scholarly journals Novel Approaches to In-Situ ATR-FTIR Spectroscopy and Spectroscopic Imaging for Real-Time Simultaneous Monitoring Curing Reaction and Diffusion of the Curing Agent at Rubber Nanocomposite Surface

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2879
Author(s):  
Shun Muroga ◽  
Yu Takahashi ◽  
Yuta Hikima ◽  
Seisuke Ata ◽  
Sergei G. Kazarian ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Real Time ◽  
Diffusion Coefficients ◽  
Heated Surface ◽  
Fickian Diffusion ◽  
Curing Agent ◽  
Ftir Imaging ◽  
Curing Reaction ◽  
Curing Agents

Here, we propose a novel attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy method for simultaneously monitoring the curing reaction and the diffusion behavior of curing agents at the surface of rubber in real-time. The proposed scheme was demonstrated by fluorine rubber (FKM) and FKM/carbon nanotube (CNT) nanocomposites with a target curing agent of triallyl-isocyanurate (TAIC). The broadening and the evolution of the C=O stretching of TAIC were quantitatively analyzed to characterize the reaction and the diffusion. Changes in the width of the C=O stretching indicated the reaction rate at the surface was even faster than that of the bulk as measured by a curemeter. The diffusion coefficient of the curing agent in the course of heating was newly calculated by the initial increase in the absorbance and our model based on Fickian diffusion. The diffusion coefficients of TAIC during curing were evaluated, and its temperature and filler dependency were identified. Cross-sectional ATR-FTIR imaging and in situ ATR-FTIR imaging measurements supported the hypothesis of the unidirectional diffusion of the curing agent towards the heated surface. It was shown that our method of in situ ATR-FTIR can monitor the degrees of cure and the diffusion coefficients of curing agents simultaneously, which cannot be achieved by conventional methods, e.g., rheological measurements.

Curing Kinetics of Polyurethane Elastomers Depending on the Amount of Curing Agent and Temperatures by Real Time FTIR Spectroscopy

Polymer Korea ◽  
2017 ◽  
Vol 41 (4) ◽  
pp. 610-618 ◽  
Author(s):  
Se Mi Kim ◽  
Seon Hong Kim ◽  
Eun Ju Lee ◽  
Hee Jung Park ◽  
Kee Yoon Lee
Keyword(s):  
Ftir Spectroscopy ◽  
Real Time ◽  
Curing Kinetics ◽  
Curing Agent ◽  
Polyurethane Elastomers ◽  
Kinetics Of

Rapid method to measure diffusion of paramagnetic species: Mn2+ in poly(ethylene-co-methacrylic acid) ionomers

2002 ◽  
Vol 17 (10) ◽  
pp. 2736-2743 ◽  
Author(s):  
Neena K. Tierney ◽  
Richard A. Register
Keyword(s):  
Methacrylic Acid ◽  
Diffusion Coefficients ◽  
Fickian Diffusion ◽  
Paramagnetic Species ◽  
Local Concentration ◽  
Spin Resonance ◽  
Broad Signal ◽  
Poly Ethylene ◽  
Concentration Diffusion

We present a facile method to measure Fickian diffusion coefficients of paramagnetic species in materials, using electron spin resonance (ESR) spectroscopy. The method requires no postannealing sample preparation, is adaptable to in situ measurement, and requires only that the spectrum of the paramagnetic species change monotonically with its local concentration. We illustrated this method with poly(ethylene-co-methacrylic acid) ionomers, using laminates prepared from the same copolymer neutralized with either paramagnetic Mn2+ or diamagnetic Zn2+. For Mn2+, the exchange interaction between neighboring Mn2+ caused the six-line hyperfine pattern to transform to a single broad signal, providing the measurement of local concentration. Diffusion coefficients of Mn2+ in this ionomer pair measured by ESR were compared with those for Zn2+ measured by conventional electron probe microanalysis and found to be in satisfactory agreement.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

Flat Flexible Thin Milli-electrode Array for Real-time in situ Water Quality Monitoring in Distribution Systems

2017 ◽  
Vol 2017 (4) ◽  
pp. 5598-5617
Author(s):  
Zhiheng Xu ◽  
Wangchi Zhou ◽  
Qiuchen Dong ◽  
Yan Li ◽  
Dingyi Cai ◽  
...  
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Distribution Systems ◽  
Electrode Array ◽  
Water Quality Monitoring ◽  
Quality Monitoring

scholarly journals Underground Microseismic Event Monitoring and Localization within Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2830
Author(s):  
Sili Wang ◽  
Mark P. Panning ◽  
Steven D. Vance ◽  
Wenzhan Song
Keyword(s):  
Sensor Networks ◽  
Real Time ◽  
Information Needs ◽  
Localization Algorithm ◽  
Distributed Sensors ◽  
Distributed Sensor ◽  
Microseismic Events ◽  
The Stability ◽  
Stability And Accuracy

Locating underground microseismic events is important for monitoring subsurface activity and understanding the planetary subsurface evolution. Due to bandwidth limitations, especially in applications involving planetarily-distributed sensor networks, networks should be designed to perform the localization algorithm in-situ, so that only the source location information needs to be sent out, not the raw data. In this paper, we propose a decentralized Gaussian beam time-reverse imaging (GB-TRI) algorithm that can be incorporated to the distributed sensors to detect and locate underground microseismic events with reduced usage of computational resources and communication bandwidth of the network. After the in-situ distributed computation, the final real-time location result is generated and delivered. We used a real-time simulation platform to test the performance of the system. We also evaluated the stability and accuracy of our proposed GB-TRI localization algorithm using extensive experiments and tests.

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