Search

Your search keyword '"Pyckhout-Hintzen, Wim"' showing total 171 results
Start Over Author "Pyckhout-Hintzen, Wim"
171 results on '"Pyckhout-Hintzen, Wim"'

3. Dynamics of Syndiotactic Polypropylene

Author

Zamponi, Michaela, primary, Pyckhout-Hintzen, Wim, additional, Wischnewski, Andreas, additional, Pipich, Vitaliy, additional, Holderer, Olaf, additional, Farago, Bela, additional, Coates, Geoffrey W., additional, Long, Brian K., additional, Monkenbusch, Michael, additional, and Richter, Dieter, additional

Published
2024
Full Text
View/download PDF

4. Structure of interacting aggregates of silica nanoparticles in a polymer matrix: Small-angle scattering and Reverse Monte-Carlo simulations

Author

Oberdisse, Julian, Hine, Peter, and Pyckhout-Hintzen, Wim

Subjects
Condensed Matter - Soft Condensed Matter
Abstract

Reinforcement of elastomers by colloidal nanoparticles is an important application where microstructure needs to be understood - and if possible controlled - if one wishes to tune macroscopic mechanical properties. Here the three-dimensional structure of big aggregates of nanometric silica particles embedded in a soft polymeric matrix is determined by Small Angle Neutron Scattering. Experimentally, the crowded environment leading to strong reinforcement induces a strong interaction between aggregates, which generates a prominent interaction peak in the scattering. We propose to analyze the total signal by means of a decomposition in a classical colloidal structure factor describing aggregate interaction and an aggregate form factor determined by a Reverse Monte Carlo technique. The result gives new insights in the shape of aggregates and their complex interaction in elastomers. For comparison, fractal models for aggregate scattering are also discussed.

Published
2007
Full Text
View/download PDF

10. List of Contributors

Author

Abitha, Vayyaprontavida Kaliyathan, primary, Borsacchi, Silvia, additional, Carbonnier, Benjamin, additional, Chakraborty, Santanu, additional, Chehimi, Mohamed M., additional, Fermeglia, Maurizio, additional, Frielinghaus, Henrich, additional, Geppi, Marco, additional, Gârea, Sorina A., additional, Hussain, Syed Arshad, additional, Iovu, Horia, additional, Jlassi, Khouloud, additional, Kanny, Krishnan, additional, Katsarava, Ramaz, additional, Khalil, Ahmed M., additional, Krupa, Igor, additional, Laurini, Erik, additional, Loganathan, Sravanthi, additional, Lopez-Cuesta, José-Marie, additional, Mahouche-Chergui, Samia, additional, Martini, Francesca, additional, Naili, Salah, additional, Nguyen, Vu-Hieu, additional, Omastová, Mária, additional, Pal, Kaushik, additional, Panwar, Vinay, additional, Patil, Shivendra S., additional, Posocco, Paola, additional, Pricl, Sabrina, additional, Pugazhenthi, G., additional, Puiggalí, Jordi, additional, Pyckhout-Hintzen, Wim, additional, Vasudeo Rane, Ajay, additional, Saad, Ali, additional, Singha, Nikhil K., additional, Snoussi, Youssef, additional, Strzemiecka, Beata, additional, Thomas, Sabu, additional, Babu Valapa, Ravi, additional, Varghese, T.O., additional, Vo, Van-Son, additional, Voelkel, Adam, additional, and Voicu, Anda I., additional

Published
2017
Full Text
View/download PDF

12. Influence of Polymer Polarity and Association Strength on the Properties of Poly(alkyl ether)-Based Supramolecular Melts

Author

Bras, Ana Rita, Arizaga, Ana, Sokolova, Daria, Agirre, Uxue, Viciosa, Maria Teresa, Radulescu, Aurel, Prevost, Sylvain Francois, Kruteva, Margarita, Pyckhout-Hintzen, Wim, Schmidt, Annette Monika, Bras, Ana Rita, Arizaga, Ana, Sokolova, Daria, Agirre, Uxue, Viciosa, Maria Teresa, Radulescu, Aurel, Prevost, Sylvain Francois, Kruteva, Margarita, Pyckhout-Hintzen, Wim, and Schmidt, Annette Monika

Abstract

The present work focuses on the impact of polymer polarity and hydrogen-bonding (H-bonding) end groups association strength on the structure and dynamics of poly(alkyl ether)-based supramolecular model polymers studied by means of small angle scattering (SAS), rheology, dielectric relaxation spectroscopy (DRS), and differential scanning calorimetry (DSC). These consist of poly (propylene oxide) (PPO) or poly(ethylene oxide) (PEO) backbone that self assembly in the bulk via hydrogen bonding (H-bonding). Diaminotriazine (DAT) and thymine-1-acetic acid (THY) as well as 2-ureido-4[1H]-pyrimidinone (UPY) are the H-bonding end groups of choice. Both PPO and PEO bearing either DAT or THY as end groups associate into linear chains, but PPO-THY/DAT forms longer chains in comparison with PEO-THY/DAT. The lower polarity of the backbone results in stronger associations for the same end groups. However, the temperature dependence of the association/dissociation lifetimes for this H-bonding type is independent of the different main chain polarity as these breaking times do not exceed the rouse chain dynamics as expected within the Cates model. PPO-UPY forms a transient network characterized by the interplay between small transient bonds controlled by the characteristic times of association/dissociation between pairs of UPY groups involving probably just two ends, revealed by the similar dielectric spectra with PPO backbone, and a more stable bond type of associate that forms phase separated UPY clusters. The latter are responsible for the physical cross-links in the network and result in the rubbery-like plateau of the rheological spectra. PPO-UPY has similar structure to PEO-UPY, as validated by small angle scattering, but the UPY detachment times in the clusters are longer for PEO-UPY than for PPO-UPY, though the activation energies are very close and match the typical energy barrier specifically imposed by the hydrogen bonds. Moreover, while the segmental relaxation times and

Published
2022

15. Chain-End Effects on Supramolecular Poly(ethylene glycol) Polymers

Author

Bras, Ana, Arizaga, Ana, Agirre, Uxue, Dorau, Marie, Houston, Judith, Radulescu, Aurel, Kruteva, Margarita, Pyckhout-Hintzen, Wim, Schmidt, Annette M., Bras, Ana, Arizaga, Ana, Agirre, Uxue, Dorau, Marie, Houston, Judith, Radulescu, Aurel, Kruteva, Margarita, Pyckhout-Hintzen, Wim, and Schmidt, Annette M.

Abstract

In this work we present a fundamental analysis based on small-angle scattering, linear rheology and differential scanning calorimetry (DSC) experiments of the role of different hydrogen bonding (H-bonding) types on the structure and dynamics of chain-end modified poly(ethylene glycol) (PEG) in bulk. As such bifunctional PEG with a molar mass below the entanglement mass M-e is symmetrically end-functionalized with three different hydrogen bonding (H-bonding) groups: thymine-1-acetic acid (thy), diamino-triazine (dat) and 2-ureido-4[1H]-pyrimidinone (upy). A linear block copolymer structure and a Newtonian-like dynamics is observed for PEG-thy/dat while results for PEG-upy structure and dynamics reveal a sphere and a network-like behavior, respectively. These observations are concomitant with an increase of the Flory-Huggins interaction parameter from PEG-thy/dat to PEG-upy that is used to quantify the difference between the H-bonding types. The upy association into spherical clusters is established by the Percus-Yevick approximation that models the inter-particle structure factor for PEG-upy. Moreover, the viscosity study reveals for PEG-upy a shear thickening behavior interpreted in terms of the free path model and related to the time for PEG-upy to dissociate from the upy clusters, seen as virtual crosslinks of the formed network. Moreover, a second relaxation time of different nature is also obtained from the complex shear modulus measurements of PEG-upy by the inverse of the angular frequency where G' and G'' crosses from the network-like to glass-like transition relaxation time, which is related to the segmental friction of PEG-upy polymeric network strands. In fact, not only do PEG-thy/dat and PEG-upy have different viscoelastic properties, but the relaxation times found for PEG-upy are much slower than the ones for PEG-thy/dat. However, the activation energy related to the association dynamics is very similar for both PEG-thy/dat and PEG-upy. Concerning the se

Published
2021

25. The segmental and chain relaxation modes in high-cis-polyisoprene as studied by thermally stimulated currents.

Author

Mora, Elsa, Brás, Ana R., Pyckhout-Hintzen, Wim, Diogo, Hermínio P., and Ramos, Joaquim J. Moura

Subjects
CHEMICAL relaxation, POLYISOPRENE, MOLECULAR dynamics, CHEMICAL kinetics, MOLECULAR weights
Abstract

The technique of Thermally Stimulated Currents is used to study the slow molecular mobility in a series of poly (1,4-cis-isoprene) samples with different molecular weights, Mw, and low polydispersity. The technique revealed a high resolution power, particularly useful in the study of the lower molecular weight samples where the chain and the segmental relaxations strongly overlap. The dynamic crossover that is reported for the normal mode by varying the molecular weight is clearly revealed by the thermally stimulated depolarization currents results through the temperature location, TMn, of the normal mode peak, the values of the relaxation time at TMn, r(TMn), and the value of the fragility index of the normal mode, mn. The kinetic features of the glass transition relaxation of polyisoprene have also been determined. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

30. Chapter 10: Neutron Scattering on different states of polymer/clay compounds: Fromsolution to dry states

Author

Frielinghaus, Henrich and Pyckhout-Hintzen, Wim

Abstract

Nanocomposites [1] in general have gained importance in nowadays products leading to improved performance of these complex compound materials. The structure of the solid particles is not limited in terms of shape in advance, but their specific function is tightly connected to their shape. Scattering experiments [2, 3, 4] are often employed to supervise production routes and the final performance, but not all possibilities of scattering experiments are exploited due to several reasons: Engineers need to enter the unknown stage of scattering experiments, and the scattering experts need to simplify their experience to simple usable recipes that are applicable and reliable. This process is still ongoing and the authors hope to contribute to this highly interesting journey. The advantages [5, 6] of clay-polymer nanocomposites [7] are already explored: mechanical improvements [8, 9], fire retardancy [5], and gas permittivity [10]. A good dispersion state is not always given a priori, and special strategies need to be employed [11, 12]: One might need strong shear fields, or even chemical modifications which either cover the clay with surfactants to reduce the surface tension or directly graft polymers to the particles. The obtained results of such measures need to be explored. Here scattering experiments come into play. They allow for characterizing the dispersion state and give feedback to the dispersion strategy. When employing microscopic models to connect the nanostructure with the macroscopic behavior, new insights might be gained that would allow for predictive tailoring of the macroscopic behavior. For instance the prediction of rheological properties of clay containing systems is still a demanding task.

Published
2017

31. Thermoresponsive copolymer hydrogels based on N-isopropylacrylamide and cationic surfactant monomers prepared from micellar solution and microemulsion in a one-step reaction

Author

Friedrich, Tatjana, Tieke, Bernd, Meyer, Mathias, Pyckhout-Hintzen, Wim, and Pipich, Vitaly

Subjects
Acrylamide -- Chemical properties, Acrylamide -- Thermal properties, Ammonium chloride -- Chemical properties, Ammonium chloride -- Thermal properties, Ammonium compounds -- Chemical properties, Ammonium compounds -- Thermal properties, Ammonium paratungstate -- Chemical properties, Ammonium paratungstate -- Thermal properties, Osmotic pressure -- Evaluation, Surface active agents -- Chemical properties, Surface active agents -- Thermal properties, Chemicals, plastics and rubber industries
Published
2010

36. Nanocomposites of Highly Monodisperse Encapsulated Superparamagnetic Iron Oxide Nanocrystals Homogeneously Dispersed in a Poly(ethylene Oxide) Melt

Author

Feld, Artur, primary, Koll, Rieke, additional, Fruhner, Lisa Sarah, additional, Krutyeva, Margarita, additional, Pyckhout-Hintzen, Wim, additional, Weiß, Christine, additional, Heller, Hauke, additional, Weimer, Agnes, additional, Schmidtke, Christian, additional, Appavou, Marie-Sousai, additional, Kentzinger, Emmanuel, additional, Allgaier, Jürgen, additional, and Weller, Horst, additional

Published
2017
Full Text
View/download PDF

37. Microscopic Structure, Conformation, and Dynamics of Ring and Linear Poly(ethylene oxide) Melts from Detailed Atomistic Molecular Dynamics Simulations: Dependence on Chain Length and Direct Comparison with Experimental Data

Author

Tsalikis, Dimitrios G., primary, Koukoulas, Thanasis, additional, Mavrantzas, Vlasis G., additional, Pasquino, Rossana, additional, Vlassopoulos, Dimitris, additional, Pyckhout-Hintzen, Wim, additional, Wischnewski, Andreas, additional, Monkenbusch, Michael, additional, and Richter, Dieter, additional

Published
2017
Full Text
View/download PDF

38. Hydrogen Bonding in a Reversible Comb Polymer Architecture: A Microscopic and Macroscopic Investigation

Author

Staropoli, Mariapaola, primary, Raba, Andreas, additional, Hövelmann, Claas H., additional, Krutyeva, Margarita, additional, Allgaier, Jürgen, additional, Appavou, Marie-Sousai, additional, Keiderling, Uwe, additional, Stadler, Florian J., additional, Pyckhout-Hintzen, Wim, additional, Wischnewski, Andreas, additional, and Richter, Dieter, additional

Published
2016
Full Text
View/download PDF

39. E02: Polymers: Structure

Author

Pyckhout-Hintzen, Wim, Angst, Manuel, Brückel, Thomas, Richter, Dieter, and Zorn, Reiner

Subjects
ddc:530, ddc:600
Published
2012

43. Structure Determination of Polymer Nanocomposites by Small Angle Scattering

Author

Oberdisse, Julian, Pyckhout-Hintzen, Wim, Straube, Ekkehard, Laboratoire des colloïdes, verres et nanomatériaux (LCVN), Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), Institut fuer Festkoeperforschung (IFF), FZ Juelich, Fachbereich Physik [Halle-Saale], Martin-Luther-Universität Halle Wittenberg (MLU), and S. Thomas, G.E. Zaikov and S.V. Valsaraj

Subjects
[PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]
Abstract

The characterization of the structure of polymer nanocomposites by the techniques of small-angle scattering of neutrons and X-rays is reviewed. Within a concise introduction to elastic small-angle scattering, the basics of shape, structure, and interactions of particles are presented, as well as the scattering from polymer chains. The scattering properties of polymer chains can be described within models that can also account for stress-strain properties. In neutron scattering, stretched polymer chains and their fluctuation width can be directly accessed by taking advantage of the difference in the scattering length between H and D atoms. Further, SANS can equally cope with the mounting interest in the characterization of polymers in nowadays popular multiphase materials. Using contrast matching or a combination of two probes, i.e. neutrons and x-rays, the solid phase can be made invisible or visible. This allows to extract new structural information about the rubbery matrix that could not be obtained separately by other methods. Current literature on filler scattering in polymer nanocomposites will be reviewed. The most common fillers where scattering has been shown to be decisive are carbon black, silica, polymeric fillers, and, to a lesser extent, clay. Scattering is a powerful tool to analyse the filler structure in a non destructive way, in the dry (pure filler) state, in solution, or inside macroscopically thick nanocomposite samples. The scattered intensity is obtained as an average over the complete sample, thereby decreasing the impact of possible artefacts as it might be the case in direct-space imaging. In this review part, it is attempted to give an overview of the morphology of the hard component typically encountered in filled polymer systems, its modes of deformation as the sample is deformed, as well as a summary of possible routes of data interpretation and modelling.

Published
2009

44. Influence of the Solvent Quality on Ring Polymer Dimensions

Author

Gooßen, Sebastian, primary, Brás, Ana R., additional, Pyckhout-Hintzen, Wim, additional, Wischnewski, Andreas, additional, Richter, Dieter, additional, Rubinstein, Michael, additional, Roovers, Jacques, additional, Lutz, Pierre J., additional, Jeong, Youncheol, additional, Chang, Taihyun, additional, and Vlassopoulos, Dimitris, additional

Published
2015
Full Text
View/download PDF

50. Linear Viscoelastic Rheology of Moderately Entangled Telechelic Polybutadiene Temporary Networks

Author

UCL - SC/CHIM - Département de chimie, UCL - FSA/MAPR - Département des sciences des matériaux et des procédés, Stadler, Florian J., Pyckhout-Hintzen, Wim, Schumers, Jean-Marc, Fustin, Charles-André, Gohy, Jean-François, Bailly, Christian, UCL - SC/CHIM - Département de chimie, UCL - FSA/MAPR - Département des sciences des matériaux et des procédés, Stadler, Florian J., Pyckhout-Hintzen, Wim, Schumers, Jean-Marc, Fustin, Charles-André, Gohy, Jean-François, and Bailly, Christian

Abstract

We investigate the time-dependent linear viscoclastic behavior of amine and alkaline metal-neutralized carboxy-telechelic 1,4-polybutadiene, and compare it with the acid precursor as well as an ester end-modified version. The ionic groups form aggregates with a aggregate spacing period around 85 A, containing about 90 chain-ends. Rheological tests highlight the existence of a strongly time-dependent terminal relaxation and an intermediate frequency relaxation, which can be assimilated to a glass transition of the ionic aggregates and their immediate environment. The terminal relaxation time after neutralization with alkali metal increases by up to 7 decades. Contrary to previously published results, this time is found to be a strongly increasing function of metal atomic mass for the equilibrated structures. The discrepancy can be rationalized by analyzing the annealing time dependence of the phenomena. Earlier studies did not report on truly equilibrated systems. While the main phase glass transition is hardly affected by neutralization, the temporary network formed by the ionic associations shows a very high and ion-dependent temperature sensitivity. Moreover, a failure of the time-temperature superposition principle is found at intermediate temperatures or frequencies, because the terminal and intermediate frequency relaxations do not follow the same temperature dependence.

Published
2009

Catalog

Books, media, physical & digital resources
See catalog results