Adventurous Chemistry - A New Generation of Nanoarchitectured Surfaces

Lead Research Organisation: University of Southampton
Department Name: Sch of Chemistry

Abstract

The electrochemical deposition of metals, often called electroplating has been used for over a century to deposit thin continuous coatings of one metal over another for decorative effect or to improve the functional properties of the structure. Obvious everyday examples are the electroplating of silver onto cutlery as used in electroplated nickel silver (EPNS), gold plating of electrical contacts in microelectronics, electroplating of jewellery for decorative effect or the chrome plating of the trim on 1950s American automobiles. In all cases the thin metal coating is deposited by passing a current through a solution of the appropriate metal salt. The thickness of the coating is controlled by the amount of current passed and the properties (smoothness, adherence, etc.) by the choice of the conditions used.In this research project we want to explore some totally new ways of using electrodeposited coatings where we control their structure on the one to one hundred nanometre scale (a nanometre is 1/1,000,000,000 of a metre; a seventy thousand times smaller than the diameter of a human hair). To do this we will use templating methods where the template controls the size and distribution of the arrays of regular pores created within the metal films or by using techniques where we guide the deposition using extremely fine carbon nanotube fibres. If we control the structures of the metal films on this scale we can introduce new and exciting properties which we can vary and tune by adjusting the template structure that we use. In addition, the electrodeposition method still allows us to control the thickness of the material that we deposit, we still have a very wide range of metals that we can choose from, and as an added bonus the method is still quite cost effective to implement.To start with we have identified six novel ideas that we want to test:- designing metal surfaces so that they are super sensitive to the presence of molecules adsorbed on their surfaces and so can be used to study these molecules through their pattern of vibration of the bonds within the molecule; - the deposition of unique metal structures which have a handedness so that they are not superimposable on their mirror image (like one of your hands), this should produce metals with some remarkable, and novel, properties;- writing nanotracks onto surfaces in a process that could be used to manufacture the next generation of computer chips;- making arrays of minute metal dots on surfaces as designer catalysts for a range of clean and efficient processes;- making novel devices which sense sound waves and can be used to generate sound waves;- creating a novel type of optical mirror whose properties can be tuned by passing a current through the nanostructured film.

Publications

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Description The electrochemical deposition of metals, often called "electroplating", has been used for over a century to deposit thin continuous coatings of one metal over another for decorative effect or to improve the functional properties of the structure. Obvious everyday examples are the electroplating of silver onto cutlery as used in electroplated nickel silver (EPNS), gold plating of electrical contacts in microelectronics, electroplating of jewelry for decorative effect or the chrome plating of the trim on 1950s American automobiles. In all cases the thin metal coating is deposited by passing a current through a solution of the appropriate metal salt. The thickness of the coating is controlled by the amount of current passed and the properties (smoothness, adherence, etc.) by the choice of the conditions used.

In this research project we explored some totally new ways of using electrodeposited coatings where we controlled their structure on the one to one hundred nanometre scale (a nanometre is 1/1,000,000,000 of a metre; a seventy thousand times smaller than the diameter of a human hair). To do this we used templating methods where the template controls the size and distribution of the arrays of regular pores created within the metal films or by using techniques where we guided the deposition using extremely fine carbon nanotube fibres.

By controlling the structures of the metal films on this scale we can introduce new and exciting properties which we can vary and tune by adjusting the template structure that we use. In addition, the electrodeposition method still allows us to control the thickness of the material that we deposit, we still have a very wide range of metals that we can choose from, and as an added bonus the method is still quite cost effective to implement.

In the project we investigated six novel ideas:

- designing metal surfaces so that they are super sensitive to the presence of molecules adsorbed on their surfaces and so can be used to study these molecules through their pattern of vibration of the bonds within the molecule;

- the deposition of unique metal structures which have a "handedness" so that they are not superimposable on their mirror image (like one of your hands), this should produce metals with some remarkable, and novel, properties;

- writing nanotracks onto surfaces in a process that could be used to manufacture the next generation of computer chips;

- making arrays of minute metal dots on surfaces as designer catalysts for a range of clean and efficient processes;

- making novel devices which sense sound waves and can be used to generate sound waves;

- creating a novel type of optical mirror whose properties can be tuned by passing a current through the nanostructured film.

Good progress was made in each area although writing nanotracks proved more difficult than anticipated. A number of new nanostructured surfaces were prepared and their properties studied leading to on going research.
Sectors Chemicals