Max Planck Institute of Colloids and Interfaces

Max Planck Institute of Colloids and Interfaces

Tiny apatite crystals in bones, vesicles formed out of membranes, pores in membranes for fuel cells and microcapsules as vehicles for medical drugs – all these are structures that are larger than an atom, yet too small to be seen with the naked eye. These are the kinds of nanostructures and microstructures that scientists at the Max Planck Institute of Colloids and Interfaces examine and create. The structures are often colloids – tiny particles in a different medium – or interfaces between two materials. Many of the structures can be found in nature. The scientists at the Potsdam-based Institute endeavour to understand how they are composed and how they work in order to imitate their behaviour in new materials or in vaccines, for example. Understanding the function of these structures can also help to identify the causes of certain diseases that occur when the folding of membranes or the transport of materials in cells fails to work properly.

Contact

Am Mühlenberg 1
14476 Potsdam-Golm
Phone: +49 331 567-7814
Fax: +49 331 567-7875

PhD opportunities

This institute has an International Max Planck Research School (IMPRS):
IMPRS on Multiscale Bio-Systems

In addition, there is the possibility of individual doctoral research. Please contact the directors or research group leaders at the Institute.

Stiff fibres spun from slime
Under the influence of shear forces, nanoparticles from the secretion of velvet worms form polymer fibres that can be recycled in water more
Deceptive teeth
Although the dentition of the wedgefish appear designed to crush shellfish, it also eats stingrays more
A sweet vaccine against pneumonia
A triple sugar induces an immune response against Streptococcus pneumoniae more
Green chemistry from the mussel foot
The byssus threads of the common mussel are produced by a combination of self-assembly processes and biologically active steps more
Wood and the influence of water

Wood and the influence of water

Forschungsmeldung October 05, 2016
A model describing the water absorption of wood could contribute to the development of new wood preservatives more
Marine microalgae: an address plaque for calcium
A biochemical mechanism controls which nanostructures are formed in calcite-forming microorganisms more
Fighting hospital germs with sugar

Fighting hospital germs with sugar

Forschungsmeldung May 11, 2016
A synthetic sugar-based molecule activates the immune system and could serve as a vaccine against C. difficile bacteria more

The carbohydrate wind tunnel

Forschungsmeldung September 30, 2015
A new method enables researchers to sequence complex sugar molecules for the first time more
Actuators that mimic ice plants

Actuators that mimic ice plants

Forschungsmeldung June 29, 2015

Materials modelled after plants may help robots to move more naturally

more
Nanostructures: customized carbon

Nanostructures: customized carbon

Forschungsmeldung April 14, 2015
A new synthesis method produces novel nanostructures from carbon more
Collagen: powerful workout with water

Collagen: powerful workout with water

Forschungsmeldung January 22, 2015
Collagen fibres not only passively support bone, tendons and ligaments, but also actively contract more
Exemplar crystallites in mussels

Exemplar crystallites in mussels

Forschungsmeldung October 31, 2014

The growth of the giant Mediterranean fan mussel’s calcitic shell adheres to physical laws already familiar from processes used to optimise steel

more
Skin that can flex its muscles

Skin that can flex its muscles

Forschungsmeldung July 21, 2014
A membrane curls fast and furiously when it comes into contact with a solvent vapour more
Sweet treatment for asthma

Sweet treatment for asthma

Forschungsmeldung July 03, 2014
A simple molecule inhibits asthma-related inflammation at an early stage more
<p>Bristling nanolayer</p>

Bristling nanolayer

Forschungsmeldung June 25, 2014
A new synthesis method enables the production of wafer-thin carbon layers for a wide range of applications more
The large wandering spider bites forever

The large wandering spider bites forever

Forschungsmeldung June 12, 2014
The fangs of the venomous spider C. salei allow it to safely pierce the chitinous armour of prey insects more
The pirate in the microbe

The pirate in the microbe

Forschungsmeldung May 27, 2014
Bacteria do not move entirely randomly as they scout the surface of host cells more
Nanotechnology in a glass sponge

Nanotechnology in a glass sponge

Forschungsmeldung February 24, 2014
The marine sponge Monorhaphis chuni (M. Chuni) forms a glass filament with a perfect periodic arrangement of nanopores employing a similar method that is used for fabrication of man-made mesoporous nanomaterials more

Biominerals point the way

Forschungsmeldung October 30, 2013
The way bacteria create their magnetic navigational aids could be an inspiration for materials scientists more
A quick test for the Black Death

A quick test for the Black Death

Forschungsmeldung July 24, 2013
Sugar-based detection method enables easy and accurate identification of the Yersinia pestis bacterium more
Electronics comes to paper

Electronics comes to paper

Forschungsmeldung May 08, 2013
Paper, being a light and foldable raw material, is a cost-efficient and simple means of generating electrically conducting structures more
Order in the chaos of a cell membrane

Order in the chaos of a cell membrane

Forschungsmeldung February 27, 2013
Crystalline areas form in model membranes based on a previously unknown mechanism more
The cradle of the nanoparticle

The cradle of the nanoparticle

Forschungsmeldung February 13, 2013
A new model facilitates predictions about how nanoparticles form and gives clues about how the process can be controlled more
Calcium carbonate templates for drug delivery

Calcium carbonate templates for drug delivery

Forschungsmeldung July 02, 2012
Microcontainers for medical substances can be produced in different sizes using calcium carbonate microspheres as templates more
A crowning success for crayfish

A crowning success for crayfish

Forschungsmeldung May 18, 2012
Australian freshwater crayfish have a tooth enamel very similar to humans more
An incisive design solution: the spider’s venomous fang
Among the factors that make spiders successful predators is the ingeniously composed and structured material of their fangs. more
Microlenses from a test tube

Microlenses from a test tube

Forschungsmeldung March 23, 2012
Max Planck researchers develop new method for the production of microlenses more
Anti-malaria drug synthesised with the help of oxygen and light
In future it should be possible to produce the best anti-malaria drug, artemisinin, more economically and in sufficient volumes for all patients more
Origami in seed capsules

Origami in seed capsules

Forschungsmeldung June 15, 2011
The lids on the seed cases of an ice plant unfold when a honeycomb structure swells on the inside of them more
A sweet defence against lethal bacteria

A sweet defence against lethal bacteria

Forschungsmeldung May 30, 2011
Synthesising a potential vaccine candidate for an antibiotic-resistant pathogen causing infections in hospitalised patients more
Nanotubes: cellular membranes on supply

Nanotubes: cellular membranes on supply

Forschungsmeldung March 11, 2011
Osmotic forces play a role in nanotube formation in cells more
Turning over a new leaf

Turning over a new leaf

Forschungsmeldung September 20, 2010
Researchers have transformed the skeleton of a leaf into iron carbide. The new technique enables the conversion of metal carbides into intricate microstructures in just one step more

Mussels - Material artists with grip

Forschungsmeldung March 04, 2010
Iron atoms convey mussel fibres with a robust but stretchy covering more
Cell growth regulates genetic circuits

Cell growth regulates genetic circuits

Forschungsmeldung January 29, 2010
Max Planck researchers discover an explanation for different growth rates of genetically identically cells more
Where droplets gently touch a membrane

Where droplets gently touch a membrane

Forschungsmeldung January 27, 2010
Max Planck researchers explain the shape of membrane vesicles containing two different fluids more
Making nanoparticles in artificial cells

Making nanoparticles in artificial cells

Forschungsmeldung June 26, 2009
Two processes can be used to control the size of nanoparticles, which could serve as tiny light sources more
A water splitter with a double role

A water splitter with a double role

Forschungsmeldung March 09, 2009
Sunlight and a familiar plastic make it possible to produce hydrogen from water more
A crystal clear view of chalk formation

A crystal clear view of chalk formation

Forschungsmeldung January 12, 2009
Chalk crystallizes differently from the way we once thought it did. This discovery will allow the development of new scale inhibitors and other materials, and has also consequences for climate change more
Tug of war in the cells

Tug of war in the cells

Forschungsmeldung March 18, 2008
Max Planck scientists shed light on transport mechanism in cells more
Transporting gold across physical boundaries

Transporting gold across physical boundaries

Forschungsmeldung November 22, 2007
Max Planck researchers create nanoparticles that move back and forth between water and oil more
Wild wheat shows its muscles

Wild wheat shows its muscles

Forschungsmeldung May 10, 2007
Cereal grains use their awns to "swim" into the soil more
Microcapsules like it Hot and Salty

Microcapsules like it Hot and Salty

Forschungsmeldung November 23, 2006
Max Planck scientists in Potsdam are developing a new method using salt content and temperature to control the permeability of microcapsules more
Nearly Unbreakable

Nearly Unbreakable

Forschungsmeldung November 10, 2006
Max Planck Scientists discover a novel construction principle at the nanoscale which prevents bones from breaking at excessive force more
Floating and Spiky

Floating and Spiky

Forschungsmeldung November 03, 2006
A team of researchers has used computer simulations to explain how cells adhere so firmly to blood vessel walls more
Fusion in the Fast Lane

Fusion in the Fast Lane

Forschungsmeldung October 19, 2006
Max Planck scientists develop new methods for the controlled initiation of membrane fusion and its observation with high temporal resolution in the microsecond regime more
Microcapsules Open in Tumour Cells

Microcapsules Open in Tumour Cells

Forschungsmeldung August 23, 2006
Max Planck researchers channel microcapsules into tumour cells and release their contents using a laser impulse more
Order by Motion

Order by Motion

Forschungsmeldung July 24, 2006
Max Planck scientists have shown that molecular motors can induce orientational order in an isotropic liquid of filaments. more
Oscillating Pattern in Nanoparticle Crystallisation

Oscillating Pattern in Nanoparticle Crystallisation

Forschungsmeldung June 30, 2006
Max Planck researchers in Potsdam demonstrate an oscillating pattern in nanoparticle crystallisation and self-organisation more
A Switch for Cell Adhesion

A Switch for Cell Adhesion

Forschungsmeldung March 29, 2006
Max Planck scientists show that the adhesion of cell membranes strongly depends on the switching rates of adhesion molecules more
Why nanolayers buckle when microbeams bend

Why nanolayers buckle when microbeams bend

Forschungsmeldung December 15, 2005
German-Austrian-French research team uses a hundred-nanometre wide x-ray beam to observe how nanolayers buckle in bent high-tech carbon fibres more
Shimmering Colours Which Change With Temperature

Shimmering Colours Which Change With Temperature

Forschungsmeldung December 02, 2005
Max Planck researchers in Potsdam, Germany expand the tool kit of colloid particles and make new coloured finishes possible more
Marathon of Nano-Sprinters

Marathon of Nano-Sprinters

Forschungsmeldung November 14, 2005
Max Planck scientists show that the cooperation of a small number of molecular mo-tors yields cargo transport over large distances more
What Mutations Tell Us about Protein Folding

What Mutations Tell Us about Protein Folding

Forschungsmeldung October 14, 2005
Max Planck scientists find a novel way to construct transition states for protein folding reactions more
How to Braid Nanoropes

How to Braid Nanoropes

Forschungsmeldung October 14, 2005
Max Planck scientists identify essential control parameters for the assembly of filament bundles more
Mother-of-Pearl in Highest Resolution

Mother-of-Pearl in Highest Resolution

Forschungsmeldung October 05, 2005
Researchers from the Max Planck Institute of Colloids and Interfaces, and the German Federal Institute for Materals Research and Testing (BAM), have discovered small new details in the structure of mother-of-pearl more
Good connections are everything

Good connections are everything

Forschungsmeldung July 12, 2005
Max Planck Scientists discover unusual dynamic properties of activity patterns on scale-free networks more
Motor Transport in Bio-Nano Systems

Motor Transport in Bio-Nano Systems

Forschungsmeldung May 03, 2005
Max Planck researchers determine optimal parameters for biomimetic transport systems based on molecular motors more
Fusion under Tension

Fusion under Tension

Forschungsmeldung March 01, 2005
Max Planck scientists use new simulation methods to observe single events of membrane fusion with molecular resolution more
Open Microfluidic and Nanofluidic Systems

Open Microfluidic and Nanofluidic Systems

Forschungsmeldung February 15, 2005
Max Planck scientists develop fundamentals for new microfluidic and nanofluidic devices more

A Scientist with a Sweet Tooth

4/2015 Material & Technology
Basic scientist, entrepreneur, citizen and family man: what Peter Seeberger, Director at the Max Planck Institute of Colloids and Interfaces in Potsdam, manages to cram into one lifetime would take others three. One of his goals is to prevent diseases that afflict particularly people in developing countries – and his weapon of choice is sugar.
During the 20th century, the pharmaceutical industry made crucial strides in advancing drug development. In recent times, however, the sector has seen noticeable cost-related cutbacks in research activity. We urgently need new drugs for the treatment of cancer, dementia and many other diseases. In developing countries, the problem is a matter of life and death. Our author pleads for a radical rethinking of the drug development system, and for the involvement of basic research.

More than Just Sweet

3/2013 Biology & Medicine
When they hear the word sugar, the first thing most people think of is candy. Some may also think of diabetes. Peter H. Seeberger from the Max Planck Institute of Colloids and Interfaces in Golm, in contrast, wants to use sugars to develop more effective drugs and vaccines. He hopes his work will benefit primarily poorer countries.
Patients with osteoporosis stand to gain just as much from artificial bone as those with serious injuries and bone cancer. Peter Fratzl, John Dunlop and Wolfgang Wagermaier are researching the optimum conditions for generating bone tissue at the Max Planck Institute of Colloids and Interfaces in Potsdam-Golm.
Active ingredients for chemotherapy, corrosion protection products or vitamins: packaging substances in tiny containers, transporting them to their intended destination – if need be, even in the human body – and unloading them there would be of interest for many applications. Helmuth Möhwald and his colleagues at the Max Planck Institute of Colloids and Interfaces are developing the methods that will make all this possible.
Magnetic nanoparticles such as those produced by magnetotactic bacteria could help detect tumors, and would be of great value in medicine.
Researchers are testing new storage solutions for hydrogen cars.
No job offers available

Controlled conditions, controlled chemistry

2017 Gilmore, Kerry*; Pieber, Bartholomäus; Seeberger, Peter H.
Chemistry Immunobiology Infection Biology Material Sciences Medicine

The success of the vast majority of chemical transformations is reliant on the degree of control exhibited over a wide range of variables. Utilizing flow chemistry – where reagents are passed through a set of conditions via thin tubing as opposed to applying conditions to a round bottom flask – has allowed for achieving chemistries and efficiencies previously inaccessible. The modular nature of this technique has facilitated the development of a novel means of chemical synthesis, which targets core functionalities, allowing for multiple derivatives to be produced with a single flow system.

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Mechanoreponsive molecules as building blocks for smart materials

2017 Blank, Kerstin G.
Cell Biology Chemistry Material Sciences Medicine Structural Biology

Smart materials are designed to convert an external stimulus into a pre-defined, programmed response. Only a limited number of materials has been developed to date that are able to report on mechanically induced defects by changing their optical properties. Of further interest are materials that are able to self-heal such defects. To obtain these unique properties, mechanoresponsive molecules are required, which respond to the applied force in a well-defined manner. The research goals are to develop such molecules, to understand the mechanisms and to integrate them into novel smart materials.

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Nanoparticles interacting with Membranes and Vesicles

2017 Agudo-Canalejo, Jaime; Lipowsky, Reinhard
Complex Systems

Nanoparticles are tiny particles with sizes between a millionth and a thousandth of a millimeter. They include natural viruses, as well as synthetic particles that are increasingly used for medical purposes. In order to enter a cell via endocytosis, a nanoparticle must first bind to the outer cell membrane. The membrane then spreads onto the particle surface until the particle is completely engulfed by the membrane. The key parameters that control this process on nanoscopic length scales have only recently been identified.

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Biorefinery and sustainable chemistry: Biomass conversion into building blocks for colloid chemistry

2016 Esposito, Davide; Antonietti, Markus
Chemistry Material Sciences

Today the sustainable generation of fine and platform chemicals from biomass is desirable but still involves many problems. The Biorefinery group of the institute develops efficient separation techniques in order to design new product flows from biomass. New efficient catalytic methodologies are synthesized which withstand the partly extreme conditions while biomass is transferred. Biorefinery and its novel successful strategies for the upgrade of biomass into an array of valuable chemicals is a chance for material science to create a new unconventional generation of polymers and colloids.

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Nature's metal-fortified polymers

2016 Harrington, Matthew J.
Cell Biology Chemistry Material Sciences Solid State Research Structural Biology

Biological organisms utilize a remarkable range of effective strategies for building high performance materials, many of which surpass the state-of-the-art in engineered materials. Researchers from the MPIKG have discovered that some organisms, including spiders and mussels, incorporate tiny amounts of metal ions into protein-based materials to vastly improve mechanical performance (e.g. high toughness, high hardness and even self-healing). Based on this work, researchers are now developing bio-inspired metallopolymers with enhanced performance.

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Multi-scale modelling of polysaccharides and polysaccharide Materials

2015 Grafmüller, Andrea
Chemistry Material Sciences

Biomolecular systems are often challenging to model, because they are inherently multiscale, i.e. small differences in the molecular building blocks can result in significant changes of the larger scale properties. Natural Polysaccharides for instance are typically assembled from a small number of basic sugar types, yet they can display a wide range of exceptional material properties, which derive from their spatial organization. Suitable models need to combine atomistic resolution with coarser representations retaining as much of the characteristics of the highly resolved system as possible.

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Different eukaryotic proteins are anchored to the cell membrane using Glycosylphosphatidyl-inositols (GPIs) and have diverse and essential biological functions. To date little is known about the functions of the glycolipid anchors, however by using synthetic methods, it is now possible to obtain these molecules in pure form and to gain details about their biological properties. Synthetic GPIs are useful for the differential diagnosis of acute and latent toxoplasmosis and open new fronts for the diagnosis and treatment of other diseases.

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Bioinspired poly(amino acid)s with stimuli-responsive properties and the ability to recognize and selectively bind to biological systems (proteins) are readily available in rather large quantities through optimized methods of synthetic polymer chemistry. Partially glucosylated polyglutamate and poly(N-alkyl glycine) may be used as “intelligent” polymers for applications in the biomedical field, for instance for therapeutic and regenerative medicine or diagnostics, as well as for the fabrication of hierarchical structures.

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From Antibacterial Coatings to Implants

2014 Skorb, Ekaterina V.; Möhwald, Helmuth
Chemistry Material Sciences
Simple methods applicable in liquids enable the construction of surfaces with defined porosity. The processes also allow the incorporation of drugs into the surface and by suitable coating also the controlled release. This enables the design of the contact between the surface and adjacent cells. For perspective hard implant materials like Ti it is thus possible to stimulate the growth of osteoblasts, the dominant cells of bones. more

Interpreting the sugar code with computers

2013 Santer, Mark
Chemistry Structural Biology

Within any living organism sugars as part of many cellular building blocks regulate inter- and intra- cellular processes. To characterize glycosylation in full, computer models are becoming increasingly significant. The example of the Glycosylphosphatidylinositol anchor shows that classical structure analysis with molecular dynamics techniques must be combined with system representations at coarser levels. Only in this way, many unspecific but important functions of sugar residues may be uncovered.

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Growth of bone tissue in-vivo and in-vitro: geometry, structure and material properties

2013 Dunlop, John; Wagermaier, Wolfgang
Cell Biology Material Sciences Structural Biology

A knowledge of the structure and properties of bone is fundamental for the understanding and treatment of bone fractures and bone diseases such as osteoporosis. Methodologies from materials science have been shown to be useful in evaluating current therapies as well as in the development of new treatments for bone disease. Bone is a complex hierarchically structured material with remarkable mechanical properties, consisting principally of mineralized collagen fibrils. A better understanding of growth, structure and mechanics will help answer clinical needs in the future.

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With nearly 1 million people dying per year, malaria is a global health problem. Artemisinin combination therapies are regarded as first-line drugs. However, their supply is limited, as artemisinin is currently solely extracted from plants. Its precursor dihydroartemisinic acid on the other hand can be obtained by a biotechnological process. A continuous flow chemistry setup was developed to produce artemisinin from this precursor in high yield just using oxygen and light. more
Interfacial properties influence the bulk phase behavior and often the bulk structure. For very small systems (nanoparticles, thin films) this is obvious. The relative amount of interfacial molecules is large. Yet, interfacial influences often are also important for macroscopically large systems because these typically originate from small nano size aggregates. In addition, the growth to macroscopic size always occurs at the interface. Local interfacial transport conditions affect the growth kinetics and thus also the structure and properties of the resulting macroscopic entity. more

Sweet polymers for medicine

2012 Hartmann, Laura
Chemistry
Synthetic sugars offer great potential e.g. for the development of new treatments or vaccines. Thus chemists have been searching for new molecules offering the same biological activity that can be synthesized more easily. One important class of such mimetics are sugar polymers, a combination of polymer chains with natural sugars. In order to understand how such sugar polymers mimic the activity of natural sugars and how to more effectively synthesize such sugar polymers, a new class of monodisperse polymers is currently developed at the MPICI and tested for their properties. more
Bioorganic-synthetic polymers are readily available in rather large quantities through modern methods of metal-free polymer synthesis and modification. Polymers based on polypeptides and saccharides can form “smart” biofunctional membranes and also hierarchical structures. Current studies deal with the understanding of fundamental mechanisms of bioinspired structure formation and with possible applications in biomedicine and materials science. more

Design principles and economy of cellular information processing

2011 Klumpp, Stefan
Complex Systems Microbiology
Natural and synthetic genetic circuits are always coupled to the physiological state of the cell in which they reside. For example, the concentrations of RNA polymerases and ribosomes that are available for the readout of the genetic information depend on the cellular growth rate. Theoretical studies can help to investigate the coupling of regulatory mechanisms and growth and to uncover principles that underlie the efficient use of molecular machines. more

From bio- to inorganic mineralization of magnetite

2010 Faivre, Damien
Chemistry Material Sciences
Magnetic nanoparticles are key components in many novel bio- and nanotechnological applications. These applications require highly uniform particle dimensions. The available chemical processes are unable to produce such crystals. Magnetotactic bacteria have resolved the complicated equation of forming such perfect particles under physiological conditions. This performance is analyzed by determining the role that key biological determinants play in the control of the properties of the biological magnets. The Mms6 protein was shown to specifically control magnetite size in vitro . more

Automated chemical synthesis of carbohydrates

2010 Seeberger, Peter H.; Kamena, Faustin; Lepenies, Bernd; Hartmann, Laura
Chemistry Structural Biology
Carbohydrates are complex molecules that are extremely difficult to synthesize by both chemical and enzymatic means. This is one of the main reasons why the entire field of glycomics is less prominent than genomics and proteomics. In the following report we discuss the introduction of the automatic chemical synthesis of carbohydrates and its impact on glycoscience. more
Modern X-ray diffraction techniques using microbeam radiation from synchrotron sources allow the imaging of the hierarchical structure of biological materials on different length scales. Moreover, in-situ X-ray diffraction provides the possibility to follow nanostructural changes of materials as a consequence of external influences such as mechanical deformation or humidity changes. This article presents a novel scientific instrument developed by the Max Planck Society at the BESSY storage ring in Berlin, which permits such experiments to be conducted with high resolution. more

Structural changes during protein folding and function

2009 Weikl, Thomas
Structural Biology
The sequence of a protein determines, in which three-dimensional structure it folds. The structure in turn enables the biological function of the protein. During function, many proteins slightly change and adapt their three-dimensional structures. These structural changes, as well as the structure formation during folding, cannot be observed directly in experiments. However, combined with theoretical modeling, mutations of a protein provide indirect access to these dynamic processes. more

Peptides at Interfaces

2008 Brezesinski, Gerald; Möhwald, Helmuth
Material Sciences Structural Biology
The characterization of molecular mechanisms of interactions between peptides and cell membranes is very important for the understanding of structure-function relations. These are studied with 2-dimensional monolayers at fluid interfaces using modern biophysical methods. This report shows how the interface influences the secondary structure of the peptides, and vice versa how the peptide adsorption leads to changes in the structure of phospholipid layers. more

Mesoporous materials, carbonaceous materials and carbon nitrides

2008 Antonietti, Markus; Thomas, Arne
Chemistry Material Sciences
The rational design of pores and channel systems within „soft materials“ such as polymers, carbonaceous materials, or carbon nitrides enables the generation of novel chemical systems with novel effects. This short overview deals with the resulting phenomena, such as metal free heterogeneous catalysis, membranes for the fuel cell, polymeric gas storage materials, but also with sustainable synthesis techniques such as the hydrothermal carbonization for the generation of sorption coals. more

Mechanical Design of Wood Cell Walls

2007 Burgert, Ingo
Cell Biology Material Sciences Plant Research
Biological systems inspire the design of new engineering materials due to their light weight structures and high adaptivity. A fist fundamental step in this biomimetic process is to understand and to extract the underlying structure-function relationships. Trees are particularly well suited for such “bio-inspired” studies since they develop high quality structures which may last for thousands of years and growing to 100 m height. This article provides an insight into recent research activities on the mechanical design of wood cell walls and emphasises how effectively trees control mechanical properties by adjusting the structural organisation of the cell wall. more
Biology and chemical synthesis provide various semiflexible polymers, which have a high bending rigidity. Important examples are filaments, which form the cytoskeleton of cells. Semiflexible polymers have unique material properties, which are relevant for biological structures. Theoretical models are presented for single polymer under external forces, filament bundles, and "active'' filaments, which are driven by motor proteins. more

Controlled Synthesis of Inorganic Nanomaterials through Organic Chemistry

2006 Niederberger, Markus; Antonietti, Markus
Chemistry Material Sciences
Nanoparticles play a crucial role in the development of advanced materials and devices. The reason lies in the fact that particles just a few nanometres in size exhibit different chemical and physical properties compared to the bulk material. The wide variety of applications of metal oxides in catalysis, sensing, energy storage and conversion, optics and electronics moved this class of materials into the centre of interest of materials science. In order to obtain metal oxides in form of nanoparticles with well-defined shape, size and crystallinity, the traditional synthesis routes are hardly suited, and novel innovative strategies have to be developed. In comparison to the complex aqueous chemistry, the synthesis of metal oxide nanoparticles in organic solvents offers the possibility to better understand and to control the reaction pathways on a molecular level, enabling a rational synthesis design for inorganic nanoparticles based on organic chemistry. more

Ion distribution and foam stability

2006 Motschmann, Hubert
Chemistry Material Sciences
Amphiphilic molecules contain a hydrophilic headgroup and a hydrophobic tail. The prevailing molecular asymmetry leads to a spontaneous adsorption of amphiphiles at the air-water or oil-water interface. As a result, the surface tension and the surface rheology are changed. We are using soluble amphiphiles as model systems to study fundamental interactions in colloid and interface science. An example is the distribution of ions at a charged interface. The puzzling ion specific effects are the result of a subtle balance of several competing evenly matched interactions consisting of a complex interplay of electrostatics, dispersion forces, thermal motion, fluctuations, hydration, ion size effects and the impact of interfacial water structure. Furthermore we try to identify correlations between observed macroscopic and the corresponding molecular properties of the adsorbed species. Surfactants enable phenomena such as foaming or emulsions. Foams can only be formed if surface active materials are present. The stability of foams is not yet completely understood and we believe that the surface rheology plays a decisive role. In the last years we developed several novel experiments to study surfactant dynamics and surface rheology. more

Biomimetic Nanostructures and Processes: Direct Imaging via Computer Simulations

2005 Shillcock, Julian; Lipowsky, Reinhard
Material Sciences Structural Biology
Biomimetic systems with fine-tuned properties have many potential applications such as drug delivery systems or biosensors. In order to design such systems, one needs a detailed understanding of the underlying nanostructures and nanoprocesses. These structures are very thin and have a thickness of a few nanometers which makes them rather flexible and mobile. There is no experimental method by which one could directly image the dynamics of these structures. Therefore, it is rather appealing to use computer simulations in order to visualize these processes. A particularly powerful simulation method is provided by Dissipative Particle Dynamics which can be used to monitor supramolecular systems with a linear dimension of up to 50 nanometers over a time period of several microseconds. In this article, we discuss three examples for such systems: lipid membranes that contain several components and form different intramembrane domains; vesicles composed of diblock copolymers which could be used as drug delivery systems; and tension-induced fusion of bilayer membranes. The method of Dissipative-Particle-Dynamics can be used to optimize nanostructures and -processes in silico before one performs many costly experiments. more

Trabecular bone remodeling

2005 Weinkamer, Richard
Material Sciences
Living bone is continuously remodeled via resorption and deposition of small bone packets. This remodeling process is controlled by a mechanical feedback loop, which allows bone to adapt to varying mechanical requirements. Being experimentally difficult to access, the feedback loop is intensively studied using computer modeling. In the simulation it is possible to discriminate between changes in the bone structure due to either aging or disease. With a better understanding of the interrelation between the feedback loop and changes in the bone structure, there is hope that improved therapies act directly on the real reasons of bone diseases. more

From Molecular Modules to Modular Materials

2004 Kurth, Dirk G.
Chemistry Material Sciences
The assembly of materials through weak competitive interactions and molecular modules provides fascinating opportunities for the development of key technologies for the 21st century. The utilization of weak intermolecular interactions for the controlled assembly of well-defined devices has become a central motive in nano-science and materials science. Here, several methods are presented that allow the spontaneous assembly of complex architectures. The integration of metal ions into the structures results in value adding functions, which are relevant for magnetic, optical and electronic applications. The modularity of this approach provides extensive control of structure and function from molecular to macroscopic length scales. In addition, the usage of structural and functional modules provides a maximum in flexibility and synthetic simplicity. more

Non-Classical Crystallization

2004 Cölfen, Helmut
Chemistry
The investigation of crystallization processes is a long established field of science. Crystals have a smallest unit called the unit cell and all crystal forms can be related to it with the consequence that crystals always exhibit planar surfaces. Crystals are built from ions or molecules. Recently, the investigation of so-called biominerals has revealed that not all crystals fit the classical textbook picture. For example biominerals, which are minerals deposited by living organisms like skeletons of algae, exhibit crystal morphologies with complex form, which even show untypical curvature. Thus they deviate significantly from the classical planar crystal surfaces. Furthermore, biominerals are often highly optimised composite materials like bones, teeth or mussle shells. This is achieved by a control of the crystallization process by structure directing molecules. Furthermore, recent investigations have revealed that these crystals are not always formed according to the rules of classical crystallography e.g. via regular attachment of ions or molecules to a growing crystal. The project group "Biomimetic Mineralization" tries to mimic and understand the control of crystallization processes via structure directing additives or non-classical structuration processes. By this approach, not only biomineralization processes can be understood, but also new environmentally friendly ways of materials synthesis in water at ambient temperature with biocompatible components can be investigated and established. more