Structure evolution in the PbO-ZrO2-TiO2 sol-gel system: Part II?Pyrolysis of acid and base-catalyzed bulk and thin film gels

1996 ◽  
Vol 6 (1) ◽  
pp. 83-106 ◽  
Author(s):  
P. R. Coffman ◽  
C. K. Barlingay ◽  
A. Gupta ◽  
S. K. Dey
Author(s):  
Arnaud Valour ◽  
Maria Alejandra Usuga Higuita ◽  
Gaylord Guillonneau ◽  
Nicolas Crespo-Monteiro ◽  
Damien Jamon ◽  
...  

Konversi ◽  
2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Muthia Elma ◽  
Nur Riskawati ◽  
Marhamah Marhamah

Abstrak: Air limbah pabrik tahu jika dibuang langsung ke lingkungan menyebabkan pencemaran lingkungan yang akan merusak kualitas air, terutama air limbah tersebut dialirkan ke badan sungai. Oleh sebab itu, sangatlah diperlukan suatu teknologi yang efisien untuk pengolahan air limbah tahu ini. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh performansi membran silika pada proses desalinasi via pervaporasi. Penelitian ini dilakukan dengan menyiapkan silika sol yang dipersiapkan dari proses sol-gel menggunakan prekursor TEOS dalam larutan etanol. Selanjutnya adalah dengan menggunakan metode “2 step acid and base catalysts” dengan menggunakan HNO3 dan NH3 sebagai katalis. Silica thin film yang dihasilkan berupa sol di-dipcoating dan kemudian dilakukan proses kalsinasi pada suhu 600oC selama 1 jam menggunakan metode RTP (Rapid Thermal Process). Jumlah lapisan/layer dari membran silika tersebut adalah berdasarkan pengulangan proses dipcoating dan kalsinasi yang mana pada penelitian ini menggunakan variasi 3 layer. Performansi membran ini dilakukan dengan proses desalinasi via pervaporasi dengan menggunakan air limbah tahu yang bertujuan untuk memperoleh air bersih. Adapun nilai water flux membrane ini berkisar antara 1,74 – 1,48 kg m-2 h-1 dengan rejection berkisar antara 93,63 – 89.27 %. Hasil ini membuktikan bahwa membrane silika bisa mengolah air limbah tahu menjadi potable water walaupun nilai water flux perlu ditingkatkan. Sebagai tambahan analisis, uji karakteristik membran seperti uji FTIR dilakukan untuk mengetahui gugus fungsi dari membran silika dan uji morfologi menggunakan SEM untuk mengetahui ketebalan lapisan membran yang dihasilkan.       Keywords: limbah tahu, water flux, rejection, membran silika dan pervaporasi.      


2020 ◽  
Vol 124 (46) ◽  
pp. 25480-25488
Author(s):  
Arnaud Valour ◽  
Maria A. Usuga Higuita ◽  
Nicolas Crespo-Monteiro ◽  
Stéphanie Reynaud ◽  
Marion Hochedel ◽  
...  

Author(s):  
George C. Ruben ◽  
Merrill W. Shafer

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.


1999 ◽  
Vol 606 ◽  
Author(s):  
Keishi Nishio ◽  
Jirawat Thongrueng ◽  
Yuichi Watanabe ◽  
Toshio Tsuchiya

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).


Author(s):  
Dong XU ◽  
Qi SONG ◽  
Ke ZHANG ◽  
Hong-Xing XU ◽  
Yong-Tao YANG ◽  
...  
Keyword(s):  
Sol Gel ◽  

2018 ◽  
Vol 15 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Chengpeng Xu ◽  
Shengying Ye ◽  
Xiaolei Cui ◽  
Quan Zhang ◽  
Yan Liang

Background: Improper storage and raw materials make peanut oil susceptible to Aflatoxin B1 (AFB1). The semiconductor TiO2 photocatalysis technology is an effective technology which is widely used in sewage treatment, environmental protection and so on. Moreover, the photocatalytic efficiency can be improved by doping I. Method: The experiment is divided into two parts. In the first part, supported TiO2 thin film (STF) was prepared on the quartz glass tube (QGT) by the sol-gel and calcination method and the supported iodine doped supported TiO2 thin film (I-STF) was synthesized using potassium iodate solution. In the second part, the photocatalytic degradation of AFB1 was performed in a self-made photocatalytic reactor. The AFB1 was detected by ELISA kit. Results: The photocatalytic degradation of AFB1 has been proven to follow pseudo first-order reaction kinetics well (R2 > 0.95). The maximum degradation rate of 81.96%, which was reached at the optimum iodine concentration of 0.1mol/L, was 11.38% higher than that with undoped STF. The doping of iodine reduces the band-gap of TiO2, thereby increasing the photocatalytic response range. The proportion of Ti4+ in I-STF has decreased, which means that Ti4+ are replaced by I. The I-STF prepared at iodine concentration of 0.1mol/L has good photocatalytic properties.


Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 200
Author(s):  
Do Won Kim ◽  
Hyeon Joong Kim ◽  
Changmin Lee ◽  
Kyoungdu Kim ◽  
Jin-Hyuk Bae ◽  
...  

Sol-gel processed SnO2 thin-film transistors (TFTs) were fabricated on SiO2/p+ Si substrates. The SnO2 active channel layer was deposited by the sol-gel spin coating method. Precursor concentration influenced the film thickness and surface roughness. As the concentration of the precursor was increased, the deposited films were thicker and smoother. The device performance was influenced by the thickness and roughness of the SnO2 active channel layer. Decreased precursor concentration resulted in a fabricated device with lower field-effect mobility, larger subthreshold swing (SS), and increased threshold voltage (Vth), originating from the lower free carrier concentration and increase in trap sites. The fabricated SnO2 TFTs, with an optimized 0.030 M precursor, had a field-effect mobility of 9.38 cm2/Vs, an SS of 1.99, an Ion/Ioff value of ~4.0 × 107, and showed enhancement mode operation and positive Vth, equal to 9.83 V.


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