Preparation and characterization of a RHA/TiO2 nanocomposite: introduction of an efficient and reusable catalyst for chemoselective trimethylsilyl protection and deprotection of alcohols and phenols

RSC Advances ◽  
2016 ◽  
Vol 6 (28) ◽  
pp. 23564-23570 ◽  
Author(s):  
Mohadeseh Seddighi ◽  
Farhad Shirini ◽  
Omid Goli-Jolodar
Keyword(s):  
Rice Husk ◽  
Amorphous Silica ◽  
Rice Husk Ash ◽  
Anatase Phase ◽  
Natural Source ◽  
Titania Nanoparticles ◽  
Reusable Catalyst

In this work, rice husk ash (RHA), as a natural source of amorphous silica, was used as a support for the synthesis of anatase-phase titania nanoparticles leading to the RHA/TiO2 nanocomposite.

scholarly journals Optimization of nanostructured/nano sized rice husk ash preparation

2020 ◽  
Vol 17 (3(Suppl.)) ◽  
pp. 0953
Author(s):  
Medhat Mostafa ◽  
Hamdy Salah ◽  
Amro B. Saddek ◽  
Nabila Shehata
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Particle Shape ◽  
Rice Husk Ash ◽  
Loss On Ignition ◽  
Shape Distribution ◽  
Disk Mill ◽  
Grinding Time

The objective of the study is developing a procedure for production and characterization of rice husk ash (RHA). The effects of rice husk (RH) amount, burning/cooling conditions combined with stirring on producing of RHA with amorphous silica, highest SiO2, lowest loss on ignition (LOI), uniform particle shape distribution and nano structured size have been studied. It is concluded that the best amount is 20 g RH in 125 ml evaporating dish Porcelain with burning for 2 h at temperature 700 °C combined with cooling three times during burning to produce RHA with amorphous silica, SiO2 90.78% and LOI 1.73%. On the other hand, cooling and stirring times affect the variation of nano structured size and particle shape distribution. However, no crystalline phases were found in RHA in all cases. Results proved that the Attritor ball mill was more suitable than vibration disk mill for pulverizing nano structured RHA with 50% of particle size (D50) lower than 45 mm and 99 % of particle size (D99) lower than 144 mm to nanosized RHA with D50 lower than 36 nm and D99 lower than 57 nm by grinding time 8.16 min to every 1 g RHA without changes in morphousity of silica.

Mechanoactivation Of Rice Husk Ash In Laboratory Conditions

2019 ◽  
pp. 20-26
Keyword(s):  
Mechanical Activation ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Silicon Oxide ◽  
Rice Husk Ash ◽  
Pozzolanic Activity ◽  
Maximum Solubility ◽  
Laboratory Conditions ◽  
Before And After ◽  
Mineral Additive

In many rice producing countries of the world, including in Vietnam, various research aimed at using rice husk ash (RHA) as a finely dispersed active mineral additive in cements, concrete and mortars are being conducted. The effect of the duration of the mechanoactivation of the RHA, produced under laboratory conditions in Vietnam, on its pozzolanic activity were investigated in this study. The composition of ash was investigated by laser granulometry and the values of indicators characterizing the dispersion of its particles before and after mechanical activation were established. The content of soluble amorphous silicon oxide in rice husk ash samples was determined by photocolorimetric analysis. The pizzolanic activity of the RHA, fly ash and the silica fume was also compared according to the method of absorption of the solution of the active mineral additive. It is established that the duration of the mechanical activation of rice husk ash by grinding in a vibratory mill is optimal for increasing its pozzolanic activity, since it simultaneously results in the production of the most dispersed ash particles with the highest specific surface area and maximum solubility of the amorphous silica contained in it. Longer grinding does not lead to further reduction in the size of ash particles, which can be explained by their aggregation, and also reduces the solubility of amorphous silica in an aqueous alkaline medium.

Synthesis and characterization of red mud and rice husk ash-based geopolymer composites

2013 ◽  
Vol 37 ◽  
pp. 108-118 ◽  
Author(s):  
Jian He ◽  
Yuxin Jie ◽  
Jianhong Zhang ◽  
Yuzhen Yu ◽  
Guoping Zhang
Keyword(s):  
Rice Husk ◽  
Red Mud ◽  
Rice Husk Ash ◽  
Synthesis And Characterization ◽  
Geopolymer Composites

Elemental Characterization of Rice Husk Ash from Local Rice Species in South Eastern Nigeria

2020 ◽  
Vol 3 (4) ◽  
pp. 1081-1085
Author(s):  
Paul S. Ogbuefi ◽  
Placid Nwaokafor ◽  
Ifeanyi J. Njoku ◽  
Ogechukwu J. Uzuegbunam
Keyword(s):  
Rice Husk ◽  
Rice Husk Ash ◽  
South Eastern ◽  
Elemental Characterization

scholarly journals Preparation and characterization of rice husk ash (RHA)-TiO2 / ZnO composites and its application in treating effluents from textile industries

2013 ◽  
Vol 47 (4) ◽  
pp. 445-448 ◽  
Author(s):  
MH Kabir ◽  
MF Kabir ◽  
F Nigar ◽  
S Ahmed ◽  
AI Mustafa ◽  
...  
Keyword(s):  
Composite Materials ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Textile Dye ◽  
X Ray ◽  
Textile Dye Effluent ◽  
Degradation Reaction ◽  
D Values ◽  
Sun Light

Photocatalytic composite materials incorporating the photocatalysts (TiO2, ZnO) with rice husk ash (RHA) have been developed to investigate the photodegradation of real textile dye effluent. The structural characterization of the composite materials was performed using XRD (X-Ray Diffractometer). The characteristic XRD peaks together with the 2? values for both TiO2 and ZnO were in excellent agreement with the standard JCPDS d-values. The efficacy of these composites was examined through the degradation of a textile dye, collected from a local dye house. The sun light was used as the source of illumination for the preceding degradation reaction. Bangladesh J. Sci. Ind. Res. 47(4), 445-448, 2012 DOI: http://dx.doi.org/10.3329/bjsir.v47i4.14075

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