Integrating in-situ Shear Rheology with Neutron Reflectometry for Structural and Dynamic Analysis of Interfacial Systems

TL;DR

This paper introduces a novel experimental setup combining neutron reflectometry and shear rheology to analyze interfacial systems' structure and dynamics simultaneously, improving reproducibility and data correlation.

Contribution

The work presents a new sample environment at the FIGARO neutron instrument that integrates shear rheometry with structural measurements for interfacial studies.

Findings

Enables simultaneous structural and rheological measurements on the same sample.

Compatible with commercial rotational rheometers and neutron reflectometry.

Improves reproducibility and correlation of interfacial data.

Abstract

The study of the structure and mechanical properties of complex fluid interfaces has gained increasing interest in recent decades as a result of its significant scientific relevance to the understanding of biological systems, drug development, and industrial applications. The in situ combination of molecular-level structural measurements with the assessment of dynamical (rheological) properties is particularly valuable, as comparing measurements conducted on separate samples under challenging-to-reproduce experimental conditions can be problematic. In this work, we present a new sample environment at the FIGARO instrument, the horizontal neutron reflectometer at the Institut Laue-Langevin, which includes an interfacial shear rheometer operating in the Double Wall-Ring (DWR) geometry, compatible with commercial rotational rheometers. This innovative setup enables simultaneous structural (neutron reflectometry) and dynamical (shear interfacial rheology) measurements on the same sample.