Rapid prototyping of membranes and membrane devices
Aachen / Publikationsserver der RWTH Aachen University (2016) [Dissertation / PhD Thesis]
Rapid prototyping, additive manufacturing and solid free-form fabrication describe technologies that translate virtual computer added design data into physical models in a fast process. The model data is divided into multiple two-dimensional cross sections of a certain thickness. The cross sections are processed by the prototyping device in order to combine and join them together in a layer-by- layer fashion into a physical part. Rapid prototyping offers freedom of design which gives access to novel shapes and geometries. Digital light processing is a rapid prototyping technique employing photopolymerization processes to additively assemble parts. It involves a liquid photopolymer in a vat that is cured throughout light activation.This thesis describes how rapid prototyping, especially digital light processing, can be applied in the field of membrane technology. The aim of this thesis is to establish a bridge between both fields and show new opportunities by focusing on the fabrication of membranes via rapid prototyping first and pursuing the design of novel membrane devices next. A literature review on rapid prototying and it’s application in process engineering is followed by the development and analysis of new membrane ge- ometries regarding mass transport and pressure drop. Furthermore, the two unprecedented methods of membrane fabrication via rapid prototyping are described. Both methods fabricate membranes are based on silicon polymers with excellent gas transport properties. Moreover, a novel membrane module is manufactured using the freedom of design of rapid prototyping. The developed membrane stirrer device for in-situ product recovery in a bioreactor is unique in function and design and remains inaccessible with conventional manufacturing techniques.Finally, additional applications in the field of rapid prototyping of dense and porous membranes are analyzed and the potential of rapid prototyping for advanced membrane modules are technology are revealed.