Does the addition of a heteropoly acid change the water percolation threshold of PFSA membranes?

2019 ◽  
Vol 21 (45) ◽  
pp. 25080-25089 ◽  
Author(s):  
Saeed Akbari ◽  
Mohammad Taghi Hamed Mosavian ◽  
Fatemeh Moosavi ◽  
Ali Ahmadpour
Keyword(s):  
Percolation Threshold ◽  
Heteropoly Acid ◽  
Heteropoly Acids ◽  
Hydration Level ◽  
Water Percolation ◽  
Percolating Network

A composite PFSA membrane containing heteropoly acids showed a continuous water percolating network and decreased by 10–20% the required hydration level to reach the percolation threshold.

Photochromic and photothermal hydrogel derived from natural amino acid and heteropoly acid

Soft Matter ◽  
2021 ◽  
Author(s):  
Xue Wang ◽  
Xiaohuan Liu ◽  
Zhiyuan Ma ◽  
Chuanling Mu ◽  
Wen Li
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Heteropoly Acid ◽  
Acidic Condition ◽  
Heteropoly Acids ◽  
Natural Amino Acid ◽  
Basic Amino Acids

A new kind of supramolecular hydrogels have been designed and synthesized via the co-assembly of basic amino acids (AAs) and heteropoly acids (HPAs) under acidic condition. The formation of gel-like...

Prediction of Water Percolation Threshold of a Microemulsion Using Electrical Conductivity Measurements and Design of Experiments

2012 ◽  
Vol 51 (30) ◽  
pp. 10147-10155 ◽  
Author(s):  
Zahra Jeirani ◽  
Badrul Mohamed Jan ◽  
Brahim Si Ali ◽  
Ishenny Mohd Noor ◽  
See Chun Hwa ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Design Of Experiments ◽  
Percolation Threshold ◽  
Conductivity Measurements ◽  
Water Percolation

Conductivity of Grains and Grain Boundaries in Polycrystalline Heteropoly Acid Salts

2005 ◽  
Vol 494 ◽  
pp. 101-106
Author(s):  
B. Škipina ◽  
T. Čajkovski ◽  
M. Davidović ◽  
D. Čajkovski ◽  
V. Likar-Smiljanić ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Heteropoly Acid ◽  
Tungstophosphoric Acid ◽  
Heteropoly Acids ◽  
Relaxation Phenomena ◽  
Frequency Range ◽  
Boundary Conductivity ◽  
Bivalent Ions

In our previous work we investigated the conductivity and dielectric relaxation phenomena in heteropoly acids and their salts. In this work, we have studied the conductivity of grains and grain boundaries in compressed powders of 12-tungstophosphoric acid (WPA) salts with univalent and bivalent ions. The method of impedance spectroscopy has been employed in the frequency range from 5 Hz to 500 kHz. We obtained grains and grain boundaries conductivities as well as corresponding activation energies. Grain conductivity in all investigated salts is always higher than the grain boundary conductivity.

Studies of heteropoly acid/polyvinylidenedifluoride–hexafluoroproylene composite membranes and implication for the use of heteropoly acids as the proton conducting component in a fuel cell membrane

2007 ◽  
Vol 172 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Jennifer L. Malers ◽  
Mary-Ann Sweikart ◽  
James L. Horan ◽  
John A. Turner ◽  
Andrew M. Herring
Keyword(s):  
Fuel Cell ◽  
Cell Membrane ◽  
Heteropoly Acid ◽  
Composite Membranes ◽  
Heteropoly Acids ◽  
Proton Conducting ◽  
Conducting Component

Homogeneous Catalysts Based on Heteropoly Acid Solutions for Redox Processes. III. Development of an Effective Method for Synthesis of 2,3,5-trimethyl-1,4-benzoquinone

2019 ◽  
Vol 19 (1) ◽  
pp. 19-32
Author(s):  
Yu. A. Rodikova ◽  
E. G. Zhizhina
Keyword(s):  
Acetic Acid ◽  
Heteropoly Acid ◽  
Heteropoly Acids ◽  
Acid Oxidation ◽  
Redox Processes ◽  
Acid Solutions ◽  
Two Stage ◽  
Two Phase ◽  
High Productivity ◽  
Target Reaction

Various methods for preparation of 2,3,5-trimethyl-1,4-benzoquinone (TMQ) – the key semiproduct for synthesis of vitamin E – through catalytic oxidation of 2,3,6-trimethylphenol (TMP) are considered. Potentials of aqueous solutions of Mo-V-P heteropoly acids (HPA) as catalysts for oxidation of TMP with oxygen are shown. Various technological modes of application of HPA for the said reaction are analyzed, among which are a one-stage homogeneous acetic acid oxidation of TMP and a two-phase two-stage method. The efficiency of the two-stage method is demonstrated; it provides a high (up to 99.5 %) selectivity to TMQ and a high productivity of the catalyst for the target reaction (ca 600–800 g TMQ·Lcat–1·h–1).

scholarly journals Heteropoly Acid Catalyzed Selective Cyclization of 6-Alkyl-3-propargylmercapto-1,2,4-triazin-5(2H)-one

2011 ◽  
Vol 8 (2) ◽  
pp. 798-802 ◽  
Author(s):  
Fatemeh Hakim ◽  
Masoumeh Tabatabaee ◽  
Majid M. Hheravi ◽  
Mina Roshani ◽  
Fatemeh F. Bamoharam
Keyword(s):  
Heteropoly Acid ◽  
Reaction Times ◽  
Keggin Structure ◽  
Heteropoly Acids ◽  
Acid Catalyzed ◽  
High Yields

Cyclization of 6-alkyl-3-propargylmercapto-1,2,4-triazin-5(2H)-one, derivatives (2) in the presence of Keggin heteropoly acids, H3PW1212O40, H3PMo12O40, H4SiW12O40and lacunary Keggin structure (K7PMo2W9O40) afforded 3 (3a = 6-dimethyl-7H-thiazolo[2,3-b][1,2,4]-triazin-7-one and 3b=6-ethyl-3-methyl-7H-thiazolo[2,3-b][1,2,4]-triazin-7-one) in high yields and short reaction times

TiO2-supported heteropoly acid catalysts for dehydration of methanol to dimethyl ether: relevance of dispersion and support interaction

2015 ◽  
Vol 5 (1) ◽  
pp. 484-491 ◽  
Author(s):  
Rosa María Ladera ◽  
Manuel Ojeda ◽  
José Luis G. Fierro ◽  
Sergio Rojas
Keyword(s):  
Dimethyl Ether ◽  
Heteropoly Acid ◽  
Heteropoly Acids ◽  
Acid Catalysts ◽  
Support Interaction

TiO2-supported heteropoly acids are very active catalysts for DME production from methanol. Due to the interaction with the support, the most active catalysts are obtained when a monolayer of HPA is deposited on the support.

Synthesis of Aromatic Cycloketones via Intramolecular Friedel - Crafts Acylation Catalyzed by Heteropoly Acids

2007 ◽  
Vol 60 (1) ◽  
pp. 80 ◽  
Author(s):  
Kun Lan ◽  
Shao Fen ◽  
Zixing Shan
Keyword(s):  
Liquid Phase ◽  
Good Yield ◽  
Heteropoly Acid ◽  
Heteropoly Acids ◽  
Benzoic Acids ◽  
Decarboxylation Reaction ◽  
First Time

Under liquid-phase conditions, the intramolecular Friedel–Crafts acylation of aryl benzoic acids catalyzed by heteropoly acids were investigated for the first time. Several aryl benzoic acids were refluxed and dehydrated in chlorobenzene in the presence of 0.2 equivalents of a heteropoly acid, and anthraquinone, anthrone, and xanthone were obtained in good yield. At the same time, an intermolecular Friedel–Crafts acylation and decarboxylation reaction were observed in this experiment.

Preparation and Photocatalytic Activity of Heteropoly Acids/Polyvinylidene Fluoride Thin Films

2012 ◽  
Vol 538-541 ◽  
pp. 158-161
Author(s):  
Li Min Wang ◽  
Zhong Cai Du ◽  
Qiang Li ◽  
Si Meng Wei
Keyword(s):  
Thin Films ◽  
Malachite Green ◽  
Polyvinylidene Fluoride ◽  
Degradation Rate ◽  
Heteropoly Acid ◽  
Catalytic Effect ◽  
Acid Catalyst ◽  
Heteropoly Acids ◽  
Orthogonal Experiments ◽  
High Degradation Rate

In this paper, catalysts of (NH4)4SiW12O40 supported on polyvinylidene fluoride(PVDF) thin films were prepared and characterized by IR and SEM.In addition,sunlight as the light source and simulation of dyes effluent (malachite green) as the research object, through the orthogonal experiments studied the factors that influence catalyst photocatalytic degradation effects,such as the amount of catalyst, pH, the amount of hydrogen peroxide . The results show that the degradation of malachite green of the heteropoly acid catalyst immobilized by membrane is best under the conditions of visible and achieve high degradation rate( 90% ). Also , the catalytic effect is also related with the oxidant dosage and the acidity. The catalyst is energy saving, easy recovery and has widest foreground.

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