Casting-evaporation process

Figure 8.19. Phase diagram of PVC/NBR/THF and optical micrograph of the solution cast fdm. Spinodal and binodal curves are shown by the broken and solid lines, respectively. The arrow indicates the casting (evaporation) process [Inoue et al., 1985],...

FIGURE 11.9 Schematic illustration of solution blending and subsequent casting-evaporation process for the preparation of CN-filled nanocomposites. See insert for color representation of the figure.)... 

Recently, an in-depth review on molecular imprinted membranes has been published by Piletsky et al. [4]. Four preparation strategies for MIP membranes can be distinguished (i) in-situ polymerization by bulk crosslinking (ii) preparation by dry phase inversion with a casting/solvent evaporation process [45-51] (iii) preparation by wet phase inversion with a casting/immersion precipitation [52-54] and (iv) surface imprinting. 

In a previous section, the effect of plasma on PVA surface for pervaporation processes was also mentioned. In fact, plasma treatment is a surface-modification method to control the hydrophilicity-hydrophobicity balance of polymer materials in order to optimize their properties in various domains, such as adhesion, biocompatibility and membrane-separation techniques. Non-porous PVA membranes were prepared by the cast-evaporating method and covered with an allyl alcohol or acrylic acid plasma-polymerized layer the effect of plasma treatment on the increase of PVA membrane surface hydrophobicity was checked [37].The allyl alcohol plasma layer was weakly crosslinked, in contrast to the acrylic acid layer. The best results for the dehydration of ethanol were obtained using allyl alcohol treatment. The selectivity of treated membrane (H20 wt% in the pervaporate in the range 83-92 and a water selectivity, aH2o, of 250 at 25 °C) is higher than that of the non-treated one (aH2o = 19) as well as that of the acrylic acid treated membrane (aH2o = 22). 

For many years, nearly all the substrate materials used in the electronics industry were ceramics produced by tape casting (Mistier, 2000). These substrates consist of multiple layers of tape-cast material acting as the insulative carrier, with layers of metal deposited by sputtering, CVD, or evaporation processes. Holes punched into the tapes fill with metal and act as vias or pathways between layers when the tapes are stacked. Stacked layers of tape-cast blanks are laminated together and then sintered to produce a monolithic substrate. This process is detailed in many handbooks on electronics packaging (e g., Harper, 2000). One of the prime benefits is that the layers of the final part can be different different hole patterns, different metallization patterns, even different dimensions on each layer. 

Thermodynamic incompatibility of the A and B block segments of amorphous AB and ABA block copolymers involves microphase separation at a critical micelle concentration (I, 2). The micelles formed at this concentration are essentially maintained through the solvent evaporation process to produce the domain structures observed in solid state (2, 3, 4). The shape and size of the micelles, and consequently of the domains, depend on the incompatibility, molecular weight, and fractional composition of the block copolymers and on the casting solvent and the temperature (3-10). 

The decrease in the birefringence for a film obtained by the prolonged evaporation process suggests that stress, i.e., molecular orientation, is relaxed. It is reasonable because the polymer chains are able to move randomly during the cast process. 

The synthesis was carried out by sol-gel process techniques. The sol into a desired shape can be cast and dried. So a nanocomposite formed from silicon dioxide into a fully-integrated matrix of chitin rods. The mechanism is based on a self-organized storage of chitin and weak forces of attraction between chitin and siloxane oligomers. Different textures and morphologies are accessible by adjusting the evaporation process or by applying external fields. 

Many factors determine the porosity and pore size of membranes formed by the solvent evaporation method. The average size of the nonsolvent droplets held in the polymer casting solution increases during the evaporation process. As Figure 8 shows, if the membrane is immersed in a nonsolvent after a short... 

The NCF based thermoplastic starch films have been synthesized using solvent casting method followed by evaporation process. Dispersion of NCF in varied amounts was prepared in water in which TPS is added in respective weight percentage till complete dissolution. Glycerol and acetic acid are added for gelatinization. Average thickness of the films formed is 0.6 mm (Savadekar and Mhaske, 2012). Properties improved as discussed in section 11.1. 

Alloin F, D Aprea A, Dufresne A, El Kissi N, Bossard F. Poly(oxyethylene) and ramie whiskers based nanocomposites influence of processing extrusion and casting/evaporation. Cellulose 2011 18 957-73. 

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