Chip Calorimetry
Conceptually, the fast scanning chip calorimetry technique is similar to DSC and RHC in that a differential heat flow is measured. Like DSC and RHC, it is a differential technique, i.e. a sample and a reference are subjected to the same temperature program, so that the influence of non-sample effects such as heat losses and addenda heat capacities (due to e.g. the membrane) is reduced. In practise, a closed tube containing an oven with both reference and sample sensors is submerged in liquid nitrogen. The oven is kept at a constant temperature, which will be the base temperature for all measurements. The liquid nitrogen acts as a heat sink, allowing cryogenic base temperatures.
The thin membrane chips consist of a 1 µm thick freestanding SiNx membrane of 900 µm by 900 µm, supported by a silicon frame. In the centre of this membrane an active area can be found where the sample is placed. The size of the active area depends on the type of chip, and will determine the maximum scanning rates that can be attained. Depending on its size, the active area will contain 1 or 2 on-chip resistive heaters and a number of polysilicon p-n thermopiles.
The very high heating and cooling rates that can be achieved using this technique can be used to avoid all kinds of undesirable non-isothermal effects (e.g. reordering), making it possible to investigate metastable structures. This technique has so far been succesfull for the study of crystallization kinetics of rapidly crystallizing materials, in bulk or in thin layers.
Projects

Nanostructuring, morphological stability, and mechanism of charge transfer in conjugated polymer/fullerene blends for organic photovoltaic cells. An experimental and theoretical study
The aim of this project is to contribute to the fundamental insights into the mechanisms and criteria that affect the efficiency and stability of 'exciton' solar cells, based on the 'bulk heterojunction' concept. In this type of photovoltaic cells, foto-induced excitons (hole-electron pairs) that are formed in a donor phase of a phase separated system, must diffuse towards the (nano)interface ...

Phase behaviour and rheology of solutions and blends of conjugated polymers
The goal of this project is to get insight in the fundamentals of the solution and phase behaviour of conjugated polymers in specific solvents, on the one hand, and to extend this knowledge to the rheological behaviour under shear or extension, on the other hand. This is extended from solutions of conducting polymers to mixtures of conjugated polymers with fullerene derivatives. These material ...
Molecular mixing in bulk heterojunction organic solar cells - nanomorphology vs performance
The photovoltaic behavior of organic bulk heterojunction (BHJ) blends of conjugated (donor) polymers and fullerene (acceptor) derivatives has been subject of many studies in fundamental chemistry and physics since its initial discovery in 1995. From the general understanding at this moment, the nanomorphology of the active layer blend seems to be crucial. The latter is the result of a complex ...