Synthesis and Confinement of Carbon Dots in Lysozyme Single Crystals Produces Ordered Hybrid Materials with Tuneable Luminescence

The hybrid materials prepared by the controlled fumigation polymerization of pyrrole on the surface of activated carbon derived from carbon dots combined the stability of carbon materials, the wettability of...

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All-Carbon Nanosized Hybrid Materials: Fluorescent Carbon Dots Conjugated to Multiwalled Carbon Nanotubes

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.6b02267 ◽

2016 ◽

Vol 120 (16) ◽

pp. 8550-8558 ◽

Cited By ~ 8

Author(s):

Theodosis Skaltsas ◽

Anastasios Stergiou ◽

Demetrios D. Chronopoulos ◽

Sihan Zhao ◽

Hisanori Shinohara ◽

...

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Hybrid Materials ◽

Carbon Dots ◽

Multiwalled Carbon ◽

Fluorescent Carbon Dots ◽

Fluorescent Carbon

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Magnesium-based Biodegradable Nanostructured Substrates: Hybrid Materials for Cellular Engraftment

MRS Proceedings ◽

10.1557/proc-1235-rr03-45 ◽

2009 ◽

Vol 1235 ◽

Cited By ~ 1

Author(s):

Tobias Schoen ◽

Tobias Wolfram ◽

Joachim P Spatz

Keyword(s):

Cell Culture ◽

Gold Nanoparticles ◽

Single Crystals ◽

Hybrid Materials ◽

Culture Medium ◽

Weight Ratio ◽

Cellular Systems ◽

Cell Culture Medium ◽

Metallic Ions ◽

Initial Adhesion

AbstractMagnesium and its alloys are used as implants because of their biocompatibility and high strength-to-weight ratio. In contrast to other commonly used implantable materials such as stainless steel and Co-Cr-alloys, which may release toxic metallic ions, magnesium belongs to the natural composition of the human body. Our work is focused on engineering a cellular carrier system based on biodegradable magnesium and magnesium alloy substrates, which are decorated with gold nanoparticles to form magnesium-gold (Mg-Au) hybrid materials. Specifically, we deposited gold nanoparticles on MgO single crystals (100 orientation) and on AZ31-Mg alloy substrates using diblock copolymer micelle nanolithography. The gold nanoparticles were arranged in ordered arrays with controllable interparticle distances of 25 to 300 nm and were further functionalized with RGD-thiols or fibronectin. This method allowed the deposition of a protein carpet on top of the surface and facilitated the initial adhesion of cells on the magnesium substrates. In order to determine the stability of the substrates in a physiological environment, their corrosive behavior was studied by comparing the weight of the substrates before and after a 24h-long submersion in water, PBS, or cell culture medium and by studying the post-submersion surface morphology with scanning electron microscopy. Corrosion rates of magnesium substrates in PBS and cell culture medium were significantly higher than in water. The spreading and survival of C2C12 mouse myoblasts and human mesenchymal stem cells cultured on MgO single crystals and AZ31-alloys were investigated with fluorescence and phase contrast microscopy. The spreading and survival of C2C12 myoblasts on the Mg-Au hybrid materials were different than on non-functionalized Mg substrates. Additionally, cells on non-functionalized MgO crystals showed reduced filopodia activity. Our results show that biofunctionalized and engineered magnesium-based substrates can be used as carriers for different cellular systems and promising initial steps have been taken towards an implantable device with a defined biological surface activity made from magnesium materials.

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The Microstructure of Shock-Synthesized Diamond

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006163x ◽

1967 ◽

Vol 25 ◽

pp. 324-325

Author(s):

Lucien F. Trueb

Keyword(s):

Single Crystals ◽

Preferred Orientation ◽

High Magnification ◽

Texture Pattern ◽

Shock Process ◽

New Type ◽

Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

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A New Defect in Polyethylene Single Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070795 ◽

1973 ◽

Vol 31 ◽

pp. 70-71

Author(s):

E. L. Thomas ◽

S. L. Sass

Keyword(s):

Single Crystals ◽

Screw Dislocation ◽

Small Distance ◽

Dipole Model ◽

Dislocation Dipole ◽

Chain Folding ◽

Black And White ◽

Polymer Crystal ◽

Different Types

In polyethylene single crystals pairs of black and white lines spaced 700-3,000Å apart, parallel to the [100] and [010] directions, have been identified as microsector boundaries. A microsector is formed when the plane of chain folding changes over a small distance within a polymer crystal. In order for the different types of folds to accommodate at the boundary between the 2 fold domains, a staggering along the chain direction and a rotation of the chains in the plane of the boundary occurs. The black-white contrast from a microsector boundary can be explained in terms of these chain rotations. We demonstrate that microsectors can terminate within the crystal and interpret the observed terminal strain contrast in terms of a screw dislocation dipole model.

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Preferential Sputtering of Ni3Al Single Crystals Studied Using Atom-Probe Field-Ion Microscopy and XPS

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096813 ◽

1981 ◽

Vol 39 ◽

pp. 16-17

Author(s):

M.P. Thomas ◽

A.R. Waugh ◽

M.J. Southon ◽

Brian Ralph

Keyword(s):

Single Crystals ◽

Photoelectron Spectroscopy ◽

Surface Composition ◽

Depth Profiling ◽

Analytical Techniques ◽

Atom Probe ◽

Probe Field ◽

Preferential Sputtering ◽

Argon Ion Bombardment ◽

Argon Ion

It is well known that ion-induced sputtering from numerous multicomponent targets results in marked changes in surface composition (1). Preferential removal of one component results in surface enrichment in the less easily removed species. In this investigation, a time-of-flight atom-probe field-ion microscope A.P. together with X-ray photoelectron spectroscopy XPS have been used to monitor alterations in surface composition of Ni3Al single crystals under argon ion bombardment. The A.P. has been chosen for this investigation because of its ability using field evaporation to depth profile through a sputtered surface without the need for further ion sputtering. Incident ion energy and ion dose have been selected to reflect conditions widely used in surface analytical techniques for cleaning and depth-profiling of samples, typically 3keV and 1018 - 1020 ion m-2.

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Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100110118 ◽

1978 ◽

Vol 36 (1) ◽

pp. 594-595

Author(s):

N.J. Long ◽

M.H. Loretto ◽

C.H. Lloyd

Keyword(s):

Flow Stress ◽

Single Crystals ◽

Room Temperature ◽

Thin Foil ◽

Age Hardening ◽

Dispersion Strengthening ◽

Accurate Picture ◽

The Matrix ◽

Very High ◽

Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

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