Substrate vertical

Figure 3.9. Scheme of the LB technique (a) deposition of the amphiphiles on the water subphase with the solid substrate submerged (b) by action of the barrier the ML is compressed (c) by pulling out the substrate vertically a ML is transferred to both sides of the substrate (d) a multilayered structure is built up by repeated up and down strokes of the substrate, (e) Distinct arrangements of LB Aims. 

Typical LB films are constructed through transferring monolayers of amphiphilic molecules at the air-water interface onto solid substrates [8,12,13]. The amphiphilic molecules are first dissolved in an organic solvent that is immiscible with water, spread on a water surface, and compressed by decreasing the area in which the molecules are confined, to form a monolayer at the air-water interface. Then the monolayer is transferred onto a solid substrate by moving the substrate vertically or horizontally. This procedure allows us to obtain ultrathin films with the struc-... 

Quality in matrix printing depends strongly on the accuracy with which individual dots are placed on substrate. Vertical placement errors are primarily caused by the inkjet system and horizontal errors by print head velocity variations. Dot placement errors fall into two general classes Those that affect all dots uniformly (either vertically... 

Figure C2.4.4. Schematic diagram of the transfer process of LB films onto a hydrophilic substrate. Vertical upward and downward strokes result in hydrophobic and hydrophilic surfaces, respectively.

In order to test these assumptions, they investigated the effects of vertical gas jets (hydrogen with 0.5% methane and acetylene) blown through the filament array with a velocity of about 1000 cm s and striking the substrate vertically. With methane, maximum growth rates of several pmh were found at the stagnation point of the jet while in the case of acetylene a growth rate depression was observed at this point. 

Fig. 3.16 Au-coated nanopillars as SERS-active substrates vertical (left) and leaning (right) nanopillars (reproduced with permission from Yang et al. 2013. Copyright 2013 American Chemical Society)...

Fig. 4.15. Angular dependence of the fluorescence radiation emitted from a Co-layered Si substrate. The Co-Ka intensity is plotted semi-logarithmically for layers of different thickness (mm). The maxima forthe ultra-thin Co-layers are located at the critical angle of Si (dashed vertical line). They are shifted to the critical angle of Co (dotted vertical line) ifthe layer is more than 10 mm thick ([4.21], after Ref [4.41]).

This test measures the ability of a tape to resist creep under applied load. The test is covered in ASTM D-3654 and PSTC-7. A specified area (typically 12.7 mmx 12.7 mm) of conditioned tape is rolled down with a specified pressure on the substrate of choice, such as polished 302 stainless steel. The panel is fixed in the vertical position or up to 2° tilted back so that there is no element of low angle peel in the test (Fig. lb). A weight (often 1000 g) is fixed to the end of the tape and the time to failure, i.e. complete detachment from the plate, is measured. Infrequently, the time required for the tape to creep a given distance is measured and reported. 

All of the eommereial alkyl eyanoaerylate monomers are low-viseosity liquids, and for some applications this can be an advantage. However, there are instances where a viseous liquid or a gel adhesive would be preferred, sueh as for application to a vertical surface or on porous substrates. A variety of viscosity control agents, depending upon the desired properties, have been added to increase the viscosity of instant adhesives [21]. The materials, which have been utilized, include polymethyl methacrylate, hydrophobic silica, hydrophobic alumina, treated quartz, polyethyl cyanoacrylate, cellulose esters, polycarbonates, and carbon black. For example, the addition of 5-10% of amorphous, non-crystalline, fumed silica to ethyl cyanoacrylate changes the monomer viscosity from a 2-cps liquid to a gelled material [22]. Because of the sensitivity of cyanoacrylate esters to basic materials, some additives require treatment with an acid to prevent premature gelation of the product. 

To make contact with the SEA experiment one has to realize that the confining surfaces are only locally parallel. Because of the macroscopic curvature of the substrate surfaces, Tzz becomes a local quantity which varies with the vertical distance Sz = Sz x,y) between the substrate surfaces (see Fig. 2). Since the sphere-plane arrangement (see Sec. II Al) is immersed in bulk fluid at pressure Pbuik the total force exerted on the sphere by the film in... 

Fig. 15—Sketch of preparation of L-B films (a) spread amphiphilic molecules on water surface, (b) compress the molecules using the barrier to get close packed and ordered molecular film, (c) transfer the film onto a substrate through the vertical immerse/retreat process, (d) transfer the film by horizontal lifting.

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