scholarly journals Structure and Properties of Silk Grafted with N, N-Dimethylaminoethyl Methacrylate via the ARGET ATRP Method

2012 ◽  
Vol 7 (2_suppl) ◽  
pp. 155892501200702
Author(s):  
Tieling Xing ◽  
Shiwei Li ◽  
Xia Xu ◽  
Guoqiang Chen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gas Permeability ◽  
Antibacterial Properties ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dimethylaminoethyl Methacrylate ◽  
Dsc Measurements ◽  
Arget Atrp

Silk with antibacterial properties was grafted using dimethylaminoethyl methacrylate (DMAEMA) in water by the ATRP method. The structure and properties of silk-grafted-PDMAEMA (Silk-g-PDMAEMA) and quaternized grafted silk (Q-Silk-g-PDMAEMA) were investigated. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) analysis confirmed the grafting of DMAEMA and the quarternization. Differential scanning calorimetry (DSC) measurements indicate that the thermal stability of Silk-g-PDMAEMA slightly increased compared with the control silk. X-ray diffraction (XRD) curves demonstrate that the crystalline structure of Silk-g-PDMAEMA remained unchanged regardless of the DMAEMA grafting. The Q-Silk-g-PDMAEMA had good antibacterial properties when exposed to both Staphylococcus aureu and Escherichia coli, and had good washing fastness. The breaking strength, whiteness and gas permeability of Silk-g-PDMAEMA slightly decreased, which had no effect on the intrinsic properties of silk fabric.

Structure and properties of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(L-lactic acid) quasi core/sheath melt-electrospun microfibers

2018 ◽  
Vol 89 (9) ◽  
pp. 1770-1781 ◽  
Author(s):  
Huaizhong Xu ◽  
Benedict Bauer ◽  
Masaki Yamamoto ◽  
Hideki Yamane
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Tensile Tests ◽  
Processing Parameters ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Diffraction Patterns

A facile route was proposed to fabricate core–sheath microfibers, and the relationships among processing parameters, crystalline structures and the mechanical properties were investigated. The compression molded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH)/poly(L-lactic acid) (PLLA) strip enhanced the spinnability of PHBH and the mechanical properties of PLLA as well. The core–sheath ratio of the fibers was determined by the prefab strip, while the PLLA sheath component did not completely cover the PHBH core component due to the weak interfacial tension between the melts of PHBH and PLLA. A rotational target was applied to collect aligned fibers, which were further drawn in a water bath. The tensile strength and the modulus of as-spun and drawn fibers increased with increasing the take-up velocities. When the take-up velocity was above 500 m/min, the jet became unstable and started to break up at the tip of the Taylor cone, decreasing the mechanical properties of the fibers. The drawing process facilitated the crystallization of PLLA and PHBH, and the tensile strength and the modulus increased linearly with the increasing the draw ratio. The crystal information displayed from wide-angle X-ray diffraction patterns and differential scanning calorimetry heating curves supported the results of the tensile tests.

scholarly journals Effect of the Degree of Substitution on the Hydrophobicity, Crystallinity, and Thermal Properties of Lauroylated Amaranth Starch

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2548
Author(s):  
Vicente Espinosa-Solis ◽  
Yunia Verónica García-Tejeda ◽  
Everth Jimena Leal-Castañeda ◽  
Víctor Barrera-Figueroa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Thermal Characterization ◽  
Fatty Acyl ◽  
Degree Of Substitution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Amaranthus Hypochondriacus ◽  
Two Samples ◽  
Acyl Chains

In this paper, we consider amaranth starch extracted from the seeds of Amaranthus hypochondriacus L. An amphiphilic character is conferred to the starch by a chemical modification, which involves an esterification by lauroyl chloride at three modification levels. The degree of substitution (DS) after the modification ranged from 0.06 to 1.16. X-ray photoelectron spectroscopy analysis confirmed the presence of fatty acyl chains on the surface of the esterified starches. The hydrophobicity of starches was confirmed by their adsorption isotherms, which showed a decrease in the moisture adsorption of lauroylated as DS increased. X-ray diffraction analysis revealed a higher crystallinity, which was observed in the two samples subjected to the highest levels of modification. A higher crystallinity is related to a higher gelatinization enthalpy. These results are in agreement with the thermal characterization obtained by differential scanning calorimetry (DSC). An inhibition of the retrogradation properties of lauroylated amaranth starches was also observed.

scholarly journals Deformation induced martensite characterization in Fe-30%Ni-5%Cu alloy

2012 ◽  
Vol 48 (2) ◽  
pp. 259-264 ◽  
Author(s):  
E. Güler ◽  
M. Güler
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dsc Measurements ◽  
Cu Alloy ◽  
The Face ◽  
Xrd Techniques ◽  
Scanning Electron

Deformation induced martensite properties were examined according to existing martensite morphology, crystallography and formation temperatures for different prior austenite homogenization conditions in Fe-30%Ni-5%Cu alloy. Scanning electron microscope (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques were employed to investigation. Scanning electron microscope observations showed elongated deformation induced martensite morphology in the austenite phase of alloy. As well, after deformation martensite start temperatures (Ms) were determined as -101?C and -105?C from DSC measurements for different homogenization conditions. In addition, X-ray diffraction analysis revealed the face centred cubic (fcc) of austenite phases and body centred cubic (bcc) deformation induced martensite phases for all studied samples.

STUDIES ON SURFACE STRUCTURE, MORPHOLOGY AND COMPOSITION OF Co–W COATINGS ELECTRODEPOSITED WITH DIRECT AND PULSE CURRENT USING GLUCONATE BATH

2013 ◽  
Vol 20 (01) ◽  
pp. 1350006 ◽  
Author(s):  
PARTHASARATHI BERA ◽  
H. SEENIVASAN ◽  
K. S. RAJAM
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pulse Current ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Force Microscopy ◽  
Dsc Studies ◽  
Atomic Force ◽  
Electrodeposited Coating

Co–W alloy coatings were deposited with direct current (DC) and pulse current (PC) electrodeposition methods using gluconate bath at pH5 and characterized by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). DSC studies hint at the possibility of formation of metallic glasses. Detailed XPS studies of these alloy coatings have been carried out to compare elemental states and composition of Co and W in DC and PC electrodeposited alloys. DC-plated alloy has significant amount of Co and W metal along with their respective oxidized species. In contrast, mainly oxidized metals are present in the following layers of as-deposited coatings prepared with PC plating. Concentration of Co metal is observed to increase during sputtering, whereas there is no change in W6+ concentration. Microhardness measurement of all the Co–W coatings shows higher hardness compared to Co metal and 1:1 and 1:4 PC electrodeposited coatings show little higher hardness compared to 1:2 PC electrodeposited coating.

Properties of SiO2CuOx Films for Nitrogen Dioxide Detection

2013 ◽  
Vol 834-836 ◽  
pp. 112-116 ◽  
Author(s):  
Tatiana Myasoedova ◽  
G.E. Yalovega ◽  
V.V. Petrov ◽  
O.V. Zabluda ◽  
V.A. Shmatko ◽  
...  
Keyword(s):  
Thin Films ◽  
Nitrogen Dioxide ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Operating Temperatures

SiOxCuOythin films were prepared by the deposition on to the Si/SiO2substrates from the alcoholic solutions employing the sol-gel technique. The various analytic techniques were applied to characterize structure and properties of the films under study . The both X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies showed the presence CuO as well as CuO2phases and formation of a dual-oxide CuSiO3with the average crystallites sizes of 35-50 nm. The conductance of the films was rather sensitive to the presence of 1-20 ppm NO2concentration at the operating temperatures in the range of 20–200◦C.

Atomic layer deposition of HfO2, Al2O3, and HfAlOx using O3 and metal(diethylamino) precursors

2007 ◽  
Vol 22 (12) ◽  
pp. 3455-3464 ◽  
Author(s):  
Rajesh Katamreddy ◽  
Ronald Inman ◽  
Gregory Jursich ◽  
Axel Soulet ◽  
Christos Takoudis
Keyword(s):  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Metal Precursors ◽  
Layer Deposition ◽  
Xrd Techniques

Tetrakis-diethylamino hafnium (TDEAH), tris-diethylamino aluminum (TDEAA), and ozone were used for the atomic layer deposition (ALD) of HfO2, Al2O3, and HfAlOx films. The ALD rates were measured to be 1.1 Å/cycle for HfO2 and 1.3 Å/cycle for Al2O3. The ALD temperature windows were found to be between 200 and 325 °C for TDEAA, and between 200 and 275 °C for TDEAH. The overlap of these ALD windows between 200 and 275 °C is critical for ALD of the composite film, HfAlOx. In addition to the overlapping ALD temperature windows, the two metal precursors have similar thermal characteristics, as shown by TGA and differential scanning calorimetry. As-deposited films and films postannealed at 600 and 800 °C films were analyzed using Fourier transformed infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy, and x-ray diffraction (XRD) techniques. FTIR spectra revealed interfacial oxide growth during deposition of both HfO2 and Al2O3 whose thickness increased with annealing temperature. The FTIR data also indicated hydroxyl and nitrate groups in the films; these species were removed after annealing in Ar at a temperature of ⩾600 °C. Both FTIR and XRD results indicated the crystallization of pure HfO2 after annealing at temperatures as low as 600 °C. On the other hand, pure Al2O3 remained amorphous after annealing at temperatures up to 800 °C. XRD data of the composite HfAlOx film show that films deposited by alternating five cycles of HfO2 and one cycle of Al2O3 remained amorphous after annealing at 600 °C. Rutherford backscattering analysis of HfAlOx deposited with a varied number of alternating HfO2 and Al2O3 cycles demonstrated a strong correlation between the cyclic dosage of TDEAA and TDEAH and the film composition.

Synthesis of Oriented BiFeO3 Thin Films by Chemical Solution Deposition: Phase, Texture, and Microstructural Development

2005 ◽  
Vol 20 (8) ◽  
pp. 2127-2139 ◽  
Author(s):  
F. Tyholdt ◽  
S. Jørgensen ◽  
H. Fjellvåg ◽  
A.E. Gunnæs
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Chemical Solution Deposition ◽  
Microstructural Development ◽  
Chemical Solution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Solution Deposition ◽  
X Ray ◽  
Glass Substrates

Textured, thin films of BiFeO3 (∼120 nm thickness) were synthesized by chemical solution deposition from a mixture of iron- and bismuth- 2-methoxyethoxides on Si(100)/SiO2/TiO2/Pt substrates. The use of alkoxides ensured good homogeneity and a low degree of organics that further facilitated low crystallization temperatures. Crystalline films were according to x-ray diffraction already obtained at 480 °C. Precursor characteristics were investigated using thermogravimetry and differential scanning calorimetry, whereas phase purity, microstructure and film topography were examined by x-ray diffraction, transmission electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy. A small (10%) Bi excess was found necessary to obtain dense, pore-free films. Such additions also prevented decomposition of BiFeO3 at high temperatures. The observed (012) texture is believed to originate from the growth mechanism as no relation to the substrate is found. This is also confirmed by observing (012) texture for films on glass substrates.

Investigation of Structure and Properties of the Al–Y–Ni–Co–Cu Metallic Glasses

2002 ◽  
Vol 17 (5) ◽  
pp. 1014-1018 ◽  
Author(s):  
Dmitri V. Louzguine ◽  
Akihisa Inoue
Keyword(s):  
Electron Microscopy ◽  
Metallic Glasses ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Partial Replacement ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron

The present paper reports the effect of partial replacement of Ni by Cu in the Al85Y8Ni5Co2 alloy. The studied alloys were produced by rapid solidification. Glass-formation, crystallization behavior, and stability of the supercooled liquid were studied by x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Partial replacement of Ni by Cu in the Al85Y8Ni5Co2 metallic glass caused formation of the nanoscale α–Al particles and resulted in a decrease in the crystallization temperature and disappearance of the supercooled liquid.

scholarly journals Прозрачные фотокаталитические ZnO-SnO-=SUB=-2-=/SUB=- нанопокрытия, полученные полимерно-солевым методом

2019 ◽  
Vol 126 (4) ◽  
pp. 515
Author(s):  
С.К. Евстропьев ◽  
Л.Л. Лесных ◽  
Н.В. Никоноров ◽  
А.В. Караваева ◽  
Е.В. Колобкова ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Chemical Processes ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Thin Oxide Films ◽  
Glass Surfaces ◽  
Physical And Chemical ◽  
Scanning Electron

AbstractThe structure and properties of transparent ZnO–SnO_2 photocatalytic coatings formed on glass surfaces by the polymer–salt method are studied. The physical and chemical processes occurring during formation of the coatings are studied by differential scanning calorimetry and X-ray diffraction analysis. The structure and optical properties of the obtained thin oxide films are studied by optical spectroscopy, photoluminescence, and scanning electron microscopy. It is shown that the polymer–salt method allows formation of homogeneous and transparent ZnO–SnO_2 coatings consisting of oxide nanoparticles completely covering the glass substrate surface. It is found that the formed transparent ZnO–SnO_2 coatings have high photocatalytic properties and can generate singlet oxygen under action of UV radiation.

Chemical synthesis and characterization of polyaniline-molybdenum trisulfide composite

1999 ◽  
Vol 14 (5) ◽  
pp. 1805-1813 ◽  
Author(s):  
Florence Fusalba ◽  
Daniel Bélanger
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Synthesis And Characterization ◽  
Scanning Electron Micrographs ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
X Ray ◽  
Scanning Electron

A novel polyaniline-molybdenum trisulfide composite has been prepared by chemical polymerization from an acidic (1 M HCl) aqueous solution containing aniline and ammonium tetrathiomolybdate. The presence of molybdenum trisulfide in the polyaniline matrix induces morphological change to the polymer as evidenced by scanning electron micrographs. X-ray diffraction and differential scanning calorimetry indicate that polyaniline-molybdenum trisulfide is slightly less crystalline than polyaniline-HCl. X-ray photoelectron spectroscopy (XPS) and elemental analysis have been used to confirm the presence of molybdenum trisulfide in the polymer matrix. The XPS data also confirm that molybdenum trisulfide and tetrathiomolybdate anions are present with polyaniline to form a new inorganic-organic composite.

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