Multiangle light scattering (MALS) describes a technique for measuring the light scattered by a sample into a plurality of angles. It is used for determining both the absolute molar mass and the average size of molecules in solution, by detecting how they scatter light. A collimated beam from a laser source is most often used, in which case the technique can be referred to as multiangle laser light scattering (MALLS). The insertion of the word laser was intended to reassure those used to making light scattering measurements with conventional light sources, such as Hg-arc lamps that low-angle measurements could now be made. Until the advent of lasers and their associated fine beams of narrow width, the width of conventional light beams used to make such measurements prevented data collection at smaller scattering angles. In recent years, since all commercial light scattering instrumentation use laser sources, this need to mention the light source has been dropped and the term MALS is used throughout.
The "multi-angle" term refers to the detection of scattered light at different discrete angles as measured, for example, by a single detector moved over a range that includes the particular angles selected or an array of detectors fixed at specific angular locations. A discussion of the physical phenomenon related to this static light scattering, including some applications, data analysis methods and graphical representations associated therewith are presented.
The measurement of scattered light from an illuminated sample forms the basis of the so-called classical light scattering measurement. Historically, such measurements were made using a single detector rotated in an arc about the illuminated sample. The first commercial instrument (formally called a "scattered photometer") was the Brice-Phoenix light scattering photometer introduced in the mid-1950s and followed by the Sofica photometer introduced in the late 1960s.
Measurements were generally expressed as scattered intensities or scattered irradiance.
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The student has a basic understanding of the physical and physicochemical principles which result from the chainlike structure of synthetic macromolecules. The student can predict major characteristic
Covers the principles and applications of Size Exclusion Chromatography, analyzing macromolecules based on their molar masses using a single solvent eluent.
The molecular mass (m) is the mass of a given molecule, for which the unit dalton (Da) is used. Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The related quantity relative molecular mass, as defined by IUPAC, is the ratio of the mass of a molecule to the atomic mass constant (which is equal to one dalton) and is unitless. The molecular mass and relative molecular mass are distinct from but related to the molar mass.
Interferometric scattering (iSCAT) microscopy enables the label-free observation of biomolecules. Consequently, single-particle imaging and tracking with the iSCAT-based method known as mass photometry (MP) is a growing area of study. However, establishing ...
In aqueous solutions, a charged surface causes the redistribution of nearby ions. The ion layers formed are known as the electrical double layer (EDL), and are widespread in many systems involving electrochemistry, colloidal science, biomedicine, and energ ...
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Recent state-to-state experiments of methane scattering from Ni(111) and graphene-covered Ni(111) combined with quantum mechanical simulations suggest an intriguing correlation between the surface-induced vibrational energy redistribution (SIVR) during the ...