Langmuir trough schematic

FIG. 27 Schematic (not to scale) of the SECM-induced transfer of oxygen across a 1-octadecanol monolayer, at the air-water interface, in a Langmuir trough. 

Figure 8.11 Schematic sectional diagram of the Langmuir trough showing a trapped film of insoluble surfactant molecules.

Figure 7.33 Langmuir-Blodgett film formed by polydiacetylene (a) schematic diagram of Langmuir trough and (b) structure of a typical polydiacetylene film. (After Williams, 1983.)... 

Fig. 6.1. Schematic drawing of Langmuir trough and balance for measuring surface pressures. (Taken from unpublished work by D Arrigo, Israelachvili and Pashley.)...

Fig. 11. (A) Design of the Langmuir trough used in the current studies. The trough is shuttled under computer control for IR illumination of the background surface and monolayer covered surface. (B) Schematic of the IRRAS instrument displaying the sections of the accessory that rotate in concert under computer control to provide the desired angle of incidence. Taken from Ref. [81] with permission from American Chemical Society.

The basic features of the original Langmuir trough are shown schematically in fig. 3.4. The trough usually consists of a rectangular tray containing the fluid phase(s). It is equipped with a barrier that floats on the surface (i.e. it is positioned in the interface). The areas at both sides of the barrier can be varied in a controlled way. 

The infrared reflection-absorption spectroscopy was performed on a Bruker IFS 66 spectrometer (Karlsruhe, Germany) equipped with a MCT detector and a modified external reflection attachment P/N 19650 of SPECAC (Orpington, UK). This included a miniaturized Langmuir-trough, permitting thermostatic measurements. An extensive description of the method can be found in Gericke et al. (1993). The IRRAS set-up as well as the experimental approach can be inferred from the schematic sketch shown in Fig. 2. 

Figure 1. Schematic diagram of a Langmuir trough. The monolayer is deposited to the right of the barrier, and the barrier can be moved across the surface to change the area accessible to the monolayer. The surface pressure can be measured either by determining the force on a float that separates the monolayer from a clean water surface, or from the difference in the force exerted on the Wilhelmy plate when the plate is suspended in pure water and in water covered by the monolayer.

Figure 12 Schematic showing transitions of a typical sur ce pres-sure/area(n/A) isotherm for a compressed mono-layer of surfactant myristic acid spread on 0.1 M HCl in a Langmuir-trough apparams. (From Ref. 141.)...

Figure 13.7 Schematic of Y-type deposition in a Langmuir trough, (a) Compressed monolayer of molecules on water surface, (b) Deposition of first monolayer on withdrawal of hydrophiUc substrate, (c) Deposition of second monolayer on insertion of hydrophilic substrate, (d) Deposition of third monolayer in a head-to-head and tail-to-tail configuration...

Fig. 1 A schematic drawing of a Langmuir trough instrument. The working electrode resides at the air/water interface. Its type and design reflect a particular type of electrochemical experiment to be carried out to characterize monolayers on the air/water interface.

Fig. 3 Schematic depiction of the Langmuir trough apparatus and the positioning of the electrodes used in the lateral monolayer flow experiments. The inset shows the Au-coated glass slide working electrode modified with a self-assembled monolayer (SAM) of dodecanethiol. The working electrode is touching the air/water interface. A compound that forms a Langmuir monolayer is deposited on the water surface. It immediately spreads to cover the entire interface. Subsequently, the Langmuir film flows across the triple phase boundary into the SAM/water interface forming a bilayer. The lateral flow is completed when the entire electrode/solution interface is coated with a bilayer (from Ref 37).

FIGURE 7.3 Schematic representation of a Langmuir trough. The harrier BB is movable over the slidings R to vary the enclosed interfacial area. The corresponding force is measured by a torsion wire T that is connected to the barrier. As an alternative, the interfacial tensions at both sides of the barrier may be measured independently. 

Figure 11.4 Schematic of a Langmuir trough. The marks on the side of the trough indicate distance and hence area of the surface. The inset indicates the compression of the molecules by the moving barrier. ...

Fig. 1 Top section, schematics of the glass cell and the electrochemical Langmuir trough. Bottom section, space-filling models of surfactants used in our studies...

FIGURE 8.17 Schematic representation of the organization of nanotube hexamers on the water surface of a Langmuir trough. 

FIG. 15 Schematic of the miniature Langmuir trough used to study particle mono-layers at oil/water and air/water interfaces. The trough, machined from Teflon, has a steel lining with sharp edges to pin the oil/water or air/water interface. For study of oil/water systems the oil is added to the water surface and overflows into the channels around the trough. The barriers enclosing the monolayer are made of steel. 

Figure C2.4.2. Schematic sideview of tlie trough. The movable barrier is used to push tire molecules on tire subphase togetlier in tire Langmuir film which is subsequently transferred to a solid substrate.

In 1934, Langmuir s trainee, Blodgett [7], built the first trough for transferring the films from air water interface onto a solid substrate, and the first LB films were prepared. The transfer is represented schematically in Figure 12.3. First a Langmuir film is prepared on the air water interface. The film is compressed until it becomes solid, after which the pressure is maintained constant. Next a vertically oriented hydrophilic substrate is slowly immersed into water. The hydrophobic tails of the amphiphiles do not have a... 

Fig. 13.13 Schematic of Langmuir-Blodgett monolayers. As the trough wall are pushed in, indicated by the arrows, the surface pressure is increased and the nanowires transition through the sequence of phases isotropic, 2-D nematic, 2-D smectic, 3-D nematic...

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