@article{JohnZimmermannBoeker2018,
  author    = {John, Daniela and Zimmermann, Marc and B{\"o}ker, Alexander},
  title     = {Generation of 3-dimensional multi-patches on silica particles via printing with wrinkled stamps},
  series = {Soft matter},
  volume    = {14},
  journal   = {Soft matter},
  number    = {16},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1744-683X},
  doi       = {10.1039/c8sm00224j},
  pages     = {3057 -- 3062},
  year      = {2018},
  abstract  = {A simple route towards patchy particles with anisotropic patches with respect to a different functionality and directionality is presented. This method is based on microcontact printing of positively charged polyethylenimine (PEI) on silica particles using wrinkled stamps. Due to the wrinkled surface, the number of patches on the particles as well as the distance between two patches can be controlled.},
  language  = {en}
}
@article{KathreinPesterRuppeletal.2016,
  author    = {Kathrein, Christine C. and Pester, Christian and Ruppel, Markus and Jung, Maike and Zimmermann, Marc and B{\"o}ker, Alexander},
  title     = {Reorientation mechanisms of block copolymer/CdSe quantum dot composites under application of an electric field},
  series = {Soft matter},
  volume    = {12},
  journal   = {Soft matter},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1744-683X},
  doi       = {10.1039/c6sm01073c},
  pages     = {8417 -- 8424},
  year      = {2016},
  abstract  = {Time- and temperature-resolved in situ birefringence measurements were applied to analyze the effect of nanoparticles on the electric field-induced alignment of a microphase separated solution of poly(styrene)-block-poly(isoprene) in toluene. Through the incorporation of isoprene-confined CdSe quantum dots the reorientation behavior is altered. Particle loading lowers the order-disorder transition temperature, and increases the defect density, favoring nucleation and growth as an alignment mechanism over rotation of grains. The temperature dependent alteration in the reorientation mechanism is analyzed via a combination of birefringence and synchrotron SAXS. The detailed understanding of the effect of nanoparticles on the reorientation mechanism is an important prerequisite for optimization of electricfield-induced alignment of block copolymer/nanoparticle composites where the block copolymer guides the nanoparticle self-assembly into anisotropic structures.},
  language  = {en}
}
@article{LeiendeckerLichtBorghsetal.2018,
  author    = {Leiendecker, Mai-Thi and Licht, Christopher J. and Borghs, Jannik and Mooney, David J. and Zimmermann, Marc and B{\"o}ker, Alexander},
  title     = {Physical polyurethane hydrogels via charge shielding through acids or salts},
  series = {Macromolecular rapid communications},
  volume    = {39},
  journal   = {Macromolecular rapid communications},
  number    = {7},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1022-1336},
  doi       = {10.1002/marc.201700711},
  pages     = {5},
  year      = {2018},
  abstract  = {Physical hydrogels with tunable stress-relaxation and excellent stress recovery are formed from anionic polyurethanes via addition of acids, monovalent salts, or divalent salts. Gel properties can be widely adjusted through pH, salt valence, salt concentration, and monomer composition. We propose and investigate a novel gelation mechanism based on a colloidal system interacting through charge repulsion and chrage shielding, allowing a broad use of the material, from acidic (pH 4-5.5) to pH-neutral hydrogels with Young's moduli ranging from 10 to 140 kPa.},
  language  = {en}
}
@article{WeberOesterheltGrossetal.2004,
  author    = {Weber, Andreas P. M. and Oesterhelt, Christine and Gross, Wolfgang and Br{\"a}utigam, Andrea and Imboden, Lori and Krassovskaya, Inga and Linka, Nicole and Truchina, Julia and Schneidereit, J{\"o}rg and Voll, Lars and Zimmermann, Marc and Jamai, Aziz and Riekhof, Wayne and Yu, Bin and Garavito, Michael R. and Benning, Christoph},
  title     = {EST-analysis of the thermo-acidophilic red microalga Galdieria sulphuraria reveals potential for lipid A biosynthesis and unveils the pathway of carbon export from rhodoplasts},
  year      = {2004},
  abstract  = {When we think of extremophiles, organisms adapted to extreme environments, prokaryotes come to mind first. However, the unicellular red micro-alga Galdieria sulphuraria (Cyanidiales) is a eukaryote that can represent up to 90\% of the biomass in extreme habitats such as hot sulfur springs with pH values of 0-4 and temperatures of up to 56 degreesC. This red alga thrives autotrophically as well as heterotrophically on more than 50 different carbon sources, including a number of rare sugars and sugar alcohols. This biochemical versatility suggests a large repertoire of metabolic enzymes, rivaled by few organisms and a potentially rich source of thermo-stable enzymes for biotechnology. The temperatures under which this organism carries out photosynthesis are at the high end of the range for this process, making G. sulphuraria a valuable model for physical studies on the photosynthetic apparatus. In addition, the gene sequences of this living fossil reveal much about the evolution of modern eukaryotes. Finally, the alga tolerates high concentrations of toxic metal ions such as cadmium, mercury, aluminum, and nickel, suggesting potential application in bioremediation. To begin to explore the unique biology of G. sulphuraria, 5270 expressed sequence tags from two different cDNA libraries have been sequenced and annotated. Particular emphasis has been placed on the reconstruction of metabolic pathways present in this organism. For example, we provide evidence for (i) a complete pathway for lipid A biosynthesis; (ii) export of triose-phosphates from rhodoplasts; (iii) and absence of eukaryotic hexokinases. Sequence data and additional information are available at http://genomics.msu.edu/galdieria},
  language  = {en}
}
@phdthesis{Zimmermann2018,
  author    = {Zimmermann, Marc},
  title     = {Multifunctional patchy silica particles via microcontact printing},
  doi       = {10.25932/publishup-42773},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427731},
  school      = {Universit{\"a}t Potsdam},
  pages     = {IX, 121, xiii},
  year      = {2018},
  abstract  = {This research addressed the question, if it is possible to simplify current microcontact printing systems for the production of anisotropic building blocks or patchy particles, by using common chemicals while still maintaining reproducibility, high precision and tunability of the Janus-balance Chapter 2 introduced the microcontact printing materials as well as their defined electrostatic interactions. In particular polydimethylsiloxane stamps, silica particles and high molecular weight polyethylenimine ink were mainly used in this research. All of these components are commercially available in large quantities and affordable, which gives this approach a huge potential for further up-scaling developments. The benefits of polymeric over molecular inks was described including its flexible influence on the printing pressure. With this alteration of the µCP concept, a new method of solvent assisted particle release mechanism enabled the switch from two-dimensional surface modification to three-dimensional structure printing on colloidal silica particles, without changing printing parameters or starting materials. This effect opened the way to use the internal volume of the achieved patches for incorporation of nano additives, introducing additional physical properties into the patches without alteration of the surface chemistry. The success of this system and its achievable range was further investigated in chapter 3 by giving detailed information about patch geometry parameters including diameter, thickness and yield. For this purpose, silica particles in a size range between 1µm and 5µm were printed with different ink concentrations to change the Janus-balance of these single patched particles. A necessary intermediate step, consisting of air-plasma treatment, for the production of trivalent particles using "sandwich" printing was discovered and comparative studies concerning the patch geometry of single and double patched particles were conducted. Additionally, the usage of structured PDMS stamps during printing was described. These results demonstrate the excellent precision of this approach and opens the pathway for even greater accuracy as further parameters can be finely tuned and investigated, e.g. humidity and temperature during stamp loading. The performance of these synthesized anisotropic colloids was further investigated in chapter 4, starting with behaviour studies in alcoholic and aqueous dispersions. Here, the stability of the applied patches was studied in a broad pH range, discovering a release mechanism by disabling the electrostatic bonding between particle surface and polyelectrolyte ink. Furthermore, the absence of strong attractive forces between divalent particles in water was investigated using XPS measurements. These results lead to the conclusion that the transfer of small PDMS oligomers onto the patch surface is shielding charges, preventing colloidal agglomeration. However, based on this knowledge, further patch modifications for particle self-assembly were introduced including physical approaches using magnetic nano additives, chemical patch functionalization with avidin-biotin or the light responsive cyclodextrin-arylazopyrazoles coupling as well as particle surface modification for the synthesis of highly amphiphilic colloids. The successful coupling, its efficiency, stability and behaviour in different solvents were evaluated to find a suitable coupling system for future assembly experiments. Based on these results the possibility of more sophisticated structures by colloidal self-assembly is given. Certain findings needed further analysis to understand their underlying mechanics, including the relatively broad patch diameter distribution and the decreasing patch thickness for smaller silica particles. Mathematical assumptions for both effects are introduced in chapter 5. First, they demonstrate the connection between the naturally occurring particle size distribution and the broadening of the patch diameter, indicating an even higher precision for this µCP approach. Second, explaining the increase of contact area between particle and ink surface due to higher particle packaging, leading to a decrease in printing pressure for smaller particles. These calculations ultimately lead to the development of a new mechanical microcontact printing approach, using centrifugal forces for high pressure control and excellent parallel alignment of printing substrates. First results with this device and the comparison with previously conducted by-hand experiments conclude this research. It furthermore displays the advantages of such a device for future applications using a mechanical printing approach, especially for accessing even smaller nano particles with great precision and excellent yield. In conclusion, this work demonstrates the successful adjustment of the µCP approach using commercially available and affordable silica particles and polyelectrolytes for high flexibility, reduced costs and higher scale-up value. Furthermore, its was possible to increase the modification potential by introducing three-dimensional patches for additional functionalization volume. While keeping a high colloidal stability, different coupling systems showed the self-assembly capabilities of this toolbox for anisotropic particles.},
  language  = {en}
}
@article{ZimmermannGrigorievPuretskiyetal.2018,
  author    = {Zimmermann, Marc and Grigoriev, Dmitry and Puretskiy, Nikolay and B{\"o}ker, Alexander},
  title     = {Characteristics of microcontact printing with polyelectrolyte ink for the precise preparation of patches on silica particles},
  series = {RSC Advances},
  volume    = {8},
  journal   = {RSC Advances},
  number    = {69},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2046-2069},
  doi       = {10.1039/c8ra07955b},
  pages     = {39241 -- 39247},
  year      = {2018},
  abstract  = {This publication demonstrates the abilities of a precise and straightforward microcontact printing approach for the preparation of patchy silica particles. In a broad particle size range, it is possible to finely tune the number and parameters of three-dimensional patches like diameter and thickness using only polyethyleneimine ink, poly(dimethoxysilane) as stamp material and a suitable release solvent.},
  language  = {en}
}
@article{ZimmermannJohnGrigorievetal.2018,
  author    = {Zimmermann, Marc and John, Daniela and Grigoriev, Dmitry and Puretskiy, Nikolay and B{\"o}ker, Alexander},
  title     = {From 2D to 3D patches on multifunctional particles},
  series = {Soft matter},
  volume    = {14},
  journal   = {Soft matter},
  number    = {12},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1744-683X},
  doi       = {10.1039/c8sm00163d},
  pages     = {2301 -- 2309},
  year      = {2018},
  abstract  = {A straightforward approach for the precise multifunctional surface modification of particles with three-dimensional patches using microcontact printing is presented. By comparison to previous works it was possible to not only control the diameter, but also to finely tune the thickness of the deposited layer, opening up the way for three-dimensional structures and orthogonal multifunctionality. The use of PEI as polymeric ink, PDMS stamps for microcontact printing on silica particles and the influence of different solvents during particle release on the creation of functional particles with three-dimensional patches are described. Finally, by introducing fluorescent properties by incorporation of quantum dots into patches and by particle self-assembly via avidin-biotin coupling, the versatility of this novel modification method is demonstrated.},
  language  = {en}
}
@misc{ZimmermannStompsSchulteOsseilietal.2020,
  author    = {Zimmermann, Marc and Stomps, Benjamin Ren{\´e} Harald and Schulte-Osseili, Christine and Grigoriev, Dmitry and Ewen, Dirk and Morgan, Andrew and B{\"o}ker, Alexander},
  title     = {Organic dye anchor peptide conjugates as an advanced coloring agent for polypropylene yarn},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1-2},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-54891},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-548913},
  pages     = {14},
  year      = {2020},
  abstract  = {Polypropylene as one of the world's top commodity polymers is also widely used in the textile industry. However, its non-polar nature and partially crystalline structure significantly complicate the process of industrial coloring of polypropylene. Currently, textiles made of polypropylene or with a significant proportion of polypropylene are dyed under quite harsh conditions, including the use of high pressures and temperatures, which makes this process energy intensive. This research presents a three-step synthesis of coloring agents, capable of adhering onto synthetic polypropylene yarns without harsh energy-consuming conditions. This is possible by encapsulation of organic pigments using trimethoxyphenylsilane, introduction of surface double bonds via modification of the silica shell with trimethoxysilylpropylmethacrylate and final attachment of highly adhesive anchor peptides using thiol-ene chemistry. We demonstrate the applicability of this approach by dyeing polypropylene yarns in a simple process under ambient conditions after giving a step-by-step guide for the synthesis of these new dyeing agents. Finally, the successful dyeing of the yarns is visualized, and its practicability is discussed.},
  language  = {en}
}
@article{ZimmermannStompsSchulteOsseilietal.2020,
  author    = {Zimmermann, Marc and Stomps, Benjamin Ren{\´e} Harald and Schulte-Osseili, Christine and Grigoriev, Dmitry and Ewen, Dirk and Morgan, Andrew and B{\"o}ker, Alexander},
  title     = {Organic dye anchor peptide conjugates as an advanced coloring agent for polypropylene yarn},
  series = {Textile Research Journal},
  volume    = {91},
  journal   = {Textile Research Journal},
  number    = {1-2},
  publisher = {Sage Publ.},
  address   = {London},
  issn      = {0040-5175},
  doi       = {10.1177/0040517520932231},
  pages     = {28 -- 39},
  year      = {2020},
  abstract  = {Polypropylene as one of the world's top commodity polymers is also widely used in the textile industry. However, its non-polar nature and partially crystalline structure significantly complicate the process of industrial coloring of polypropylene. Currently, textiles made of polypropylene or with a significant proportion of polypropylene are dyed under quite harsh conditions, including the use of high pressures and temperatures, which makes this process energy intensive. This research presents a three-step synthesis of coloring agents, capable of adhering onto synthetic polypropylene yarns without harsh energy-consuming conditions. This is possible by encapsulation of organic pigments using trimethoxyphenylsilane, introduction of surface double bonds via modification of the silica shell with trimethoxysilylpropylmethacrylate and final attachment of highly adhesive anchor peptides using thiol-ene chemistry. We demonstrate the applicability of this approach by dyeing polypropylene yarns in a simple process under ambient conditions after giving a step-by-step guide for the synthesis of these new dyeing agents. Finally, the successful dyeing of the yarns is visualized, and its practicability is discussed.},
  language  = {en}
}