An Alternative and Simple Method for the Preparation of Bare Silica Nanoparticles Using Sugarcane Waste Ash, an Abundant and Despised Residue in the Brazilian Industry

Abstract

Sugarcane waste ash, a Si-rich waste product, is generated in large quantities and creates a serious disposal problem in the Brazilian ethanol-sugar industry, affecting the environment and public health. Here, a simple method capable of generating bare silica nanoparticles utilizing this residue is demonstrated. Firstly, the crystalline silica present in sugarcane waste ash (SWA) was converted into amorphous by melting a mixture of sodium hydroxide and SWA at 550 °C for 1 h. The silica nanoparticles (SiO 2 NPs) were formed by lowing pH. This production process of SiO 2 NPs from SWA was optimized varying the ash:NaOH mass ratio, increasing the silica extraction up to 96%. The sample's composition was characterized by total X-ray fluorescence spectroscopy, morphology and physical-chemical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, specific surface area measurements, Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA), followed by use as adsorbent for the removal of methylene blue dye. With this process of extraction, nanoparticles smaller than 100 nm were generated, with a surface area of 63 m 2 g-1 and a maximum adsorption capacity of 37 mg g-1 for methylene blue. The results indicate a successful process for obtaining an adsorbent from an industrial waste product using a cost effective and rapid synthesis procedure rendering renewable product.

WITHDRAWN: The effect of crystallization level of silica nanoparticles on cell proliferation of MRC-5 cell line and its prediction using artificial neural network

“…Because drying occurred at low temperature (70-150 °C), at which temperature the silica was amorphous (22). In previous studies, the XRD peak for amorphous and crystalline SiO 2 NPs was also 14-21 and 26-27°, respectively (7,23,24).…”

Fast, efficient and clean adsorption of bisphenol-A using renewable mesoporous silica nanoparticles from sugarcane waste ash

“…The renewable adsorbent material, mesoporous silica nanoparticles functionalized with hexadecyltrimethylammonium (MSN-CTAB) was prepared according to Rovani et al 2018. 23 Briey, in a round bottom ask, CTAB (2%, w:w) was dissolved in a mixture of water and butyl alcohol (1 : 1, v/v) and heated to 60 C. To this biphasic system, the sodium silicate solution (concentration 5.42%, w:w) obtained from sugarcane waste ash (as previously reported [23][24][25] ) was added, under constant agitation. Then, a solution of sulfuric acid (0.5 mol L À1 ) was added to this solution, drop by drop, until the pH decreased to 4, and the resulting gel was aged at 60 C for 8 h. The gel of silica nanoparticles aged was washed with distilled water, ltered and oven dried at 120 C. 23 2.2.2.…”

“…Then, $10.0 mg was weighed and analysed under an oxygen atmosphere with a ow of 50.0 mL min À1 , using an alumina-port sample heated to 900 C with a heating rate of 10 C min. 23,25 To obtain FTIR-ATR spectra and TG curves of MSN-CTAB aer an interaction with BPA, the MSN-CTAB were isolated by centrifugation, dried for 5 h at 100 C, and analysed. 23…”

Development of Interlocking Concrete Blocks with Added Sugarcane Residues

“…As a result, residual products composed of sand, ash [6][7][8][9][10], and non-burned bagasse are generated from the boilers. The sugarcane residues are generated in large quantities and create a serious disposal problem for the ethanol-sugar industry, affecting the environment and public health [11].…”