• Westphalen, Miriam Von
• Simml, David
• Rädler, Joachim O.
• Nickel, Bert
• Ehm, Tamara
• Philipp, Julian
• Ober, Martina
• Barkey, Martin
• Brinkop, Achim Theo

Abstract

<jats:p>3D printing changes the scope of how samples can be mounted for small-angle X-ray scattering (SAXS). In this paper a 3D-printed X-ray chamber, which allows for <jats:italic>in situ</jats:italic> exchange of buffer and <jats:italic>in situ</jats:italic> optical transmission spectroscopy, is presented. The chamber is made of cyclic olefin copolymers (COC), including COC X-ray windows providing ultra-low SAXS background. The design integrates a membrane insert for <jats:italic>in situ</jats:italic> dialysis of the 100 µl sample volume against a reservoir, which enables measurements of the same sample under multiple conditions using an in-house X-ray setup equipped with a 17.4 keV molybdenum source. The design's capabilities are demonstrated by measuring reversible structural changes in lipid and polymer systems as a function of salt concentration and pH. In the same chambers optical light transmission spectroscopy was carried out measuring the optical turbidity of the mesophases and local pH values using pH-responsive dyes. Microfluidic exchange and optical spectroscopy combined with <jats:italic>in situ</jats:italic> X-ray scattering enables vast applications for the study of responsive materials.</jats:p>

Topics

• impedance spectroscopy
• molybdenum
• copolymer
• small angle x-ray scattering
• pH value
• dialysis