Nanoparticle layer

Up to now, a variety of non-zeolite/polymer mixed-matrix membranes have been developed comprising either nonporous or porous non-zeolitic materials as the dispersed phase in the continuous polymer phase. For example, non-porous and porous silica nanoparticles, alumina, activated carbon, poly(ethylene glycol) impregnated activated carbon, carbon molecular sieves, Ti02 nanoparticles, layered materials, metal-organic frameworks and mesoporous molecular sieves have been studied as the dispersed non-zeolitic materials in the mixed-matrix membranes in the literature [23-35]. This chapter does not focus on these non-zeoUte/polymer mixed-matrix membranes. Instead we describe recent progress in molecular sieve/ polymer mixed-matrix membranes, as much of the research conducted to date on mixed-matrix membranes has focused on the combination of a dispersed zeolite phase with an easily processed continuous polymer matrix. The molecular sieve/ polymer mixed-matrix membranes covered in this chapter include zeolite/polymer and non-zeolitic molecular sieve/polymer mixed-matrix membranes, such as alu-minophosphate molecular sieve (AlPO)/polymer and silicoaluminophosphate molecular sieve (SAPO)/polymer mixed-matrix membranes. 

When some NC particles are surface treated to make them hydrophobic by, e.g., silylation and floated on the surface of water, a nanoparticle layer can be made on a solid substrate by a method similar to Langmuir-Blodgett film formation. Interparticle separation is well controlled by choosing an appropriate surface pressure prior to making LB film, as discussed next. 

The multilayer nanocomposite films containing layers of quasi-spherical Fe nanoparticles (d — 5.8 nm) separated by dielectric layers from boron nitride (BN) are synthesized by the repeated alternating deposition of BN and Fe onto a silicon substrate [54]. In this work the authors managed to realize the correlation in the arrangement of Fe nanoparticles between the layers the thin BN layer deposited on the Fe layer has a wave-like relief, on which the disposition of Fe nanoparticles is imprinted as a result, the next Fe layer deposited onto BN reproduces the structure of the previous Fe layer. Thus, a three-dimensional ordered system of the nanoparticles has been formed on the basis of the initial ordered Fe nanoparticle layer deposited on silicon substrate [54]. The analogous three-dimensional structure composed of the Co nanoparticles layers, which alternate the layers of amorphous A1203, has been obtained by the PVD method [55]. 

Figure 13.5 LbL assembly of bishydroxamate-fiinctionalized Au nanoparticles onto the bishydroxa-mate disulfide SAMs by Zr4+ as binding ions. Controlled spacing of nanoparticle layer was achieved using multilayer branched hexahydroxamate ligands.15...

The melting behavior can be extracted from the dynamic viscosity [3,4], The dynamic viscosity also affects the morphology of the char, which may improve the shielding efficiency from the fire by the nanoparticle layer formed on the polymer [5-7],... 

Fig. 5. a SEM image of hollow Ti02 spheres, b TEM image of hollow Ti02 spheres. The spheres were produced after calcining 640 nm diameter PS spheres coated with four layers of Ti02 nanoparticles (5 nm diameter). Each nanoparticle layer was separated by three polyelectrolyte layers. The hollow spheres are composed of anatase crystals. (Adapted from [41] by permission of the American Chemical Society)... 

The positron lifetimes for different defects in MgO are calculated using the insulator model of Puska and co-workers. In this model, the annihilation rates are determined by the positron density overlapping with the enhanced electron density that is proportional to the atomic polarizability of MgO [8, 9]. Based on comparison between experimental and calculated values [5, 6], the positron lifetime of the embedded Au nanoparticle layer, 0.41 ns, suggests that positrons are predominantly trapped in clusters consisting of... 

Figure 13.3 (left) Two-dimensional spectrum of annihilation radiation of positrons injected into a p-Si (100), with 8 fl-cm. The diagonal feature indicates the condition of E) + E2= 1.022 MeV (right) Normalized annihilation lines as a function of photon energy for Au nanoparticle layer (solid circles), MgO layer (open circles), and Au film (solid line) [6],... 

Figure 13.5 Probability density functions (right) as a function of positron me, resulting from Laplace inversion (CONTIN) of lifetime spectra (left) Au nanoparticle layers generated in H2 (triangles) and 02 (circles) annealing atmospheres [13].

QDs that had an emission spectrum red-shifted (at 667 nm) compared to the SPR of gold nanoparticles (although the SPR of the gold nanoparticle layer is not shown) showed the maximum enhancement, which was reached with six polyelectrolyte bilayers. 

Figure 11.8 Left Schematic illustration of gold nanoparticle, polyelectrolyte layer and QD layer construction for expmments. Right Plots of fluorescence of QDs with various emission maxima as a function of number of polyelectrolyte bilayers between QDs and gold nanoparticle layer. The emission spectra are shown in the inset. Reprinted with permission from reference [30]. (2006) American Institute of Physics.

Scheme 20.4. Method for the construction of oligocation-crosslinked Au-nanoparticle multilayers by electrostatic interactions. The first nanoparticle layer is formed by the...

Liang et al. introduced a covalently linked layer-by-layer assembly of a PPV polymer with CdSe nanoparticles [260]. In this method the subsequent deposition of polymer and nanoparticle layers is accompanied by a covalent cross-linking at the interlayers. This resulted in a good control of total layer thickness in the device and very stable films. A first photovoltaic application was also demonstrated. 

Screening of interparticle interactions using LbL assembly has also been demonstrated by depositing inert monolayers between each two consecutive metal [11] or magnetic [15] nanoparticle layers. In such methods, only interlayer interactions are screened, so that spatially modulated coupling can be achieved and polarization effects on the reflection coefficient can be obtained. 

In this paper, we discuss the problem of optical diagnostics for 2D noble-metal nanoparticle layers assembled by self-organization techniques [1,4]. We show the possibility of reconstruction of size and concentration parameters for spherical silver nanoparticles from the plasmon absorbance spectra. 

Typical absorbance spectra of self-assembled silver nanoparticle layers are shown in Fig. 1. They demonstrate high sensitivity of the SPR to the packing density of nanoparticles, which we define in terms of the overlap parameter tj. Fig. 2 represents the red shift of the SPR wavelength for dipole nanoparticles depending on concentration due to an increase in degree of near-range ordering... 

Endo, T., Yamamura, S., Nagatani, N., Morita, Y., Takamura, Y., Tamiya, E. (2005b). Localized surface plasmon resonance based optical biosensor using surface modified nanoparticle layer for label-free monitoring antigenantibody reaction. Sci Technol Adv Mater 6, 491-500. 

Figure 11-23. 250- uti wide Ag nanoparticle lines ink-jet printed onto ferrite nanoparticle layer (also ink-jet printed)... 

Keywords Hollow spheres Nanoparticles Layer-by-layer assembly Tandem assembly Nanoparticle assembled capsule Interfacial stabilization - Particle stabilized emulsion... 

Carbon nanohibes [multiwall (MWNT) Engineered Nanoparticles Layered silica... 

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