Welcome to The Gröschel Group
08.12.17 Publication in Polymer Chemistry
In the article "Supracolloidal Chians of Patchy Micelles in Water" Tai-Lam Nghiem and Tina I. Löbling synthesized a series of bishydrophilic triblock terpolymers via RAFT polymerization with the aim to form supracolloidal chains through a hierarcchical self-assembly process. For that, Tai assembled the terpoylmers PEO-b-PS-b-P2VP in "soft" organic solvents to obtain very homogeneous micelles with a PS core and mixed/patchy corona of PEO/P2VP. Transfer to water pH2 then stabilized these micelles due to the double hydrophilic corona. In pH6 however, P2VP collapses and micelles start to form supracolloidal chains of different length and connectivity. The superstructures were analyzed with DLS in our laboratory as well as TEM in the Imaging Center Essen. Follow-up work will focus on polymorphism as well as different stimuli for supracolloidal structure formation.
01.12.17 New group member Alexander Tjaberings
We welcome Alexander Tjaberings from UDE who joined the group on 01.12.17.
He will do his PhD in the Emmy Noether Independent Junior Research Group on the synthesis of functional triblock terpoylmers and their self-assembly into topographic nanoparticles and 3D nanoparticle lattices.
01.12.17 New group member Giada Quintieri
We welcome Giada Quintieri from RUB who joined the group on 01.12.17.
She will do her PhD in the Emmy Noether Independent Junior Research Group on the synthesis of functional triblock terpoylmers and their self-assembly into topographic nanoparticles and 3D nanoparticle lattices.
01.12.17 New group member Ramzi Chakroun
We welcome Ramzi Chakroun to our group who joined on 01.12.17!
He will be responsible for our dynamic light scattering setup and do his PhD on self-assembled triblock terpolymer nanostructures with special emphasis on following self-assembly kinetics and structure evolution in solution.
15.11.17 New group member Stefanie Tjaberings
We welcome Stefanie Tjaberings from UDE who joined the group on 15.11.17.
She will do her PhD on complex block copolymer nanostructrues with special emphasis on block copolymer/metal hybrid materials for energy conversion.
10.11.17 Publication in Polymer Chemistry
In the article "Polymer brush guided templating on well-defined rod-like cellulose nanocrystals" Maria Morits synthesized cylindrical polymer brushes by grafting diverse polymer chains from the backbone of cellulose nanocrystals (CNCs). CNCs are rod-like nanoparticcles of purely crystalline cellulose and have attracted much attention. These biomaterials are usually incompatible with many other materials and compatibilization of the surface further applications is necessary. Maria could show that grafting can be realized in controlled manner and that sol gel processes in the polyer shell leads to spatially controlled bioinorganic hybrids.
30.10.17 Master Thesis Finished!
Congratulations to Ramzi Chakroun for successfully completing his Master thesis!
25.10.2017 Publication in Advanced Science
In the article "Imaging Inelastic Fracture Processes in Biomimetic Nanocomposites and Nacre by Laser Speckle for Better Toughness" Tuukka Verho studies the behaviour of nacre mimetic nanocomposites under flexural stress and analyses the deformation with laser speckle imaging. We find that this technique allows detecting plastic deformations before crack formation and provides insight into origin and propagation of cracks. We compared the results with measurements on real nacre samples and find differences in failure bahaviour. These results will help in the design of better matrix/reinforcement adhesion to further boost the performance of lightweight structural bionanocomposites.
23.10.2017 Publication in Advanced Materials
In the Review "Novel materials through assembly of nanocelluloses" we summerize the exponentially growing field on nanocellulose and functional materials derived thereof. This extensive review covers amongst others synthesis and properties of diverse nanocelluloses, processing with polymers, grating polymers from cellulose, cellulose protein and nanoparticles nanocomposites, fiberspinning, hydrogels, biomimetic nanocomposites, nanocellulose materials with magnetic, conductive, optic and catalytic properties.
16.10.17 New group member Chen Chen
We welcome Chen Chen from Sichuan University in China who joined the group on 16.10.17. He received the prestigeous CSC Scholarship and will do his PhD within the next 48 months. He will be working on polymer self-assembly and precise nanoparticle clusters.
22.09.17 New group member Xiaoliang Qiang
We welcome Xiaolian Qiang from Sichuan University in China who joined the group on 22.09.17. She received the prestigeous CSC Scholarship and will do her PhD within the next 48 months. She will be working on block copolymer self-assembly, nanoemulsions, and topologically complex particles.
15.09.17 Master Thesis Finished!
Congratulations to Stefanie Tjaberings for successfully completing her Master thesis!
15.09.17 Guest Presentation on Photodynamic Therapy by Prof. Weian Zhang
Prof. Weian Zhang from the East China University of Science and Technology (Shanghai, China) visited the group on Friday 15.09.2017 and gave a talk on a series of porphyrin-containing polymers using porphyrins as initiators, monomers, RAFT transfer agents and “click chemistry” agents. He presented a variety of assemblies based on porphyrin-containing amphiphilic polymers useful in photodynamic therapy (PDT), where assemblies effectively improve the water solubility of the porphyrinic photosensitizers and enhance cellular internalization.
06.09.17 Bachelor Thesis Finished!
We congratulate Suna Azhdari for successfully completing her Bachelor thesis.
02.09.17 3 PhD Positions available
We are currently serching for 3 talented PhD students conducting research as part of an Emmy Noether Project launching November 2017. If you are a highly motivated researcher with background or interest in polymer and colloid science you can apply until 29.09.2017.
05.08.2017 On the Move!
The group is working on interdisciplary projects (see research) and energy conversion is one of them. Many synthetic concepts and matrials in our group may serve as advanced scaffolds and templates for catalytic materials, separators, and compatibilizers. Since the group is also expanding quickly, the current laboratories at the Schützenbahn are not sufficient anymore. Thus, we applied for laboratory space at the newly errected nano energy technic centre (NETZ) and are now allowed to move into more sophisticated research environment! From mid Semptember onwards the group will be mainly located here and is looking forward to fruitful collaborations and a great time at the NETZ.
31.07.2017 Emmy-Noether Programm
The application for an Emmy Noether Independent Research Group was accepted by the German Research Fundation (DFG). From today onwards, the Gröschel Group is one of four Emmy Noether Groups in Polymer Chemistry in Germany and thus, part of an elite network withint the Emmy Noether Programm.
10.07.2017 Publication in ACS Sustainable Chemistry & Engineering
In the article "Polymer Brushes on Cellulose Nanofibers: Modification SI-ATRP, and Unexpected Degradation Processes" Maria Morits explores routs to modify cellulose nanofibers for controlled radical surface-initiated polymerization. Nanocelluloses are fascinating biomaterials harvested from plants trees and other biological sources. Nanocelluloses have received much attention reccently due to their exceptional mechanical properties while being a green material with low ecological footprint. To make nanoccellulsoes attractive for various applications, compatibilization through surface modification is necessary. Concepts are in demand and successful SI-ATRP opens a whole new toolbox for diverse chemical surface functions through choie of monomer.
17.07. – 21.07.2017 16th ICC Clay Conference in Granada
Upon invitation from the organizers, André traveled to Granada to give a talk on 20.07. at 42 °C on "Fracture properties of nacre-mimetic clay-based bionanocomposites". The conference took place in the scienec park of Granada, which was an interesting place with lots to discover. The excursion to Alhambra was a very special trip into an old city with marvelous architecture and designs. André Gröschel acknowledges the DAAD for supporting this trip to a really interesting conference, where polymer chemistry meets high value silicates to creat novel functional materials.
05.07.2017 Highlight in Angewandte Chemie
In "Block Copolymer Micelles with Inverted Morphologies" we highlight an emerging field in polymer research dealing with the self-assembly of highly asymmetric block copolymers into inverse micelles (see also research). Inverse micelles are obtained when the hydrophobic block becomes large enough so that the packing parameter becomes larger than one (p > 1). Fascinating microparticles develop with nanoscale periodicities and high symmetry lattices (cubic, hexagonal, double diamond,...). This research field is relatively new but bares high application potential given the immense interfacial area the grows linearly with particle size (unlike e.g. vesicles 1/R). Applications range from delivery, storage, replicas and energy conversion. The latter will be part of research conduccted at the nano energy technic centre.
26.06.2017 Bachelor Thesis Finished!
We congratulate Alexander Eiland for successfully completing his Bachelor thesis.
17.06. – 24.06.2017 9th International Symposium Molecular Mobility and Order in Polymer Systems
Conference St. Petersburg à photo
14.06.2017 New Bachelor-Project
Suna Azhdari is welcome in our team to prepare her bachelor thesis on polystyrenesulfonate containing block copoylmers.
07.06. – 08-07.2017 Physics Lecture in Luxenbourg
Trip to Luxembourg
23.05.2017 Guest Talk of Polyferrocenes by Dr.-Ing. Markus Gallei
Markus Galei from the TU Darmstadt visited the group to discuss projects and gave a presentation on ferrocene based polymers and advanced materials applications at the UDE. In the evening we went to dinner with the entire group.
18.05. – 21.05.2017 HYBER Meeting in Helsinki
Conference Helsinki à photo
17.05.2017 Inaugural and GDCh Lecture
The first inaugural lecture in the frame of a GDCH lecture given by André presenting the work of the group and work to come infront of a big audience. After the talk everyone enjoyed beer, bratwurst and bretzel. Special thanks to Andrea, Tai for setting up the evening event, Sebastian for standing behind the grill (andmaking excellent saussages/steaks) and Suna for documenting everything with her camera. Some selected photos can be found in the gallery here.
15.05.2017 New Master-Project
Ramzi Chakroun has started his master thesis, after he successfully completed his advanced labcourse on block copoylmer self-assembliesin solution at our working group
12.05.2017 Group Excursion
The group went to the horror labyrinth in Bottrop and later to dinner at Woodpeckers
09.05. – 10.05.2017 Symposium at MPI-Polymer Research, Mainz
Symposium at the MPI-Polymer Research, Mainz, in honour of Prof Axel H.E. Müllers 70th Birthday. The organizers Felix Schacher, Markus Retsch, Anja Goldmann, Andreas Walther and André Gröschel could bring together an exciting line-up of world renowned researchers: Line-up The two days were are great success sharing ideas and getting together with good food and drinks (topped of with a Janus Cake).
02.05.2017 Chinese Guests & Evonik Fellows
Joint seminar between six Evonik fellows at UDE and six visiting Evonik fellows Jiao Tong University, Shanghai China. Together with Dr. Felix Müller from Evonik we organized an afternoon full of presenations and research discussions with newest results from both universities. Our thanks to the visitors and André is looking forward to travel to the partner university next year.
03.05.2017 New Instruments Arrived!
The groups first Size-Exclusion Chromatigraphy (SEC/GPC) arrived for polymer characterization. The GPC was sucessfully installed and is running on THF or DMAc/LiBr. At the same time a Flow Box arrived which will allow to prepare samples free of any dust for light scattering experiemnts. Some photos of hte instruments can be found in the gallery here.
31.04.2017 New Master-Project
Stefanie Tjaberings has started her master thesis, after successfully completing her advanced labcourse on block copoylmer templates for hybrids materials within the group.
05.04. – 07.04.2017 13th Zsigmondy Colloquium of the German Colloid Society
Talk in Saarbrücken on "Block Copolymer Hexosomes"
03.04.2017 New Bachelor-Project
Alexander Eiland is welcome to our team to conduct his bachelor thesis on PEGylation of gold nanoparticles for SERS applications
21.03.2017 Visit in Leiden (Netherlands)
Tai-Lam Nghiem and Andrea Steinhaus are visiting the University in Leiden (Netherlands) to be instructed in cryo-TEM measurements.
04.03. – 12.03.2017 5th International Conference on Multifunctional, Hybrid and Nanomaterials
Conference Lisbon giving a talk on "Nanoparticles with chemical and structural topography" and serving as chairman.
15.02. – 18.02.2017 Macromolecular Colloquium in Freiburg
The first conference visit of the entire group. great experiencce and insightful talks at the biggest conference on macromolecular chemsitry in germany (as always). The group will visit the next year for sure. The program can be found here.
15.02.2017 New Group Member
The group welcomes M.Sc. Andrea Steinhaus. She just started her PhD on block copolymer microphases in the confinement of nanoemulsions with the aim to create complex microparticles, porous latex particles and novel soft nanoparticles.
09.02.2017 First GDCh Lecture
André gave his first GDCh Lecture while visiting Prof. Thomas Hellweg of the Physical Chemsitry Department at the Universit of Bielefeld. The presentation was titled "From coffee mugs and doughnuts to complex soft matter nanostructures" and deals with novel block copolymer nanostructures that are decortated with specific surface pattern. In particular, tstriped patterns on flat and curved objects and the emergence of inevitable topological defects. These defects adapt to the substrate curvature and follow specific mathematical rules that are universal from magnetic monopols to everybodies hair to galaxies. Before and after the presentation there was much discussion with research groups in Bielefeld with potential projects developing on emulsion polymerization and micromulsions.
18.01.2017 CENIDE Science Talk
Together with our guest Prof. Olli Ikkala of the Aalto University, Helsinki Finland, André is presenting the recent results on Toughness and fracture properties iof self-assembled biomimetic nanocomposites. The flyer to this event can be found here.
08.12.2016 Publication in Advanced funcitional materials
The article "Toughness and fracture properties in nacre-mimetic clay/polymer nanocomposities" combines biomimetics, materials science and engineering. Maria Morits was able to creat ethe first bulk nanocomposite with globally aligned nanoplatelets (2D clay platelets 1nm thickness). These materials exhibit high strength (250MPa) and stiffness (25GPa), and display toughness, whrere fracture mechanics stringly depend on relative humidity. Interestingly, the material is tough in wet conditions due to plasticity and tough in dry state due to stepwise frature. We estimate the maximum modulus to 70GPa and strength of 500MPa provided more defined (synthetic) clays are used as compared to the natural ones.
22.08.2016 Publication in ACS Macro Letters
In the paper "Rod-like nanoparticles with striped and helical topography" Jani-Markus Malho modified cellulose nanocrystlas (CNCs) with polyelectrolyte brushes through surfaceinitiated atom transfer radical polymerization (SI-ATRP). After complexation of the brushes with complementarily charged block copolymers, the surface spontaneously changed its shape to adopt a screw-like morphology or helix. well-developed helices were monohelices which is untypical in spontaneous self-assembly processes. The Structures were analyszed with cryogenic electron tomography, one of the most advanced imaging techniques in nanosciencce.
22.08.2016 Publication in ACS Macro Letters
in the paper "Controlling Multicompartment Morphologies using Solvent Conditions and Chemical Modification" Tina Löbling studied possibilities to alter the morphology of triblock terpoylmers in selective solvents. We utilized versatile thiol-ene click reactions to change the volume of one of the blocks as well as the interaction parameters. Amongst the morphologies we found double helices and triple helices.
01.08.2016 New Group Member
The group welcomes M.Sc. Tai-Lam Nghiem. He just started his PhD on "Complex block copolymer self-assemblies" with the aim to create stimuli-responsive superstructures, precise colloidal polymers, and interpolyelectrylyte complexes. Information about him can be found here and his personal page is here.
31.05.2016 Publication in Polymer
In the paper "Controlling the shape of Janus nanostructures through supramolecular modification of ABC terpolymer bulk morphologies" panu Hiekkataipale analyses bulk morphologies of ABC triblock terpoylmers with supramolecular binding sites. The poly(4-vinylpyridine) (P4VP) is able to accomodate various organic compounds through hydrogen-bonding. We utilized this feature to attach photoresponsive azobenzene moieties thereby changing the volume fraction of the P4VP phase and hence the morphology. We were able to create various Janus nanostructures from one single terpolymer including Janus cylinders, Janus sheets, and novel hexagonally perforated Janus sheets.
09.05.2016 Publication in Nature Communication
In the paper "Rational design of ABC triblock terpolymer solution nanostructures with controlled patch morphology" Tina Löbling synthesized 14 ABC triblock terpolymers and studied their hierarchical self-assembly in selective solvents. We found that a large range of previously unknown nanostructure can not only be generated but also targeted with proper planning of the block composition. We thereby subdivided the four solution topologies known since the year 1995 (spheres, cylinders, sheesta and vesicles) into four new subclasses, including patchy cylinders, double helical cylinders, perforated sheets and striped and perforated vesicles.