scholarly journals 2D Correlation Spectroscopy (2DCoS) Analysis of Temperature-Dependent FTIR-ATR Spectra in Branched Polyethyleneimine/TEMPO-Oxidized Cellulose Nano-Fiber Xerogels

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 528
Author(s):  
Giuseppe Paladini ◽  
Valentina Venuti ◽  
Vincenza Crupi ◽  
Domenico Majolino ◽  
Andrea Fiorati ◽  
...  
Keyword(s):  
Functional Groups ◽  
Three Dimensional ◽  
Correlation Spectroscopy ◽  
Water Remediation ◽  
Temperature Dependent ◽  
Nano Fiber ◽  
Novel Material ◽  
Intramolecular Hydrogen ◽  
Increasing Temperature ◽  
2D Correlation Spectroscopy

Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR), combined with a 2D correlation analysis, was here employed to investigate temperature-induced spectral changes occurring in a particular type of novel cellulosic-based nano-material prepared using 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) oxidized and ultra-sonicated cellulose nano-fibers (TOUS-CNFs) as three-dimensional scaffolds, and branched polyethyleneimine (bPEI) as cross-linking agent. The aim was to highlight the complex sequential events involving the different functional groups of the polymeric network, as well as to gain insight into the interplay between the amount of bPEI and the resulting sponge-like material, upon increasing temperature. In this framework, synchronous and asynchronous 2D spectra were computed and analyzed in three wavenumber regions (900–1200 cm−1, 1500–1700 cm−1 and 2680–3780 cm−1), where specific vibrational modes of the cellulosic structure fall, and over a T-range between 250 K and 340 K. A step-by-step evolution of the different arrangements of the polymer functional groups was proposed, with particular regard to how the cooperativity degree of inter- and intramolecular hydrogen bonds (HBs) changes upon heating. Information acquired can be useful, in principle, in order to develop a next-generation, T-sensitive novel material to be used for water remediation applications or for drug-delivery nano-vectors.

Two-Dimensional Infrared Spectroscopy and Principal Component Analysis Studies on a New Azobenzene Derivative Supramolecular System Based on Hydrogen Bonds

2003 ◽  
Vol 57 (8) ◽  
pp. 933-942 ◽  
Author(s):  
Yuqing Wu ◽  
Ya-Qiong Hao ◽  
Min Li ◽  
Chaowei Guo ◽  
Yukihiro Ozaki
Keyword(s):  
Principal Component Analysis ◽  
Hydrogen Bonds ◽  
Supramolecular Assembly ◽  
Principal Component ◽  
Correlation Spectroscopy ◽  
Supramolecular System ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
2D Correlation Spectroscopy ◽  
2D Correlation Analysis

Infrared (IR) spectra of a supramolecular assembly with an azobenzene derivative and intermolecular hydrogen bonds have been measured in the temperature range from 30 to 200 °C to investigate heat-induced structural changes and thermal stability. Principal component analysis (PCA) and two kinds of two-dimensional (2D) correlation spectroscopy, variable–variable (VV) 2D and sample–sample (SS) 2D spectroscopy, have been employed to analyze the observed temperature-dependent spectral variations. The PCA and SS 2D correlation analyses have demonstrated that the complete decoupling of hydrogen bonds in the supramolecular assembly occurs between 110 and 115 °C, which is in good agreement with the results of a differential scanning calorimetry (DSC) study for the heating process. The PCA of the IR spectra in the region of 3600–3100 cm−1 has illustrated that there are at least four principal components for the different NH2 and CONH species in the present supramolecular system. The VV 2D correlation spectroscopy study has provided information about the structure and strength of hydrogen bonds of NH2 and CONH groups and their temperature-dependent variations. The different species of hydrogen-bonded NH2 and CONH groups in the supramolecular system can be clarified by the VV 2D correlation analysis. The VV 2D correlation analysis has also revealed the specific order of the temperature-induced changes in the hydrogen bonds of NH2 and CONH groups.

Temperature-Dependent Magnetic Damping Constant of Fe2Co Films Doped by Rare-Earth Yb

SPIN ◽  
2017 ◽  
Vol 07 (01) ◽  
pp. 1740002 ◽  
Author(s):  
Kai Wu ◽  
Dong Li ◽  
Xiaobin Guo ◽  
Baoshan Cui ◽  
Jijun Yun ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Uniaxial Anisotropy ◽  
Domain Wall Motion ◽  
Anisotropy Constant ◽  
Common Source ◽  
Temperature Dependent ◽  
Spin Orbital ◽  
Magnetic Damping ◽  
Increasing Temperature ◽  
Different Origins

The temperature-dependent magnetic properties are investigated in amorphous (Fe2Co)[Formula: see text]Ybx ([Formula: see text], 0.64) thin films with in-plane uniaxial anisotropy. The decreases of saturation magnetization and easy axis coercivity with increasing temperature were observed and quite well explained by the Bloch’s law of [Formula: see text] dependence based on three-dimensional (3D) spin wave excitations and the thermally activated domain wall motion model of [Formula: see text] dependence, respectively. The decrease of in-plane uniaxial anisotropy constant is also observed and can be quite well fitted at temperature below 300[Formula: see text]K. The magnetic damping constant, which was deduced from the angular dependent ferromagnetic resonance spectra, shows a minima over the temperature range 100–435[Formula: see text]K, just like the previous results from 3D-transition metals based on Kamberský’s torque-correlation model. However, a positive correlation between damping and the in-plane uniaxial anisotropy constant was obtained with a clear deviation from the linear relationship. This deviation indicates that temperature-dependent damping and anisotropy may have different origins instead of the common source of the temperature-dependent spin-orbital coupling strength.

HYDROXYAPATITE, ALGINATE, AND CHITOSAN FOR BONE SCAFFOLDS: SPECTROSCOPY STUDY

2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Functional Groups ◽  
Bone Growth ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Tissue Engineering Scaffolds ◽  
Hydroxyapatite Powder ◽  
Materials Used

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.

Modeling of Thermoplastic Materials for the Process-Simulation of Press-Fit Interconnections on Moulded Interconnected Devices

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Thomas Fellner ◽  
Elena Zukowski ◽  
Jürgen Wilde ◽  
H. Kück ◽  
H. Richter ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Base Material ◽  
Creep Model ◽  
Assembly Process ◽  
Temperature Dependent ◽  
Reliability Modeling ◽  
Finite Element Software ◽  
Press Fit ◽  
Temperature Loads

This investigation is aimed at the modeling of both the fabrication process and the reliability of press-fit interconnections on moulded interconnect devices (MID). These are multifunctional three-dimensional substrates, produced by thermoplastic injection moulding for large-series applications. The assembly process and subsequently the durability of press-fit interconnections has been modeled and proved with a finite element software. Especially, a simulation tool for process optimizations was created and applied. In order to obtain realistic results, a creep model for the investigated base material, a liquid-crystal polymer (LCP), was generated and verified by experiments. Required friction coefficients between metal pin and base material were determined by adapting simulations and experiments. Retention forces of pins pressed into substrate holes during as well after the assembly process, and after temperature loads were predicted by simulations. Additionally, the decreasing extraction forces over time due to creep in the thermoplastic base material have been predicted for different storage temperatures as well with finite element analyses. Following, the numerical results of the process and reliability modeling were verified by experiments. It is concluded that the behavior of the mechanical contact of the pin-substrate system, can be suitably described time- and temperature-dependent.

Theory of ultrasonic attenuation in one and two dimensional metals

1976 ◽  
Vol 54 (14) ◽  
pp. 1454-1460 ◽  
Author(s):  
T. Tiedje ◽  
R. R. Haering
Keyword(s):  
Ultrasonic Attenuation ◽  
Three Dimensional ◽  
Electronic Systems ◽  
Two Dimensional ◽  
Temperature Dependent ◽  
One Dimensional ◽  
The Difference

The theory of ultrasonic attenuation in metals is extended so that it applies to quasi one and two dimensional electronic systems. It is shown that the attenuation in such systems differs significantly from the well-known results for three dimensional systems. The difference is particularly marked for one dimensional systems, for which the attenuation is shown to be strongly temperature dependent.

scholarly journals Monitoring the temperature-dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy

2016 ◽  
Vol 10 (6) ◽  
pp. 2821-2829 ◽  
Author(s):  
Matthew J. Vaughan ◽  
Kasper van Wijk ◽  
David J. Prior ◽  
M. Hamish Bowman
Keyword(s):  
Sea Ice ◽  
Ice Cores ◽  
Compressional Wave ◽  
Temperature Dependent ◽  
Resonant Ultrasound Spectroscopy ◽  
Polycrystalline Ice ◽  
Passive Seismic ◽  
Resonant Ultrasound ◽  
Increasing Temperature ◽  
Quality Factor Q

Abstract. The elastic and anelastic properties of ice are of interest in the study of the dynamics of sea ice, glaciers, and ice sheets. Resonant ultrasound spectroscopy allows quantitative estimates of these properties and aids calibration of active and passive seismic data gathered in the field. The elastic properties and anelastic quality factor Q in laboratory-manufactured polycrystalline isotropic ice cores decrease (reversibly) with increasing temperature, but compressional-wave speed and attenuation prove most sensitive to temperature, indicative of pre-melting of the ice. This method of resonant ultrasound spectroscopy can be deployed in the field, for those situations where shipping samples is difficult (e.g. remote locations), or where the properties of ice change rapidly after extraction (e.g. in the case of sea ice).

Carbon-Based Sorbents with Three-Dimensional Architectures for Water Remediation

Small ◽  
2015 ◽  
Vol 11 (27) ◽  
pp. 3319-3336 ◽  
Author(s):  
Bo Chen ◽  
Qinglang Ma ◽  
Chaoliang Tan ◽  
Teik-Thye Lim ◽  
Ling Huang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Water Remediation ◽  
Carbon Based
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