scholarly journals Distinguishing Adsorbed and Deposited Ionomers in the Catalyst Layer of Polymer Electrolyte Fuel Cells Using Contrast-Variation Small-Angle Neutron Scattering

ACS Omega ◽  
2021 ◽  
Author(s):  
Masashi Harada ◽  
Shin-ichi Takata ◽  
Hiroki Iwase ◽  
Shuji Kajiya ◽  
Hiroaki Kadoura ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Neutron Scattering ◽  
Polymer Electrolyte ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cells ◽  
Contrast Variation

scholarly journals Microstructure and water distribution in catalysts for polymer electrolyte fuel cells, elucidated by contrast variation small-angle neutron scattering

2019 ◽  
Vol 52 (4) ◽  
pp. 791-799 ◽  
Author(s):  
Satoshi Koizumi ◽  
Satoru Ueda ◽  
Takumi Inada ◽  
Yohei Noda ◽  
Robert A. Robinson
Keyword(s):  
Fuel Cells ◽  
Neutron Scattering ◽  
Polymer Electrolyte ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Water Distribution ◽  
Grazing Incidence ◽  
Polymer Electrolyte Fuel Cells ◽  
Contrast Variation ◽  
Mixed Water

By using small-angle neutron scattering (SANS) reinforced by scanning electron microscopy, the fine structure of catalysts for polymer electrolyte fuel cells has been investigated. The experimental data resulting from contrast variation with mixed light and heavy water (H2O/D2O) are well described by a core–shell model with fluctuations in concentration between water and Nafion. In particular, SANS obtained with the mixed water ratio 30/70, which corresponds to a matching point between mixed water and Nafion, shows a broad scattering maximum, which is attributed to a 5 nm-thick Nafion shell on the surface of the larger carbon particles. After swelling by water, the ionomer layer absorbs water at the 17 wt% level. By changing the H2O/D2O ratio, it was further confirmed that the catalyst with the ionomer exhibits water repellence, whereas the bare catalyst without the ionomer is wetted by water. Because it is very difficult to extract more information, for instance regarding the Pt–Nafion interactions, by means of small-angle scattering, reflectometry and grazing-incidence scattering experiments with neutrons should be attempted on a model catalyst prepared on a flat substrate.

Ultra-Small-Angle Neutron Scattering Study of Colloidal Alloys. 1. Contrast Variation Experiments for Mixtures of Hydrogenated and Deuterated Polystyrene Latices in H2O/D2O

Langmuir ◽  
1999 ◽  
Vol 15 (2) ◽  
pp. 293-296 ◽  
Author(s):  
Hideki Matsuoka ◽  
Takashi Ikeda ◽  
Hitoshi Yamaoka ◽  
Mitsuhiro Hashimoto ◽  
Toshio Takahashi ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation ◽  
Scattering Study ◽  
Neutron Scattering Study

Mechanically Interlocked Structure of Polyrotaxane Investigated by Contrast Variation Small-Angle Neutron Scattering

2009 ◽  
Vol 42 (16) ◽  
pp. 6327-6329 ◽  
Author(s):  
Koichi Mayumi ◽  
Hitoshi Endo ◽  
Noboru Osaka ◽  
Hideaki Yokoyama ◽  
Michihiro Nagao ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation

Small angle neutron scattering experiments on nanostructured matter using contrast variation

1997 ◽  
Vol 9 (1-8) ◽  
pp. 327-330
Author(s):  
S. Janßen ◽  
J. Wagner ◽  
H. Natter ◽  
J. Prewo ◽  
R. Rupp ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Contrast Variation

Structure of Nanocomposite Hydrogel Investigated by Means of Contrast Variation Small-Angle Neutron Scattering

2008 ◽  
Vol 41 (14) ◽  
pp. 5406-5411 ◽  
Author(s):  
Hitoshi Endo ◽  
Sho Miyazaki ◽  
Kazutoshi Haraguchi ◽  
Mitsuhiro Shibayama
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Nanocomposite Hydrogel ◽  
Contrast Variation

Fabrication of Cathode Catalyst Layer By Use of Multi-Nozzle Electrospray Method on Polymer Electrolyte Fuel Cells

2021 ◽  
Vol MA2021-02 (37) ◽  
pp. 1087-1087
Author(s):  
Makoto Uchida ◽  
Kayoko Tamoto ◽  
Takumi Nagasaka ◽  
Chihiro Taguchi ◽  
Shimao Yoneyama
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cells ◽  
Cathode Catalyst ◽  
Cathode Catalyst Layer

scholarly journals Amphiphilic Comb Polymers as New Additives in Bicontinuous Microemulsions

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2410
Author(s):  
Debasish Saha ◽  
Karthik R. Peddireddy ◽  
Jürgen Allgaier ◽  
Wei Zhang ◽  
Simona Maccarrone ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Amphiphilic Polymers ◽  
Side Chain ◽  
Side Chains ◽  
Contrast Variation ◽  
Dna Complexes ◽  
Comb Polymers ◽  
Polymer Architectures

It has been shown that the thermodynamics of bicontinuous microemulsions can be tailored via the addition of various different amphiphilic polymers. In this manuscript, we now focus on comb-type polymers consisting of hydrophobic backbones and hydrophilic side chains. The distinct philicity of the backbone and side chains leads to a well-defined segregation into the oil and water domains respectively, as confirmed by contrast variation small-angle neutron scattering experiments. This polymer–microemulsion structure leads to well-described conformational entropies of the polymer fragments (backbone and side chains) that exert pressure on the membrane, which influences the thermodynamics of the overall microemulsion. In the context of the different polymer architectures that have been studied by our group with regards to their phase diagrams and small-angle neutron scattering, the microemulsion thermodynamics of comb polymers can be described in terms of a superposition of the backbone and side chain fragments. The denser or longer the side chain, the stronger the grafting and the more visible the brush effect of the side chains becomes. Possible applications of the comb polymers as switchable additives are discussed. Finally, a balanced philicity of polymers also motivates transmembrane migration in biological systems of the polymers themselves or of polymer–DNA complexes.

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