Date/Time
24.05.2022
2:00 pm – 3:00 pm
Location
Lecture Hall 55.02
Pfaffenwaldring 55
70569 Stuttgart
We are very happy to welcome within the CRC 1333 Colloquium Series:
Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, USA /Department of Chemical & Biomolecular Engineering, University of Delaware, Newark, USA
Tuesday, May 24, 2022, 2:00 – 3:00 pm
Topic: “Studying heterogeneous porous materials with neutron scattering”
Prof. Liu is a soft matter physicist in the SANS group at NIST Center for Neutron Research, and also an affiliated full professor at the Department of Chemical Engineering at University of Delaware.
His research presently concentrates on the following focus areas:
- Structure and dynamics of colloidal systems, such as nucleation/clusterization in colloidal and biological molecular assembly systems, ion/counterion association in polyelectrolyte solution, and colloidal interactions.
- Interaction of small molecules on the surface or porous media, such as hydrogen storage, green-house gas capture, molecular recognition based on surface selection, molecular sieving, small molecule dynamics on functionalized surface.
- Neutron and X-ray scattering techniques
The CRC cordially invites all who are interested to the lecture.
ABSTRACT
Neutron scattering has been widely used to study complex porous materials due to its high penetration power, good sensitivity to light elements, and flexibility to control the contrast of gas/liquid inside pores. In this talk, I will provide a few research examples to demonstrate the power of neutron scattering to study porous material by using different neutron scattering instruments. The first example is to study the kerogen distribution in shale rocks. Even though kerogens are believed to be responsible for shale gas/oil storage, it has been challenging to study the kerogen distribution inside shale rocks. Aided by a recently developed simultaneous neutron and x-ray tomography system at NIST, we had systematically studied the kerogen distribution in a few rocks and have found an interesting correlation between the enriched kerogen distribution and its orientation relative to the bedding.[1] The second example discusses a new approaching using small angle neutron scattering (SANS) to measure the variation of pore surface properties when the surfaces have heterogenous chemical compositions. By loading gas at different pressures to vary the scattering contrast between pore surfaces and the filling gases, we demonstrated that the variation of the scattering length density of the pore surfaces can be quantitatively obtained. As the scattering length density is related with only chemical formula and density of the pore matrix, this allows us to probe the surface compositional heterogeneity of porous materials non-invasively.[2-3] In the last example, we investigated the methane adsorption in model mesoporous materials, such as MCM-41 and SBA-15. The effects of the pore size and surface roughness on the methane gas adsorption are quantified. [4-5]
References:
[1] Wei-Shan Chiang et al., Petrophysics 59(02): 153-161 (2018).
[2] Wei-Shan Chiang, Daniel Georgi, Taner Yildirim, Jin-Hong Chen, Yun Liu, Nat. Commun. 9, 784 (2018).
[3] Wei-Shan Chiang, Jin-Hong Chen, David Jacobi, Taner Yildirim, Danyal Turkoglu, Stacey Althaus, Yun Liu, Energy & Fuel 34(10), 12354 (2020).
[4] Wei-Shan Chiang, Emiliano Fratini, Piero Baglioni, Jin-Hong Chen, Yun Liu, Langmuir 32, 8849 (2016)
[5] Wei-Shan Chiang, Emiliano Fratini, Piero Baglioni, Daniel Georgi, Jin-Hong Chen, Yun Liu, J. Phys. Chem. C 120(8), 4354 (2016).