scholarly journals PENGARUH PENAMBAHAN DUAL KATALIS PADA SILICA-CARBON XEROGEL SEBAGAI MATERIAL PELAPIS ORGANO SILICA MEMBRANES

Konversi ◽  
2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Muthia Elma ◽  
Adhe Paramita ◽  
Anna Sumardi

Abstrak- Proses sol-gel adalah proses polimerisasi senyawa kimia (precursor) melalui reaksi hidrolisis dan kondensasi dalam larutan pada suhu rendah. Nlai pH mempengaruhi daya larut precursor dan rasio konfigurasi ion yang dapat larut dan mengendap. Secara fundamental larutan sol yang memiliki pH > 7 akan memiliki morfologi  makroskopik sedangkan pH < 7 memiliki morfologi mikroskopik. Tujuan dari penelitian ini adalah untuk menentukan kondisi optimum dari thin film yang dihasilkan dari proses sol-gel yang nantinya bisa diaplikasikan sebagai pelapis pada membrane organo-silica untuk proses desalinasi air asin. Metode yang digunakan pada penelitian ini adalah sol-gel menggunakan dua katalis (basa dan asam organik), dengan perbandingan 1:38:X:5:Y (molar rasio). Dimana X:Y adalah asam sitrat (C6H8O7):ammonia (NH3). Perbandingan molar rasio katalis asam sitrat:ammonia yaitu 0.01 : (0.01; 0.0015; 0.001)  dan 0.001 : (0.01; 0.0015; 0.001) dengan suhu proses 0OC. Hasilnya dikarakterisasi menggunakan uji FTIR. Hasil penelitian ini menunjukkan semakin rendah katalis molar rasio asam sitrat maka pH yang didapatkan semakin tinggi dan ukuran pori-pori semakin besar. Sampel menghasilkan pH berkisar 5,32-8,56. Pada pH asam menghasilkan silanol (2.0) dan siloxane (7.4) sedangkan pada pH basa menghasilkan silanol (1.7) dan dan siloxane (6.2). Jadi, sols optimum sebagai thin film yang dihasilkan adalah pada pH 6.0 yang memiliki silanol (1.0) dan siloxane (4.7) dengan kalsinasi xerogel yang optimum terdapat pada suhu kaslinasi 175OC, karena adanya kandungan ikatan karbon yaitu struktur C=C-H (alkena) pada peak 3750cm-1. Ikatan karbon pada membran dapat membuat membran stabil.  Kata kunci: ammonia, citrit acid, silica-carbon thin film, xerogel 

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.


2021 ◽  
Vol 46 (24) ◽  
pp. 12961-12980
Author(s):  
Amanda Chen ◽  
Wen-Fan Chen ◽  
Tina Majidi ◽  
Bernadette Pudadera ◽  
Armand Atanacio ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1629
Author(s):  
Hyeon-Joong Kim ◽  
Do-Won Kim ◽  
Won-Yong Lee ◽  
Sin-Hyung Lee ◽  
Jin-Hyuk Bae ◽  
...  

In this study, sol–gel-processed Li-doped SnO2-based thin-film transistors (TFTs) were fabricated on SiO2/p+ Si substrates. The influence of Li dopant (wt%) on the structural, chemical, optical, and electrical characteristics was investigated. By adding 0.5 wt% Li dopant, the oxygen vacancy formation process was successfully suppressed. Its smaller ionic size and strong bonding strength made it possible for Li to work as an oxygen vacancy suppressor. The fabricated TFTs consisting of 0.5 wt% Li-doped SnO2 semiconductor films delivered the field-effect mobility in a 2.0 cm2/Vs saturation regime and Ion/Ioff value of 1 × 108 and showed enhancement mode operation. The decreased oxygen vacancy inside SnO2 TFTs with 0.5 wt% Li dopant improved the negative bias stability of TFTs.


2021 ◽  
Vol 45 (7) ◽  
pp. 3469-3478
Author(s):  
Zongyu Liu ◽  
Ying Tian ◽  
Xuewei Dong ◽  
Xiaohui Zhou ◽  
Xiao Liu ◽  
...  

A Ni/CTF was used as the cathode for electroreduction of imidacloprid, achieving a 92.1% removal efficiency for the electroreduction of imidacloprid.


Author(s):  
Arnaud Valour ◽  
Maria Alejandra Usuga Higuita ◽  
Gaylord Guillonneau ◽  
Nicolas Crespo-Monteiro ◽  
Damien Jamon ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1099
Author(s):  
Ye-Ji Han ◽  
Se Hyeong Lee ◽  
So-Young Bak ◽  
Tae-Hee Han ◽  
Sangwoo Kim ◽  
...  

Conventional sol-gel solutions have received significant attention in thin-film transistor (TFT) manufacturing because of their advantages such as simple processing, large-scale applicability, and low cost. However, conventional sol-gel processed zinc tin oxide (ZTO) TFTs have a thermal limitation in that they require high annealing temperatures of more than 500 °C, which are incompatible with most flexible plastic substrates. In this study, to overcome the thermal limitation of conventional sol-gel processed ZTO TFTs, we demonstrated a ZTO TFT that was fabricated at low annealing temperatures of 350 °C using self-combustion. The optimized device exhibited satisfactory performance, with μsat of 4.72 cm2/V∙s, Vth of −1.28 V, SS of 0.86 V/decade, and ION/OFF of 1.70 × 106 at a low annealing temperature of 350 °C for one hour. To compare a conventional sol-gel processed ZTO TFT with the optimized device, thermogravimetric and differential thermal analyses (TG-DTA) and X-ray photoelectron spectroscopy (XPS) were implemented.


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