Scattering Methods and their Application in Colloid and Interface Science

Otto Glatter

• Publisher: Elsevier
• Year: 2018
• Print ISBN: 9780128135808
• eBook ISBN: 9780128135815
• Topic: Technology & Engineering
• Subtopic: Physical & Theoretical Chemistry
• Index: Technology & Engineering

Scattering Methods and their Application in Colloid and Interface Science offers an overview of small-angle X-ray and neutron scattering techniques (SAXS & SANS), as well as static and dynamic light scattering (SLS & DLS). These scattering techniques are central to the study of soft matter, such as colloidal dispersions and surfactant self-assembly. The theoretical concepts are followed by an overview of instrumentation and a detailed description of the evaluation techniques in the first part of the book. In the second part, several typical application examples are used to show the strength and limitations of these techniques. - Features the latest input from the world-leading expert with personal experience in all the fields covered (SAXS, SANS, SLS and DLS) - Includes unified notation throughout the book to enhance its readability - Provides—in a single source—scattering theory, evaluation of techniques and a variety of applications

Chapter 1

Interference, Rayleigh–Debye–Gans Theory

Abstract

This chapter gives an overview of the principles of small-angle X-ray and neutron scattering. The description of these scattering experiments is based on the interference of coherently scattered waves. The phase difference of waves that come from different scattering centers is based on the path length difference. The Rayleigh–Debye–Gans theory of scattering is the rigorous application of the idea of coherent interference to scattering, assuming that the wave propagates into and through the particle regularly and homogeneously. Here we are dealing only with dilute, monodisperse, nonoriented systems. This means one has to average over all orientations in space, and particle interactions can be ignored. The angle-dependent scattering intensity, the form factor, is related to the particle pair–distance distribution function by a Fourier transformation. The scatterers may also be characterized by their correlation function, correlation length, and chord distribution in real space, or by their second moment—the invariant—in reciprocal space.

Keywords

Correlation function; form factor; interference; invariant; Rayleigh–Debye–Gans theory; pair–distance distribution function

Interference of Scattered Waves

When an electromagnetic wave is sent through a thin slab of material, the electric field will introduce a polarization of the atoms, leading to the formation of little dipoles. The electric field oscillates with a frequency that is defined by the wavelength of the radiation sent into the material, so the dipoles will oscillate in a forced motion with the same frequency.

Around the turn of the last century, H.A. Lorentz¹ developed a classical theory of the optical properties of matter. He treated electrons and ions as simple harmonic oscillators (springs), which are moved by the driving force of the electromagnetic field. The results of this procedure are qualitatively identi...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Chapter 1. Interference, Rayleigh–Debye–Gans Theory
• Chapter 2. General Theorems and Special Cases
• Chapter 3. The Inverse Scattering Problem
• Chapter 4. Concentration Effects, Interactions
• Chapter 5. Absolute Intensity, SAXS, and SANS
• Chapter 6. Contrast Variation
• Chapter 7. Instrumentation for SAXS and SANS
• Chapter 8. Numerical Methods
• Chapter 9. Static Light Scattering From Small Particles
• Chapter 10. Light Scattering From Large Particles: Lorenz−Mie Theory
• Chapter 11. Dynamic Light Scattering (DLS)
• Chapter 12. Dilute Systems: Practical Aspects—Applications
• Chapter 13. Concentrated, Interacting Systems: Practical Aspects, Applications
• Chapter 14. Glasses, Liquid Crystals, and Gels
• Appendix
• References
• Index