Incorporation, particles

Honeywell has also been active in developing a combined active-passive oxygen barrier system for polyamide-6 materials [201]. Passive barrier characteristics are provided by nanoclay particles incorporated via melt processing techniques, while active contribution comes from an oxygen-scavenging ingredient (undisclosed). Oxygen transmission results reveal substantial... 

Ogawa, S., Fan, F.-R.F. and Bard, A. J. (1995) Scanning tunneling microscopy, tunneling spectroscopy, and photoelectrochemistry of a film of Q-CdS particles incorporated in a self-assembled monolayer on a gold surface. J. Phys. Chem., 99, 11182-11189. 

Recent advances in measurement methods have allowed for the more complete determination of the aerosol size distribution for particles incorporating Po-218. 

Silica particles have been exploited in virtually every assay or detection strategy that polymer particles have been used in for bioapplication purposes. Recently, fluorescent dye-doped silica nanoparticles have been developed by a number of groups that have similar fluorescence characteristics to quantum dot nanocrystals (Chapter 9, Section 10). Fluorescent silica nanoparticles can be synthesized less expensively than quantum dots due to the fact that the silica particles incorporate standard organic dyes (Ow et al., 2005 Wang et al., 2006) and are not dependent on making reproducible populations of semiconductor particles with precise diameters to tune emission wavelengths. 

Electrocodeposition is the process of particle incorporation during the electrolytic deposition of metal, as shown in Fig. 1. This process produces composite films con-... 

From the research on electrocodeposition to date, a number of variables appear to be influential in the process, which include hydrodynamics, current density, particle characteristics, bath composition, and the particle-bath interaction. The influence that a particular variable has on the process is typically assessed by the change in the amount of particle incorporation obtained when that variable is adjusted. Although the effect of each of these process variables has been reported in the literature, the results are often contradictory. The effects of the process variables, of which many are interrelated, can also vary for different particle-electrolyte systems and electrodeposition cell configurations used. This review will summarize these effects and the contradictions in the literature on electrocodeposition. 

For the Ni-Al2C>3 system [27] there was little effect of pH on the amount of incorporation above a pH of 2. However, decreasing the pH below 2 resulted in a sharp decrease in the amount of incorporation. Below a pH of 2.0, reportedly no particle incorporation was obtained for copper plating with SiC or AI2O3 [27], Other researchers [25] found no effect of pH on amount of BaS04 incorporated within a copper matrix, in the presence of tetraethylene pentamine, although in the presence of thallous ions incorporation for the same system was found to increase with pH. 

As is the case for most of the process variables, the effect of the bath temperature on the amount of particle incorporation seems to vary for different particle-electrolyte combinations [19]. For the Cu-polystyrene system, codeposition increased when the... 

Although Buelens et al. evaluated a broader range of hydrodynamic conditions than had previously been done using a RDE [30], the amounts of particle incorporation used to establish the codeposition trends reported for the AU-AI2O3 system, as shown in Fig. 2, are very low in the range of 0.018 to 0.024 wt%. The initial decrease in codeposition observed in the transition region is only 0.006 wt%, the increase just prior to the turbulent region is only 0.0015 wt%, followed by a drop of 0.002 wt%. There is no discussion about the reproducibility or accuracy of these low incorporation amounts. 

Additional research using a RDE [38] also showed that the shear force near the surface of the electrode affects the amount of particle incorporation. The shear force... 

Fig. 3. Normalized particle incorporation vs. percent limiting current density as a function of RCE rotational rate at 120 g/1 particle loading.

Recently, composites of Ni-Al203 [58] and compositionally-graded Ni-P deposits containing SiC particles [59] were obtained using jet electroplating. The amount of SiC particles incorporated in the deposit could be controlled by the electrolyte jet velocity the incorporation increased from 0 to 30 vol.% as the jet velocity decreased from 16 to 0.5 m/s [59],... 

X-ray diffraction of the Buehler-supplied gamma alumina powder used in a RCE study showed the powder to be actually a combination of alpha and gamma phase alumina [28], However, the relatively high particle incorporation obtained with this alpha-gamma alumina cannot be attributed to the partial alpha crystallographic character of the powder, since the pure alpha alumina codeposited to a lesser extent. 

In general, the effects of the process variables on electrocodeposition are often interdependent and therefore, are ill understood. Often a slight change of one variable can sometimes lead to a dramatic change in the amount of particle incorporation. For specific systems, the current density at which maximum incorporation occurs seems to be related to a change in the slope of the current-potential relation-... 

The burning rates of AP-RDX composite propellants are dependent on the physicochemical properhes of the AP, RDX, and fuel used, such as particle size, as well as on mixture raho and the type of binder. The results of burning rate measurements are reported in AlAA Paper No. 81-1582.125] Various combinahons of AP and RDX parhcles are used to formulate AP-RDX composite propellants, as shown in Table 7.6.125] pjjg particles incorporated into the propellants have bimodal combinations of sizes, where large RDX particles (RDX-I), small RDX particles (RDX-S), large AP particles (AP-I), and small AP particles (AP-S) are designated by d, d, dj, and da, respectively. HTPB binder is used in all of the propellants shown in Table 7.6. 

The AN particles incorporated into GAP-AN pyrolants form a molten layer on the burning surface and decompose to form oxidizer fragments. The fuel-rich gas produced by the decomposition of GAP interdiffuses with these oxidizer fragments on and above the burning surface and produces a premixed flame. A luminous flameis formed above the burning surface. 

Metal particles incorporated into a gas-generating pyrolant act as flame holders to keep the flame in the ramburner. Fach metal particle flows with the combustible gas and becomes a hot metal or metal oxide particle. Since the flow velocity of such a hot particle is lower than that of the combustible gas, the flow velocity of the combustible gas just downstream of the hot particle is decreased due to the aerody-... 

Figure 3.5 shows aTEM picture of the core/double shell latex particles incorporated into an styrene/acrylonitrile (SAN) copolymer matrix (thin cut through the particle-filled matrix).The particles are very homogeneous in size and can also be used to prepare ar-tifical opals. 

Ogawa S, Fu K, Fan FRF, Bard AJ (1997) Photoelectrochemistiy of films of quantum sized lead sulfide particles incorporated in self-assembled monolayer of gold. J Phys Chem 101 5707-5711... 

Ion Sensitive electrodes Metal hexacyanoferrate film electrodes as well as metal hexacyanoferrate particles incorporated in solid composite electrodes have been used for the quantitative analysis of the ions... 

Ichimura et al. (51) have prepared silica particles showing photocontrol led reversible dispersibility in organic solvent. The silica particles incorporated spiropy-ran photochromic units, which showed reversible photoisomerization, were floccu-... 

Though the physical structures of CMDB propellants are heterogeneous, similar to those of composite propellants, the base matrix used as a binder burns by itself and the combustion mode of CMDB propellants appears to be different from that of composite propellants and double-base propellants. The burning rate of a CMDB propellant is dependent on the type of crystalline particles incorporated. 

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