engleski

Channel surface modification of 3D printed droplet generators

The use of emulsions is increasing in the food, cosmetics and pharmaceutical industries. The size of the droplets has a strong influence on the final product. The aim of this study was to investigate the influence of channel size, shape and connection type, as well as the influence of different types of surface modifiers on the liquid flow in the channel and the droplet size obtained. Test samples of different materials were made to determine the optimum material in terms of surface free energy. The droplet generators were fabricated using a stereolithographic 3D printer. Fourier transform infrared spectroscopy (FTIR) was used to analyze the surface coating. In addition, contact angle measurements were performed on untreated and surface-treated samples. A system of two immiscible liquids, water and oil, was used to form the emulsion in the droplet generators. From the results obtained in the experiment, the optimum combination of material and surface agents was selected. In the final part of the study, two surface modifiers were tested to see the influence of connection and surface modifiers on the stability of the formed emulsion. The influence of the surface modifiers was confirmed, as the hydrophilic/hydrophobic properties strongly influenced the shape and number of droplets generated in the channel (Figure 1). Moreover, the droplet formation could be easily controlled by changing the flow ratio of the two liquids in the droplet generator. The emulsions formed were unstable and an emulsifier must be used for stabilization.

surface modification ; additive manufacturing ; droplet generator

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