Eco-fabrication of hierarchical porous silica monoliths by ice-templating of rice husk ash

2017 ◽  
Vol 19 (1) ◽  
pp. 188-195 ◽  
Author(s):  
Amin Bahrami ◽  
Ulla Simon ◽  
Niloofar Soltani ◽  
Sara Zavareh ◽  
Johannes Schmidt ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Porous Silica ◽  
Synthesis Process ◽  
Sustainable Chemistry ◽  
Silica Monoliths ◽  
Hierarchical Porous ◽  
Ice Templating

In this study, within a sustainable chemistry approach, a clean and eco-friendly synthesis process of silica monoliths compatible with environmental limitations is developed.

Synthesis of bimodal porous silica from rice husk ash via sol–gel process using chitosan as template

2008 ◽  
Vol 62 (10-11) ◽  
pp. 1476-1479 ◽  
Author(s):  
T. Witoon ◽  
M. Chareonpanich ◽  
J. Limtrakul
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Porous Silica ◽  
Sol Gel Process

Hydrothermal Synthesis of TiO2/SiO2 Hybrid Photocatalyst from Rice Husk Ash

2007 ◽  
Vol 352 ◽  
pp. 281-285 ◽  
Author(s):  
P. Sujaridworakun ◽  
Supatra Jinawath ◽  
W. Panpa ◽  
Akira Nakajima ◽  
Masahiro Yoshimura
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Uv Light ◽  
Porous Silica ◽  
Chemical Properties ◽  
Nano Crystalline ◽  
Ultraviolet Ray ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
Fine Tio2

Photocatalyst materials were prepared as a hybrid between TiO2 /SiO2 via low temperature hydrothermal method (150oC) without further heat treatment. Porous silica from rice husk ash was used as a support for fine TiO2 particles which acted as a photocatalyst when radiated with a UV light. TiO2-deposited SiO2 was successfully prepared through hydrolysis of TiOSO4 solution by controlling synthesis parameters such as pH ,concentration of TiOSO4, temperature and time under hydrothermal treatment. The obtained products were characterized for physical and chemical properties by means of XRD, XRF, BET and TEM . It was found that pH had an influence on the crystallization of TiO2, and under an appropriated pH, only anatase presented along with amorphous phase. High crystallinity of nano-crystalline anatase ( about 5 nm) deposited on silica surface was observed through TEM. Adsorption and photocatalytic performances of the prepared catalyst were evaluated in methylene blue aqueous solution in the dark and under ultraviolet ray irradiation, respectively. Due to the synergetic functions of adsorption by porous substrate and decomposition by TiO2 photocatalyst, an enhancing of photocatalytic activity for decomposition of organic pollutants in water under UV rays was obtained.

Fabrication of SiO2 Porous Ceramics from Rice Husk Ash

2014 ◽  
Vol 881-883 ◽  
pp. 1035-1039
Author(s):  
Hui Chen ◽  
Lei Zhao ◽  
Xi Tang Wang ◽  
Shu Jing Li ◽  
Liang Feng ◽  
...  
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
Soft Clay ◽  
Porous Silica ◽  
Porous Ceramics ◽  
Linear Shrinkage ◽  
High Porosity ◽  
Porous Texture ◽  
Comprehensive Properties ◽  
Grain Packing

Porous silica ceramics were prepared from rice husk ash with a small amount of soft clay as workability agent by the in situ combustion pore-forming technique. Then, the effects of the forming pressures on the linear shrinkage, density, porosity, absorption of water and mechanical strength were investigated. The results showed that the pores in the samples consisted of two groups. One was original porous texture from rice husk silica, which ranged from 1-10 μm. The other was formed by burning of carbon and grain packing. Obviously, the greater the forming pressure, the denser the sample. Especially, the amounts of the pores with bigger diameter dropped significantly when the forming pressure was greater than 25KN. Porous ceramics with density 1.07g/cm3have high porosity and excellent comprehensive properties up to 10MPa.The preparation of porous ceramics utilizing high content rice husk would provide advantages of economical and ecological aspect.

Production of Al2O3/SiC Nanoparticles from Rice Husk Ash by Self-Propagating High-Temperature Synthesis Process and Ball Milling

2017 ◽  
Vol 904 ◽  
pp. 93-97 ◽  
Author(s):  
Morteza Hoseini ◽  
Ghasem Dini ◽  
Azam Fatemi
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Ball Milling ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
Sic Nanoparticles ◽  
High Temperature Synthesis

In this study, silica obtained from the rice husk was used to synthesis of Al2O3/SiC nanoparticles. For this reason, the ash obtained from the burning of the rice husk which contains more than 93 wt. % silica, aluminum and carbon powders with the molar ratios of 3:4:6 were mixed and then compacted into pellets by using a cylindrical die under a pressure 50MPa. In order to conduct the self-propagating high-temperature synthesis (SHS), the produced pellets were placed in an electrical furnace at 850°C under the argon gas atmosphere. Then, a planetary ball milling for 4 to 24h was used to decrease the particle size of the synthesized composite. The results of XRF, XRD, SEM and DLS investigations shown that the rice husk ash can be used to fabricate Al2O3/SiC nanoparticles with an average particle size of about 80 to 65nm via SHS process and ball-milling for 12 to 24h.

Silk fibroin as a biotemplate for hierarchical porous silica monoliths for random laser applications

2018 ◽  
Vol 6 (11) ◽  
pp. 2712-2723 ◽  
Author(s):  
Moliria V. Santos ◽  
Édison Pecoraro ◽  
Silvia H. Santagneli ◽  
André L. Moura ◽  
Maurício Cavicchioli ◽  
...  
Keyword(s):  
Bombyx Mori ◽  
Silk Fibroin ◽  
Porous Silica ◽  
Random Laser ◽  
Laser Applications ◽  
Silica Monoliths ◽  
Hierarchical Porous

Bombyx mori silk fibroin offers unlimited opportunities for functionalization, processing, and biological integration.

Microstructure silica leached by NaOH from semi-burned rice husk ash for moisture adsorbent

2021 ◽  
Vol 1 (108) ◽  
pp. 5-15
Author(s):  
D.Q. A’yuni ◽  
A. Subagio ◽  
H. Hadiyanto ◽  
A.C. Kumoro ◽  
M. Djaeni
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Water Adsorption ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Silica Particles ◽  
Synthesis Process ◽  
Positive Contribution

Purpose: This work aims to study the water vapor adsorption property of fine silica particles from semi-burned rice husk ash. The semi-burned rice husk ash is selected as the raw material since it contains high silica and is easily found as a by-product of pottery furnace combustion. Design/methodology/approach: The silica adsorbent from semi-burned rice husk ash was prepared through a sol-gel method using various NaOH concentrations. In doing so, the different pH precipitation was also observed. Here, the fine silica powder was obtained by pulverizing dry sol-gel. The product characterizations were conducted based on water adsorption capacity at different air relative humidity. Findings: The results show no significant effects of different treatments in the extraction and gelation process. The fine silica particles exhibit large porous surfaces with agglomerated nano-sized particles that formed pores. This porous structure is related to the distributions of pore size of each sample, which mostly obey the mesoporous characteristics. From sorption isotherm, weak adsorbent-adsorbate bonding was observed and demonstrated multilayer adsorption of mesoporous materials. Research limitations/implications: The study of water adsorption was carried out at room temperature, which can change at any time, even though has no significant effect on the humidity. However, it is needed to study the adsorption in an incubated area to receive a constant temperature. Practical implications: The products namely silica prepared from semi-burned rice husk ash show a high moisture uptake, especially at a high relative humidity region. This property can be comparable with the other silica preparation methods. So, this product can be a highly potential adsorbent for air or gas dehumidification systems. Originality/value: The silica-based semi-burned rice husk ash as a water adsorbent is more sustainable than commercial silica. This is a positive contribution to find a potentially develop water vapor adsorbent with good adsorption capacity. Besides, the synthesis process is a simple and low-cost process.

scholarly journals Hierarchical porous silica monoliths: A novel class of microreactors for process intensification in catalysis and adsorption

2016 ◽  
Vol 19 (1-2) ◽  
pp. 231-247 ◽  
Author(s):  
Anne Galarneau ◽  
Alexander Sachse ◽  
Bilel Said ◽  
Carl-Hugo Pelisson ◽  
Paolo Boscaro ◽  
...  
Keyword(s):  
Porous Silica ◽  
Process Intensification ◽  
Silica Monoliths ◽  
Hierarchical Porous
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