Polarized microbeam FT-IR analysis of single fibers

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

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Microbeam polarization infrared spectroscopy: single fiber discrimination

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138841 ◽

1995 ◽

Vol 53 ◽

pp. 494-495

Author(s):

Liling Cho ◽

David L. Wetzel

Keyword(s):

Infrared Spectroscopy ◽

Phase Measurement ◽

Single Fiber ◽

Synthetic Fiber ◽

Liquid Crystal Phase ◽

Synthetic Fibers ◽

Polyester Fibers ◽

Fixed Reference ◽

Ft Ir ◽

Ir Microspectroscopy

FT-IR microspectroscopy of single fiber can produce useful information to distinguish among synthetic fibers. Certain fibers can be readily discriminated on the basis of spectra obtained by this technique. Polarization infrared spectroscopy has been used to measure macromolecular properties such as precipitate crystallinity, polymer film draw ratio, and liquid crystal phase. Measurement of IR dichroism requires light polarized both parallel and perpendicular to a fixed reference direction of the sample. Dichroism may be used to compare and discriminate between different polyester fibers and possibly to establish new groups within a subclass. Four fundamental bands (872, 973,1505 and 1579 cm-1) and two overtone bands (1960 and 3435 cm-1) were chosen because they were relatively free from overlapping bands, and they were weak enough not to be over-absorbing in the spectra of thick, unflattened fibers. During industrial production, the process of drawing can impart many useful properties to a synthetic fiber. When this occurs, molecular chains may become oriented in the long direction of the fiber.

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Sc Modification Induced Short-range Ordering in ZnGa2O4 Spinel Leading to High Microwave Dielectric Performance

10.21203/rs.3.rs-98833/v1 ◽

2020 ◽

Author(s):

xiaochi Lu ◽

Bin Quan ◽

Kailai Zheng ◽

Peng Chu ◽

Jian Wang ◽

...

Keyword(s):

Short Range ◽

Microwave Dielectric Properties ◽

Solid State Method ◽

Microwave Dielectric ◽

Governing Factor ◽

Short Range Ordering ◽

Dielectric Performance ◽

Ft Ir ◽

Ir Analysis ◽

The Relationship

Abstract Sc3+ (0,0.1,0.3,0.5,0.7mol%) modified ZnGa2O4 (abbreviated Sc-ZGO) ceramics were synthesized by solid-state method. The relationship between microwave dielectric performance and bonds vibration of Sc-ZGO as a function of Sc3+ modification has been systematically investigated. With Sc3+ modification, the εr of Sc-ZGO ceramics keeps steady (~10). While the τf of Sc-ZGO shows linear correlation with Sc3+ concentration increasing from -71ppm/℃ to -39ppm/℃, and the Q×f value climbs up to a maximum value (5Sc-ZGO) and then ramp down. 5Sc-ZGO sintered at 1350oC for 2 h exhibits the best microwave dielectric properties with εr = 9.9, Q×f = 124,147 GHz, tanδ = 7.98×10-5, and τf = -56 ppm/°C (@9.9 GHz). Q×f value of Sc modified ZGO increased by almost 45% compared with normal spinel ZnGa2O4 ceramics. The enhancement of τf and Q×f on Sc modified ZnGa2O4 can be attributed to higher densification, however, further Raman and FT-IR analysis elucidated that short-range cation ordering degree is another governing factor. The influence of Sc3+ modification on ZnGa2O4 bonds vibration has been discussed in detail.

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A simplification of the deuterium oxide dilution technique using FT-IR analysis of plasma, for estimating piglet milk intake

Australian Journal of Agricultural Research ◽

10.1071/a97037 ◽

1997 ◽

Vol 48 (8) ◽

pp. 1099 ◽

Cited By ~ 6

Author(s):

Brett D. Glencross ◽

Bruce P. Mullan ◽

Robert C. Tuckey ◽

Peter E. Hartmann

Keyword(s):

Deuterium Oxide ◽

Direct Analysis ◽

Milk Composition ◽

Milk Intake ◽

Strongly Correlated ◽

Modified Technique ◽

Ft Ir ◽

Ir Analysis ◽

Piglet Growth ◽

The Relationship

Previous studies estimating milk intake using deuterium oxide (D2O) as a tracer have required sublimation of the sample fluid (usually plasma) to remove solids and retrieve total water. This procedure has been simplified by directly measuring the D2O content of plasma with a Fourier transform-infrared (FT-IR) spectrometer, removing the requirement for sample sublimation. Comparisons of samples that were split and then analysed as water of sublimation and as total plasma were performed. It was found that the direct analysis of the plasma could be achieved without a loss in fidelity of the results (sublimated v. plasma, r2 = 0·976;n = 26). Linearity of assay standards was very high (r2 > 0·997). The modified technique was used to determine the milk intake by piglets from litters of 7 sows during established lactation (Days 10-15). Water turnover (WTO) was shown to be the primary point by which differences in the piglet milk intakes were influenced. Differences in the milk composition had minimal effect on the milk intake determinations. Milk intake by each piglet was shown to be strongly correlated to piglet growth (r2 = 0·59, P < 0·01). The relationship between milk intake and piglet growth was even stronger when examined based on the data from all piglet litters (r2 = 0·84, P < 0·01).

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Computational Study of the Transport Properties of Molten CaO-SiO2-P2O5-FeO System

High Temperature Materials and Processes ◽

10.1515/htmp-2016-0159 ◽

2018 ◽

Vol 37 (2) ◽

pp. 141-147

Author(s):

Jiang Diao ◽

Quan Zhang ◽

Yong Qiao ◽

Lu Jiang ◽

Bing Xie

Keyword(s):

Transport Properties ◽

Diffusion Coefficients ◽

Computational Study ◽

Md Simulations ◽

Self Diffusion ◽

Ca Ions ◽

Ft Ir ◽

Ir Analysis ◽

The Relationship ◽

Good Agreement

AbstractMD simulations have been accomplished to study the transport properties of molten CaO-SiO2-P2O5-FeO system. The self-diffusion coefficients of Ca, Si, P, Fe and O ions increase with increasing slag basicity and FeO content, while decrease with increasing P2O5 content. The diffusivities of these ions in the quaternary melts follow the sequence of Ca>Fe>O>P>Si. The calculated viscosities are in good agreement with the experimental ones. It is obvious that increasing the amount of network formers (e. g., Si and P ions) leads to larger viscosity and degree of slag polymerization, while adding network modifiers (e. g., Fe and Ca ions) causes viscosity and slag polymerization to decrease. Except for the calculation, the FT-IR analysis also confirmed the relationship between structural properties of the slag and composition. The viscosity of the slag increases linearly with increasing the parameter of Q(Si+P).

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Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

Revista de Chimie ◽

10.37358/rc.20.8.8275 ◽

2020 ◽

Vol 71 (8) ◽

pp. 21-26

Author(s):

Elena-Emilia Oprescu ◽

Cristina-Emanuela Enascuta ◽

Elena Radu ◽

Vasile Lavric

Keyword(s):

Maximum Yield ◽

Strength Distribution ◽

Point Of View ◽

Reaction Parameters ◽

X Ray ◽

Ethyl Levulinate ◽

Ft Ir ◽

Ir Analysis ◽

Biodiesel Blend ◽

Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

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Formulation, Optimization,and Ex-Vivo Evaluation of Novel Lipid Carriers for Enhanced Transdermal Delivery of Hydroquinone

Micro and Nanosystems ◽

10.2174/1876402912999200831105145 ◽

2020 ◽

Vol 12 ◽

Author(s):

Shivani Verma ◽

Sukhjinder Kaur ◽

Lalit Kumar

Keyword(s):

Ex Vivo ◽

Skin Permeation ◽

Topical Delivery ◽

Gelling Agent ◽

Minimum Size ◽

Prolonged Release ◽

Freeze Dried ◽

Ft Ir ◽

Ir Analysis ◽

Skin Retention

Background: HQ is used for hyper-pigmentation treatment using conventional creams and gels. These formulations show various disadvantages like poor skin permeation, allergic reactions, and repeated use decreasing patient compliance. Objectives: The present work involved formulation, statistical optimization, and characterization of nanostructured lipid carriers (NLCs) for efficient topical delivery of hydroquinone (HQ) for hyperpigmentation treatment. Methods: The NLCs were optimized exploring Box–Behnken design (BBD) using three independent variables and two dependent variables. Formulation having the minimum size and maximum drug entrapment was considered as optimized formulation. Optimized formulation was evaluated for drug release followed by its freeze-drying. The freeze-dried formulation was subjected to differential scanning calorimetry (DSC) analysis, X-raydiffraction (XRD) analysis, and Fourier transform-infrared spectroscopy (FT-IR) analysis. Furthermore, NLCs based gel was prepared by using Carbopol 934 as a gelling agent. NLCs based gel was evaluated for skin permeation, skin retention, and skin distribution (through confocal microscopic analysis) using pig ear skin. Results: Optimized NLCs showed smaller particle size [(271.9 ± 9) nm], high drug entrapment [(66.4 ± 1.2) %], tolerable polydispersity index (PDI) (0.221 ± 0.012), and zeta potential [(-25.9± 1.2) mV]. The FT-IR analysis revealed excellent compatibility between HQ and other excipients. The Carbopol 934 gel containing NLCs showed high transdermal flux [(163 ± 16.2) μg/cm2/h], permeability coefficient (0.0326 ± 0.0016), and skin permeation enhancement ratio (3.7 ± 0.4) compared to marketed cream of HQ. The results of confocal microscopic (CLSM) analysis revealed the accumulation of optimized NLCs in the lower epidermal layers of skin. Conclusion: NLCs based gel was considered effective in the topical delivery of HQ to treat hyper-pigmentation due high skin permeation, skin retention, and prolonged release of HQ.

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A finite element model of terahertz substrate-based wire-grid polarizer

Mathematics and Computers in Simulation ◽

10.1016/j.matcom.2021.04.005 ◽

2021 ◽

Vol 188 ◽

pp. 404-414

Author(s):

Nazariy Jaworski ◽

Nazariy Andrushchak ◽

Mykhailo Lobur ◽

Marek Iwaniec

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Element Model ◽

Wire Grid ◽

Wire Grid Polarizer

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Impact of Chemical Modification on the Physical and Mechanical Properties of Tropical Wood Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.576.314 ◽

2012 ◽

Vol 576 ◽

pp. 314-317

Author(s):

Sinin Hamdan ◽

M. Saiful Islam

Keyword(s):

Mechanical Properties ◽

Diazonium Salt ◽

Treated Wood ◽

Coupling Reaction ◽

Physical And Mechanical Properties ◽

Modulus Of Rupture ◽

Ft Ir ◽

Ir Analysis ◽

D Values ◽

Benzene Diazonium

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.

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