@inproceedings{BreuerRaueMangetal.2015, author = {Breuer, Lars and Raue, Markus and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, Ronald and Wagner, Torsten}, title = {Light-stimulated hydrogel actuators with incorporated graphene oxide for microfluidic applications}, series = {12. Dresdner Sensor-Symposium 2015}, booktitle = {12. Dresdner Sensor-Symposium 2015}, doi = {10.5162/12dss2015/P5.8}, pages = {206 -- 209}, year = {2015}, language = {en} } @article{BreuerRaueStrobeletal.2016, author = {Breuer, Lars and Raue, Markus and Strobel, M. and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, R. and Wagner, Torsten}, title = {Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems}, series = {Physica status solidi (a)}, volume = {213}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6300}, doi = {10.1002/pssa.201533056}, pages = {1520 -- 1525}, year = {2016}, abstract = {Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium.}, language = {en} } @book{MuellerRath2015, author = {M{\"u}ller, Bodo and Rath, Walter}, title = {Formulierung von Kleb- und Dichtstoffen: das kompetente Lehrbuch f{\"u}r Studium und Praxis}, edition = {3., vollst. {\"u}berarb. Aufl.}, publisher = {Vincentz Network}, address = {Hannover}, isbn = {978-3-86630-605-9}, pages = {375 S. : Ill., graph. Darst}, year = {2015}, language = {de} } @article{HeinzeMangPopescuetal.2016, author = {Heinze, D. and Mang, Thomas and Popescu, C. and Weichold, O.}, title = {Effect of side chain length and degree of polymerization on the decomposition and crystallization behaviour of chlorinated poly(vinyl ester) oligomers}, series = {Thermochimica Acta}, volume = {637}, journal = {Thermochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0040-6031 (electronic)}, doi = {10.1016/j.tca.2016.05.015}, pages = {143 -- 153}, year = {2016}, abstract = {Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl₃-(CH₂CH (OCO(CH₂)ₘCH₃))ₙ-Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated. All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain.}, language = {en} } @article{BreuerMangSchoeningetal.2017, author = {Breuer, Lars and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, Ronald and Wagner, Torsten}, title = {Investigation of the spatial resolution of a laser-based stimulation process for light-addressable hydrogels with incorporated graphene oxide by means of IR thermography}, series = {Sensors and Actuators A: Physical}, volume = {268}, journal = {Sensors and Actuators A: Physical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0924-4247}, doi = {10.1016/j.sna.2017.11.031}, pages = {126 -- 132}, year = {2017}, language = {en} } @article{EckertRudolphGuoetal.2018, author = {Eckert, Alexander and Rudolph, Tobias and Guo, Jiaqi and Mang, Thomas and Walther, Andreas}, title = {Exceptionally Ductile and Tough Biomimetic Artificial Nacre with Gas Barrier Function}, series = {Advanced Materials}, volume = {30}, journal = {Advanced Materials}, number = {32}, publisher = {Wiley-VCH}, doi = {10.1002/adma.201802477}, pages = {Article number 1802477}, year = {2018}, abstract = {Synthetic mimics of natural high-performance structural materials have shown great and partly unforeseen opportunities for the design of multifunctional materials. For nacre-mimetic nanocomposites, it has remained extraordinarily challenging to make ductile materials with high stretchability at high fractions of reinforcements, which is however of crucial importance for flexible barrier materials. Here, highly ductile and tough nacre-mimetic nanocomposites are presented, by implementing weak, but many hydrogen bonds in a ternary nacre-mimetic system consisting of two polymers (poly(vinyl amine) and poly(vinyl alcohol)) and natural nanoclay (montmorillonite) to provide efficient energy dissipation and slippage at high nanoclay content (50 wt\%). Tailored interactions enable exceptional combinations of ductility (close to 50\% strain) and toughness (up to 27.5 MJ m⁻³). Extensive stress whitening, a clear sign of high internal dynamics at high internal cohesion, can be observed during mechanical deformation, and the materials can be folded like paper into origami planes without fracture. Overall, the new levels of ductility and toughness are unprecedented in highly reinforced bioinspired nanocomposites and are of critical importance to future applications, e.g., as barrier materials needed for encapsulation and as a printing substrate for flexible organic electronics.}, language = {en} } @inproceedings{SauerbornLiebenstundRaueetal.2017, author = {Sauerborn, Markus and Liebenstund, Lena and Raue, Markus and Mang, Thomas and Herrmann, Ulf and Dueing, Andreas}, title = {Analytic method for material aging and quality analyzing to forecast long time stability of plastic micro heliostat components}, series = {AIP Conference Proceedings}, volume = {1850}, booktitle = {AIP Conference Proceedings}, number = {1}, doi = {10.1063/1.4984388}, pages = {030045-1 -- 030045-8}, year = {2017}, language = {en} } @article{Delaittre2019, author = {Delaittre, Guillaume}, title = {Telechelic Poly(2-Oxazoline)s}, series = {European Polymer Journal}, journal = {European Polymer Journal}, number = {In Press, Journal Pre-proof, 109281}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2019.109281}, year = {2019}, language = {en} } @misc{FriedericiHojdis2018, author = {Friederici, Nadja-Annette and Hojdis, Nils}, title = {Fahrzeugreifen}, year = {2018}, abstract = {Die Erfindung betrifft einen Fahrzeugreifen mit zumindest einem radial außen befindlichen Gummilaufstreifen, Wulstbereichen f{\"u}r den Anschluss an eine Felge und mit auf einer Gummimischung basierenden Seitenwandbereichen zwischen Gummilaufstreifen und den Wulstbereichen. Ferner betrifft die Erfindung Verfahren zur Herstellung solcher Fahrzeugreifen. Um den Anteil der umweltsch{\"a}dlichen Substanzen, insbesondere im Innenstadtbereich, zu reduzieren weisen die Seitenwandbereiche auf der {\"a}ußeren Oberfl{\"a}che eine f{\"u}r den oxidativen Abbau von Molek{\"u}len photokatalytisch aktive Substanz auf.}, language = {de} } @misc{HojdisMulthauptReckeretal.2019, author = {Hojdis, Nils and Multhaupt, Hendrik and Recker, Carla and Wark, Michael}, title = {Schwefelvernetzbare Kautschukmischung, Vulkanisat der Kautschukmischung und Fahrzeugreifen}, year = {2019}, abstract = {Die Erfindung betrifft eine schwefelvernetzbare Kautschukmischung, deren Vulkanisat und einen Fahrzeugreifen. Die erfindungsgem{\"a}ße Kautschukmischung enth{\"a}lt wenigstens folgende Bestandteile: - Wenigstens einen Dienkautschuk; - wenigstens eine Kohle (HTC-Kohle), die mittels hydrothermaler Karbonisierung von wenigstens einer Ausgangssubstanz hergestellt ist. Der erfindungsgem{\"a}ße Fahrzeugreifen weist in wenigstens einem Bauteil wenigstens ein erfindungsgem{\"a}ßes Vulkanisat der Kautschukmischung auf.}, language = {de} } @misc{DauerHojdisMuelleretal.2019, author = {Dauer, David-Raphael and Hojdis, Nils and M{\"u}ller, Norbert and Recker, Carla and Schax, Fabian and Sch{\"o}ffel, Julia and Tarantola, Gesa and Weber, Christine}, title = {Schwefelvernetzbare Kautschukmischung, Vulkanisat der Kautschukmischung und Fahrzeugreifen}, year = {2019}, abstract = {Die Erfindung betrifft eine schwefelvernetzbare Kautschukmischung, deren Vulkanisat und einen Fahrzeugreifen. Die schwefelvernetzbare Kautschukmischung enth{\"a}lt wenigstens die folgenden Bestandteile: - wenigstens einen Dienkautschuk; und - 10 bis 300 phr wenigstens einer Kiesels{\"a}ure; und - 1 bis 30 phf wenigstens eines Silans A mit der allgemeinen Summenformel A-I) A-I)(R1)oSi-R2-(S-R3)q-S-X; und - 0,5 bis 30 phf wenigstens eines Silans B mit der allgemeinen Summenformel B-I) B-I) (R1)oSi-R2-(S-R3)u-S-R2-Si(R1)o wobei q =1, 2 oder 3 ist; und u = 1, 2 oder 3 ist; und X ein Wasserstoffatom oder eine -C(=O)-R8 Gruppe ist wobei R8 ausgew{\"a}hlt ist aus Wasserstoff, C1-C20 Alkylgruppen, vorzugsweise C1-C17, C6-C20- Arylgruppen, vorzugsweise Phenyl, C2-C20-Alkenylgruppen und C7-C20-Aralkylgruppen.}, language = {de} } @article{ElMoussaouiTalbiAtmaneetal.2020, author = {El Moussaoui, Noureddine and Talbi, Sofian and Atmane, Ilyas and Kassmi, Khalil and Schwarzer, Klemens and Chayeb, Hamid and Bachiri, Najib}, title = {Feasibility of a new design of a Parabolic Trough Solar Thermal Cooker (PSTC)}, series = {Solar Energy}, volume = {201}, journal = {Solar Energy}, number = {Vol. 201 (May 2020)}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0038-092X}, doi = {10.1016/j.solener.2020.03.079}, pages = {866 -- 871}, year = {2020}, abstract = {In this article, we describe the structure, the functioning, and the tests of parabolic trough solar thermal cooker (PSTC). This oven is designed to meet the needs of rural residents, including Urban, which requires stable cooking temperatures above 200 °C. The cooking by this cooker is based on the concentration of the sun's rays on a glass vacuum tube and heating of the oil circulate in a big tube, located inside the glass tube. Through two small tubes, associated with large tube, the heated oil, rise and heats the pot of cooking pot containing the food to be cooked (capacity of 5 kg). This cooker is designed in Germany and extensively tested in Morocco for use by the inhabitants who use wood from forests. During a sunny day, having a maximum solar radiation around 720 W/m2 and temperature ambient around 26 °C, maximum temperatures recorded of the small tube, the large tube and the center of the pot are respectively: 370 °C, 270 °C and 260 °C. The cooking process with food at high (fries, ..), we show that the cooking oil temperature rises to 200 °C, after 1 h of heating, the cooking is done at a temperature of 120 °C for 20 min. These temperatures are practically stable following variations and decreases in the intensity of irradiance during the day. The comparison of these results with those of the literature shows an improvement of 30-50 \% on the maximum value of the temperature with a heat storage that could reach 60 min of autonomy. All the results obtained show the good functioning of the PSTC and the feasibility of cooking food at high temperature (>200 °C).}, language = {en} } @article{MayerHentschkeHageretal.2017, author = {Mayer, Jan and Hentschke, Reinhard and Hager, Jonathan and Hojdis, Nils and Karimi-Varnaneh, Hossein Ali}, title = {A Nano-Mechanical Instability as Primary Contribution to Rolling Resistance}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {Article number 11275}, publisher = {Springer}, address = {Berlin}, issn = {2045-2322}, year = {2017}, language = {en} } @article{SvaneborgKarimiVarzanehHojdisetal.2016, author = {Svaneborg, Carsten and Karimi-Varzaneh, Hossein Ali and Hojdis, Nils and Fleck, Franz and Everaers, Ralf}, title = {Multiscale approach to equilibrating model polymer melts}, series = {Physical Review E}, volume = {94}, journal = {Physical Review E}, number = {032502}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {2470-0053}, doi = {10.1103/PhysRevE.94.032502}, year = {2016}, abstract = {We present an effective and simple multiscale method for equilibrating Kremer Grest model polymer melts of varying stiffness. In our approach, we progressively equilibrate the melt structure above the tube scale, inside the tube and finally at the monomeric scale. We make use of models designed to be computationally effective at each scale. Density fluctuations in the melt structure above the tube scale are minimized through a Monte Carlo simulated annealing of a lattice polymer model. Subsequently the melt structure below the tube scale is equilibrated via the Rouse dynamics of a force-capped Kremer-Grest model that allows chains to partially interpenetrate. Finally the Kremer-Grest force field is introduced to freeze the topological state and enforce correct monomer packing. We generate 15 melts of 500 chains of 10.000 beads for varying chain stiffness as well as a number of melts with 1.000 chains of 15.000 monomers. To validate the equilibration process we study the time evolution of bulk, collective, and single-chain observables at the monomeric, mesoscopic, and macroscopic length scales. Extension of the present method to longer, branched, or polydisperse chains, and/or larger system sizes is straightforward.}, language = {en} } @article{SchwabHojdisLacayoetal.2016, author = {Schwab, Lukas and Hojdis, Nils and Lacayo, Jorge and Wilhelm, Manfred}, title = {Fourier-Transform Rheology of Unvulcanized, Carbon Black Filled Styrene Butadiene Rubber}, series = {Macromolecular Materials and Engineering}, volume = {301}, journal = {Macromolecular Materials and Engineering}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-2054}, doi = {10.1002/mame.201500356}, pages = {457 -- 468}, year = {2016}, abstract = {Rubber materials filled with reinforcing fillers display nonlinear rheological behavior at small strain amplitudes below γ0 < 0.1. Nevertheless, rheological data are analyzed mostly in terms of linear parameters, such as shear moduli (G′, G″), which loose their physical meaning in the nonlinear regime. In this work styrene butadiene rubber filled with carbon black (CB) under large amplitude oscillatory shear (LAOS) is analyzed in terms of the nonlinear parameter I3/1. Three different CB grades are used and the filler load is varied between 0 and 70 phr. It is found that I3/1(φ) is most sensitive to changes of the total accessible filler surface area at low strain amplitudes (γ0 = 0.32). The addition of up to 70 phr CB leads to an increase of I3/1(φ) by a factor of more than ten. The influence of the measurement temperature on I3/1 is pronounced for CB levels above the percolation threshold.}, language = {en} } @article{HarishWriggersJungketal.2016, author = {Harish, Ajay B. and Wriggers, Peter and Jungk, Juliane and Hojdis, Nils and Recker, Carla}, title = {Mesoscale Constitutive Modeling of Non-Crystallizing Filled Elastomers}, series = {Computational Mechanics}, volume = {57}, journal = {Computational Mechanics}, publisher = {Springer}, address = {Berlin}, issn = {1432-0924}, doi = {10.1007/s00466-015-1251-1}, pages = {653 -- 677}, year = {2016}, abstract = {Elastomers are exceptional materials owing to their ability to undergo large deformations before failure. However, due to their very low stiffness, they are not always suitable for industrial applications. Addition of filler particles provides reinforcing effects and thus enhances the material properties that render them more versatile for applications like tyres etc. However, deformation behavior of filled polymers is accompanied by several nonlinear effects like Mullins and Payne effect. To this day, the physical and chemical changes resulting in such nonlinear effect remain an active area of research. In this work, we develop a heterogeneous (or multiphase) constitutive model at the mesoscale explicitly considering filler particle aggregates, elastomeric matrix and their mechanical interaction through an approximate interface layer. The developed constitutive model is used to demonstrate cluster breakage, also, as one of the possible sources for Mullins effect observed in non-crystallizing filled elastomers.}, language = {en} } @article{HentschkeHagerHojdis2014, author = {Hentschke, Reinhard and Hager, Jonathan and Hojdis, Nils}, title = {Molecular Modeling Approach to the Prediction of Mechanical Properties of Silica-Reinforced Rubbers}, series = {Journal of Applied Polymer Science}, volume = {131}, journal = {Journal of Applied Polymer Science}, number = {18}, publisher = {Wiley}, address = {New York, NY}, issn = {1097-4628}, doi = {10.1002/app.40806}, pages = {1 -- 9}, year = {2014}, abstract = {Recently, we have suggested a nanomechanical model for dissipative loss in filled elastomer networks in the context of the Payne effect. The mechanism is based on a total interfiller particle force exhibiting an intermittent loop, due to the combination of short-range repulsion and dispersion forces with a long-range elastic attraction. The sum of these forces leads, under external strain, to a spontaneous instability of "bonds" between the aggregates in a filler network and attendant energy dissipation. Here, we use molecular dynamics simulations to obtain chemically realistic forces between surface modified silica particles. The latter are combined with the above model to estimate the loss modulus and the low strain storage modulus in elastomers containing the aforementioned filler-compatibilizer systems. The model is compared to experimental dynamic moduli of silica filled rubbers. We find good agreement between the model predictions and the experiments as function of the compatibilizer's molecular structure and its bulk concentration.}, language = {en} } @misc{FingerHojdisMenglong2020, author = {Finger, Sebastian and Hojdis, Nils and Menglong, Huang}, title = {Sekund{\"a}re galvanische Zelle}, year = {2020}, abstract = {Die vorliegende Erfindung betrifft eine sekund{\"a}re galvanische Zelle, umfassend eine Kathode, eine Anode und einen Separator, der zwischen der Kathode und der Anode angeordnet ist, wobei die Kathode ein erstes elastomeres Polymer umfasst, welches mit einem ersten F{\"u}llstoff als Kathodenmaterial gef{\"u}llt ist, wobei die Anode ein zweites elastomeres Polymer umfasst, welches mit einem zweiten F{\"u}llstoff als Anodenmaterial gef{\"u}llt ist, wobei der Separator ein drittes elastomeres Polymer umfasst, wobei das erste elastomere Polymer, das zweite elastomere Polymer und das dritte elastomere Polymer unabh{\"a}ngig voneinander aus vernetzungsf{\"a}higen Dienkautschuken ausgew{\"a}hlt sind, und wobei zumindest eines von dem ersten elastomeren Polymer, dem zweiten elastomeren Polymer und dem dritten elastomeren Polymer eine ionische Fl{\"u}ssigkeit und/oder ein elektrisch leitf{\"a}higes Polymer enth{\"a}lt. Die vorliegende Erfindung betrifft ferner eine wiederaufladbare Batterie, umfassend die erfindungsgem{\"a}ße sekund{\"a}re galvanische Zelle, ein Verfahren zur Herstellung einer sekund{\"a}ren galvanischen Zelle sowie die Verwendung der erfindungsgem{\"a}ßen sekund{\"a}ren galvanischen Zelle sowie der erfindungsgem{\"a}ßen wiederaufladbaren Batterie.}, language = {de} } @misc{HojdisRecker2020, author = {Hojdis, Nils and Recker, Carla}, title = {Schwefelvernetzte Kautschukmischung f{\"u}r Fahrzeugreifen enthaltend Carbon Nanotubes (cnt), Fahrzeugreifen, Der Die schwefelvernetzte Kautschukmischung aufweist, sowie Verfahren zur Herstellung der schwefelvernetzten Kautschukmischung enthaltend Cnt}, year = {2020}, language = {de} } @misc{EhmkeFingerHojdisetal.2020, author = {Ehmke, Tobias and Finger, Sebastian and Hojdis, Nils and Kurz, Martin and Nawrocka-Herczynska, Monika}, title = {Funkeinheit und Vorrichtung mit einer Funkeinheit}, year = {2020}, abstract = {Dargestellt und beansprucht ist eine Funkeinheit mit einem Funkbauteil, einer elektrisch leitf{\"a}higen Antenne und einem Kunststoffverbindungsmittel. Das Funkbauteil weist einen Antennenanschluss auf. Das Kunststoffverbindungsmittel weist ein erstes Elastomermaterial mit elektrisch leitf{\"a}higem Zusatzmaterial auf, so dass das Kunststoffverbindungsmittel elektrisch leitf{\"a}hig ist. Das Kunststoffverbindungsmittel bildet eine mechanische und elektrisch leitf{\"a}hige Verbindung zwischen dem Antennenanschluss und der Antenne. Weiterhin wird eine Vorrichtung mit einem ein Matrixmaterial mit oder aus einem zweiten Elastomermaterial und einer Funkeinheit beschrieben und beansprucht, wobei die Funkeinheit vollst{\"a}ndig in das Matrixmaterial eingebettet ist. Die Vorrichtung kann insbesondere ein Fahrzeugreifen sein.}, language = {de} } @misc{Hojdis2019, author = {Hojdis, Nils}, title = {Verfahren zum Bestimmen einer Sitzeinstellung eines Sitzes eines Kraftfahrzeugs, Computerprogrammprodukt, Servereinrichtung, Kommunikationsendger{\"a}t und Kraftfahrzeug}, year = {2019}, abstract = {Die Erfindung betrifft ein Verfahren zum Bestimmen einer Sitzeinstellung (23) eines Sitzes (3) eines Kraftfahrzeugs (1), bei welchem folgende Schritte durchgef{\"u}hrt werden:- Bereitstellen einer K{\"o}rperabmessung (12) eines Nutzers (6) des Kraftfahrzeugs (1);- Bereitstellen einer Sitzeigenschaft (13) des Sitzes (3) des Kraftfahrzeugs (1);- Bereitstellen eines mit zumindest einer Referenzsitzeigenschaft (20), zumindest einer Referenzk{\"o}rperabmessung (21) und zumindest einer Referenzsitzeinstellung (22) trainiertes k{\"u}nstliches neuronales Netz (14); und- Bestimmen der Sitzeinstellung (23) durch Eingabe der K{\"o}rperabmessung (12) und der Sitzeigenschaft (13) in das k{\"u}nstliche neuronale Netz (14).}, language = {de} } @misc{DauerHojdisMuelleretal.2019, author = {Dauer, David-Raphael and Hojdis, Nils and M{\"u}ller, Norbert and Recker, Carla and Schax, Fabian and Sch{\"o}ffel, Julia and Tarantola, Gesa and Weber, Christine}, title = {Schwefelvernetzbare Kautschukmischung, Vulkanisat der Kautschukmischung und Fahrzeugreifen}, year = {2019}, abstract = {Die Erfindung betrifft eine schwefelvernetzbare Kautschukmischung, deren Vulkanisat und einen Fahrzeugreifen.Die schwefelvernetzbare Kautschukmischung enth{\"a}lt wenigstens die folgenden Bestandteile:- wenigstens einen Dienkautschuk; und- 10 bis 300 phr wenigstens einer Kiesels{\"a}ure ; und- 1 bis 30 phf wenigstens eines Silans A mit der allgemeinen Summenformel A-I)und- 0,5 bis 30 phf wenigstens eines Silans B mit der allgemeinen Summenformel B-I)wobei u gleich 0, 1, 2 oder 3 und v gleich 0 oder 1 ist.}, language = {de} } @article{EveraersKarimiVarzanehFlecketal.2020, author = {Everaers, Ralf and Karimi-Varzaneh, Hossein Ali and Fleck, Franz and Hojdis, Nils and Svaneborg, Carsten}, title = {Kremer-Grest Models for Commodity Polymer Melts: Linking Theory, Experiment, and Simulation at the Kuhn Scale}, series = {Macromolecules}, volume = {53}, journal = {Macromolecules}, number = {6}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1520-5835}, doi = {10.1021/acs.macromol.9b02428}, pages = {1901 -- 1916}, year = {2020}, abstract = {The Kremer-Grest (KG) polymer model is a standard model for studying generic polymer properties in molecular dynamics simulations. It owes its popularity to its simplicity and computational efficiency, rather than its ability to represent specific polymers species and conditions. Here we show that by tuning the chain stiffness it is possible to adapt the KG model to model melts of real polymers. In particular, we provide mapping relations from KG to SI units for a wide range of commodity polymers. The connection between the experimental and the KG melts is made at the Kuhn scale, i.e., at the crossover from the chemistry-specific small scale to the universal large scale behavior. We expect Kuhn scale-mapped KG models to faithfully represent universal properties dominated by the large scale conformational statistics and dynamics of flexible polymers. In particular, we observe very good agreement between entanglement moduli of our KG models and the experimental moduli of the target polymers.}, language = {en} } @article{MeyerHentschkeHageretal.2017, author = {Meyer, Jan and Hentschke, Reinhard and Hager, Jonathan and Hojdis, Nils and Karimi-Varzaneh, Hossein Ali}, title = {Molecular Simulation of Viscous Dissipation due to Cyclic Deformation of a Silica-Silica Contact in Filled Rubber}, series = {Macromolecules}, volume = {50}, journal = {Macromolecules}, number = {17}, issn = {1520-5835}, doi = {10.1021/acs.macromol.7b00947}, pages = {6679 -- 6689}, year = {2017}, language = {en} } @article{HagerHentschkeHojdisetal.2015, author = {Hager, Jonathan and Hentschke, Reinhard and Hojdis, Nils and Karimi-Varzaneh, Hossein Ali}, title = {Computer Simulation of Particle-Particle Interaction in a Model Polymer Nanocomposite}, series = {Macromolecules}, volume = {48}, journal = {Macromolecules}, number = {24}, issn = {1520-5835}, doi = {10.1021/acs.macromol.5b01864}, pages = {9039 -- 9049}, year = {2015}, language = {en} } @article{WallerBraunHojdisetal.2007, author = {Waller, Mark P. and Braun, Heiko and Hojdis, Nils and B{\"u}hl, Michael}, title = {Geometries of Second-Row Transition-Metal Complexes from Density-Functional Theory}, series = {Journal of Chemical Theory and Computation}, volume = {3}, journal = {Journal of Chemical Theory and Computation}, number = {6}, issn = {1549-9626}, doi = {10.1021/ct700178y}, pages = {2234 -- 2242}, year = {2007}, language = {en} } @article{SvaneborgKarimiVarzanehHojdisetal.2018, author = {Svaneborg, Carsten and Karimi-Varzaneh, Hossein Ali and Hojdis, Nils and Fleck, Franz and Everaers, Ralf}, title = {Kremer-Grest Models for Universal Properties of Specific Common Polymer Species}, series = {Soft Condensed Matter}, journal = {Soft Condensed Matter}, number = {1606.05008}, year = {2018}, abstract = {The Kremer-Grest (KG) bead-spring model is a near standard in Molecular Dynamic simulations of generic polymer properties. It owes its popularity to its computational efficiency, rather than its ability to represent specific polymer species and conditions. Here we investigate how to adapt the model to match the universal properties of a wide range of chemical polymers species. For this purpose we vary a single parameter originally introduced by Faller and M{\"u}ller-Plathe, the chain stiffness. Examples include polystyrene, polyethylene, polypropylene, cis-polyisoprene, polydimethylsiloxane, polyethyleneoxide and styrene-butadiene rubber. We do this by matching the number of Kuhn segments per chain and the number of Kuhn segments per cubic Kuhn volume for the polymer species and for the Kremer-Grest model. We also derive mapping relations for converting KG model units back to physical units, in particular we obtain the entanglement time for the KG model as function of stiffness allowing for a time mapping. To test these relations, we generate large equilibrated well entangled polymer melts, and measure the entanglement moduli using a static primitive-path analysis of the entangled melt structure as well as by simulations of step-strain deformation of the model melts. The obtained moduli for our model polymer melts are in good agreement with the experimentally expected moduli.}, language = {en} } @article{HafidiElHatkaSchmitzetal.2024, author = {Hafidi, Youssef and El Hatka, Hicham and Schmitz, Dominik and Krauss, Manuel and Pettrak, J{\"u}rgen and Biel, Markus and Ittobane, Najim}, title = {Sustainable soil additives for water and micronutrient supply: swelling and chelating properties of polyaspartic acid hydrogels utilizing newly developed crosslinkers}, series = {Gels}, volume = {10}, journal = {Gels}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2310-2861}, doi = {10.3390/gels10030170}, pages = {Artikel 170}, year = {2024}, abstract = {Drought and water shortage are serious problems in many arid and semi-arid regions. This problem is getting worse and even continues in temperate climatic regions due to climate change. To address this problem, the use of biodegradable hydrogels is increasingly important for the application as water-retaining additives in soil. Furthermore, efficient (micro-)nutrient supply can be provided by the use of tailored hydrogels. Biodegradable polyaspartic acid (PASP) hydrogels with different available (1,6-hexamethylene diamine (HMD) and L-lysine (LYS)) and newly developed crosslinkers based on diesters of glycine (GLY) and (di-)ethylene glycol (DEG and EG, respectively) were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) and regarding their swelling properties (kinetic, absorbency under load (AUL)) as well as biodegradability of PASP hydrogel. Copper (II) and zinc (II), respectively, were loaded as micronutrients in two different approaches: in situ with crosslinking and subsequent loading of prepared hydrogels. The results showed successful syntheses of di-glycine-ester-based crosslinkers. Hydrogels with good water-absorbing properties were formed. Moreover, the developed crosslinking agents in combination with the specific reaction conditions resulted in higher water absorbency with increased crosslinker content used in synthesis (10\% vs. 20\%). The prepared hydrogels are candidates for water-storing soil additives due to the biodegradability of PASP, which is shown in an exemple. The incorporation of Cu(II) and Zn(II) ions can provide these micronutrients for plant growth.}, language = {en} } @article{SchmidtTurgutLeetal.2020, author = {Schmidt, Aaron C. and Turgut, Hatice and Le, Dao and Beloqui, Ana and Delaittre, Guillaume}, title = {Making the best of it: nitroxide-mediated polymerization of methacrylates via the copolymerization approach with functional styrenics}, series = {Polymer Chemistry}, volume = {11}, journal = {Polymer Chemistry}, number = {2}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, doi = {10.1039/C9PY01458F}, pages = {593 -- 604}, year = {2020}, abstract = {The SG1-mediated solution polymerization of methyl methacrylate (MMA) and oligo(ethylene glycol) methacrylate (OEGMA, Mₙ = 300 g mol⁻¹) in the presence of a small amount of functional/reactive styrenic comonomer is investigated. Moieties such as pentafluorophenyl ester, triphenylphosphine, azide, pentafluorophenyl, halide, and pyridine are considered. A comonomer fraction as low as 5 mol\% typically results in a controlled/living behavior, at least up to 50\% conversion. Chain extensions with styrene for both systems were successfully performed. Variation of physical properties such as refractive index (for MMA) and phase transition temperature (for OEGMA) were evaluated by comparing to 100\% pure homopolymers. The introduction of an activated ester styrene derivative in the polymerization of OEGMA allows for the synthesis of reactive and hydrophilic polymer brushes with defined thickness. Finally, using the example of pentafluorostyrene as controlling comonomer, it is demonstrated that functional PMMA-b-PS are able to maintain a phase separation ability, as evidenced by the formation of nanostructured thin films.}, language = {en} } @article{EckertAbbasiMangetal.2020, author = {Eckert, Alexander and Abbasi, Mozhdeh and Mang, Thomas and Saalw{\"a}chter, Kay and Walther, Andreas}, title = {Structure, Mechanical Properties, and Dynamics of Polyethylenoxide/Nanoclay Nacre-Mimetic Nanocomposites}, series = {Macromolecules}, volume = {53}, journal = {Macromolecules}, number = {5}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1520-5835}, doi = {10.1021/acs.macromol.9b01931}, pages = {1716 -- 1725}, year = {2020}, abstract = {Nacre-mimetic nanocomposites based on high fractions of synthetic high-aspect-ratio nanoclays in combination with polymers are continuously pushing boundaries for advanced material properties, such as high barrier against oxygen, extraordinary mechanical behavior, fire shielding, and glass-like transparency. Additionally, they provide interesting model systems to study polymers under nanoconfinement due to the well-defined layered nanocomposite arrangement. Although the general behavior in terms of forming such layered nanocomposite materials using evaporative self-assembly and controlling the nanoclay gallery spacing by the nanoclay/polymer ratio is understood, some combinations of polymer matrices and nanoclay reinforcement do not comply with the established models. Here, we demonstrate a thorough characterization and analysis of such an unusual polymer/nanoclay pair that falls outside of the general behavior. Poly(ethylene oxide) (PEO) and sodium fluorohectorite form nacre-mimetic, lamellar nanocomposites that are completely transparent and show high mechanical stiffness and high gas barrier, but there is only limited expansion of the nanoclay gallery spacing when adding increasing amounts of polymer. This behavior is maintained for molecular weights of PEO varied over four orders of magnitude and can be traced back to depletion forces. By careful investigation via X-ray diffraction and proton low-resolution solid-state NMR, we are able to quantify the amount of mobile and immobilized polymer species in between the nanoclay galleries and around proposed tactoid stacks embedded in a PEO matrix. We further elucidate the unusual confined polymer dynamics, indicating a relevant role of specific surface interactions.}, language = {en} } @article{ElBerguiAbouabdillahBouriougetal.2023, author = {El Bergui, Omnia and Abouabdillah, Aziz and Bourioug, Mohamed and Schmitz, Dominik and Biel, Markus and Aboudrare, Abdellah and Krauss, Manuel and Jomaa, Ahlem and Romuli, Sebastian and M{\"u}ller, Joachim and Fagroud, Mustapha and Bouabid, Rachid}, title = {Innovative solutions for drought: Evaluating hydrogel application on onion cultivation (Allium cepa) in Morocco}, series = {Water}, volume = {15}, journal = {Water}, number = {11}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/w15111972}, pages = {Artikel 1972}, year = {2023}, abstract = {Throughout the last decade, and particularly in 2022, water scarcity has become a critical concern in Morocco and other Mediterranean countries. The lack of rainfall during spring was worsened by a succession of heat waves during the summer. To address this drought, innovative solutions, including the use of new technologies such as hydrogels, will be essential to transform agriculture. This paper presents the findings of a study that evaluated the impact of hydrogel application on onion (Allium cepa) cultivation in Meknes, Morocco. The treatments investigated in this study comprised two different types of hydrogel-based soil additives (Arbovit® polyacrylate and Huminsorb® polyacrylate), applied at two rates (30 and 20 kg/ha), and irrigated at two levels of water supply (100\% and 50\% of daily crop evapotranspiration; ETc). Two control treatments were included, without hydrogel application and with both water amounts. The experiment was conducted in an open field using a completely randomized design. The results indicated a significant impact of both hydrogel-type dose and water dose on onion plant growth, as evidenced by various vegetation parameters. Among the hydrogels tested, Huminsorb® Polyacrylate produced the most favorable outcomes, with treatment T9 (100\%, HP, 30 kg/ha) yielding 70.55 t/ha; this represented an increase of 11 t/ha as compared to the 100\% ETc treatment without hydrogel application. Moreover, the combination of hydrogel application with 50\% ETc water stress showed promising results, with treatment T4 (HP, 30 kg, 50\%) producing almost the same yield as the 100\% ETc treatment without hydrogel while saving 208 mm of water.}, language = {en} } @book{Lauth2023, author = {Lauth, Jakob}, title = {Physical chemistry in a nutshell: Basics for engineers and scientists}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-662-67636-3 (Softcover)}, doi = {10.1007/978-3-662-67637-0}, pages = {XIII, 248 Seiten}, year = {2023}, abstract = {This book is based on a multimedia course for biological and chemical engineers, which is designed to trigger students' curiosity and initiative. A solid basic knowledge of thermodynamics and kinetics is necessary for understanding many technical, chemical, and biological processes. The one-semester basic lecture course was divided into 12 workshops (chapters). Each chapter covers a practically relevant area of physical chemistry and contains the following didactic elements that make this book particularly exciting and understandable: - Links to Videos at the start of each chapter as preparation for the workshop - Key terms (in bold) for further research of your own - Comprehension questions and calculation exercises with solutions as learning checks - Key illustrations as simple, easy-to-replicate blackboard pictures Humorous cartoons for each workshop (by Faelis) additionally lighten up the text and facilitate the learning process as a mnemonic. To round out the book, the appendix includes a summary of the most popular experiments in basic physical chemistry courses, as well as suggestions for designing workshops with exhibits, experiments, and "questions of the day." Suitable for students minoring in chemistry; chemistry majors are sure to find this slimmed-down, didactically valuable book helpful as well. The book is excellent for self-study.}, language = {en} }