Pressure cell for investigations of solid-liquid interfaces by neutron reflectivity

Area of Science:

• Materials Science
• Surface Chemistry
• Neutron Scattering Physics

Background:

• Understanding molecular layer behavior at interfaces is crucial for material design.
• High hydrostatic pressure significantly influences interfacial properties and molecular structures.
• In situ characterization methods are needed to study dynamic interfacial processes under pressure.

Purpose of the Study:

• To develop and present a novel apparatus for in situ characterization of molecular layers at solid-liquid interfaces.
• To enable measurements of scattering length density and structure under high hydrostatic pressure conditions.
• To investigate the stability of lipid coatings on silicon surfaces against aqueous phases.

Main Methods:

• Neutron reflectometry was employed for in situ characterization.
• A specialized pressure cell was designed for pressures ranging from 0.1 to 100 MPa.
• Measurements were conducted on crystalline substrates (silicon, quartz, sapphire) with a surface area of 28 cm(2).

Main Results:

• The apparatus allows for precise measurement of scattering length density profiles.
• Reflectivity measurements down to 10(-5) were achieved, facilitating detailed structural analysis.
• The system is capable of probing molecular layer stability as a function of applied hydrostatic pressure and temperature.

Conclusions:

• The developed apparatus provides a powerful tool for studying solid-liquid interfaces under high pressure.
• It enables detailed in situ analysis of molecular layer structure and stability.
• The device has broad applicability for various solid-liquid interface investigations.