethylacetamide/lithium chloride (DMAc/LiCl).…”

“…It is released from the geothermal power plant in Dieng . The geothermal silica is widely used in various applications, such as an adsorbent, chitosan coating, preparation of silicon, synthesis of silica xerogel, synthesis of silica aerogel, synthesis of mesoporous silica, , and superhydrophobic coating . Meanwhile, fly ash, bamboo leaves, , rice husks, ,, and bagasse were extensively studied for their silica content.…”

Synthesis of Aminopropyl-Functionalized Mesoporous Silica Derived from Geothermal Silica for an Effective Slow-Release Urea Carrier

“…In this study, SRU with MS as the matrix medium was prepared from geothermal silica. Geothermal silica can be applied as the silica source to synthesize MS due to its high content of SiO 2 , which has been utilized in numerous applications. − The geothermal silica was purified using acid-leaching treatment before it was used. The purified silica was converted to sodium silicate as the precursor of silica source in MS preparation.…”

Superhydrophobic coating based on silica derived from bagasse modified with vinyltriethoxysilane and copper (Cu) as antibacterial agent

“…Thus, a safer, cheaper, and environmentally friendly silica precursor is needed [23]. Natural silica can be found in many types of plants and agricultural waste such as rice husks [24][25][26], geothermal waste [27,28,37,38,[29][30][31][32][33][34][35][36], rice straws [39,40], bamboo leaf [41,42], corncobs [43,44], as well as bagasse [45][46][47]. Bagasse is a sugarcane processing waste that is abundant and is often only used as fuel for steam boilers that produce a significant amount of ash [48].…”