Background and Motivation
Fouling on heat transfer surfaces is a critical challenge in many industrial applications, particularly in thermal processes like the treatment of milk proteins, cooling systems, and polymerization reactions. Thermally induced fouling often occurs when a certain temperature threshold is exceeded, leading to the deposition of substances on heat transfer surfaces. Understanding and predicting the initiation of fouling is crucial for improving process efficiency, reducing energy consumption, and preventing unwanted deposits.

One promising approach for investigating fouling is the use of microstructured heat exchangers, which allow for precise control over fluid and wall temperatures. However, to advance the under-standing of fouling mechanisms, especially at the initial stages, it is necessary to create synthetic fouling layers with controlled characteristics that can be used for systematic studies. Inkjet printing has emerged as an effective method for fabricating these synthetic fouling layers due to its ability to precisely control layer thickness, structure, and material properties.

This master's thesis aims to develop a reliable inkjet printing method for creating synthetic silica-based fouling layers and to characterize these layers in terms of their thickness, surface morpholo-gy, and thermal properties. The goal is to provide insights into the characteristics of synthetic fouling layers, laying the foundation for future research into their impact on heat transfer and fluid flow in microchannel devices.

Task description
The goal of this master thesis is to investigate the development and characterization of silicon-based synthetic fouling layers in microchannels using inkjet printing. The work will involve optimizing ink formulations and printing parameters to achieve controlled fouling layers with precise thickness and uniformity. The following tasks will be carried out:

•    Formulate and optimize silica-based inks suitable for inkjet printing.
•    Characterize critical ink properties such as surface tension, viscosity, and drying behavior.
•    Deposit controlled silicon-based fouling layers in microchannels using inkjet printing
•    Preliminary analysis of fouling layer effects.

Start date: as soon as possible
Supervisor: Dr. Jinju Zhang
Contract: jinju.zhang2@kit.edu Tel: 0721-608-24088