Green densities

Miscellaneous Processes. Metal strip for cladding can be produced by cold pressing metal powder into alow density green strip, foUowed by sintering to compact the powder. AHoy powders can be made into strip, along with specialized strip with one powder bonded to a different powder on the opposite side. 

Aggregation of soap in micelles. The electrostatic potential map of a soap molecule shows high electron density in the negatively charged head and medium electron density (green) in the hydrocarbon tail. In water, soap forms a cloudy solution of micelles, with the hydrophilic heads in contact with water and the hydrophobic tails clustered in the interior. The Na+ ions (not shown) are dissolved in the water surrounding the micelle. 

Pellet pressing Binder removal 138-207 MPa, 53% theoretical density green density... 

Figure 30 The /t Fobs —D Fca C map around Phe331 of the second PDZ domain of SAP97 contoured at -3a (red) and 3a (green) after misplacing the side chain. The positive density (green) shows where the side chain should be and the negative density (red) shows where atoms should be removed.

Fig. 4 Schematic illustration of the coordinated Co -phenoxyl radical, bearing coordinated acetate groups, derived from [Co(l)] after addition of acetic acid under aerobic conditions. Top (a, c) the X- and W-band CW EPR spectra of [Co°(r)(OAc) ](OAc) (n = m = 1 or n = 2, m = G) and (b) the X-band CW-EPR spectrum of [Co (l )(Py)2]. Bottom the DFT-computed spin densities of [Co(l )(OAc)] shown from the side and top elevation. Blue is positive spin density, green represents negative spin density. Adapted and reprinted with permission from [85]. Copyright 2011 American Chemical Society...

All of these UV-curable systems have very different chemistries than those used in solvent-based systems. Most contain a dispersant, a plasticizer (not necessary in all cases), a photopolymerizable binder, and an initiator to activate the UV curing. A typical binder/initiator system found in the literature is a polyester acrylate binder and an initiator such as 2-hydroxy-2methyl-l-phenyl-propan-l-one. The binder is a liquid low-viscosity monomer diluted into hydroxy-ethyl methacrylate. Most of the UV-curable systems contain an acrylate monomer of some sort, since they have relatively low viscosities (100 mPa s or cP) and excellent reactivity with the UV radiation. The low viscosity allows the preparation of ceramic slurries with a relatively high solids loading, and the resulting high-density green sheets have excellent mechanical properties. 

The UO2 powder is then compacted in a hydraulic press/rotary compactor to increase the bulk density, granulated, and mixed with a binder. The binder-mixed granules are subjected to final compaction to give the cylindrical-shaped pellets of specified dimensions and density (Green Pellets). 

Figm 3 Depletion potentials between two colloids caused by spherical depletants with a log-normal distribution of sizes with a coefficient of variance monodisperse spheres (full line). The curves with the symbols ate calculated for the same volume fraction (black), the same mass concentration (red), and the same number density (green) as for the monodisperse case. 

Unpaired electron spin density map for the allyl radical. Unpaired electron density (green cones) appears only on carbons 1 and 3. 

Apparent powder density Apparent powder volume Bulk powder density Effective solid density Green density Pressed density Immersed density... 

Clasen R. Preparation and sintering ofhigh-density green bodies to high-purity silica glass. J. Non-Cryst. SoUds 1987 89 335-344... 

Figure 3 Snapshot from molecular dynamics simulation of a two-dimensional Lennard-Jones SCF at Tr= 1.06 and Pr = 0.86. showing atoms in locally high-density (red), low-density (green), and average-density (black) regions...

---