Langmuir-Schaefer transfer method

Fig. 8 shows an AFM image of a DPPC bilayer formed using a combination of the LB technique and the Langmuir-Schaefer (LS) method [18]. In this approach, the first monolayer is deposited onto the substrate using the LB dipping technique. The second monolayer is deposited on the first using the LS approach where the substrate is positioned parallel with the air-water interface and transferred through the interface. This results in a Y-type lipid bilayer supported on a substrate. 

Another procedure for transferring monolayers is the Langmuir-Schaefer (LS) method, in which the solid support is moved downward until it horizontally touches the monolayer at the liquid interface. After contacting for a few or a few tens of seconds the solid substrate is withdrawn or pushed down into the liquid subphase. The LS method is far less popular than the LB method but it may be preferred for use with monolayers that are rather rigid. 

The other method of monolayer transfer from the air/water interface onto solid substrates is illustrated in Figure 2. This method is called the Langmuir-Schaefer technique, or horizontal lift. It was developed in 1938 by I. Langmuir and V. Schaefer for deposition of protein layers. Prepared substrate horizontally touches the monolayer, and the layer transfers itself onto the substrate surface. The method is often used for the deposition of rigid monolayers and for protein monolayers, hi both cases the apphcation of the Lang-muir-Blodgett method produces defective films. 

In the Langmuir-Schaefer method, a flat substrate is placed horizontally onto a compressed monolayer on the liquid-air interface. When the substrate is lifted horizontally and separated from the water subphase, the monolayer is transferred onto the substrate (Figure 4). The method is useful to transfer viscous films as well as monolayers of lipids and proteins. ... 

The grafting-to method is based on the synthesis of polymer chains in solution, which are then physically or covalently bound to a solid surface. Various grafting-to methods have been used (i) spreading and fusion of micelles or vesicles on solid supports, (ii) transfer of monolayers (Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS)), and (iii) LbL methods. ... 

The second way of preparing L-B monolayer structures, the horizontal lifting method, was introduced by Langmuir and Schaefer. In this method, a compressed monolayer first is formed at the water-air interface, and a flat substrate is then placed horizontally on the monolayer film. When the substrate is lifted and separated from the water surface, the monolayer is transferred onto the substrate, as depicted in Fig. 15(d). 

Another way of transferring monolayers to solid substrates is the horizontal dipping method, first applied by Langmuir and Schaefer to deposit proteins onto... 

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