Optical Imaging of Surface Chemistry and Dynamics in Confinement
- Resource Type
- Authors
- Halil I. Okur; Sylvie Roke; Igor Nahalka; Carlos Macias-Romero
- Source
- Science
Sygma
arXiv.org e-Print Archive
- Subject
- Surface (mathematics)
Chemical Physics (physics.chem-ph)
Multidisciplinary
Aqueous solution
Microscope
Chemistry
FOS: Physical sciences
02 engineering and technology
010402 general chemistry
021001 nanoscience & nanotechnology
Electrochemistry
01 natural sciences
0104 chemical sciences
law.invention
Condensed Matter::Soft Condensed Matter
law
Chemical physics
Electric field
Physics - Chemical Physics
Molecule
Microtechnology
Surface charge
Physics::Chemical Physics
0210 nano-technology
Geology
- Language
- English
The interfacial structure and dynamics of water in a microscopically confined geometry is imaged in three dimensions and on millisecond time scales. We developed a 3D wide-field second harmonic microscope that employs structured illumination. We image pH induced chemical changes on the curved and confined inner and outer surfaces of a cylindrical glass micro-capillary immersed in aqueous solution. The image contrast reports on the orientational order of interfacial water, induced by charge-dipole interactions between water molecules and surface charges. The images constitute surface potential maps. Spatially resolved surface pKa,s values are determined for the silica deprotonation reaction. Values range from 2.3