Carbon spheres with hierarchical micro/mesopores for water desalination by capacitive deionization

2016 ◽  
Vol 4 (41) ◽  
pp. 16094-16100 ◽  
Author(s):  
Xingtao Xu ◽  
Hongmei Tang ◽  
Miao Wang ◽  
Yong Liu ◽  
Yanjiang Li ◽  
...  

Carbon spheres with a hierarchy of micropores and mesopores were prepared via a sol–gel process using a surfactant-directing assembly strategy and were applied for capacitive deionization.

2019 ◽  
Vol 280 ◽  
pp. 03010 ◽  
Author(s):  
Dwi Rasy Mujiyanti ◽  
Muthia Elma ◽  
Mufidah Amalia

Interlayer-free glucose carbonized template silica membranesbased on tetraethyl orthosilicate (TEOS) and glucose were successfullyprepared using an acid-base catalysed sol-gel method for artificial brinewater desalination (7.5% wt NaCl solution %) at temperatures range from25, 40 and 60 °C. These membranes calcined at 250 and 400 °C. Themembranes were fabricated through sol-gel process by using TEOS(tetraethyl orthosilicate); ethanol; nitric acid; ammonia; aquadest andglucose as a template. By molar ratio is 1: 38: 0.0007: 0.0003: 5 and0.25%; 0.5%, 1% w/v glucose as template. The results show the highestwater fluxes of 1.8, 2.2 and 4.8 kg m−2 h−1 for 25, 40 and 60 °Cdesalination process with excellent salt rejections of 99.5, 99.5 and 99.7%, respectively. It was found that the higher the NaCl solution temperature asfeed solution as well as glucose concentration (0.25% to 1% wt) astemplate attached in the silica matrixes, the higher water fluxes eventhough the salt rejection remain the same. This study demonstrates that theorganosilica membranes offered the carbonized silica mesostructuremembranes with excellent separation of water from the hydrated salt ions, particularly for processing brine salt solutions.


2020 ◽  
Vol 148 ◽  
pp. 07006 ◽  
Author(s):  
Riani Ayu Lestari ◽  
Muthia Elma ◽  
Aulia Rahma ◽  
Dewi Suparsih ◽  
Syarifah Anadhliyah ◽  
...  

Wetland saline water has great potential to overcome water scarcity due to high salinity of intruded seawater. This work determines performance of silica membranes using organo catalyst applied for wetland saline water desalination via pervaporation and investigates the effect of calcination temperatures. These membranes were prepared from precursor tetraethyl orthosilicate (TEOS) for 3 h through sol-gel process refluxed at 0°C (membrane A) and 50°C (membrane B). The sols were dipcoated onto alumina (Al2O3) support for 4 layers followed by calcination for 1 h. Performance of membranes were evaluated by feeding wetland saline water through desalination at room temperature. Results show the water flux for membrane A were 0.27 & 0.15 kg.m-2.h-1 and salt rejection were 97.5 & 99 % as a function of calcination temperature (200 & 250°C), respectively. Furthermore, water flux of membranes B were 0.90 & 0.93 kg.m-2.h-1 and excellent salt rejection (>99.9 %) for both calcination temperatures. The highest water flux and salt rejection were found for membranes B. For both using citric acid under refluxed and calcination process, it gives more vibration of Si-C formation and membrane pores. This membrane is the very first and mesoporous organo silica membranes which is successfully fabricated from organo catalyst.


2021 ◽  
Author(s):  
Rasha Kamel ◽  
Shaimaa Mohamed ◽  
Ahmed Shahat ◽  
Hassan Hassan ◽  
Sara Abd Elsalam

Capacitive deionization is emerging as an energy-efficient technology for water desalination and research is continued to find better electrode materials in order to achieve favorable properties and good desalination behavior....


2019 ◽  
Vol 280 ◽  
pp. 03017 ◽  
Author(s):  
Isna Syauqiyah ◽  
Muthia Elma ◽  
Meilana D. Putra ◽  
Aulia Rahma ◽  
Amalia E. Pratiwi ◽  
...  

For the first time the interlayer-free silica-carbon templatesmembrane has been successfully fabricated employed pectin as carbonsource. This membrane was compared to interlayer-free silica-P123membrane that were fabricated via Rapid Thermal Processing (RTP). Theaim of this work is to investigate the performance of interlayer-free silicapectinand silica-P123 membranes. Sol-gel process has been utilised toproduce silica thin film using TEOS as precursor, EtOH, HNO3 and NH3 with two-step acid-based catalyst (50 °C, 3 hours). Pectin and P123 weretemplated into silica sols. Subsequently, the alumina tubular supportmembranes were dip-coated into these sols and calcined at 400 °C (pectin)and 350 °C (P123), respectively with 4 layers each membrane. Theinterlayer-free silica-pectin shows excellent water flux (5.73 kg m-2 h-1) incomparison to interlayer-free silica-P123 (1.449 kg m-2 h-1). Both silicapectinand silica-P123 membranes show very good salt rejection (>99%). The performance of silica-pectin membrane is much better than silica-P123membrane (~4 times higher). It is influenced by the length of carbonschains where carbon chains of pectin is much lower than P123. Due to that, P123 connected to silica networks create dense film of membrane andreduce the membranes performance.


2021 ◽  
Vol 16 (1) ◽  
pp. 11-18
Author(s):  
Muthia Elma ◽  
Aptar Eka Lestari ◽  
Anna Sumardi ◽  
Zaini Lambri Assyaifi ◽  
Adi Darmawan ◽  
...  

The sol gel process is one of the processes used in the manufacture of thin films on membranes because it can control the pore size in the resulting silica matrix. In addition, another way to build membrane size can be done by adding catalysts and precursors to be used. In this study, using a combination of tetraethyl ortho silicate (TEOS) and triethoxy vinyl silane (TEVS) precursors and citric acid as a catalyst to produce a silica matrix with mesoporous size so that it is suitable for application in the desalination process. The organo silica membrane was calcined at 350 ° C for 1 hour using the RTP calcination technique under vacuum, thus preventing the decomposition of carbon in the silica matrix. The membrane was dipcoated 4 times to obtain 4 layers. The FTIR (Fourier-transform Infrared Spectroscopy) test was carried out to see the functional groups on xerogel, namely silanol, siloxane and carbon. In addition, the performance of this membrane is carried out by desalination through pervaporation using 0.3% NaCl feed water with variations in feed air temperature, namely 25 ℃, 40 ℃ and 60 ℃. The resulting flux of air value increased with increasing feed water temperature, namely 6.1; 11.2; and 12.1 kg.m-2h-1 while the resulting salt rejection was 99.72; 99.64 and 99.23%. So that the organo silica membrane is suitable when applied to the desalination process through pervaporation.  


2017 ◽  
Vol 5 (8) ◽  
pp. 6635-6644 ◽  
Author(s):  
Yang Li ◽  
Junwen Qi ◽  
Jiansheng Li ◽  
Jiaming Shen ◽  
Yuxin Liu ◽  
...  

Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.


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).


2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥


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