Title

Surface structure of linear nanopores in amorphous silica: Comparison of properties for different pore generation algorithms

Publication Date

9-25-2020

Department

Ames Laboratory; Chemistry; Physics and Astronomy

Campus Units

Ames Laboratory, Chemistry, Physics and Astronomy

OSTI ID+

1668273

Report Number

IS-J 10309

DOI

10.1063/5.0021317

Journal Title

The Journal of Chemical Physics

Volume Number

153

Issue Number

12

First Page

124708

Abstract

We compare the surface structure of linear nanopores in amorphous silica (a-SiO2) for different versions of “pore drilling” algorithms (where the pores are generated by the removal of atoms from the preformed bulk a-SiO2) and for “cylindrical resist” algorithms (where a-SiO2 is formed around a cylindrical exclusion region). After adding H to non-bridging O, the former often results in a moderate to high density of surface silanol groups, whereas the latter produces a low density. The silanol surface density for pore drilling can be lowered by a final dehydroxylation step, and that for the cylindrical resist approach can be increased by a final hydroxylation step. In this respect, the two classes of algorithms are complementary. We focus on the characterization of the chemical structure of the pore surface, decomposing the total silanol density into components corresponding to isolated and vicinal mono silanols and geminal silanols. The final dehyroxylation and hydroxylation steps can also be tuned to better align some of these populations with the target experimental values.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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