Glossary

All A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Term Definition
Secregation

Latin secernere - segregate. Release of important substances for the organism (for example hormones, digestive enzymes) by specialised cells, especially glandular cells. The substances themselves are called secretions.

Sedimentation

Settling of particles from liquids influenced by gravity and other forces, e.g. the centrifugal forces generated in a centrifuge. The sedimentation rate is determined by the particle size and density of the material.

Sediments (natural)

Caused by deposition or settling of particles (e.g. sand, suspended solids or organic remains) on land or in waters under the influence of cold, wind and water.

SEM

Abbreviation for Scanning Electron Microscope. A device to study smallest samples by scanning the object using electron beams. The resulting images are detailed illustrations of the object surfaces and have a great depth of field.

Sintering

Technical process, in which granular or powdery materials are mixed and then connected to each other by heating. They are baked together (similar to the burning clay or porcelain). The substances are heated to temperatures which are below the melting temperatures of the substance or at least one component of a mixture of substances. This method is used in many nanotechnology application processes.

smart textiles

Also called intelligent textiles. They are able to sense stimuli from the environment, to react to them and adapt to them by integration of functionalities in the textile structure. The stimulus and response can have an electrical, thermal, chemical, magnetic or other origin.

Solubility

The solubility of a substance indicates whether and to what extent a substance in a solvent (usually a liquid) can be solved. It describes the property of a substance to be evenly mixed with the solvent. Inorganic nanoparticles (mostly metals and metal oxides) decompose into ions. The solubility depends i.a. of temperature and pH of the solution.

SPION

Short for superparamagnetic iron oxide nanoparticles.

Stabilisation

Auxiliary substances that contribute significantly to obtaining or maintaining a stable condition. This can for example be a certain particle size (preventing the agglomeration), or composition. Commonly used stabilising agents for nanomaterials include citrate, phosphates, or polymers such as polyethylene glycol (PEG).

Subacute

Refers to a course or effect, which is located between acute and chronic, e.g. a less intense course, in time neither fast nor slow running.

Surface charge

Is the electric charge present at the interface of the nanoparticle surface with a polar fluid such as water. The water contains positive and negative ions, which interact with the particle surface. If the number of adsorbed e.g. positive ions exceeds the number of negative ions, surface charge would be positive. Since direct measurement of the surface charge of particles measured is difficult, the zeta potential is calculated as a proxy for the surface charge.

Surface defects

are gaps in an otherwise regular arrangement of atoms. These vacancies are responsible for exceptional properties of some nanomaterials such as high reactivity. In many cases, however, surface effects are undesirable and covered by surface coatings.

Surface modification

Are chemical changes on the surfaces of nanomaterials, which are commonly employed to impart certain improved properties to the surface of nanomaterials, e.g. improved solubility, resistance to UV light or scratch resistance.

Surfactant

Short for surface active agent. Its function is to lower the surface tension and to improve the solubility in aqueous solutions. As medical term it describes the thin liquid film lining the lung for stability reasons.

Suspension

Solid particles suspended in a liquid, i.e. a more or less thick sludge or slurry. Normally, the solid particles deposit on the bottom if one allows the suspension to rest for a while in the vessel.

 

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