Nanotechnology. Kozhemyakin Nikita, 11b.

What is nanotechnology?• Nanotechnology — the field of fundamental and applied science and engineering dealing with the totality of theoretical justifications, practical methods of research, analysis and synthesis as well as methods of production and use of products with a specified atomic structure by the controlled manipulation of individual atoms and molecules.

Molecular rotors.• Molecular motors are nanoscale machines

capable of rotation upon application thereto of energy. Traditionally, the term "molecular motor" is used when talking about organic protein compounds, however, currently it is used to denote inorganic molecular motors and are used as General concepts. The possibility of creating molecular motors was first articulated by Richard Feynman in 1959.

•Methods of rotation: •1) chemical method; •2) light method;•3) tunneling of electrons;

Сhemical method.

• For the first time about the creation of a molecular rotation engine said Ross Kelly in her work in 1999. His system consisted of three rotors and triptycene galicinao parts, and was able to perform unidirectional rotation in the plane 120 °.

• Rotation takes place in 5 stages. The amino group on triptolemou part of the molecule is converted to solenovo the band by condensing the molecules of phosgene. Rotation around the Central axis through the passage isocyanato group in the vicinity of the hydroxyl group located on galicinao part of the molecule, making these two groups react with each other. This reaction creates a trap for urethane groups, which increases its tension and provides a beginning of the rotational movement at a sufficient level of incoming thermal energy. After bringing molecular rotor in motion, all you need is a small amount of energy for the implementation of a rotational cycle. Finally, the cleavage of the urethane group restores the amine group and provides further functionality to the molecule.

Light method.• In 1999 from the laboratory of Dr. Ben Ferringhi at

the University of Groningen (the Netherlands) reported the creation of a unidirectional molecular rotor[4]. Their molecular motor rotation 360 ° consists of a bis-helicene United axial double bond and having two stereocenter.

• One cycle of unidirectional rotation takes 4 stages. In the first stage, low temperature causes an endothermic reaction in the TRANS-isomer (P, P) converting it into CIS-isomer (M, M), where P is pravonarusheniy spiral, and M is left-twisted spiral (1, 2). In this process, the two axial methyl group is converted to Equatorial. By increasing the temperature to 20 °C the methyl groups are converted back to ectodermally (P, P) CIS axial groups (3). As the axial isomers are more stable than the Equatorial isomer, reverse rotation is impossible. Photoisomerization converts the CIS-isomer (P, P) TRANS-isomer (M, M), again with the formation of Equatorial mailovych groups (3, 4). Thermal process of isomerization at 60 °C closes 360 ° cycle of rotation with respect to its initial position.

Тunneling of electrons.• By analogy with the traditional motor, nanoscale

molecular motors can be powered by resonant or nonresonant electron tunneling. Nanoscale rotary machines based on these principles were developed by Peter Krala and his staff at the University of the state of Illinois in Chicago.

• In a homogeneous electrostatic field E, oriented along the vertical direction, periodic charging and discharging the vane motor via tunnelirovaniya electrons from two neutral metallic electrodes. Each fullerene switch changes the sign of the charge with the help of two electrons with positive (q) negative (-q) through the tunnel between the neutral electrode and the fullerene. To rotate the blade motor electrode lose two electrons (resulting in him changing the battery) and the blade makes a half loop rotation in the electric field E. the Other half cycle of rotation is similar (only the electrode receives two electrons). Thus there is a continuous rotation of three (six) blades with fullerenes. Molecular motor performs its dipole P, which is in the middle ortogonali in the direction of the electric field E, generating a constant torque rotation. The efficiency of the method of tunneling electrons is comparable to the efficiency of the drive macroscopic motors, but it may decrease because of noise and structural defects.

Thanks for watching.