@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} } @article{DengWangXuaetal.2020, author = {Deng, Zijun and Wang, Weiwei and Xua, Xun and Gould, Oliver E. C. and Kratz, Karl and Ma, Nan and Lendlein, Andreas}, title = {Polymeric sheet actuators with programmable bioinstructivity}, series = {PNAS}, volume = {117}, journal = {PNAS}, number = {4}, publisher = {National Academy of Sciences}, address = {Washington, DC}, issn = {1091-6490}, doi = {10.1073/pnas.1910668117}, pages = {1895 -- 1901}, year = {2020}, abstract = {Stem cells are capable of sensing and processing environmental inputs, converting this information to output a specific cell lineage through signaling cascades. Despite the combinatorial nature of mechanical, thermal, and biochemical signals, these stimuli have typically been decoupled and applied independently, requiring continuous regulation by controlling units. We employ a programmable polymer actuator sheet to autonomously synchronize thermal and mechanical signals applied to mesenchymal stem cells (MSC5). Using a grid on its underside, the shape change of polymer sheet, as well as cell morphology, calcium (Ca2+) influx, and focal adhesion assembly, could be visualized and quantified. This paper gives compelling evidence that the temperature sensing and mechanosensing of MSC5 are interconnected via intracellular Ca2+. Up-regulated Ca2+ levels lead to a remarkable alteration of histone H3K9 acetylation and activation of osteogenic related genes. The interplay of physical, thermal, and biochemical signaling was utilized to accelerate the cell differentiation toward osteogenic lineage. The approach of programmable bioinstructivity provides a fundamental principle for functional biomaterials exhibiting multifaceted stimuli on differentiation programs. Technological impact is expected in the tissue engineering of periosteum for treating bone defects.}, language = {en} } @article{HartliebMansfieldPerrier2020, author = {Hartlieb, Matthias and Mansfield, Edward D. H. and Perrier, Sebastien}, title = {A guide to supramolecular polymerizations}, series = {Polymer Chemistry}, volume = {11}, journal = {Polymer Chemistry}, number = {6}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c9py01342c}, pages = {1083 -- 1110}, year = {2020}, abstract = {Supramolecular polymers or fibers are non-covalent assemblies of unimeric building blocks connected by secondary interactions such as hydrogen bonds or pi-pi interactions. Such structures hold enormous potential in the development of future materials, as their non-covalent nature makes them highly modular and adaptive. Within this review we aim to provide a broad overview over the area of linear supramolecular polymers including the different mechanisms of their polymerization as well as methods essential for their characterization. The different non-covalent interactions able to form supramolecular polymers are discussed, and key examples for each species are shown. Particular emphasis is laid on the development of living supramolecular polymerization able to produce fibers with a controlled length and low length dispersity, and even enable the production of supramolecular block copolymers. Another important and very recent field is the development of out-of-equilibrium supramolecular polymers, where the polymerization process can be temporally controlled enabling access to highly adaptive materials.}, language = {en} } @article{FranzToebbensLehmannetal.2020, author = {Franz, Alexandra and T{\"o}bbens, Daniel M. and Lehmann, Frederike and K{\"a}rgell, Martin and Schorr, Susan}, title = {The influence of deuteration on the crystal structure of hybrid halide perovskites: a temperature-dependent neutron diffraction study of FAPbBr(3)}, series = {Acta crystallographica; Section B, Structural science, crystal engineering and materials}, volume = {76}, journal = {Acta crystallographica; Section B, Structural science, crystal engineering and materials}, number = {2}, publisher = {Wiley-Blackwell}, address = {Oxford [u.a.]}, issn = {2052-5206}, doi = {10.1107/S2052520620002620}, pages = {267 -- 274}, year = {2020}, abstract = {This paper discusses the full structural solution of the hybrid perovskite formamidinium lead tribromide (FAPbBr(3)) and its temperature-dependent phase transitions in the range from 3 K to 300 K using neutron powder diffraction and synchrotron X-ray diffraction. Special emphasis is put on the influence of deuteration on formamidinium, its position in the unit cell and disordering in comparison to fully hydrogenated FAPbBr(3). The temperature-dependent measurements show that deuteration critically influences the crystal structures, i.e. results in partially-ordered temperature-dependent structural modifications in which two symmetry-independent molecule positions with additional dislocation of the molecular centre atom and molecular angle inclinations are present.}, language = {en} } @article{WojcikBrinkmannZduneketal.2020, author = {Wojcik, Michal and Brinkmann, Pia and Zdunek, Rafał and Riebe, Daniel and Beitz, Toralf and Merk, Sven and Cieslik, Katarzyna and Mory, David and Antonczak, Arkadiusz}, title = {Classification of copper minerals by handheld laser-induced breakdown spectroscopy and nonnegative tensor factorisation}, series = {Sensors}, volume = {20}, journal = {Sensors}, number = {18}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s20185152}, pages = {17}, year = {2020}, abstract = {Laser-induced breakdown spectroscopy (LIBS) analysers are becoming increasingly common for material classification purposes. However, to achieve good classification accuracy, mostly noncompact units are used based on their stability and reproducibility. In addition, computational algorithms that require significant hardware resources are commonly applied. For performing measurement campaigns in hard-to-access environments, such as mining sites, there is a need for compact, portable, or even handheld devices capable of reaching high measurement accuracy. The optics and hardware of small (i.e., handheld) devices are limited by space and power consumption and require a compromise of the achievable spectral quality. As long as the size of such a device is a major constraint, the software is the primary field for improvement. In this study, we propose a novel combination of handheld LIBS with non-negative tensor factorisation to investigate its classification capabilities of copper minerals. The proposed approach is based on the extraction of source spectra for each mineral (with the use of tensor methods) and their labelling based on the percentage contribution within the dataset. These latent spectra are then used in a regression model for validation purposes. The application of such an approach leads to an increase in the classification score by approximately 5\% compared to that obtained using commonly used classifiers such as support vector machines, linear discriminant analysis, and the k-nearest neighbours algorithm.}, language = {en} } @article{KayaDebsharmaSchlaadetal.2020, author = {Kaya, Kerem and Debsharma, Tapas and Schlaad, Helmut and Yagci, Yusuf}, title = {Cellulose-based polyacetals by direct and sensitized photocationic ring-opening polymerization of levoglucosenyl methyl ether}, series = {Polymer Chemistry}, volume = {11}, journal = {Polymer Chemistry}, number = {43}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/d0py01307b}, pages = {6884 -- 6889}, year = {2020}, abstract = {This study aims to explore the photoinitiated cationic ring-opening polymerization of levoglucosenyl methyl ether (LGME), a chemical obtained from the most abundant biomass - cellulose. Direct and sensitized photopolymerizations of LGME using photoinitiators acting at the near UV or visible range in conjunction with diphenyliodonium hexafluoroantimonate (DPI) yielded unsaturated polyacetals with varying molar masses and distributions.}, language = {en} } @article{YanOschatzWu2020, author = {Yan, Runyu and Oschatz, Martin and Wu, Feixiang}, title = {Towards stable lithium-sulfur battery cathodes by combining physical and chemical confinement of polysulfides in core-shell structured nitrogen-doped carbons}, series = {Carbon}, volume = {161}, journal = {Carbon}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {0008-6223}, doi = {10.1016/j.carbon.2020.01.046}, pages = {162 -- 168}, year = {2020}, abstract = {Despite intensive research on porous carbon materials as hosts for sulfur in lithium-sulfur battery cathodes, it remains a problem to restrain the soluble lithium polysulfide intermediates for a long-term cycling stability without the use of metallic or metal-containing species. Here, we report the synthesis of nitrogen-doped carbon materials with hierarchical pore architecture and a core-shell-type particle design including an ordered mesoporous carbon core and a polar microporous carbon shell. The initial discharge capacity with a sulfur loading up to 72 wt\% reaches over 900 mA h g(sulf)(ur)(-1) at a rate of C/2. Cycling performance measured at C/2 indicates similar to 90\% capacity retention over 250 cycles. In comparison to other carbon hosts, this architecture not only provides sufficient space for a high sulfur loading induced by the high-pore-volume particle core, but also enables a dual effect of physical and chemical confinement of the polysulfides to stabilize the cycle life by adsorbing the soluble intermediates in the polar microporous shell. This work elucidates a design principle for carbonaceous hosts that is capable to provide simultaneous physical-chemical confinement. This is necessary to overcome the shuttle effect towards stable lithium-sulfur battery cathodes, in the absence of additional membranes or inactive metal-based anchoring materials.}, language = {en} } @article{ZhangBehlBalketal.2020, author = {Zhang, Pengfei and Behl, Marc and Balk, Maria and Peng, Xingzhou and Lendlein, Andreas}, title = {Shape-programmable architectured hydrogels sensitive to ultrasound}, series = {Macromolecular rapid communications}, volume = {41}, journal = {Macromolecular rapid communications}, number = {7}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1022-1336}, doi = {10.1002/marc.201900658}, pages = {7}, year = {2020}, abstract = {On-demand motion of highly swollen polymer systems can be triggered by changes in pH, ion concentrations, or by heat. Here, shape-programmable, architectured hydrogels are introduced, which respond to ultrasonic-cavitation-based mechanical forces (CMF) by directed macroscopic movements. The concept is the implementation and sequential coupling of multiple functions (swellability in water, sensitivity to ultrasound, shape programmability, and shape-memory) in a semi-interpenetrating polymer network (s-IPN). The semi-IPN-based hydrogels are designed to function through rhodium coordination (Rh-s-IPNH). These coordination bonds act as temporary crosslinks. The porous hydrogels with coordination bonds (degree of swelling from 300 +/- 10 to 680 +/- 60) exhibit tensile strength sigma(max) up to 250 +/- 60 kPa. Shape fixity ratios up to 90\% and shape recovery ratios up to 94\% are reached. Potential applications are switches or mechanosensors.}, language = {en} } @article{KocSchardtNolteetal.2020, author = {Koc, Julian and Schardt, Lisa and Nolte, Kim and Beyer, Cindy and Eckhard, Till and Schwiderowski, Philipp and Clarke, Jessica L. and Finlay, John A. and Clare, Anthony S. and Muhler, Martin and Laschewsky, Andr{\´e} and Rosenhahn, Axel}, title = {Effect of dipole orientation in mixed, charge-equilibrated self-assembled monolayers on protein adsorption and marine biofouling}, series = {ACS applied materials \& interfaces}, volume = {12}, journal = {ACS applied materials \& interfaces}, number = {45}, publisher = {American Chemical Society}, address = {Washington}, issn = {1944-8244}, doi = {10.1021/acsami.0c11580}, pages = {50953 -- 50961}, year = {2020}, abstract = {While zwitterionic interfaces are known for their excellent low-fouling properties, the underlying molecular principles are still under debate. In particular, the role of the zwitterion orientation at the interface has been discussed recently. For elucidation of the effect of this parameter, self-assembled monolayers (SAMs) on gold were prepared from stoichiometric mixtures of oppositely charged alkyl thiols bearing either a quaternary ammonium or a carboxylate moiety. The alkyl chain length of the cationic component (11-mercaptoundecyl)-N,N,N-trimethylammonium, which controls the distance of the positively charged end group from the substrate's surface, was kept constant. In contrast, the anionic component and, correspondingly, the distance of the negatively charged carboxylate groups from the surface was varied by changing the alkyl chain length in the thiol molecules from 7 (8-mercaptooctanoic acid) to 11 (12-mercaptododecanoic acid) to 15 (16-mercaptohexadecanoic acid). In this way, the charge neutrality of the coating was maintained, but the charged groups exposed at the interface to water were varied, and thus, the orientation of the dipoles in the SAMs was altered. In model biofouling studies, protein adsorption, diatom accumulation, and the settlement of zoospores were all affected by the altered charge distribution. This demonstrates the importance of the dipole orientation in mixed-charged SAMs for their inertness to nonspecific protein adsorption and the accumulation of marine organisms. Overall, biofouling was lowest when both the anionic and the cationic groups were placed at the same distance from the substrate's surface.}, language = {en} } @article{LoewenbergTripodoJulichGruneretal.2020, author = {L{\"o}wenberg, Candy and Tripodo, Giuseppe and Julich-Gruner, Konstanze K. and Neffe, Axel T. and Lendlein, Andreas}, title = {Supramolecular gelatin networks based on inclusion complexes}, series = {Macromolecular bioscience}, volume = {20}, journal = {Macromolecular bioscience}, number = {10}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-5187}, doi = {10.1002/mabi.202000221}, pages = {8}, year = {2020}, abstract = {Hydrogel forming physical networks based on gelatin are an attractive approach toward multifunctional biomaterials with the option of reshaping, self-healing, and stimuli-sensitivity. However, it is challenging to design such gelatin-based hydrogels to be stable at body temperature. Here, gelatin functionalized with desaminotyrosine (DAT) or desaminotyrosyl tyrosine (DATT) side chains is crosslinked with cyclodextrin (CD) dimers under formation of inclusions complexes. The supramolecular networks displayed at room temperature decreased water uptake (200-600 wt\% for DAT-based systems, 200 wt\% for DATT based systems), and increased storage moduli up to 25.6 kPa determined by rheology compared to DAT(T) gelatin. The gel-sol transition temperature increased from 33 up to 42 degrees C. The presented system that is completely based on natural building blocks may form the basis for materials that may potentially respond by dissolution or changes of properties to changes in environmental conditions or to the presence of CD guest molecules.}, language = {en} }