Nanostructured composites

Hu, Y., etal., Graphene-gold nanostructure composites fabricated by electrodeposition and their electrocatalytic activity toward the oxygen reduction and glucose oxidation. Electrochimica Acta, 2010. 56(1) p. 491-500. 

S. Orimo, H. Fujii, K. Ikeda, Notable hydriding properties of a nanostructured composite material of the Mg Ni-H system synthesized by reactive mechanical grinding, Acta mater. 45 (1997) 331-341. 

The synthesized nanostructured composites (nanocomposites) (MgH -i- LiAlH ) were subjected to desorption experiments after ball milling for 20 h. Figure 3.34 shows desorption curves obtained under continuous heating up to 300°C (quasi-TPD)... 

Preparation of a new type of nanostructured composite thin film in which one component possesses unidirectional order while the other component is randomly oriented. 

Figure 9. P-XRD pattern of nanostructured composites of chromium (III) oxide and dodecylphosphate synthesized with different surfactant concentrations...

Polysilane-based nanostructured composites were synthesized by the inclusion of poly(di-w-hexylsilane) (Mw = 53,600) into mesoporous, Si-OH-rich silica with a pore size of 2.8 nm.81 Two PL bands are observed for the composite. A narrow band at 371 nm, assigned to a PDHS film on a quartz substrate is blue shifted by 20 nm, a shift attributed to the polymer being incorporated into the pores.82 The size of the monomeric unit of the PDHS is about 1.6 nm, so only one polymer chain can be incorporated into a mesopore with a diameter of 2.8 nm. The narrow PL band at 350 nm is due to the reduction of the intermolecular interactions between polymer chains. This narrow PL band at 350 nm is assigned to the excited state of the linear polymer chain.81 Also, a new broad band of visible fluorescence at 410 nm appeared, which is assigned to localized states induced by conformational changes of the polymer chains caused by its interaction with the silanol (Si-OH) covered pore surface. Visible luminescence in nanosize PDHS is observed only when the polymer was incorporated in hexagonal pores of 2.8 nm and is not seen for the polymer incorporated into cubic pores of 2.8 nm diameter or hexagonal pores of 5.8 nm diameter. 

Kryukov A.I., Kuchmii S.Y., Pokhodenko V.D. (1997) Nanostructured composite photocatalysts based on polycrystalline cadmium sulfide, Theoret. Experim. Chem. 33(5), 306-321. 

Fig. 3. Nanostructured composite of p-nitroaniline (pNA, top left) and AIPO4-5. Top right Anisotropic absorption of the composite The crystals appear yellow only when the electric field vector E of the linearly polarized light oscillates in the direction of the transition dipole moment of the blue absorption of the pNA molecules. When E and these dipole moments are perpendicular to each other, no absorption occurs in the visible region, so that the pNA/AlPO -S crystals appear colourless. Center Experiment to measure the second harmonic generation (SHG) of the pNA/AIP04-5 composite. Bottom right The measured SHG effect is a function of cos q>, where q> is the rotation angle of the polarization rotator. This result is in agreement with the expectation if it is assumed that the pNA molecules are aligned in the channels and their dipoles all possess the same orientation. After the work of Caro, Marlow and co-workers [30-32],...

BN fibers are used in aluminum matrices because they are one of the few materials easily wet by molten aluminum. hBN-AlN composites are described ". Gel methods resulted in an hAlN-turbostratic hBN composite. zBN-based composites, e.g., with Al, Si, Ti nitride matrices, were reported. A nanostructure composite was made by low temperature conversion of an aqueous solution of simple Al, B, and N-containing compounds to intermediate precursor (gel) materials. BN-AIN composite fabrication is also described . 

Cylindrically converging shock waves on powders were used to make mixtures of diamonds and hBN. BN fiber reinforced Zr02 was described . A nanostructured composite of magnetic particles of FOj N in a nonmagnetic matrix of BN is made via an inorganic geP. Fabrication of BN-B4 composites was reported . Consolidation of novel sintered composites formed from high pressure crystallization of amorphous ceramics was also described. The literature discusses other ceramics reinforced with BN fibers, as welF . ... 

Ordered mesoporous materials, due to their periodic and size-controllable pore channels and high surface areas, have been regarded as a nano-reactor to construct novel ordered and well dispersed nanostructured composites with controlled size and size distribution.[303] A number of studies have reported on the encapsulation of guest materials, such as metal oxides,[304] semiconductors, metal sulfides,[305] carbon, metals,[306] and polymers into mesoporous silica hosts. 

In this chapter there are presented two types of the nanocomposite materials the first one is the nanostructured composite with a structure of nanoparticles embedded in polymers, abbreviated to NIP, the second one is the nanocomposite with a structure of polymers deposited on nanopwrous thin films, called as PON. 

We have given an overview of the recent works on nanocomposites used for optoelectronic devices. From the review it is seen that a very rich publication has been issued regarding the nanostructured composites and nano-hybrid layers or heterojunctions which can be applied for different practical purposes. Among them there are organic light emitting diodes (OLED) and excitonic or organic solar cells (OSC). 

Dinh, N. N. Chi L. H., Thuy, T.T.C Trung T.Q. Vo, Van Truong. (2009). Enhancement of current, voltage characteristics of multilayer organic light emitting diodes by using nanostructured composite films,. Appl. Phys. 105, pp. 093518-1+ 093518-7. 

Source Reprinted from O. Figovsky, L. Shapovalov, A. Leykin, O. Birukova, and R. Potesshnikova, Nonisocyanate Polyurethanes Based on Cyclic Carbonates and Nanostructures Composites, J. Scientific Israel Technology Advanced 14, no. 4 (2012) 95—106. With permission. 

Chemical resistance and thermostability of nano-heterogenic coatings with fluorine surface active additives (FSAA) are approximately 5%-10% higher than for unmodified ones. At the same time, addition of about 3 mass% of metal oxides in epoxy-rubber nanostructured compositions significantly decreases their permeability and increases their chemical resistance in water and water solutions of acids, salts, and alkalis (Figure 6.3) [8],... 

FIGURE 1.24 Emission spectra for MEH-PPV in different environments and under different excitation conditions, (a) Normalized steady-state PL spectra of MEH-PPV in chlorobenzene (CB) solution, THF solution, and the mesoporous silica composite with excitation and collection polarizations parallel to the pore direction (VVV). (b) PL of MEH-PPV in the nanostructured composite with excitation light polarized along the pore direction. The heavy solid curve [VVV, same as in (a)] shows emission collected polarized along the pore direction. The dotted curve (VVH) is for emission collected polarized perpendicular to the pore direction, (c) PL of MEH-PPV in the nanostructured composite with excitation light polarized perpendicular to the pore direction. The dot-dashed curve (VHV) shows emission collected polarized along the pore direction, and the thin solid curve is for emission collected polarized perpendicular to the pores (VHH). (Source Ref. [35].)... 

Nanostructured Composites Structure, Properties, and Applications in Electrochemistry... 

---