scholarly journals Synthesis and Characterization of Silica Aerogel from Rice Husk with Ambient Pressure Drying Method

2020 ◽  
Vol 1535 ◽  
pp. 012049
Author(s):  
Nor Fadilah Mohamad ◽  
Noor Hidayu Abdul Rani ◽  
Omar Syah Jehan Elham ◽  
Siti Hajar Anaziah Muhamad ◽  
Siti Afifah Muda ◽  
...  
2016 ◽  
Vol 694 ◽  
pp. 106-110 ◽  
Author(s):  
Zulhelmi Alif Abdul Halim ◽  
Muhamad Azizi Mat Yajid ◽  
Halimaton Hamdan

Low density silica aerogel beads were synthesized from rice husk ash via sodium silicate route. The gel beads were prepared by the ball dropping method and dried at ambient pressure after surface modification (silylation) with trimethylchlorosilane (TMCS) solution. The characteristics of porous structure of silica aerogel beads were measured by Brunauer-Emmett-Teller (BET) nitrogen adsorption and desorption method. The silica aerogel beads showed a specific surface area as high as 773 m2/g. They also displayed water-repellant effect (hydrophobic) due to silylation as revealed by Fourier transform infrared spectroscopy (FTIR).


2013 ◽  
Vol 544 ◽  
pp. 144-147 ◽  
Author(s):  
Hui Xu ◽  
Gui Ln Fu ◽  
Yu Qiang Guo ◽  
Jing Chun Tu ◽  
Yong Chen

Silica aerogel has been prepared by ambient pressure drying technique using water glass as starting materials. Solvent exchange and surface modification were simultaneously conducted by immersing the wet hydrogel in EtOH/TMCS(Tri Methyl Chloro Silane)/hexane solution. The silica aerogel was obtained with the density of 0.110g•cm-3 and 95.2% porosity. The specific surface area of the silica aerogel was 472.5m2•g-1 with a average pore size distrubution of 27.5nm. FT-IR spectrum analysis showed that the surface of the silica aerogel was modified by Si-CH3 groups, which allowed the aerogel to be hydrophobic.


Author(s):  
A.R. Hidayu ◽  
N.F. Mohammad ◽  
S.I.S. Jamaludin ◽  
N.F.M.K. Teo ◽  
N.S.M. Sah ◽  
...  

Abstract: Rice husk has attracted considerable attention in the recent years due to its chemical component that are beneficial to a wide range of application. . In this paper, silica aerogel from rice husk ash (RHA) was prepared through sol-gel processing and ambient pressure drying. The silica RHA was extracted with sodium hydroxide solution to produce sodium silicate solution and neutralized with sulphuric acid to form silica gel. Then, the silica aerogel was further modified with amine, which is 3-(aminopropyl) triethoxysilane (APTES) because amine groups provide specific adsorption sides for CO2 adsorption. The functional group, surface morphology and elemental composition of rice husk, silica aerogel and modified silica aerogel were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning Electronic Microscopy (SEM) and Elemental analyser (EA). For amine modified silica aerogel, it was found that the sample consists of N-H band at a certain peak. FTIR and SEM analysis revealed the synthesized silica aerogel has fibrous morphology and indicates similar trend with previous researches. The amine modified silica aerogel (AMSA) is able to adsorb 0.88 mol CO2/kg AMSA. This study shows that the rice husk silica aerogel modified with APTES could enhance the CO2 adsorption performance due to the physisorption and chemisorption


2019 ◽  
Vol 16 (3(Suppl.)) ◽  
pp. 0770 ◽  
Author(s):  
Israa F. Al-sharuee

         The varied thermal conductivity (insulation) of silica aerogel with heating for different pH has been investigated, it has been depended on ambient pressure drying method in the preparing silica aerogel samples, also six different pH of samples (1, 2, 3, 7, 8 and 9) were treated under five degree of heating with (50,100,150,200 and 250) ᴼC. This technique is important to test the carry-outs hydrophobic silica to temperature without high-quality material changes in the basic characteristics. The hot-wire technique is used in this work to examine the thermal conductivity, Fourier Transform Infrared Spectroscopy (FTIR) depended to characterize the bonds and their artificial by heating. Results show that the samples affected by heating through decreasing the density leading to obtaining more insulation metal, moreover varied pH is an important role in thermal conductivity. The average thermal conductivity of all aerogel samples in this work is (0.01- 0.0061 mW m-10 C-1) this means that it is still below thermal conductivity for air equals to (0.02257) mW m-10 C-1 . Meanwhile, we concluded that the insulation property of silica aerogel is affected by heat treatment and gives it more thermal insulation property.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
S. Chakraborty ◽  
A. A. Pisal ◽  
V. K. Kothari ◽  
A. Venkateswara Rao

Using tetraethoxysilane (TEOS) as the source of silica, fibre reinforced silica aerogels were synthesized via fast ambient pressure drying using methanol (MeOH), trimethylchlorosilane (TMCS), ammonium fluoride (NH4F), and hexane. The molar ratio of TEOS/MeOH/(COOH)2/NH4F was kept constant at 1 : 38 : 3.73 × 10−5 : 0.023 and the gel was allowed to form inside the highly porous meta-aramid fibrous batting. The wet gel surface was chemically modified (silylation process) using various concentrations of TMCS in hexane in the range of 1 to 20% by volume. The fibre reinforced silica aerogel blanket was obtained subsequently through atmospheric pressure drying. The aerogel blanket samples were characterized by density, thermal conductivity, hydrophobicity (contact angle), and Scanning Electron Microscopy. The radiant heat resistance of the aerogel blankets was examined and compared with nonaerogel blankets. It has been observed that, compared to the ordinary nonaerogel blankets, the aerogel blankets showed a 58% increase in the estimated burn injury time and thus ensure a much better protection from heat and fire hazards. The effect of varying the concentration of TMCS on the estimated protection time has been examined. The improved thermal stability and the superior thermal insulation of the flexible aerogel blankets lead to applications being used for occupations that involve exposure to hazards of thermal radiation.


2014 ◽  
Vol 804 ◽  
pp. 199-202
Author(s):  
Hong Wei Li ◽  
Na Lv ◽  
Pan Yan Lu ◽  
Gang Qiang Geng ◽  
Wei Wang

In this study, the powder of hydrophobic silica aerogel remaining nanopore by ambient pressure drying was successfully introduced into polystyrene beads during suspension polymerization. nanosilica powder without nanopore was also used. Pure polystyrene, silica aerogel/polystyrene (PS) and nanosilica/polystyrene beads were fabricated, respectively. The structure and properties of silica aerogel @PS composite beads were characterized by SEM, EDS, TG-DSC and FT-IR. The results of TG-DSC, FT-IR and EDS show silica aerogel is located in the PS beads, but it is difficult to be observed by SEM because of its low content. The introduction of silica and silica aerogel both decrease the transparency of PS beads. Silica aerogel loosen the microstructure of PS beads.


Sign in / Sign up

Export Citation Format

Share Document