In chemical engineering, many reactions have been transferred to chemical reactors, which are the heart of the chemical process. The reactor is basically the piece of equipment, in which conversion of reactant to desired product takes place. Several factors must be considered in selecting the physical configuration and mode of operation to be used to accomplish a specific task.
In terms of the physical configurations encountered, there are basically only two types of reactors: the tank (batch, semibatch and continuous flow) and the tube. When filled with solid particles, the reactors are referred to as fixed or packed bed reactors.
Our goal is to develop reactors for the reliable, fast, and efficient surface derivatization of nanoparticles. Surface functionalization of nanoparticles in general still remains a difficult task up to now. The most important challenge in the synthesis of surface derivatized particles is colloidal stability of the particles since solvents, pH and ionic concentrations are constantly changing, which often results in irreversible agglomeration.
We have developed a fixed bed reactor with a quadrupole repulsive arrangement of permanent magnets to allow for magnetic immobilization of (superpara)magnetic nanoparticles in order to perform the derivatization step(s) on the immobilized particles.
Starting with the first prototype 3 years ago, the current fully automated reactor is used in many projects that require sophisticated surface engineered nanoparticles.
In comparative studies, we showed the advantages of the developed reactor:
In ongoing investigations we focus on the opportunities and limits of the reactor, where we use the immobilized magnetic particles as supports for e.g. catalytic reactions. In addition, we are currently about to transfer general concept to much smaller scale, a so-called microreactor, and it is our goal to apply the obtained know-how to other, non-magnetic, nanoparticles.