Our manuscript has been accepted for publication in the Journal of Non-Crystalline Solids published by Elsevier (Impact factor: 1.597); a journal on the chemical electronic, optical and mechanical properties of glasses, amorphous semiconductors and metals, sol-gel materials, the liquid state of these solids and the process by which they are formed.
Using bagasse ash as a silica source when preparing silica aerogels via ambient pressure drying
N. Nazriati, Heru Setyawan, Samsudin Affandi, Minta Yuwana, Sugeng Winardi
HIGHLIGHTS
- A novel and cheap approach for producing silica aerogels is proposed.
- The silica aerogels have very high surface area which can reach > 1000 m2/g.
- The silica aerogels exhibit strong hydrophobicity.
- Bagasse ash, a solid waste of sugar mills, is a viable material to produce silica aerogels.
ABSTRACT
Silica aerogels were prepared using bagasse ash as a silica source through a route involving the surface modification of wet gels and ambient pressure drying (APD). The silica in the bagasse ash was extracted using a NaOH solution to form the sodium silicate precursor for the silica aerogels. Trimethylchlorosilane (TMCS) and hexamethyldisalazane (HMDS) were used to replace the surface silanol groups with alkyl groups to prevent the condensation and shrinkage of the gel structure during APD. The prepared silica aerogels exhibited strong hydrophobicity. The silica aerogels aged in water possess a higher surface area than those aged in hexane. The mixing time for the silylating agents with the silica precursor influences the surface area of the silica aerogels. The highest surface area and pore volume of the silica aerogels were 1114 m2/g and 2.16 cm3/g, respectively.
Keywords: bagasse ash; silica aerogel; ambient pressure drying; surface modification; silylation.
GRAPHICAL ABSTRACT
Elkimkor 