Expose samples to visible light of UV radiation
The DSC-Photocalorimetry allows enthalpy changes in a material to be measured during and after exposure to light of certain wavelengths for different periods of time at different temperatures.
- Versatile experimental parameters – the effect of light intensity, wavelength range, temperature, and time on photoinitiated reactions can easily be investigated
- Simulation of production conditions – curing times can be studied in the laboratory, which greatly reduces costs
- Product development optimization – the stability behavior of materials and aging effects can be quickly determined
Because of its modularity a DSC 3+, DSC 3, DSC 2, DSC 1 or a DSC82xe can be easily upgraded to a DSC-Photocalorimetry System. The optical arrangement with the interchangeable light source is designed so that the sample can be exposed
- to a defined light intensity
- of a particular wavelength range
- for different periods of time
- at different temperatures.
The DSC sensor measures the sample temperature and enthalpy changes that occur in the sample during the course of the reaction.
| ||Influence of UV exposure time on olive oil|
The action of UV light on foodstuffs can lead to degradation and depolymerization with an accompanying negative effect on aroma and taste. In the example shown, olive oil was exposed to UV light (100 mW/cm2) for different periods of time. After exposure, the crystallization behavior of the samples was investigated. The results show that UV light exposure clearly has a significant effect. With increasing exposure time, crystallization occurs at lower temperatures. In addition, the enthalpy of crystallization decreases.
|Curing of a dental composite|
Light-curing composites are nowadays widely used in dentistry to fill cavities in teeth. DSC-photocalorimetric measurements enable the curing process of these dental fillings to be followed. This is demonstrated in the example showing the curing of a composite filling material under the action of light. In this application, a white light source with a high percentage of light between 400 and 500 nm was used. The glass transition of the cured composite filling is at about 38 °C and is relatively broad. The endothermic peak following the glass transition is due to the melting of a constituent of the composite.