Rice Hull Micro and Nanosilica: Synthesis and Characterization

2016 ◽  
Vol 718 ◽  
pp. 77-80 ◽  
Author(s):  
Worawat Jansomboon ◽  
Khatawut Boonmaloet ◽  
Suradet Sukaros ◽  
Paweena Prapainainar

Rice hull is a by-product natural material composing of high amount of silica. In this work, silica microparticles were synthesized from rice hull using 3 temperature levels of calcination at 500, 600, and 850 ºC. Then, they were transformed to silica nanoparticles by precipitation method using sodium silicate as an initial substance synthesized from rice hull. Finally, the properties of silica particle were studied such as characteristics, morphology of particle, component, and size of silica. The result showed the silica structure became more crystalline when the temperature was increased. When the concentration of sodium silicate increased, more agglutination occurred in the silica structure. The results also indicated that the particle size and component of silica synthesized by heating rice hull at 600 ºC followed by precipitation method were the same as those of commercial silica.

2020 ◽  
Vol 16 (2) ◽  
pp. 250
Author(s):  
Sunardi Sunardi ◽  
Erlynda Desy Krismawati ◽  
Argoto Mahayana

<p>Pencegahan osteoporosis dilakukan dengan mengkonsumsi kalsium. Pada umumnya kalsium yang dikonsumsi dalam bentuk mikro kalsium. Ukuran mikro kalsium hanya diserap tubuh sekitar 50%, sehingga sering menyebabkan defisiensi. Sehingga, teknologi untuk membuat ukuran nanokalsium telah dikembangkan agar penyerapan kalsium dalam tubuh lebih besar. Penelitian ini bertujuan untuk mensintesis nanokalsium dari cangkang telur yang merupakan limbah industri roti. Sintesis nanokalsium oksida dari cangkang telur dengan metode presipitasi. Sintesis dilakukan dengan mereaksikan cangkang telur yang telah bersih dan kering dengan HCl 2 N. Hasil reaksi dipisahkan dengan penyaringan sehingga diperoleh filtrat. Filtrat yang diperoleh direaksikan dengan NaOH sampai pengendapan tidak terbentuk lagi. Endapan yang diperoleh kemudian dipisahkan, dioven, dan dibakar dalam tanur pada suhu 600 °C selama 1 jam. Serbuk hasil sintesis dikarakterisasi menggunakan SEM-EDX, XRD dan FTIR. Hasil penelitian menunjukkan bahwa cangkang telur dapat disintesis menjadi nanokalsium oksida berupa kristal berwarna putih. Karakterisasi menggunakan SEM-EDX diperoleh hasil bahwa nanokalsium oksida dari cangkang telur berbentuk speris, teraglomerasi dengan ukuran partikel 12,41582 ± 0,13961 nm, mengandung unsur yaitu O (55,83%), C (33,24%), dan Ca (10,94%). Karakterisasi dengan XRD menunjukkan bahwa ukuran kristal nanokalsium oksida diperoleh hasil sebesar 10,46 nm. Karakterisasi dengan FTIR diperoleh puncak pada bilangan gelombang 1477,54 cm-1, 1053,15 cm-1, 8863,68 cm-1 dan ikatan Ca-O pada bilangan gelombang 512 cm-1.</p><p><strong>Synthesis and Characterization of Nano-Calcium Oxide from Eggshells. </strong>Consumption of calcium can prevent osteoporosis. Usually, calcium is consumed in the form of micro calcium. The micro size calcium is only absorbed by the body at around 50%, causing calcium deficiency. Therefore, technology to produce nano-size calcium has been developed to increase the amount of adsorption. This study aims to synthesize nano calcium from eggshells as a solid waste of bread industries. The synthesis was conducted by precipitation method. The synthesis was carried out by reacting clean and dry eggshells with HCl 2 N, and then followed by filtering to obtain the filtrate. The filtrate obtained was reacted with NaOH until the calcium was precipitated. The precipitate obtained was then separated, roasted, and burned in a furnace at 600 °C for 1 hour. The synthesized powders were characterized using SEM-EDX, XRD, and FTIR. The results showed that eggshells could be synthesized into nano-calcium oxide in the form of white crystals. Characterization using SEM-EDX showed that nano-calcium oxide from spherical eggshells, agglomerated with the particle size of 12.41582 ± 0.13961 nm, with elemental content of O (55.83%), C (33.24%), and Ca (10.94%). Characterization with XRD shows that the size of nano calcium oxide crystals was 10.46 nm. Characterization with FTIR shows peak at wavenumbers 1477.54 cm<sup>-1</sup>, 1053.15 cm<sup>-1</sup>, 8863.68 cm<sup>-1</sup>, and the Ca-O bond reveals at 512 cm<sup>-1</sup>.</p><strong></strong>


2020 ◽  
Vol 16 (2) ◽  
pp. 99
Author(s):  
Sunardi Sunardi ◽  
Erlynda Desy Krismawati ◽  
Argoto Mahayana

<p>Pencegahan osteoporosis dilakukan dengan mengkonsumsi kalsium. Pada umumnya kalsium yang dikonsumsi dalam bentuk mikro kalsium. Ukuran mikro kalsium hanya diserap tubuh sekitar 50%, sehingga sering menyebabkan defisiensi. Sehingga, teknologi untuk membuat ukuran nanokalsium telah dikembangkan agar penyerapan kalsium dalam tubuh lebih besar. Penelitian ini bertujuan untuk mensintesis nanokalsium dari cangkang telur yang merupakan limbah industri roti. Sintesis nanokalsium oksida dari cangkang telur dengan metode presipitasi. Sintesis dilakukan dengan mereaksikan cangkang telur yang telah bersih dan kering dengan HCl 2 N. Hasil reaksi dipisahkan dengan penyaringan sehingga diperoleh filtrat. Filtrat yang diperoleh direaksikan dengan NaOH sampai pengendapan tidak terbentuk lagi. Endapan yang diperoleh kemudian dipisahkan, dioven, dan dibakar dalam tanur pada suhu 600 °C selama 1 jam. Serbuk hasil sintesis dikarakterisasi menggunakan SEM-EDX, XRD dan FTIR. Hasil penelitian menunjukkan bahwa cangkang telur dapat disintesis menjadi nanokalsium oksida berupa kristal berwarna putih. Karakterisasi menggunakan SEM-EDX diperoleh hasil bahwa nanokalsium oksida dari cangkang telur berbentuk speris, teraglomerasi dengan ukuran partikel 12,41582 ± 0,13961 nm, mengandung unsur yaitu O (55,83%), C (33,24%), dan Ca (10,94%). Karakterisasi dengan XRD menunjukkan bahwa ukuran kristal nanokalsium oksida diperoleh hasil sebesar 10,46 nm. Karakterisasi dengan FTIR diperoleh puncak pada bilangan gelombang 1477,54 cm-1, 1053,15 cm-1, 8863,68 cm-1 dan ikatan Ca-O pada bilangan gelombang 512 cm-1.</p><p><strong>Synthesis and Characterization of Nano-Calcium Oxide from Eggshells. </strong>Consumption of calcium can prevent osteoporosis. Usually, calcium is consumed in the form of micro calcium. The micro size calcium is only absorbed by the body at around 50%, causing calcium deficiency. Therefore, technology to produce nano-size calcium has been developed to increase the amount of adsorption. This study aims to synthesize nano calcium from eggshells as a solid waste of bread industries. The synthesis was conducted by precipitation method. The synthesis was carried out by reacting clean and dry eggshells with HCl 2 N, and then followed by filtering to obtain the filtrate. The filtrate obtained was reacted with NaOH until the calcium was precipitated. The precipitate obtained was then separated, roasted, and burned in a furnace at 600 °C for 1 hour. The synthesized powders were characterized using SEM-EDX, XRD, and FTIR. The results showed that eggshells could be synthesized into nano-calcium oxide in the form of white crystals. Characterization using SEM-EDX showed that nano-calcium oxide from spherical eggshells, agglomerated with the particle size of 12.41582 ± 0.13961 nm, with elemental content of O (55.83%), C (33.24%), and Ca (10.94%). Characterization with XRD shows that the size of nano calcium oxide crystals was 10.46 nm. Characterization with FTIR shows peak at wavenumbers 1477.54 cm<sup>-1</sup>, 1053.15 cm<sup>-1</sup>, 8863.68 cm<sup>-1</sup>, and the Ca-O bond reveals at 512 cm<sup>-1</sup>.</p><strong></strong>


2015 ◽  
Vol 16 (7) ◽  
pp. 661-667 ◽  
Author(s):  
Gisela Alvarez ◽  
Maria Echazu ◽  
Christian Olivetti ◽  
Martin Desimone

1989 ◽  
Vol 54 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Milan Stakić ◽  
Slobodan Milonjić ◽  
Vladeta Pavasović ◽  
Zoja Ilić

Ultrafiltration of three laboratory made silica and two commercial silica sols was studied using Amicon YC membrane in a 200 ml capacity batch-cell. The effect of silica particle size, stirring conditions, pressure, pH and silica contents on ultrafiltration was investigated. The results obtained indicate that the smaller particles have, disregarding the stirring conditions, lower filtration flux. The differences observed in filtration flux are more pronounced in the conditions without stirring. The obtained value of the membrane resistance is independent of the conditions investigated (stirring, pressure, pH, silica contents and particle size). The values of the resistance of polarized solids, specific resistance, and the mass of gel per membrane surface unit were calculated for all experimental conditions.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 574
Author(s):  
Nikhat Perween ◽  
Sultan Alshehri ◽  
T. S. Easwari ◽  
Vivek Verma ◽  
Md. Faiyazuddin ◽  
...  

Molecules with poor aqueous solubility are difficult to formulate using conventional approaches and are associated with many formulation delivery issues. To overcome these obstacles, nanosuspension technology can be one of the promising approaches. Hence, in this study, the feasibility of mefenamic acid (MA) oral nanosuspension was investigated for pediatric delivery by studying the role of excipients and optimizing the techniques. Nanosuspensions of MA were prepared by adopting an antisolvent precipitation method, followed by ultrasonication with varying concentrations of polymers, surfactants, and microfluidics. The prepared nanosuspensions were evaluated for particle size, morphology, and rheological measures. Hydroxypropyl methylcellulose (HPMC) with varying concentrations and different stabilizers including Tween® 80 and sodium dodecyl sulfate (SLS) were used to restrain the particle size growth of the developed nanosuspension. The optimized nanosuspension formula was stable for more than 3 weeks and showed a reduced particle size of 510 nm with a polydispersity index of 0.329. It was observed that the type and ratio of polymer stabilizers were responsive on the particle contour and dimension and stability. We have developed a biologically compatible oral nanoformulation for a first-in-class drug beautifully designed for pediatric delivery that will be progressed toward further in vivo enabling studies. Finally, the nanosuspension could be considered a promising carrier for pediatric delivery of MA through the oral route with enhanced biological impact.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.


2015 ◽  
Vol 659 ◽  
pp. 394-398 ◽  
Author(s):  
Nutthaphon Liawthanyarat ◽  
Sarawut Rimdusit

Polybenzoxazine nanocomposites filled with three different sizes of silica nanoparticles are investigated for their mechanical and thermal properties. In this research, silica nanoparticles with primary particle sizes of 7, 14 and 40 nm were incorporated in polybenzoxazine matrix at a fixed content of 3% by weight. From the experimental results, the storage modulus of the polybenzoxazine nanocomposite was found to systematically increase with decreasing the particle sizes of nanosilica suggesting better reinforcement of the smaller particles. Glass transition temperature was found to slightly increase with the addition of the silica nanoparticles. The uniformity of the composite samples were also evaluated by thermogravimetric analysis to show good dispersion of the silica nanoparticles in the composite samples as a result of high processability of the benzoxazine resin used i.e. low A-stage viscosity with good wetting behaviors. Degradation temperature at 5% weight loss (Td,5) of polybenzoxazine nanocomposites filled with different particle sizes of silica nanoparticles was found to increase from the value of 325 °C of the neat polybenzoxazine to the maximum value of about 340 °C with an addition of the nanosilica of the smallest particle size used. Finally, the smaller nanosilica particle size was also found to show more pronounced effect on Td,5enhancement of the composite samples as a result of greater barrier effect from larger surface area of the smaller particles.


2007 ◽  
Vol 5 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Abdülhadi Baykal ◽  
Yüksel Köseoğlu ◽  
Mehmet Şenel

AbstractHeating hydrous manganese (II) hydroxide gel at 85 °C for 12 hours produces Mn3O4 nanoparticles. They were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (FTIR). The particle size estimated from the SEM and X-ray peak broadening is approximately 32 nm, showing them to be nanocrystalline. EPR measurements confirm a typical Mn2+signal with a highly resolved hyperfine structure.


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