In a typical light scattering experiment, a well collimated, single frequency, polarized light beam (i.e., from a laser) is used to illuminate a solution containing a suspension of the macromolecules or nanoparticles of interest. The electric field of the polarized light beam is preferably produced perpendicular to the plane in which the intensity and angular dependence of the subsequently scattered light is to be measured.
The overall intensity carries information about the molar mass, while the angular dependence within the horizontal plane carries information about the size of the macromolecule.
Coupling MALS with an in-line concentration detector following a sample separation technique such as AF4 or SEC permits to determine the molar mass of the eluting sample in addition to its root-mean-square radius.
AF4-MALS is applicable to a wide range of analytes including proteins, polymers, viruses, gene vectors, liposomal drug nanoparticles, engineered nanoparticles, colloids and nanoemulsions.
Multi Angle Light Scattering (MALS) (nanoparticle sizing)
AF4-MALS is applicable to a wide range of analytes including proteins, polymers, viruses, gene vectors, liposomal drug nanoparticles, engineered nanoparticles, colloids and nanoemulsions. Coupling MALS with an in-line concentration detector following a sample separation technique such as AF4 or SEC permits to determine the molar mass of the eluting sample in addition to its root-mean-square radius.
XPS is a surface spectroscopic technique for quantitative measurements of the elemental composition or stoichiometry and the chemical state of the present elements, like their oxidation state and chemical bonds. XPS is highly surface sensitive, giving chemical and binding energy information from the a narrow region close to the surface.
In TEM/Scanning TEM (STEM) high energy electrons incident on ultra-thin samples, allow imaging, diffraction, electron energy loss spectroscopy and chemical analysis of solid materials with a spatial resolution on the order of 1-2 Å. Samples must have a thickness of a few tens of nanometres and are prepared in sample preparation laboratory.
SAXS is a non-destructive and versatile method to study the nanoscale structure of any type of material (solid, liquid, aerosols) ranging from new nanocomposites to biological macromolecules. Averaged particle sizes, shapes and distributions, porosity, degree of crystallinity and electron density maps with nanometer precision can be obtained.
Ellipsometry is a contact-free, nondestructive method for characterization of the dielectric and optical properties (refractive index, absorption and thickness) of layered nanostructures in the size range of < 1 nm to several μm.
The Brunauer-Emmett-Teller method can be applied for determination of the specific surface area of a solid material. The volume specific surface area of a particulate material might be the basis of a decision whether it is considered to be nanomaterial according to the European Commission’s Recommendation on the definition of nanomaterial.
