Pinhole Mirror-Based Ultra-Small Angle Light Scattering Setup for Simultaneous Measurement of Scattering and Transmission

Published

April 12, 2022

Author(s)

Samim Ali, Yimin Mao, Vivek Prabhu

Abstract

An ultra-small angle light scattering setup with the ability of simultaneous registration of the scattered light by a charge-coupled device (CCD) camera and the transmitted direct beam by a pin photodiode (PPD) was developed. A pinhole mirror was used to reflect the scattered light; the transmitted direct beam was focused at and passed through the central pinhole with a diameter of 500 μm. Time-resolved static light scattering measurement were carried out over the angular range 0.2° ≤ θ ≤ 8.9° with a time resolution of approx. 33 ms. The measured scattering pattern in the q-range between 5×10^(-5) and 1.5×10^(-3) 〖nm〗^(-1) enables investigating structures of few micrometers to submillimeter, where q is the modulus of the scattering vector. A LabVIEW-based graphical user interface (GUI) was developed, which integrates the data acquisition of the scattering pattern and the transmitted intensity. The Peltier temperature-controlled sample cells of varying thicknesses allow for a rapid temperature equilibration and minimization of multiple scattering. The spinodal decomposition for coacervation (phase separation) kinetics of an aqueous mixture of oppositely charged polyelectrolytes was demonstrated.

Citation

Review of Scientific Instruments

Volume

93

Pub Type

Journals

Download Paper

https://doi.org/10.1063/5.0086146

Local Download

Keywords

light scattering, polyelectrolyte, phase separation, instrumentation, SALS, USALS

Citation

Ali, S. , Mao, Y. and Prabhu, V. (2022), Pinhole Mirror-Based Ultra-Small Angle Light Scattering Setup for Simultaneous Measurement of Scattering and Transmission, Review of Scientific Instruments, [online], https://doi.org/10.1063/5.0086146, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=934002 (Accessed October 14, 2025)