A5088550850- Polymer crystallization and properties
- Carbon Nanotubes in Composites
- Advanced Sensor and Energy Harvesting Materials
- Polymer Nanocomposites and Properties
- Ultrasonics and Acoustic Wave Propagation
- Material Dynamics and Properties
- Epoxy Resin Curing Processes
- Thermal and Kinetic Analysis
- Conducting polymers and applications
- Dielectric materials and actuators
- Additive Manufacturing and 3D Printing Technologies
- Force Microscopy Techniques and Applications
- Photopolymerization techniques and applications
- Rheology and Fluid Dynamics Studies
- Composite Material Mechanics
- Corrosion Behavior and Inhibition
- Smart Materials for Construction
- Injection Molding Process and Properties
- Microfluidic and Capillary Electrophoresis Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Cultural Heritage Materials Analysis
- Nanopore and Nanochannel Transport Studies
- Advanced Polymer Synthesis and Characterization
- Spectroscopy and Chemometric Analyses
- Fiber-reinforced polymer composites
Fraunhofer Institute for Structural Durability and System Reliability
2014-2025
Technical University of Darmstadt
2012
Institut für das Bauen mit Kunststoffen
2003-2012
Bavarian Polymer Institute
2011
Foundation for Research and Technology Hellas
2000
FORTH Institute of Electronic Structure and Laser
2000
Martin Luther University Halle-Wittenberg
1994
Merseburg University of Applied Sciences
1992
As for nanofillers in general, the properties of carbon nanotube (CNT) -polymer composites depend strongly on filler arrangement and structure network. This article reviews our actual understanding relation between processing conditions, state CNT dispersion network one hand, resulting electrical, melt rheological mechanical properties, other hand. The as-produced rather compact agglomerates CNTs (initial agglomerates, >1 μm), whose can vary different tube manufacturers, synthesis and/or...
Abstract A general method is described to prepare high‐performance conductive polymer fibers or tapes. In this method, bicomponent tapes/fibers containing two layers of composites (CPCs) filled with multiwall carbon nanotubes (MWNT) black (CB) based on a lower‐melting‐temperature and an unfilled core higher melting temperature are fabricated by melt‐based process. Morphological control the network formed nanofillers realized solid‐state drawing annealing. Information morphological electrical...
Abstract Investigations on electric conductivity have been performed polycarbonate (PC) containing 0.6 vol% of multi‐walled carbon nanotubes (MWNT) in a rheometer, where the plates act as capacitor for dielectric spectroscopy. The time dependent recovery DC‐conductivity was recorded rest after transient shear deformation. shows tremendous increase with shearing. This is explained by reorganization conducting MWNT‐network, which destroyed shear. reformation kinetics MWNT‐clusters considered...
Abstract A series of samples with different content multi‐walled carbon nanotubes (0.5‐7.5 wt%) in polycarbonate was investigated by electrical conductivity measurements. During isothermal annealing the as‐produced melt state an increase time observed. similar recovery found after a short shear deformation melt. The time‐dependent transition from insulating to conductive is explained dynamic formation network interconnected nanotube agglomerates. networks were be stable cooling below their...
ABSTRACT Raman spectra from the same sample might differ between instruments and over time depending on spectrometer, optical path, or environment, among others. There is a need to harmonize standardize characterization by spectroscopy, enabling end users share reuse digital spectroscopic data through FAIR databases. In this context, we present an open‐source, MIT‐licensed, Python package called ramanchada2 that collects existing novel state‐of‐the‐art algorithms, allowing generate, read,...
The paper reviews the state-of-the-art of in-line and on-line monitoring during polymer melt processing by compounding, extrusion injection moulding. Different spectroscopic scattering techniques as well conductivity viscosity measurements are reviewed compared concerning their potential for different process applications. In addition to information on chemical composition state process, in situ detection morphology, which is specific interest multiphase systems such composites blends,...
The superconducting magnets of future particle accelerators will be exposed to high irradiation doses at cryogenic temperatures. To investigate the effect temperature and atmosphere on aging behavior, we have characterized changes in thermomechanical properties six epoxy resins for potential use after up 20 MGy ambient air, inert gas, liquid helium. Based results obtained by Dynamic Mechanical Analysis (DMA), discuss presence oxygen. can a strong influence rates which cross-linking chain...
Abstract Electrocalorics (EC) is potentially more efficient than refrigeration and heat pumps based on compressors does not need detrimental fluids. Current EC-prototypes use solid-state contact or forced convection with liquids to transfer the generated from EC-material, which inhibits high cycle frequencies thus limits power density. Here we present a heatpipe system solution, where realized through condensation evaporation of ethanol as fluid. Our prototype lead scandium tantalate (PST)...
We report a shear wave reflection technique which allows time- and temperature-dependent measurements of the complex dynamic modulus (G*=G′+iG′′) or viscosity (ηs′) in ultrasonic frequency range (3–40 MHz). The method developed by Mason et al. [Phys. Rev. 75, 936 (1949)] was adapted to possibilities high-frequency digital technique. A conventional single-frequency pulse-burst system broadband pulsed spectroscopic using Fourier analysis for detection phase amplitude changes reflected signals...
Abstract Determination of melt composition and/or morphology by fast, reliable and accurate in‐line methods is highly desired in polymer industry. In‐line spectroscopic like near infrared (NIR), Raman or ultrasonic spectroscopy are such for process control without time consuming sampling off‐line analytics. As the number techniques available increasing, it becomes increasingly difficult manufacturers plastic processors to choose right method combination their needs keep track growing amount...
Abstract Time resolved electrical conductivities of polycarbonate‐ and polyamide‐multiwalled carbon nanotube composites were measured inline in an injection moulding machine. During the first few seconds cycle, conductivity varies with melt temperature pressure, but then stays nearly constant for some seconds, until part vitrifies breaks off sensor. The values extracted from time section are shown dependence different conditions: velocity, mould temperature. It turns out that varied by 7...
Abstract We report on shear‐induced nanotube network formation in multi‐wall nanotubes/polycarbonate (MWNT/PC) composite melts which was directly monitored by the time‐resolved DC‐conductivity measurements during steady shear. A small shear applied for 1 h to a non‐conductive with initially well‐dispersed nanotubes found induce insulator‐to‐conductor transition resulting conductivity increase about six orders of magnitude. Similar melt annealed without demonstrates much slower process what...
We investigate the molecular features of high-performance gel-spun ultrahigh-molecular-weight polyethylene UHMWPE fibers (SK75, invented and manufactured by DSM) propose a multiscale structural model that describes organization molecules from unit cell to filament level, based on X-ray diffraction in static dynamic conditions (during tensile testing). The emphasizes discontinuous nature crystalline phase, which is embedded percolating amorphous phase connected tie running through phase. play...