LbL-modification of UF-capillary membranes

Funding: TUHH
Duration: 01.02.2017 – 31.01.2017

project management / project work:
 

Prof. Dr.-Ing. M. Ernst / S. Dillmann, M.Sc.

Situation:

Commercial ultrafiltration membranes with a pore diameter of 10-20 nm are not suitable for the removal of dissolved water compounds. The layer-by-layer (LbL) technique is a possibility for the modification of these membranes to reach adequate rejection of substances like sulphate, hardness or dissolved organic compounds. The removal of these substances is currently realised by energy-intensive or environmentally critical processes like nanofiltration, reverse osmosis or ion exchange.
The process conditions of the LbL-modification have a great impact on the resulting membrane. Parameters as the number of double layers, the molecular weight of the polyelectrolytes, temperature, pressure, pH value or ionic strength during the coating influence the properties of the coated membrane.

 

Methodology:

The aim of this project is the determination of the process conditions during the LbL-coating of an UF-capillary membrane and the optimization of the separation properties of the resulting membrane. A laboratory filtration unit is used for the investigation of the permeability and rejection, as well as the inquiry of the stability of the coating and the backwash behaviour. Electron microscopy and the measurement of the zeta potential provide additional information about the coating structure.
 

Recent project results: Download