scholarly journals Production and Optimization of Bio-Based Silica Nanoparticle from Teff Straw (Eragrostis tef) Using RSM-Based Modeling, Characterization Aspects, and Adsorption Efficacy of Methyl Orange Dye

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Temesgen Abeto Amibo ◽  
Surafel Mustefa Beyan ◽  
Tsegaye Markos Damite

The brown teff straw was utilized in this study to produce silica using the sol-gel technique. After pretreatment, the raw material of brown teff straw was characterized. The data were analyzed using the central composite design and response surface technique, and four independent parameters, namely, temperature, NaOH concentration, rotational speed, and extraction time, were evaluated for process optimization. Before extracting silica with an alkaline solution, the silica content in the ash was determined using an AAS spectrometer. The silica content of teff straw ash is around 92.89%. The ash was treated with NaOH solution in the concentrations range of 1 M to 3 M (0.5 M interval). The extraction time varied at intervals of 55, 70, 85, 100, and 115 minutes. Temperatures were changed using magnetic stirrer equipment in the range of 80°C to 100°C (5°C interval). At 350 rpm, 400 rpm, 450 rpm, 500 rpm, and 550 rpm, the rotating speed was adjusted. The best extraction conditions for amorphous silica were 1.50 M NaOH, 109.99 min, 94.98°C, and a rotating speed of 499.57 rpm, with a maximum yield of 85.85%. XRD and FTIR analyses were used to assess the physicochemical characteristics of the extracted silica. The aqueous solutions of methyl orange were used to test the adsorption efficiency of silica. The percent of removal efficiency for methyl orange was 90.48%.

Author(s):  
Nik ‘Amirah Farhana Nik Ahmad Lutfi ◽  
Mohd Farid Atan ◽  
Nazeri Abdul Rahman ◽  
Shanti Faridah Salleh ◽  
Noraziah Abdul Wahab

The main objective of this study is to improve the mathematical modelling of Cymbopogon winterianus essential oil extraction by steam distillation proposed by Cassel and Vargas by minimum 5% error reduction. Two process variable of steam distillation which are extraction time and raw material state (dry or natural) has been optimized by using factorial experimental planning to obtain high yields of citronella essential oil from twig and leaves of lemongrass species Cymbopogon winterianus (C.winterianus). The optimal condition for maximum yield (0.942%) were found to be an extraction time, 4 hr, state, natural plant. The study of Cassel and Vargas was subsequently continued with five proposed kinetics model of the extraction process. The modelling of the extraction process is optimized by using one adjustable parameter of the model and the adequacy of the fit of the models to the experimental data are analyzed by using three statistical criteria that are correlation coefficient (r) ,the root mean square error (RMSE) and the mean relative deviation modulus (E). The result has shown that the mathematical model developed by Ana based on mass transfer fundamentals is the optimum mathematical model for the extraction of Cymbopogon winterianus essential oil by steam distillation.


2017 ◽  
Vol 9 (10) ◽  
pp. 47
Author(s):  
Nitalo André Farias Machado ◽  
Hosana Aguiar Freitas De Andrade ◽  
Luisa Julieth Parra-Serrano ◽  
Marileia Barros Furtado ◽  
Raissa Rachel Salustriano da Silva-Matos ◽  
...  

The wood-based panel industry is growing all over the world, and in many countries the raw material is becoming increasingly inadequate and increasingly expensive. Therefore, new inputs are needed to reduce production costs. The residue of babassu palm fruit after nut extraction process is an alternative, due to its fibrous characteristics, the high availability in the large agroindustrial complexes in the North of Brazil and the low cost. Thus the research was: (i) to determine the mechanical characteristics (tensile strength and elasticity), physicochemical characteristics (density, pH, extractives content and chemical composition) and micro-structural of the babassu residue, comparing it with the particles of Pinus sp., used in commercial panels; (ii) to evaluate the quality of panels manufactured with babassu residue by physical conditions (swelling in thickness and water absorption) and mechanical characterization (elasticity and rupture) based on Brazilian Technical Standards (NBR 14810-2: 2013), American (ANSI A208.1: 2009) and European (EN 312: 2003). Statistical analysis of the data was performed with the aid of Infostat software through analysis of variance using Tukey test at the 5% probability level. The babassu residue has technological characteristics that allow its use in particleboard production. However, there are particularities that may compromise its use, such as high silica content and high density.  Particleboard made from babassu residue presented mechanical performance above that required by current normative documents. However, for the physical properties, especially for the porosity of the particleboard of babassu, the obtained values were lower than the required minimum.


2011 ◽  
Vol 399-401 ◽  
pp. 666-672
Author(s):  
Shi Xiang Lu ◽  
Lian Dai ◽  
Wen Guo Xu ◽  
Cheng Xiang Ma

Quantum-sized TiO2 had been prepared by using Ti(n-OC4H9)4 as the raw material via a microwave-assisted sol-gel method. The influence of different processing temperature and time on the size of TiO2 was researched. The TiO2 was characterized by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). The prepared TiO2 presents anatase phase structure by TEM and XRD. The photocatalytic activity of TiO2 was evaluated by the degradation rate of methyl orange in aqueous solution. The particle size of TiO2 was about 9.10 nm when the processing temperature was 160°C and the processing time was 90 min (160°C-90min), and the photocatalytic performance was the best under this size. When the initial concentration of methyl orange was 10 mg/L and the amount of quantum-sized TiO2 was 0.6 g/L, the degradation rate of methyl orange under ultraviolet and solar irradiation at room temperature in 60 min were 40% and 86%, respectively.


Author(s):  
Hikmet Ibrahimov ◽  
Sara Malikli ◽  
Zenfira Ibrahimova ◽  
Rahim Babali ◽  
Sevinc Aleskerova

Abstractγ-Al2O3 was synthesized by the Sol–gel method, Ni (NO3)2 was placed in the pores by the impregnation method, and Ni-γ-Al2O3 was obtained by pyrolysis in a hydrogen stream in a CVD device. By the method of chemical vapors phase deposition (CVD) on Ni-Al2O3 catalytic converter with decomposition of methane in the natural gas produced carbon nanotubes (CNT) (Chunduri et al. in Mater Express 4(3):235–241, 2014; Zhou et al. in Appl Catal B 208:44–59, 2017). The catalytic activity of the catalysts in methane decomposition was examined from 650 °C to 900 °C by the method of chemical vapors phase deposition (CVD), the yield of CNTs tends to increase with the growth at the ratio of natural gas supply to hydrogen. The specific surface increases with an increase of nickel content and can reach 265.5 m2/g for a sample of 2% Ni-A12O3 at 850 °C. Growth at the temperature of methane decomposition leads to reduction in its specific surface. It has been established that the use of the Ni-Cu/γ-Al2O3 catalytic system, in which copper acts as a stabilizing additive, makes it possible to double the maximum yield of the carbon product during the decomposition of natural gas.


2019 ◽  
Vol 14 (7) ◽  
pp. 1934578X1986290 ◽  
Author(s):  
Massimo Tacchini ◽  
Ilaria Burlini ◽  
Immacolata Maresca ◽  
Alessandro Grandini ◽  
Tatiana Bernardi ◽  
...  

Vitis vinifera L. leaves from pruning are by-products of the wine industry and represent an important source of secondary raw material, thanks to their polyphenols content. Optimization of the extraction processes is a key factor for their valorization, and Design of Experiment (DOE) could be a tool to obtain the most performing extract in terms of polyphenols quality/quantity and bioactivity. Vitis vinifera Lambrusco leaves were subjected to ultrasound-assisted extractions guided by a 23 factorial design. Three independent parameters (% solvent, time of extraction, and solvent:solid ratio) were considered to evaluate the extraction process by analyzing the extraction yield, the total phenolic content (Folin-Ciocalteu assay), and the antioxidant capacity (DPPH assay). Moreover, the content of the main molecules was identified and quantified by reversed-phase high-performance liquid chromatography coupled with diode array detection and mass spectrometry. The DOE highlighted the best extraction conditions that showed slight changes considering the different evaluating parameters. The highest extraction yield was obtained by extraction with 100% water, 60 minutes of extraction time, and 30:1 solvent:solid ratio, but it was neither the richest in polyphenols nor antioxidant capacity. The latter 2 characteristics were associated with the extraction performed using 50% ethanol, 35 minutes of extraction time, and a 20:1 solvent:solid ratio. That extract also exhibited the highest quantity of flavonols.


2011 ◽  
Vol 287-290 ◽  
pp. 2199-2202
Author(s):  
Gui Qin Hou ◽  
Wen Li Zhang ◽  
Shui Jing Gao ◽  
Xiao Yan Wang

The ZnFe2O4 and TiO2 nanocomposite films was prepared by Sol-Gel method on conductive glass, and the influence factors of it’s photoelectrocatalytic performence such as the film layer, pole and voltage was investigated. The results indicated that: the photocatalytic effects of composite films with ZnFe2O4+ TiO2+ ZnFe2O4 was the best. The decomposing ratio of methyl orange with the photoelectrocatalysis of composite films at voltage 0.2-6V all increased unstably.At the same time, the distance from films to pole plank also had the effects on the photocatalytic activities of the films.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xiujuan Qin ◽  
Li Cui ◽  
Guangjie Shao

Ti-doped ZnO sol-composite films were prepared on the glass substrate by the two-step sol-gel technique. X-ray diffraction, Uv-Vis spectrophotometer, and FS spectrum of composite films were used to help make structure characterization and optical performance testing. The results showed that the composite was a mixture of ZnO + Zn2TiO4. Because of synergistic effect of both semiconductor oxides, composite films had a wide range of spectral response in the visible region, and the absorption band edge was about 510 nm, and the Green Belt of composite films luminous significantly enhanced. Photocatalytic oxidation experiments showed that using the composite films treatment (16.5 ml, l0 mg/L methyl orange aqueous solution)/cm2, the decolorization rate of methyl-orange was 90% after 3 hours irradiation.


2010 ◽  
Vol 148-149 ◽  
pp. 1152-1162 ◽  
Author(s):  
Wen Zhi Zheng ◽  
Li Chen ◽  
Xiang Hua Huang ◽  
Lei Fu

Under microwave radiation and using trimethyl chlorosilane as modifier, hydrophobic SiO2 aerogel was prepared through fractional hydrophobic modification and ambient pressure drying of the raw material, tetraethoxysilane (TEOS), in the process of sol-gel and acid-base catalysis. Hydrophilic SiO2 aerogels were also prepared using the microwave method and water bath heating method. The SiO2 aerogels prepared using the three methods, including their morphology and chemical composition, were analyzed and compared using scanning electron microscopy, Brunauer-Emmett-Teller analysis method, Fourier transform infrared spectroscopy, X-ray diffraction, and themogravimetric-differential scanning calorimetry. The results indicate that by adopting the microwave reaction, the specific surface area of the SiO2 aerogels was effectively increased and the structure of the internal nanoscale pores of petal-coated shape was found to exist under the dense external surface of the SiO2 aerogels. Thermal stability of the hydrophobic SiO2 aerogels prepared through fractional modification assisted by the microwave method was increased with the hydrophobic angle at153°, which showed super hydrophobicity.


2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Liza Md Salleh ◽  
Stashia ELeaness Rosland Abel ◽  
Gholamreza Zahedi ◽  
Russly Abd Rahman ◽  
Hasmida Mohd Nasir ◽  
...  

This current study focuses on the modelling and optimization of supercritical fluid extraction of Quercus infectoria galls oil. In this case, response surface methodology (RSM) and artificial neural network (ANN) were applied for the modelling and prediction of extraction yield of galls oil. A 17-run Box-Behnken Design (BBD) was employed to statistically optimize the process parameters of SC-CO2 extraction of Quercus infectoria galls at a condition as follows: pressure (5000, 6000, 7000 Psi), temperature (40, 50, 60°C) and extraction time (30, 45, 60 min). The maximum yield of the extracted oil is1.12 % and the optimum conditions are at an extraction pressure of 5574 Psi; extraction temperature of 75°C and extraction time of 54 min. Under the optimal conditions, the experimental results agree with the predicted values obtained through analysis of variance (ANOVA). This indicates a successful response surface methodology and highly satisfactory goodness of fit of the model used. The analysis of experimental design for process optimization results demonstrates that temperature and extraction time are the main parameters that influence the oil extraction of Quercus infectoria.


2018 ◽  
Vol 67 ◽  
pp. 01010
Author(s):  
Alfonsina Abat Amelenan Torimtubun ◽  
Anniza Cornelia Augusty ◽  
Eka Maulana ◽  
Lusi Ernawati

Indonesia is located along the equator lines with the high intensity of solar radiation averaging about 4.5 kWh of electrical energy/day. This potential leads to the selfsustaining energy possibility fulfilling the electricity needs. Due to their unique electronic structures and high-cost merit over the existing commercial PV technologies, perovskite solar cells (PSCs) have emerged as the next-generation photovoltaic candidate. Their highest power efficiency can be achieved of up to 22.1% in the last 5-6 years. However, this high efficiency came from CH3NH3PbI3 materials which contain lead, a toxic material. Herein calcium titanate (CT) as a lead-free perovskite material were synthesized through sintering of calcium carbonate (CaCO3) and titanium oxide (TiO2) by the sol-gel method. CT powders were characterized by SEM, XRF, FTIR and XRD then applied it onto the mesoporous heterojunction PSCs, with a device architecture ITO/TiO2/CaTiO3/C/ITO. By manipulating the raw material stoichiometry and heating temperature in the synthesis of CaTiO3, the device shows the highest power conversion efficiency (PCE) of 2.12%, shortcircuit current density (JSC) of 0.027 mA cm-2, open circuit voltage (VOC) of 0.212 V and fill factor (FF) of 53.90%. This sample can be an alternative way to create lead-free, largescale, and low-cost perovskite solar cells.


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