By Marotti F.
The Langmuir strategy is likely one of the commonest equipment for getting ready twodimensionalmolecular assemblies. during this strategy, an answer of an amphiphilic compound in a low-boiling solvent, often immiscible with water, is unfold on a water subphase. After the solvent has evaporated, the amphiphilic molecules shape a monolayer during which their hydrophilic heads engage with the water subphase and the hydrophobic tails are directed clear of it. Compression of the monolayer at the water subphase results in a discount of the world to be had in step with molecule (A), hence inflicting a rise in floor strain (!). The ensuing π-A isotherm (surface strain as a functionality of the molecular region at consistent temperature) presents details at the molecular packing in the monolayer, the orientation of the headgroups, the molecular quarter requirement, and attainable interactions with molecules or ions dissolved within the aqueous subphase. The monolayer shaped on the air-water interface will be transferred onto a fantastic help (Langmuir-Blodgett deposition). as a result of the ease in assembling amphiphiles right into a number of skinny movies with outlined composition, constitution, and thickness, the Langmuir and Langmuir-Blodgett (LB) recommendations have allowed the improvement of novel practical fabrics by way of many scientists.
Read or Download Cavitand-, Fullerene-, and Porphyrin Porphyrincontaining Mechanically and Optically Active Monolayers PDF
Best physics books
This e-book presents a entire advent to the starting to be box of nuclear good kingdom physics with synchrotron radiation, a strategy that's discovering a couple of distinctive functions in fields akin to magnetism, floor technology, and lattice dynamics. because of the outstanding brilliance of contemporary synchrotron radiation resources, the tactic is especially suited to the learning skinny movies, nanoparticles and clusters.
Conceived as a reference handbook for training engineers, device designers, carrier technicians and engineering scholars. The comparable fields of physics, mechanics and arithmetic are usually included to augment the knowledge of the subject material. historic anecdotes way back to Hellenistic occasions to fashionable scientists support illustrate in an pleasing demeanour rules starting from impractical innovations in heritage to those who have replaced our lives.
- Technische Mechanik 3.. Kinetik (Springer, 2004)(ISBN 3540221670)(300s)
- Transistor Physics
- The Physics of the Cosmic Microwave Background
- The Astronomer Jules Janssen: A Globetrotter of Celestial Physics
- Trapped Particles and Fundamental Physics
Extra info for Cavitand-, Fullerene-, and Porphyrin Porphyrincontaining Mechanically and Optically Active Monolayers
At a surface pressure of ca. 37 mN m–1, image 3 shows bright spots, indicating the formation of small condensation nuclei or germs corresponding to the start of the monolayer collapse. These spots cluster (image 4) and fuse as the surface pressure is further raised, evidencing collapse of the monolayer. These results are in full agreement with those reported by Seoane et al. , demonstrating the accuracy of the employed instrument. 2 Grazing Incidence X-Ray Diffraction X-Ray diffraction techniques have been extensively used in order to determine the monolayer thickness of LB films [117-119].
Cavitands with cavities of various sizes can be used as chemical sensors. Schematically, a chemical sensor consists of both a sensing 6 Chapter 1 material, interacting with the species present in the environment, and a transducer which converts the chemical informations into measurable data . 6) carrying four dialkyl sulfide chains as a model system. 6 SAM of MeCav-thioether 5 reported by Dalcanale and coworkers . They observed the response of cavitand 5 to different analytes by exposing the SAM to a range of vapor concentrations between 0 and 2000 ppm.
Diederich, Pretsch, and co-workers prepared a gold electrode 4 The wetting contact angle or wettability (θ ) is measured by placing a small drop of a liquid (water or hexadecane) on the horizontal substrate and measuring the angle subtended by the edge of the drop and the substrate. Depending on the polarity of the surface and the liquid, the droplet may spread on the horizontal substrate assuming different shapes and consequently different contact angles which provide information about the polarity of the outer surface of the SAM (static experiment), as well as the packing of the monolayer (dynamic experiment).
Cavitand-, Fullerene-, and Porphyrin Porphyrincontaining Mechanically and Optically Active Monolayers by Marotti F.