A simple trick generates custom-tailored pores. Maryam Radjabian has developed a surprisingly uncomplicated method for obtaining the desired pore size in block copolymer membranes. The results of her research were published in the distinguished international scientific journal Advanced Materials.
Whether it’s water treatment or virus and protein separation, porous membranes are utilised in many different separation functions. What is particularly fascinating and highly promising is isoporous membrane production from block copolymers.
Under suitable conditions, block copolymers can form highly ordered structures, ideally uniform pores, through self-assembly (see “Block Copolymer Information” below).
In order to develop effective membranes for special separation functions, the correct pore size is crucial. This objective presents the greatest challenge: how must the block copolymer be composed in order to obtain the desired pore size?
To date, for every newly developed isoporous membrane a special block copolymer was synthesized, which then resulted in the necessary pore size. In cooperation with the director of Geesthacht’s Institute of Polymer Research, Prof. Volker Abetz, Dr. Maryam Radjabian has now developed a time-saving and surprisingly simple method: by blending of two block copolymers, the pore size can be adjusted via the blending ratio.
The two block copolymers consist of the same monomers but differ in the number of repetition units in the blocks. A different pore size then arises in the particular membrane cast from each block copolymer. Dr. Radjabian’s concept of obtaining an average pore size by blending two block copolymers has been corroborated in experiments.
This opens up entirely new possibilities for designing new membranes. The scientist at the Institute of Polymer Research explains, “There is a substantial advantage in not having to synthesize a precisely suitable block copolymer to obtain the desired pore size, but in simply mixing two approximately suitable copolymers together.”
Block Copolymer Information:
Block copolymers consist of at least two types of monomers, each covalently linked together as polymer blocks (a group of the same monomers) in the form of a macromolecule. Because the blocks of macromolecules are selected so that they are not mixable (“immiscible”), self-assembly of the macromolecules takes place through rejection reactions (microphase separation).
Isoporous Membranes can be produced from a block copolymer solution under defined conditions by utilising the phase inversion principle. The foundations for this research were developed within the HZG-coordinated European Union project SELFMEM (2009-2012).
DOI: 10.1002/adma.201404309: Tailored Pore Sizes in Integral Asymmetric Membranes Formed by Blends of Block Copolymers, Maryam Radjabian, Volker Abetz
Advanced Materials 2015, 27, 352-355, (online 20 Nov.V 2014)
http://www.hzg.de/public_relations_media/news/058880/index.php.en - website HZG
http://dx.doi.org/10.1002/adma.201404309 -- Publication
Dr. Torsten Fischer | Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung
An innovative high-performance material: biofibers made from green lacewing silk
20.01.2017 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Treated carbon pulls radioactive elements from water
20.01.2017 | Rice University
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
20.01.2017 | Awards Funding
20.01.2017 | Materials Sciences
20.01.2017 | Life Sciences