Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Nondestructive and noncontact evaluation of cellulose nanofiber-reinforced composites using terahertz time-domain spectroscopy.

ABSTRACT: Cellulose nanofibers (CNFs) can be obtained from natural sources, such as plants and wood fibers. Thermoplastic resin composites reinforced with CNFs exhibit various features, including superior mechanical strength. As the mechanical properties of composites reinforced with CNFs are affected by the amount of fiber addition, it is important to determine the concentration of the CNF filler in the matrix after injection or extrusion molding. We confirmed that there was good linearity between the CNF concentration and terahertz absorption. We could distinguish the difference in the 1%-point-CNF concentration with terahertz time-domain spectroscopy. Furthermore, we estimated the mechanical properties of the CNF nanocomposites using terahertz information.

SUBMITTER: Nakanishi A

PROVIDER: S-EPMC9652471 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Nondestructive and noncontact evaluation of cellulose nanofiber-reinforced composites using terahertz time-domain spectroscopy.

Nakanishi Atsushi A Kanno Naoko N Satozono Hiroshi H

Scientific reports 20221111 1

Cellulose nanofibers (CNFs) can be obtained from natural sources, such as plants and wood fibers. Thermoplastic resin composites reinforced with CNFs exhibit various features, including superior mechanical strength. As the mechanical properties of composites reinforced with CNFs are affected by the amount of fiber addition, it is important to determine the concentration of the CNF filler in the matrix after injection or extrusion molding. We confirmed that there was good linearity between the CN ...[more]

PMID: 36369469

Similar Datasets

Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging.

Project description:Terahertz (THz) time-domain spectroscopy (TDS) imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP) composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations.

| S-EPMC4934301 | biostudies-literature

Doubly curved nanofiber-reinforced optically transparent composites.

Project description:Doubly curved nanofiber-reinforced optically transparent composites with low thermal expansion of 15 ppm/k are prepared by hot pressing vacuum-filtered Pickering emulsions of hydrophobic acrylic resin monomer, hydrophilic chitin nanofibers and water. The coalescence of acrylic monomer droplets in the emulsion is prevented by the chitin nanofibers network. This transparent composite has 3D shape moldability, making it attractive for optical precision parts.

| S-EPMC4639763 | biostudies-other

Determination of plane stress state using terahertz time-domain spectroscopy.

Project description:THz wave has been increasingly applied in engineering practice. One of its outstanding advantages is the penetrability through certain optically opaque materials, whose interior properties could be therefore obtained. In this report, we develop an experimental method to determine the plane stress state of optically opaque materials based on the stress-optical law using terahertz time-domain spectroscopy (THz-TDS). In this method, two polarizers are combined into the conventional THz-TDS system to sense and adjust the polarization state of THz waves and a theoretical model is established to describe the relationship between phase delay of the received THz wave and the plane stress applied on the specimen. Three stress parameters that represent the plane stress state are finally determined through an error function of THz wave phase-delay. Experiments were conducted on polytetrafluoroethylene (PTFE) specimen and a reasonably good agreement was found with measurement using traditional strain gauges. The presented results validate the effectiveness of the proposed method. The proposed method could be further used in nondestructive tests for a wide range of optically opaque materials.

| S-EPMC5099881 | biostudies-literature

Corneal hydration assessment indicator based on terahertz time domain spectroscopy.

Project description:Terahertz technology has shown broad prospects for measuring corneal water content, which is an important parameter of ocular health. Based on terahertz time-domain spectroscopy, a new indicator named characteristic ratio (CR) of the sum of low (0.2-0.7 THz) and high (0.7-1.0 THz) frequency spectral intensities, for characterizing corneal hydration is introduced in this work. CR is calculated from the real-time reflection spectra after error elimination of ex vivo human corneal stroma samples which is collected during dehydration under natural conditions (temperature: 22.4?±?0.3°C; humidity: 20.0?±?3%). The corresponding relationships between CR and corneal water content are reported. Comparing the linear fitting results with the published similar study, the coefficients of variation of the fitting slope and intercept are 39.4% and 27.6% lower, respectively. This indicates that this approach has the potential to achieve corneal water content in-vivo detection in the future.

| S-EPMC7173912 | biostudies-literature

Optical and Geometrical Properties from Terahertz Time-Domain Spectroscopy Data.

Project description:Terahertz waves are nondestructive and non-ionizing to synthetic and natural materials, including polymeric and biological materials. As a result, terahertz-based spectroscopy has emerged as a suitable technique to uncover fundamental molecular mechanisms and material properties in this electromagnetic spectrum regime. In terahertz time-domain spectroscopy (THz-TDS), the material's optical properties are resolved using the raw time-domain signals collected from the sample and air reference data depending on accurate prior knowledge of the sample geometry. Alternatively, different spectral analysis algorithms can extract the complex index of refraction of optically thick or optically thin samples without specific thickness knowledge. A THz-TDS signal without apparent Fabry-Pérot oscillations is commonly associated with optically thin samples, whereas the terahertz signal of optically thick samples exhibits distinct Fabry-Pérot oscillations. While several extraction algorithms have been reported a priori, the steps from reducing the time-domain signal to calculating the complex index of refraction and resolving the correct thickness can be daunting and intimidating while obscuring important steps. Therefore, the objective is to decipher, demystify, and demonstrate the extraction algorithms for Fabry-Pérot-absent and -present terahertz signals for various polymers with different molecular structure classifications and nonlinear optical crystal zinc telluride. The experimental results were in good agreement with previously published values while elucidating the contributions of the molecular structure to the stability of the algorithms. Finally, the necessary condition for manifesting Fabry-Pérot oscillations was delineated.

| S-EPMC11642474 | biostudies-literature

Microscopic ion migration in solid electrolytes revealed by terahertz time-domain spectroscopy.

Project description:Terahertz spectroscopy is one of the most suitable methods for the analysis of electron transport in solids, and has been applied to various materials. Here, we demonstrate that terahertz spectroscopy is the technique of choice to characterize solid electrolytes. We measure the terahertz conductivity of stabilized zirconia, a widely used solid electrolyte material, by terahertz time-domain spectroscopy at high temperatures, providing a wealth of information unavailable from conventional techniques. It is found that the conductivity reflects the microscopic motion of the ion just before hopping to an unoccupied site. Our results suggest a powerful approach in probing the ionic conduction mechanism and could help us explore other solid electrolytes for fuel cells and all-solid-state batteries.

| S-EPMC6572842 | biostudies-literature

Terahertz time-domain attenuated total reflection spectroscopy integrated with a microfluidic chip.

Project description:The integration of a microfluidic chip into terahertz time-domain attenuated total reflection (THz TD-ATR) spectroscopy is highly demanded for the accurate measurement of aqueous samples. Hitherto, however little work has been reported on this regard. Here, we demonstrate a strategy of fabricating a polydimethylsiloxane microfluidic chip (M-chip) suitable for the measurement of aqueous samples, and investigate the effects of its configuration, particularly the cavity depth of the M-chip on THz spectra. By measuring pure water, we find that the Fresnel formulae of two-interface model should be applied to analyze the THz spectral data when the depth is smaller than 210 μm, but the Fresnel formula of one-interface model can be applied when the depth is no less than 210 μm. We further validate this by measuring physiological solution and protein solution. This work can help promote the application of THz TD-ATR spectroscopy in the study of aqueous biological samples.

| S-EPMC10040880 | biostudies-literature

Evaluation of Fossil Amber Birefringence and Inclusions Using Terahertz Time-Domain Spectroscopy.

Project description:Using a cross-polarization transmission geometry, stress maps for the normalized birefringence and intrinsic stress direction of polymeric materials may be obtained using terahertz nondestructive evaluation. The analysis method utilizes a deconvolution method to determine the arrival times and amplitude of the cross-polarized terahertz pulses through a birefringent material. Using amber (a naturally occurring polymer) as a material of interest, stress maps show that inclusion-free Lebanese amber samples behave as classic uniaxial birefringent (photoelastic) materials whose principal stress directions, as inferred in the terahertz spectral range, agree well with visible photoelasticity measurements. Since amber samples, depending upon their source, may be either transparent or opaque to visible light, comparing birefringence measurements in the visible and terahertz spectral ranges cross-validates the stress measurements, thereby establishing a strong and unique stress analysis methodology for visibly opaque samples. While the material of interest for this paper is amber, the method is generally applicable for any terahertz-transparent polymer. The cross-polarization experimental configuration enables stress levels within the amber matrix to be visualized while also outlining highly localized regions of stress surrounding inclusions. Birefringence stress maps clearly show localized increases in stress magnitude and directional changes surrounding inclusions.

| S-EPMC9780848 | biostudies-literature

Identification of black plastics with terahertz time-domain spectroscopy and machine learning.

Project description:Several optical spectroscopy and imaging techniques have already proven their ability to identify different plastic types found in household waste. However, most common optical techniques feasible for plastic sorting, struggle to measure black plastic objects due to the high absorption at visible and near-infrared wavelengths. In this study, 12 black samples of nine different materials have been characterized with Fourier-transform infrared spectroscopy (FTIR), hyperspectral imaging, and terahertz time-domain spectroscopy (THz-TDS). While FTIR validated the plastic types of the samples, the hyperspectral camera using visible and near-infrared wavelengths was challenged to measure the samples. The THz-TDS technique was successfully able to measure the samples without direct sample contact under ambient conditions. From the recorded terahertz waveforms the refractive index and absorption coefficient are extracted for all samples in the range from 0.4 to 1.0 THz. Subsequently, the obtained values were projected onto a two-dimensional map to discriminate the materials using the classifiers k-Nearest Neighbours, Bayes, and Support Vector Machines. A classification accuracy equal to unity was obtained, which proves the ability of THz-TDS to discriminate common black plastics.

| S-EPMC10725460 | biostudies-literature

Developing Hydration Maps of Polymer Latex Film Formation Using Terahertz Time-Domain Spectroscopy.

Project description:The dynamics of the drying process of polymer latexes after casting as a wet film onto a substrate are important to track as they influence the physical and mechanical properties and performance of the dried polymer films. Current methods used to follow this drying process include gravimetric analysis, coupled with advanced techniques like GARField-NMR or optical coherence tomography. The latter two methods provide height and spatial information in the z-direction, normal to the substrate, and occasionally in the xz- or yz-planes. Terahertz time-domain spectroscopy (THz-TDS) is a welcome addition as it provides both the structural and spectroscopic information in the parallel xy-plane, filling the geometric gap. Herein, we utilize THz-TDS to study the drying and film formation process of various polymer latexes with a broad range of glass transition temperatures. We showcase the applicability of this technique in obtaining 2D parallel hydration maps of the drying dispersions, in the form of droplets, using latex-dependent calibration lines. Our findings display known phenomena arising from the drying of the colloidal dispersions.

| S-EPMC11603779 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data