Examples of projects offered during the summerschool
(Some changes may still be made to the projects being provided.)
Analytical chemistry; Painkillers Various analysis techniques will be used in this project to study an everyday product. These techniques are: UV spectrophotometry (UV), liquid chromatography (HPLC), gas chromatography (GC) and electrophoresis (CZE). Pain control has a long history. As early as 400 years before Christ, the Greece doctor Hippocrates used sap from the bark of willow trees to treat various types of pain. Today, a headache can be quickly eased: a couple of paracetamol, ibuprofen or aspirin and your pain is gone. But what brand should you buy to get the best treatment for your headache? In this research project, you will be able to synthesize aspirin or paracetamol and then establish the ingredients (composition) of different commercial brands.
Protection against UV radiation Many people use sunscreen products. They offer protection against UVA radiation, UVB radiation, or a combination of the two. A sunscreen product with a UVB filter protects the skin mainly against sunburn. A sunscreen product with a UVA filter protects the skin mainly against ageing. In this project, we will try to find an answer to the following questions: What does protection factor 10 mean? Can we measure the difference between factor 10 and factor 20? How well do clothes protect you against sunburn? Do plants protect themselves against radiation? If so, how?
Biodiesel We are running out of fossil fuels. Consequently, efforts have been made in recent decades to develop alternative fuels. One of the fuels that have been invented is BIODIESEL. This is a diesel fuel made from plant oils. In this project you will use the oil derived from rapeseed. You will find out what criteria a good diesel must meet, and how you can make such a product. Then you will actually make the biodiesel and see whether it meets the requirements you found out about. Then you can compare your product with commercial diesel. The techniques you will use in this project are gas chromatography (GC), mass spectrometry (MS), and methods for determining the viscosity and flash point.
(Dye-sensitized solar cells) The aim of this research project is to make a working solar cell based on titanium dioxide, using a dye rather than the customary silicon. This type of solar cell is considerably cheaper than the cells made of silicon that are currently used. The disadvantage is the yield: at most 10% for dye-sensitized solar cells compared to 22% for silicon. Your group will actually make this solar cell. As you do this, you will be able to vary various characteristics of the cell. Afterwards, you can take a number of measurements to calculate the cell's yield. As a group, you will become more familiar with the scientific method and some analysis techniques such as the recording of a UV-visible absorption spectrum, and viewing the cell surface using confocal microscopy and, possibly, an electron microscope.
Living on water; water repellence caused by chemistry and structure Many living organisms have developed ways and means to live in a watery environment. Fine examples are the lotus plants with their shiny, water-repellent leaves that stay clean on the water's surface, and insects like the common pond skater, which has special feet for walking on water. The secret behind "living on water” like this is called super-hydrophobicity. This relies on a combination of surface chemistry (hydrophobic chemical groups) and relief (surface structure). Many of the materials we use today have a coating that protects them against contact with water or that makes it easier to rinse away surface dirt. These coatings are self-cleaning. In this project you will be introduced to a simple method for making a superhydrophobic coating with the same sort of self-cleaning properties as those found in nature. Particles of silver and gold with different morphologies will be deposited on a metal substrate (base layer), and covered with a hydrophobic layer. In order to compare the coatings and evaluate the self-cleaning, you will use various techniques, such as electron microscopy and contact angle measurements.
Synthesis of liquid crystals In this project three different liquid crystals will be made. This process involves a reaction known as a condensation reaction. The liquid crystals made will include N-4-tolyl 4-hexyloxybenzaldimine. Besides this, you will be introduced to the analysis technique known as nuclear magnetic resonance spectometry (NMR), and you will use a polarization microscope to record at different temperatures the various liquid crystalline phases of the liquid crystals you have made.
Clean energy: Chemical Looping Combustion Eventually we will have to switch to producing renewable energy. However, in the coming decades it seems likely that we will remain largely dependent on fossil fuels to meet our energy requirements. The problem with using fossil fuels to produce energy is that they involve CO2 emissions, and these harm our climate. Simply capturing CO2 from the waste gas flows tends not to be an ideal solution. We are working on processes and reactors in which the CO2 has already been separated out in the reactor, so that a significant energy saving can be achieved. A very interesting process is this regard is Chemical Looping Combustion (CLC). In CLC direct contact between air and the fossil fuel is prevented by using an oxygen carrier. This is a sort of catalyst particle that can be oxidized (oxygen is gained) and then reduced (oxygen is lost). The reactions take place in what are called fluidized bed reactors and by transporting the oxygen carriers from the air-reactor to the fuel-reactor and back, we can make a continuous process of energy production. In this project, the concept will be worked out in greater detail and, using tests, it will be explained to you what fluidized bed reactors are, and what the particular characteristics and benefits of these reactors are, and why they are used in such high numbers in the chemical industry. Next, you will investigate which conditions good oxygen carriers must satisfy and, using a technique called thermogravimetric analysis (TGA), you will conduct experiments to find out how quickly oxygen carriers react.
Perfume from biomaterial Many of the everyday cosmetic products we use contain all kinds of aromas. Many of these aromas were originally extracted from plants and flowers and subsequently mixed to achieve different scent experiences. While many aromas are now made synthetically (using artificial substances), it is still difficult to imitate the aromas of plants; the synthetic aromas often have a very chemical odor. What's more, it is not easy to make a perfume; the scents have to sit together well, and some aromas in the complex mixtures evaporate more quickly than others (so you smell them sooner). In this project you will extract and/or distil aromas from various plants and study their composition. The main tool for analyzing the extracts is GC-MS. At the end of the project, you should be able to go home with a perfume you have made yourself.
Accelerating reactions with light A life without sunlight is inconceivable for both people and the natural world. Many chemical processes in nature are triggered by solar energy. Think, say, of photosynthesis in plants. This makes it astonishing that solar energy is very rarely used in the chemical industry. This is due mainly to the absorption of the light in the initial layers of the chemical reactor. In this project we will build our own microreactor that can solve this problem. What's more, we will demonstrate that when everyday light sources are used, reactions can happen extremely quickly in such reactors.
Photonic crystals Colored materials have a color because they absorb certain colors from the light that falls on them. The remaining light determines the color that we see. We also know of another way in which natural objects can get their color. The gemstone opal and the Morpho menelaus butterfly, for example, get their color from the interference of the light they reflect. The presence of photonic crystals makes this possible. Scientists are interested in imitating these photonic crystals because their color depends not on a chemical structure but only on their size, which means the color remains stable. During this project we will make photonic crystals, each with a different color. First of all, we will make polystyrene balls measuring 200 to 600 nm in diameter; then between these balls we will grow calcium carbonate crystals, and then the polymer will be baked off. We can make materials of different colors, depending on the size of the original polystyrene balls.
Solar concentrators Luminescent solar concentrators (LSCs) can convert solar energy into electricity at locations where standard silicon solar panels cannot be used. LSCs are colorful plastic sheets that can be produced in almost any shape, and that work in both sunny and overcast weather. These materials are not yet widely used because they are not very efficient. However, we can reduce the amount of energy lost inside the concentrator and how much light escapes on the top and underside of the plastic. We can do this by better controlling the direction in which the dyes show their fluorescence (in other words, their polarization). In this project we will use what are called liquid crystals to achieve this and to increase the efficiency. These materials can then be used as switchable LSCs to make heat-absorbing, energy-generating windows.