Chemical–physical and dynamical–mechanical characterization on Spartium junceum L. cellulosic fiber treated with softener agents: a preliminary investigation

AbstractLong cellulose fiber (10–30 cm), extracted from Spartium junceum, was chemically treated with different softening agents with the aim to improve its textile applicability. A preliminary sensory evaluation of the treated fibers revealed an evident, though qualitative, improvement of the fiber softness. The effects of the softening agents on the fiber was evaluated quantitatively, by means of macroscopic measurements of the wettability, viscoelasticity, and thermal (thermal gravimetry) properties. Moreover, the effects of the softening treatments on the microscopic structure of the fiber and on its properties at a molecular level, were studied by optical and scanning electron microscope and X-ray diffraction (XRD), respectively. The macroscopic analysis showed that the softeners used increases the hydrophilicity and water wettability of the cellulose fiber with respect to the raw one. Moreover, the dynamical mechanical analysis on sample yarns showed that the softeners increase the interfiber frictional forces. A linear correlation between the interfiber friction and the increase of hydrophilicity and fiber wettability was shown. The treated fiber exhibits a more homogeneous thermal behaviour, due to more homogeneous structural features, since the thermal-induced cellulose fibrils depolimerization undergoes a marked temperature range contraction. These data can be well related with those obtained by microscopy analysis, showing that the fiber surface, after the treatment, appears thinner and less rough, as well as with the XRD analysis, which shows that softeners induce a significant decrease of the fiber crystallinity.

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A preliminary investigation on microstructure and mechanical properties of dissimilar Al to Cu friction stir welds prepared using silver interlayer

Metallurgical and Materials Engineering ◽

10.30544/294 ◽

2018 ◽

Vol 24 (1) ◽

pp. 45-57

Author(s):

Shailesh N. Pandya ◽

Jyoti Menghani

Keyword(s):

Friction Stir Welding ◽

Preliminary Investigation ◽

Pure Copper ◽

Xrd Analysis ◽

Fusion Welding ◽

Dissimilar Welding ◽

X Ray Diffraction ◽

Friction Stir ◽

Ag Particles ◽

Particle Form

Due to its solid-state nature, friction stir welding (FSW) process can be considered a better alternative for dissimilar welding metals. However, like fusion welding techniques, in friction stir welding growth of thick layers of brittle intermetallics - Cu9Al4 and CuAl2 is a significant issue. One solution to this problem is the use of the suitable interlayer material. Use of interlayer material modifies the joint microstructure with the replacement of thick, brittle intermetallics by more ductile intermetallics in a thin layer or particle form. The present study is a preliminary investigation about joining of AA6082-O to pure copper joints with and without silver (Ag) wire interlayer. Friction stir welded joints were characterized regarding optical microscopy, X-Ray Diffraction (XRD) analysis, microhardness measurement, tensile testing and Scanning Electron Microscopy (SEM) based fractography. The Al-Cu weld prepared using silver interlayer was stronger than without it. The higher strength of the weld with silver interlayer is attributed to the formation of a composite type of structure with intercalation of more ductile Ag2Al intermetallics along with dispersion of Ag particles in stir zone.

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Synthesis of lead-based 1212 and 3212 superconductors by an aqueous sol-gel method

Open Chemistry ◽

10.2478/s11532-009-0025-z ◽

2009 ◽

Vol 7 (3) ◽

pp. 362-368 ◽

Cited By ~ 1

Author(s):

Giedre Nenartaviciene ◽

Ramunas Skaudzius ◽

Rimantas Raudonis ◽

Aivaras Kareiva

Keyword(s):

Sol Gel ◽

Xrd Analysis ◽

Structural Features ◽

Complexing Agents ◽

X Ray Diffraction ◽

X Ray ◽

Resistivity Measurements ◽

Ceramic Samples ◽

Xrd Patterns ◽

Sol Gel Synthesis

AbstractThe aqueous sol-gel synthesis technique for the preparation of (Pb,Sr)Sr2(Y,Ca)Cu2O7±x (Pb-1212) and (Pb2,Cu)Sr2(Y,Ca)Cu2O8±x (Pb-3212) superconductors using two different complexing agents, namely 1,2-ethanediol and tartaric acid was studied. The phase transformations, composition and micro-structural features in the polycrystalline samples were studied by powder X-ray diffraction analysis (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD analysis of the ceramic samples obtained by calcination of Pb-Sr-Y-Ca-Cu-O acetate-glycolate precursor gels in air, for 10 hours at 800°C and at 825°C, showed the presence of homogeneous Pb-1212 and Pb-3212 crystallites as major phases. The XRD patterns of the ceramics obtained from Pb-Sr-Y-Ca-Cu-O acetate-tartrate precursor gels, however, showed multiphasic character. The critical temperature of superconductivity (TC (onset)) observed by resistivity measurements were found to be 91 K and 75 K for Pb-1212 and Pb-3212 samples, respectively.

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Influence of Functionality of Polyhedral Oligomeric Silsesquioxane (POSS) Dispersed in Epoxy Resin for Application in Hybrid Coating

Materials Science Forum ◽

10.4028/www.scientific.net/msf.899.278 ◽

2017 ◽

Vol 899 ◽

pp. 278-282 ◽

Cited By ~ 1

Author(s):

Marielen Longhi ◽

Vinicius Pistor ◽

Lucas Pandolphi Zini ◽

Sandra Raquel Kunst ◽

Ademir José Zattera

Keyword(s):

Epoxy Resin ◽

Polyhedral Oligomeric Silsesquioxane ◽

Xrd Analysis ◽

Mechanical Analysis ◽

Diglycidyl Ether ◽

Hybrid Coating ◽

X Ray Diffraction ◽

Characteristic Peak ◽

X Ray ◽

Oligomeric Silsesquioxane

The present study aimed to characterize the structure of nanocomposites obtained from the incorporation of three different polyhedral oligomeric silsesquioxane (POSS) in an epoxy resin. glycidylisobutyl-POSS, triglycidylisobutyl-POSS and glycidyl-POSS were added (5% by weight) in an epoxy matrix, diglycidyl ether of bisphenol-A (DGEBA), through a sonication process. The nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and dynamic mechanical analysis (DMA). The XRD analysis presented a characteristic peak of POSS. The incorporation of glycidylisobutyl-POSS showed a significant increase in the value of glass transition temperature (Tg), being also the most effective in terms of dispersion. It should also be noted that glycidyl-POSS presented a greater influence on the thermal stability.

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Porous calcium niobate nanosheets prepared by an exfoliation–restacking route

Water Science & Technology ◽

10.2166/wst.2015.610 ◽

2015 ◽

Vol 73 (6) ◽

pp. 1378-1386 ◽

Cited By ~ 4

Author(s):

Fatemeh Hashemzadeh

Keyword(s):

Wide Band ◽

Xrd Analysis ◽

Structural Features ◽

Ammonium Ion ◽

Layered Perovskite ◽

X Ray Diffraction ◽

Wide Band Gap ◽

Quantum Size ◽

Calcium Niobate ◽

Molecular Aspects

The single phase layered perovskite-type niobate KCa2Nb3O10 was obtained by a solid state reaction of the starting materials (K2CO3, CaCO3 and Nb2O5) at 1,200 °C. Then the H+-exchanged form (HCa2Nb3O10) was successfully exfoliated into colloidal porous single layers on the intercalating action of tetra(butyl)ammonium ion. The various characterization techniques such as X-ray diffraction (XRD), ﬁeld-emission scanning electron microscopy, N2 absorption–desorption and diffuse reflectance UV–visible spectrometry gave important information on the unusual structural features of the perovskite-related niobate nanosheets. XRD analysis of the exfoliated nanosheets showed a unique proﬁle with wide peaks that represented individual molecular aspects of the nanosheets. The Brunauer–Emmett–Teller isotherm of the exfoliated coiled nanosheets showed a sharp increase in the surface area by a factor of >30 in comparison to parent layered material, which is due to the exfoliation and restacking process. The nanosheets in this study were also found to act as a semiconductor with a wide band gap that is due to the quantum size effect.

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Production of Magnesium Titanate-Based Nanocomposites via Mechanochemical Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.478.1 ◽

2011 ◽

Vol 478 ◽

pp. 1-6

Author(s):

Abbas Fahami ◽

Reza Ebrahimi-Kahrizsangi ◽

Bahman Nasiri-Tabrizi

Keyword(s):

Electron Microscopy ◽

Phase Evolution ◽

Xrd Analysis ◽

Dielectric Materials ◽

Weight Percent ◽

Structural Features ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Increasing Temperature

The mechanical activation was employed to study the phase evolution of the Mg–TiO2–CaHPO4–CaO nanocrystalline system. The powders mixture with certain weight percent was grinded. Thermal annealing process at 650°C, 900°C and 1100°C temperatures resulted in generation of different compounds like MgTiO3/MgO/Hydroxyapatite (HAp) and MgTiO3/MgO/β-TCP and MgTiO3/Mg2TiO4/MgO/β-TCP, respectively. The compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The consequences of XRD analysis revealed that by increasing temperature, some composites with different morphological and structural features were detected. Beside, due to decomposing of HAp around 800°C, HAp converted to whitlockite (β-TCP) with growth of temperature. According to SEM and TEM observations, it was found that the synthesized powder contained large agglomerates which significant content of finer particles and agglomerates with spherical morphology. Because magnesium titanates based dielectric materials are useful for electrical applications, the electrical property of HAp has been proved, and the incorporation of these materials could result in new nanocrystalline dielectric materials.

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Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽

10.32964/tj10.1.17 ◽

2011 ◽

Vol 10 (1) ◽

pp. 17-23

Author(s):

KEVIN TAYLOR ◽

RICH ADDERLY ◽

GAVIN BAXTER

Keyword(s):

Calcium Sulfate ◽

Membrane Filter ◽

Sulfamic Acid ◽

Xrd Analysis ◽

Metal Sulfides ◽

X Ray Diffraction ◽

X Ray ◽

Gypsum Formation ◽

Acid Washing ◽

Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

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Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽

10.3390/molecules25245970 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5970

Author(s):

Nabil Al-Zaqri ◽

Mohammed Suleiman ◽

Anas Al-Ali ◽

Khaled Alkanad ◽

Karthik Kumara ◽

...

Keyword(s):

Density Functional ◽

Energy Gap ◽

Structural Parameters ◽

Population Analysis ◽

Xrd Analysis ◽

X Ray Diffraction ◽

Optical Energy Gap ◽

Functional Theory ◽

Reactivity Descriptors ◽

Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

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Bio-Based Polyurethane Networks Derived from Liquefied Sawdust

Materials ◽

10.3390/ma14113138 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3138

Author(s):

Kamila Gosz ◽

Agnieszka Tercjak ◽

Adam Olszewski ◽

Józef Haponiuk ◽

Łukasz Piszczyk

Keyword(s):

Biomass Conversion ◽

Structural Features ◽

Mechanical Analysis ◽

Process Efficiency ◽

Hydroxyl Number ◽

Step Method ◽

One Step ◽

Liquefaction Process ◽

The Fourier Transform ◽

Liquefaction Temperature

The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.

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A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411921996565 ◽

2021 ◽

pp. 095441192199656

Author(s):

Erdoğan Karip ◽

Mehtap Muratoğlu

Keyword(s):

Body Fluid ◽

Xrd Analysis ◽

Cold Isostatic Pressing ◽

Expanded Perlite ◽

X Ray Diffraction ◽

Pressing Method ◽

X Ray ◽

Infra Red ◽

Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

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Relationship between the Stereocomplex Crystallization Behavior and Mechanical Properties of PLLA/PDLA Blends

Polymers ◽

10.3390/polym13111851 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1851

Author(s):

Hye-Seon Park ◽

Chang-Kook Hong

Keyword(s):

Mechanical Properties ◽

Lactic Acid ◽

Crystallization Behavior ◽

Mechanical Analysis ◽

X Ray Diffraction ◽

Nucleation Agent ◽

Scanning Calorimetry ◽

Nucleation Sites ◽

Wide Range ◽

Degree Of Crystallization

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

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