Maze Solving Using Fatty Acid Chemistry

This study demonstrates that the Marangoni flow in a channel network can solve maze problems such as exploring and visualizing the shortest path and finding all possible solutions in a parallel fashion. The Marangoni flow is generated by the pH gradient in a maze filled with an alkaline solution of a fatty acid by introducing a hydrogel block soaked with an acid at the exit. The pH gradient changes the protonation rate of fatty acid molecules, which translates into the surface tension gradient at the liquid–air interface through the maze. Fluid flow maintained by the surface tension gradient (Marangoni flow) can drag water-soluble dye particles toward low pH (exit) at the liquid–air interface. Dye particles placed at the entrance of the maze dissolve during this motion, thus exhibiting and finding the shortest path and all possible paths in a maze

Reduction of Carbon-Carbon Double Bonds by Hydrazine

A study was made of the mechanism of reduction of olefinic bonds by hydrazine. It was established that reduction takes place only in presence of oxygen (or a suitable oxidising agent) and that two molecules of hydrazine are required to hydrogenate one double bond. The overall stoichiometry of the reaction was found to be represented by the following equation: -CH=CH- + 2N2H4 +3/2 02 —> -CH2-CH2- +2N2 + 3 H2O Investigations of the effects on the reaction of the appropriate variables shown it to occur only in presence of weak acids, though under alkaline conditions, and in ionizing media. These results, supported by measurements of conductance changes during the reaction, indicate that the hydrazonium ion, and not the hydrazine molecule, is the initial reactant. The above facts, together with detailed studies of reaction kinetics, led to the suggestion of the following reaction mechanism. It is postulated that the overall reaction consists of three main stages: (i) oxidation of hydrazonium ion to protonated diimide (diimide cation): (ii) less of the proton by the diimide cation under the action of hydroxyl ions with the formation of an equimolar mixture of syn- and anti- diimide; (iii) hydrogenation of the double bond by the syn- diimide via the formation of a cyclic, hydrogen-bonded complex. The anti- diimide is not capable of reducing the olefinic link and it is further oxidised to nitrogen and water. The experimental work on the mechanism of reaction was performed with oleic acid and oleyl alcohol. However, reduction by hydrazine has also been successfully applied to a variety of other unsaturated compounds, including acids, alcohols, hydrocarbons, carbonyl and ring compounds. Hydrogenation of the double bonds always occurred provided there was no interference from side reactions with hydrazine