Bioinspired synthesis of self-assembled calcium phosphate nanocomposites using block copolymer-peptide conjugates

2008 ◽  
Vol 23 (12) ◽  
pp. 3196-3212 ◽  
Author(s):  
Yusuf Yusufoglu ◽  
Yanyan Hu ◽  
Mathumai Kanapathipillai ◽  
Matthew Kramer ◽  
Yunus E. Kalay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Phosphate ◽  
Small Angle ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Assembling ◽  
Transmission Electron ◽  
Angle Scattering ◽  
Inorganic Content

Thermoreversibly gelling block copolymers conjugated to hydroxyapatite-nucleating peptides were used to template the growth of inorganic calcium phosphate in aqueous solutions. Nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), transmission electron microscopy, x-ray diffraction, and small-angle scattering were used to characterize these samples and confirm that the peptides promoted the growth of hydroxyapatite as the inorganic phase. Three different polymer templates were used with varying charges on the polymer chains (nonionic, anionic, and zwitterionic), to investigate the role of charge on mineralization. All of the polymer-inorganic solutions exhibited thermoreversible gelation above room temperature. Nanocomposite formation was confirmed by solid-state NMR, and several methods identified the inorganic component as hydroxyapatite. Small angle x-ray scattering and electron microscopy showed thin, elongated crystallites. Thermogravimetric analysis showed an inorganic content of 30–45 wt% (based on the mass of the dried gel at ∼200 °C) in the various samples. Our work offers routes for bioinspired bottom-up approaches for the development of novel, self-assembling, injectable nanocomposite biomaterials for potential orthopedic applications.

Structural characterization of manganese-substituted nanocrystalline zinc oxide using small-angle neutron scattering and high-resolution transmission electron microscopy

2009 ◽  
Vol 42 (6) ◽  
pp. 1085-1091 ◽  
Author(s):  
B. Roy ◽  
B. Karmakar ◽  
J. Bahadur ◽  
S. Mazumder ◽  
D. Sen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Zinc Oxide ◽  
High Resolution ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A series of zinc oxide (ZnO) nanoparticles, substituted with manganese di-oxide, have been synthesized through a modified ceramic route using urea as a fuel. X-ray diffraction and high-resolution transmission electron microscopy studies indicate that the sizes of the ZnO particles are of nanometer dimension. Particles remain as single phase when the doping concentration is below 15 mol%. Small-angle neutron scattering indicates fractal-like agglomerates of these nanoparticles in powder form. The size distributions of the particles have been estimated from scattering experiments as well as microscopy studies. The average particle size estimated from small-angle scattering experiments was found to be somewhat more than that obtained from X-ray diffraction or electron microscopy measurement.

scholarly journals Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials

2014 ◽  
Vol 5 ◽  
pp. 1553-1568 ◽  
Author(s):  
Ahmed Salama ◽  
Mike Neumann ◽  
Christina Günter ◽  
Andreas Taubert
Keyword(s):  
Electron Microscopy ◽  
Ionic Liquid ◽  
Calcium Phosphate ◽  
Hybrid Materials ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Regenerative Therapies ◽  
Scanning Electron

Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies.

scholarly journals Crystallization of BaF2 from droplets of phase separated glass – evidence of a core–shell structure by ASAXS

CrystEngComm ◽  
2020 ◽  
Vol 22 (30) ◽  
pp. 5031-5039
Author(s):  
Armin Hoell ◽  
Vikram Singh Raghuwanshi ◽  
Christian Bocker ◽  
Andreas Herrmann ◽  
Christian Rüssel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Shell Structure ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Core Shell Structure

Glasses with the mol% compositions 1.88 Na2O·15.04 K2O·7.52 Al2O3·69.56 SiO2·6.00 BaF2 and 1.88 Na2O·15.03 K2O·7.52 Al2O3·69.52 SiO2·6.00 BaF2·0.05 SmF3 were studied using X-ray diffraction, transmission electron microscopy, and anomalous small-angle X-ray scattering.

Polypropylene/Ethylene-Octene Copolymer/Organic-Montmorillonite Nanocomposites

2005 ◽  
Vol 13 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Minyan Guo ◽  
Xiaodong Zhou ◽  
Gance Dai ◽  
Fuzeng Hu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Tests ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Organic Montmorillonite ◽  
Melt Compounding ◽  
Transmission Electron ◽  
Ethylene Octene Copolymer

Melt compounding was employed to prepare polypropylene (PP)/ethylene-octene copolymer (POE)/organic-montmorillonite (OMMT) nanocomposites. Polypropylene grafted with maleic anhydride (MPP) was added as a compatibilising agent. Analyses by wide-angle X-ray diffraction, transmission electron microscopy and scanning electron microscopy indicated that polymer chains intercalated into OMMT and that some of the OMMT delaminated into nano-layers dispersed in the PP matrix. Mechanical tests showed that the addition of POE increases the toughness of PP, but it decreases the stiffness. When OMMT and MPP were added, the toughness of PP increased greatly and the stiffness was not changed profoundly. Differential scanning calorimetry was used to study the melt and crystallization behavior of the composites. The results indicate that OMMT and MPP act as effective nucleating agents.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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