Small‐Angle Neutron Scattering

Abstract

Small‐angle neutron scattering (SANS) probes structural details at the nanometer scale in a nondestructive way. This chapter gives an introduction to scientists who have no prior small‐angle scattering knowledge but seek a technique that allows elucidating structural information in challenging situations that thwart approaches by other methods. SANS is applicable to a wide variety of materials including metals and alloys, ceramics, concrete, glasses, polymers, composites, and biological materials. Isotope and magnetic interactions provide unique methods for labeling and contrast variation to highlight specific structural features of interest. In situ studies of a material's responses to temperature, pressure, shear, magnetic and electric fields, etc., are feasible as a result of the high penetrating power of neutrons. SANS provides statistical information on significant structural features averaged over the probed sample volume, and one can use SANS to quantify with high precision the structural details that are observed, for example, in electron microscopy. Neutron scattering is nondestructive; there is no need to cut specimens into thin sections, and neutrons penetrate deeply, providing information on the bulk material, free from surface effects. The basic principles of a SANS experiment are fairly simple, but the measurement, analysis, and interpretation of small‐angle scattering data involve theoretical concepts that are unique to the technique and that are not widely known. This chapter includes a concise description of the basics, as well as practical know‐how that is essential for a successful SANS experiment.

Scattering Neutrons along the Polyelectrolyte Complex/Coacervate Continuum

“…Traditional or modified light scattering techniques were also employed to gain insight into the mechanism of polycation–protein complexation. , Small-angle X-ray scattering (SAXS) was used to study polyelectrolytes in their free or bound form. , Though these scattering techniques provide information on single polymer chains in solution or on the internal construction of complexes, they fall short of elucidating the molecular structure of single polymers within their materials. Small-angle neutron scattering (SANS) is a powerful tool that delivers this additional information . Taking advantage of selective isotopic labeling, SANS allows the monitoring of the chain in any surrounding .…”

“…Small-angle neutron scattering (SANS) is a powerful tool that delivers this additional information. 21 Taking advantage of selective isotopic labeling, SANS allows the monitoring of the chain in any surrounding. 22 It has been employed to observe polyelectrolytes in salt-free solutions, 23,24 salt-containing solutions, 25 and polyelectrolyte− protein complexes and coacervates.…”

Complex pH-Dependent Interactions between Weak Polyelectrolyte Block Copolymer Micelles and Molecular Fluorophores

“…Small Angle Neutron Scattering (SANS). SANS 38 was performed using the CG-3 Bio-SANS instrument 39 on pBd−pAA micelles at 0.27 mass % in 100% D 2 O, at pH 3 and 6 (Figure S4). Measurement and data analysis followed approaches as in our preceding work, described elsewhere.…”

Oligomerization state and pigment binding strength of the peridinin‐Chla‐protein

“…SANS is a powerful tool for investigating macromolecules at length scales of 1 nm to 1 lm [19]. Since neutrons are non-destructive, SANS has been widely used to study the structural properties of proteins and protein/membrane interactions, etc.…”