Synthesis and Characterization of Organic/Inorganic Interpenetrating Polymer Networks

1995 ◽  
Vol 385 ◽  
Author(s):  
Barry J. Bauer ◽  
Catheryn L. Jackson ◽  
Da-Wei Liu
Keyword(s):  
Sol Gel ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Pure Phases ◽  
Hydrolysis Of ◽  
Polymerization Conditions

ABSTRACTInterpenetrating polymer networks have been synthesized by performing sol-gel chemistry and conventional organic polymerizations in mixtures of the monomers. The organic polymers were acrylates, and the inorganic phase was SiO2 formed by hydrolysis of orthosilicates. Polymerizations were conducted at a variety of relative rates, and the chemistry was designed to allow different amounts of grafting between the components. The morphology was characterized by transmission electron microscopy and small angle neutron and x-ray scattering. Wide variations in morphology were observed depending on the polymerization conditions, ranging from grossly phase separated to dendritic to finely divided structures (at a 100Å size scale). The phases ranged from mixtures of the two components to relatively pure phases. The interface between the phases ranged from very narrow to relatively broad.

Characterization of ordered mesoporous films on silicon (001) surface using X-ray and electron diffraction

2005 ◽  
Vol 38 (1) ◽  
pp. 211-216 ◽  
Author(s):  
Pang-Hung Liu ◽  
Kuei-Jung Chao ◽  
Xing-Jian Guo ◽  
Kuo-Ying Huang ◽  
Yen-Ru Lee ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Film ◽  
Continuous Film ◽  
X Ray ◽  
Transmission Electron ◽  
Ordered Mesoporous ◽  
Direction Dependence

A continuous silica film with well aligned mesochannels parallel to the Si(001) surface was found to be formed through sol–gel dip-coating of a silica precursor with nonionic ethylene oxide surfactant. Two two-dimensional mesoporous structures in centered and non-centered rectangular symmetries and with the short axes of elongated ellipsoidal pores normal to the surface were observed by X-ray and electron diffraction. Detailed transmission electron microscopy investigations were employed to view the direction dependence of the channel or pore packing in the continuous film.

Potentialities of an Innovative Technique Like 129Xe NMR and of Saxs for the Characterization of Microporous Sol-Gel Derived SiO2

1996 ◽  
Vol 431 ◽  
Author(s):  
L. C. de Menorval ◽  
A. Julbe ◽  
H. Jobic ◽  
J. A. Dalmon ◽  
C. Guizard
Keyword(s):  
Chemical Shifts ◽  
High Surface ◽  
Sol Gel ◽  
Narrow Pore Size Distribution ◽  
X Ray ◽  
Porous Texture ◽  
129Xe Nmr ◽  
Line Shapes ◽  
X Ray Scattering

AbstractAddition of surfactants in TEOS derived sols leads to micro- or mesoporous materials whose porous texture can be varied by changing the surfactant quantity and/or chain length. This series of materials, with a relatively narrow pore size distribution, is well adapted to study the potentialities of an innovative characterization technique like 129Xe Nuclear Magnetic Resonance in comparison with Small Angle X-ray Scattering and N2 adsorption. SAXS revealed a high surface rugosity of the materials and a good correlation with pore hydraulic radius distributions measured by N2 adsorption. Using 129Xe NMR, we have studied the Xe chemical shifts (δXe,) as a function of pXe, and have pointed out several original results showing the importance, for microporous materials, of the NMR line shapes and of the slope of the lines δXe.=f(pXe).

Sol-Gel Synthesis and Characterization of Nanocrystalline Bi4Ti3O12 Powders

2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan
Keyword(s):  
Phase Inversion ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis ◽  
Source Materials

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.

Small-angle x-ray scattering and pulsed NMR studies of polyurethane interpenetrating polymer networks

1993 ◽  
Vol 26 (8) ◽  
pp. 1922-1929 ◽  
Author(s):  
Thomas P. Russell ◽  
Doo Sung Lee ◽  
Toshio Nishi ◽  
Sung Chul Kim
Keyword(s):  
Small Angle ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Nmr Studies ◽  
X Ray ◽  
X Ray Scattering ◽  
Pulsed Nmr ◽  
Ray Scattering

Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

1997 ◽  
Vol 12 (3) ◽  
pp. 596-599 ◽  
Author(s):  
Ji Zhou ◽  
Qing-Xin Su ◽  
K. M. Moulding ◽  
D. J. Barber
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

scholarly journals The disease associated Tau35 fragment has an increased propensity to aggregate compared to full-length tau

2021 ◽  
Author(s):  
Chen Lyu ◽  
Stefano Da Vela ◽  
Youssra K Al-Hilaly ◽  
Karen Marshall ◽  
Richard Thorogate ◽  
...  
Keyword(s):  
Progressive Increase ◽  
Full Length ◽  
Motor Dysfunction ◽  
Truncated Form ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Transmission Electron

Tau35 is a truncated form of tau found in human brain in a subset of tauopathies. Tau35 expression in mice recapitulates key features of human disease, including progressive increase in tau phosphorylation, along with cognitive and motor dysfunction. The appearance of aggregated tau suggests that Tau35 may have structural properties distinct from those of other tau species that could account for its pathological role in disease. To address this hypothesis, we performed a structural characterization of monomeric and aggregated Tau35 and compared the results to those of two longer isoforms, 2N3R and 2N4R tau. We used small angle X-ray scattering to show that Tau35, 2N3R and 2N4R tau all behave as disordered monomeric species but Tau35 exhibits higher rigidity. In the presence of the poly-anion heparin, Tau35 increases thioflavin T fluorescence significantly faster and to a greater extent than full-length tau, demonstrating a higher propensity to aggregate. We used atomic force microscopy, transmission electron microscopy and X-ray fiber diffraction to demonstrate that Tau35 aggregates are morphologically similar to previously reported tau fibrils but they are more densely packed. These data increase our understanding of the aggregation inducing properties of clinically relevant tau fragments and their potentially damaging role in the pathogenesis of human tauopathies.

scholarly journals Characterization of Modified Magnetite Nanoparticles for Albumin Immobilization

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
A. K. Bordbar ◽  
A. A. Rastegari ◽  
R. Amiri ◽  
E. Ranjbakhsh ◽  
M. Abbasi ◽  
...  
Keyword(s):  
Sol Gel ◽  
Xrd Analysis ◽  
Covalent Immobilization ◽  
Initial Value ◽  
X Ray ◽  
Buffer Solutions ◽  
Transmission Electron ◽  
Ft Ir ◽  
Chemical Coprecipitation Method

Magnetite Fe3O4 nanoparticles (NPs) were prepared by chemical coprecipitation method. Silica-coated magnetite NPs were prepared by sol-gel reaction, subsequently coated with 3-aminopropyltriethoxysilane (APTES) via silanization reaction, and then were activated with 2,4,6-trichloro-1,3,5-triazine (TCT) and covalently immobilized with bovine serum albumin (BSA). The size and structure of the particles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and dynamic light scattering (DLS) techniques. The immobilization was confirmed by Fourier transform infrared spectroscopy (FT-IR). XRD analysis showed that the binding process has not done any phase change to Fe3O4. The immobilization time for this process was 4 h and the amount of immobilized BSA for the initial value of 1.05 mg BSA was about 120 mg/gr nanoparticles. Also, the influences of three different buffer solutions and ionic strength on covalent immobilization were evaluated.

Ultra Small Angle X-Ray Scattering Characterization of Temperature-Sensitive Ferrogels Prepared Using Magnetic Nanoparticles

2013 ◽  
Vol 1453 ◽  
Author(s):  
Kamlesh J. Suthar ◽  
Muralidhar K. Ghantasala ◽  
Derrick C. Mancini ◽  
Jan Ilavsky
Keyword(s):  
Small Angle ◽  
Quantum Interference ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Hydrogel Particle ◽  
Ray Scattering

ABSTRACTTemperature-sensitive ferrogel prepared using Fe3O4 nanoparticles are characterized under varying temperature conditions. The nanoparticles were distributed in Nisopropylacrylamide (NIPAm) during their polymerization to form hydrogel. Particle distribution and agglomeration characteristics of the prepared ferrogels were investigated using ultra small angle x-ray scattering (USAXS) at various temperatures through the Lower Critical Solution Temperature (LCST). Transmission electron microscopy (TEM) was used to estimate the particle size distribution. The magnetic property was investigated using direct current superconducting quantum interference device (DC-SQUID) under hydrated conditions. The USAXS analysis showed an increase in the volume of particles without changing the agglomeration characteristics as the temperature is increased during the measurements. The ferrogel did not show any sedimentation or particle detachment from the gel under thermal cycling. Details of our results and analysis are presented.

Preparation and Characterization of TiO2 Nanoparticle with SiO2 Shell

2011 ◽  
Vol 233-235 ◽  
pp. 1188-1191
Author(s):  
Hong Cai ◽  
Yan Chen ◽  
Yun Ying Wu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Chemical Components ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Bonding Phase ◽  
Hydrolysis Of

Nano-TiO2 particles were prepared by sol-gel method, of which the surfaces were coated by SiO2. The coating was achieved by the hydrolysis of sodium silicate (Na2SiO3) in ammonium chloride (NH4Cl). The surface bonding, phase constitution and chemical components of the samples were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy (XPS). The mechanism of the SiO2 coating process onto TiO2 surface was analyzed. Results show that SiO2 particles were immobilized on the TiO2 surface via Ti—O—Si bondings, which formed at the interface. The SiO2 layer on TiO2 surface was amorphous, the photocatalytic performance was decreased of the TiO2 while its stability was enhanced after surface modification.

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