Deep Eutectic Solvents (DES) can be formed between a variety of quaternary ammonium salts and carboxylic acids. The physical properties are significantly affected by the structure of the carboxylic acid but the phase behavior of the mixtures can be simply modeled by taking account of the mole fraction of carboxylic acid in the mixture. The physical properties such as viscosity, conductivity, and surface tension of these DES are similar to ambient temperature ionic liquids and insight into the cause of these properties is gained using hole-theory. It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts. The DES are also shown to be good solvents for metal oxides, which could have potential application for metal extraction.

Deep Eutectic Solvents Formed between Choline Chloride and Carboxylic Acids: Versatile Alternatives to Ionic Liquids

Statistics: Methods and Applications.

Co–P alloy coatings were electrodeposited from a Watts type base electrolyte using a galvanostatic pulse plating technique. Alloy deposits of P content as low as 1% were obtained operating at very high pulse current density and low duty cycle from an electrolyte with a small concentration of phosphorous acid, in the presence of a surfactant and a stress reliever. Alloy deposits with low P content – in the range 1–2% – had a peculiar mixed nanocrystalline-amorphous structure; a fully amorphous deposit was obtained when the P content was in excess of about 5–6%. A short and relatively low temperature annealing of the mixed structure triggered a strong enhancement of the hardness, in connection with the precipitation of a phosphide phase in a slightly regenerated nanocrystalline structure. The remarkable thermal stability of the transformed structure of the alloy was lost in conjunction with the on-set of the allotropic transformation from hcp to fcc-Co. A side effect of the hardening was the cracking of the layer and its obvious impact on the protective performance of the Co–P alloy deposit. Alloy deposits with low P content and a mixed nanocrystalline–amorphous structure hold promise as alternative to traditional electroplated hard coatings.

Mixed amorphous-nanocrystalline cobalt phosphorous by pulse plating

A brief critical review is presented of papers on pulse plating, published in recent years in Transactions.

Pulse plating in third millennium

Co–P multilayer film electrodeposited under DC electrolysis

Optimal conditions for a laser-enhanced electrodeposition of nickel coatings have been specified. Comparative results of structure and mechanical properties of electrically deposited nickel coatings produced by a laser-enhanced galvanostatic method and without laser emission were analysed. It was found that laser medium wave IR radiation has a local thermal effect on the process of electrodeposition and stimulates formation of a nickel coating structure which is of a more equilibrium state, less defective and has reduced internal stress in the area of local laser heating. Studies of plating rate showed a 1.4 times increase for nickel coatings in conditions of laser-enhanced electrodeposition due to reduction of common cathode overpotentional and increase of cathode metal efficiency, that involves generation of a more coarse microcrystal structure. Results of studies of the laser radiation effect on structure and properties of nickel coatings show potential for increased adhesion of electrodeposited coatin...

Laser-enhanced electrodeposition of nickel coatings

The influence of the quantity and thickness of successive crystalline and amorphous layers on magnetic properties of multilayer Co 100 N P N (8<x<12) films has been studied. Being dependent of the thickness and quantity of successive layers of crystalline Co v2 P 8 and amorphous Co 88 P 12 phases, the coeicivity of multilayer films, has been found to have a value in a range of 31-65 kA m -1 .

Multilayer Compound Co-P Films with Controlled Magnetic Properties

The structure and thermal stability of Ni 100-x P x films (8<x<14.5) under isothermal annealing have been studied by X-ray and D TA methods. Equilibrium Ni and Ni 3 P phases have been found to be the final breakdown products on crystallisation of amorphous Ni-P films. The start of the crystallisation process for the concentration range studied has been shown to be shifted towards a higher temperature region with increasing phosphorus concentration. Non-equilibrium conditions of crystallisation using pulsed electrodeposition have been shown to have an essential effect on the processes of structure relaxation.

Structural transitions of Ni-P films electrodeposited by pulsed current

The parameters of program-controlled current pulses for obtaining stable protective coatings with low internal stress are established by analysing theoretical calculations and experimental data.

The Application of Program-Controlled Pulsed Current for Obtaining Metallic Coatings with Specific Properties

The processes of structural relaxation in amorphous Co 1x P x (5<x<16) films obtained by deposition with pulsed current have been studied by X-ray, DTA and isothermal annealing methods. The start of the crystallization process has been found to be shifted towards the higher temperature region as the phosphorus concentration increases. It has been determined that the final products of crystallization of amorphous Co-P films are β-Co and Co 2 P phases. The nonequilibrium nature of the crystallization process caused by pulsed current has been shown to essentially affect the processes of structural relaxation.

E. Ph. Shtapenko

Papers

Laser-enhanced electrodeposition of nickel coatings

Multilayer Compound Co-P Films with Controlled Magnetic Properties

Structural transitions of Ni-P films electrodeposited by pulsed current

The Application of Program-Controlled Pulsed Current for Obtaining Metallic Coatings with Specific Properties

The structural relaxation of amorphous Co-P films obtained by pulsed current