Figure 1.1: Some examples of polymers. On top: polyisoprene which is the main component of rubber. In the middle: chitin which is the main component in the exoskeletons of arthropods. On the bottom Nylon which is used to make fibres for ropes and clothing. Project Description The goal of my PhD project was to investigate how the properties of the individual polymers, that form these networks, influence the properties of the gel. Within this project three Phd students worked together. Two of them, Wolf Rombouts 12 and Ma lgorzata Bohdan 7 , did experiments in the lab while I worked on computer simulations. Gosia Bohdan used telechelic polymers with a PEO middle block end capped by hydrophobic or metal binding end groups. She made micelles with a varying ratio of mono-to difunctionalized telechelic polymers Monte Carlo With a Monte Carlo method an estimate of a property is made by randomly sampling states of the system and averaging of the value of the property over all states. The Monte Carlo method was first conceived by Enrico Fermi when he studied neutron diffusion. Later Stanislaw Ulam had the same idea when he tried to determine the probability that a particular solitaire game was winnable. He failed to do this with mathematical methods and wondered whether he should have simply played many games while keeping track of the percentage of games he won. He then realized that the problem of how neutrons would Mean Field Models With mean field models one does not try to determine individual particle configurations, instead we determine their distribution based on the average interactions the particles have with their environment. This