Synthesis of Nanoparticulate Silica Composite Membranes by the Pressurized Sol-Gel Technique

1994 ◽  
Vol 77 (12) ◽  
pp. 3093-3098 ◽  
Author(s):  
Sang H. Hyun ◽  
Beom S. Kang
2011 ◽  
Vol 14 (2) ◽  
pp. 87-91 ◽  
Author(s):  
A. Alvarez ◽  
C. Guzman ◽  
C. Peza-Ledesma ◽  
Luis A. Godinez ◽  
R. Nava ◽  
...  

In this work, composite membranes were prepared from a mixture of Nafion® ionomer with mesoporous (SBA-15) and microstructured silica (SiO2). The silica-based materials were synthesized using the sol-gel technique and their properties were characterized by TEM, BET, SEM and XRD. A glass cell with two chambers was used to evaluate the permeability of methanol of the composite membranes and its performance was compared with a commercial Nafion 115 membrane. The composite membranes showed smaller value of methanol permeability (around 19%) than that obtained when was used a commercial membrane. In terms of the fuel cell performance, the composite membranes showed a larger maximum power density (62 and 29 mWcm-2 for the SiO2 and SBA-15 composite membrane respectively) than that obtained for the commercial membrane at high temperature conditions (100°C).


2013 ◽  
Vol 1 (2) ◽  
pp. 59-69 ◽  
Author(s):  
Sarbjit Kaur ◽  
Niraj Bala ◽  
Charu Khosla
Keyword(s):  
Sol Gel ◽  

2011 ◽  
Vol 4 (3) ◽  
pp. 224-237 ◽  
Author(s):  
Aurica P. Chiriac ◽  
Loredana E. Nita ◽  
Iordana Neamtu ◽  
Manuela T. Nistor
Keyword(s):  
Sol Gel ◽  

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 430-442 ◽  
Author(s):  
Rajdeep Mukherjee ◽  
Arun Kumar Mandal ◽  
Susanta Banerjee

AbstractSulfopropylated polysilsesquioxane and –COOH containing fluorinated sulfonated poly(arylene ether sulfone) composite membranes (SPAES-SS-X) have been prepared via an in situ sol–gel reaction through the solution casting technique. The composite membranes showed excellent thermal and chemical stability, compared to the pristine SPAES membrane. The uniform dispersion of the sulfonated SiOPS nanoparticles on the polymer matrix was observed from the scanning electron microscope images. Atomic force microscopy and transmission electron microscopy images indicated significantly better phase-separated morphology and connectivity of the ionic domains of the composite membranes than the pristine SPAES membrane. The composite membranes showed considerable improvement in proton conductivity and oxidative stability than the pristine copolymer membrane under similar test conditions.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1263
Author(s):  
Elvira Mahu ◽  
Cristina Giorgiana Coromelci ◽  
Doina Lutic ◽  
Iuliean Vasile Asaftei ◽  
Liviu Sacarescu ◽  
...  

A mesoporous titania structure has been prepared using the ultrasound-assisted sol-gel technique in order to find out a way to tailor its structure. The TiO2 obtained was compared to the same version of titania but synthesized by a conventional sol-gel method with the objective of understanding the effect of ultrasound in the synthesis process. All synthesis experiments were focused on the preparation of a titania photocatalyst. Thus, the anatase photocatalytic active phase of titania was proven by X-ray diffraction. Additionally, the ultrasonation treatment proved to increase the crystallinity of titania samples, being one of the requirements to having good photocatalytic activity for titania. The influence of surfactant/titania precursor weight ratio on the structural (XRD), textural (N2-sorption measurements), morphological (TEM), surface chemistry (FTIR) and optical properties (UVDR) was investigated. It was observed that the crystallite size, specific surface area, band gap energy and even photocatalytic activity was affected by the synergism occurring between cavitation effect and the surfactant/titania precursor weight ratio. The study yielded interesting great results that could be considered for further application of ultrasound to tailor mesoporous titania features via sol-gel soft template synthesis, against conventional sol-gel process.


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