Lars Peters

24 Aug 2012

Career

12/2011- PhD student, RWTH Aachen University, Germany

11/2011 - Diploma thesis - Topic: Fabrication and characterization of mixed matrix membranes for the separation of biomolecules

04/2010 – 07/2010 - MEMFO – Chemical Engineering Department of the Norwegian Engineering Department, NTNU, Norway

Student research project - Topic: CO2 removal from natural gas by employing amine absorption and membrane technology – a technical and economical analysis

06/2009 - Three months student research project

Topic: Aspen Plus Simulation of an Amine   Absorption Process for CO2 recovery from power plant flue gases

10/2006 – 11/2011 – Student, RWTH Aachen University, Germany - Chemical Engineering

Internships and Work Experience

02/2011 – 04/2011 – Evonik – Trainee, Membrane Process Development

09/2010 – 12/2010 - Vaperma, Quebec, Canada – Trainee, Development of a gas permeation membrane for Nitrogen/Oxygen

Abstract


Layer-by-Layer assembly of polyelectrolyte multilayers on polyethersulfone hollow fibres: dry-wet spinning, physicochemical characterizations and performance assessment

The development of asymmetric membranes in the 1960s was a major breakthrough for membrane technologies. Hollow fibre membranes combine the advantages of a large specific surface area with high mechanical strength and have found use in various industrial applications. In this work we report the fabrication of hollow fibres produced via a dry-wet spinning process [1] from polyethersulfone (PES) and polyvinylpyrrolidone (PVP). The outer surface of the obtained hollow fibres was then modified using the layer-by-layer (LbL) technique [2], a technique that involves the direct sequential adsorption of polyelectrolyte multilayers onto the membrane surface [3]. The polyelectrolytes used in this work are polyethyleneimine (MW=750 KDa), or PEI, and polystyrene sulfonate (MW = 70 KDa), or PSS. The formation and growth of the polyelectrolyte multilayers were monitored by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). ATR-FTIR confirms that the deposition of the layers stay on the outer surface of the hollow fibres and do not penetrate into the membrane during coating. The stability of the layers will also be discussed with regard to common chemical cleaning procedure such as exposure to sodium hypochlorite (NaOCl). Bundles of 10Layer-, 20L-, 30L-, 40L-, and 50L-coated hollow fibres (between 3 and 10) were encased into modules to assess their performance in terms of clean water permeability. To the best of our knowledge, this is the first time attempt is also made to (i) evaluate the effective pore size of LbL-coated hollow fibre membranes (dry and wet conditions) and (ii) assess the tensile strength directly on the wet (operating condition) LbL-coated hollow fibres.