Dispersion Stability Test Aids Characterisation of Functionalised Graphene Materials

A new technical poster from Haydale Ltd. describes a cost-effective and repeatable method for characterisation of functionalised carbon nanomaterials.

Two key, but independent, problems facing the graphene industry are the requirement for chemical functionalisation (essential for homogenous dispersion and application) and the pressing need for reliable, cost-effective, rapid, easy-to-use and accurate characterisation techniques to determine the type and extent of functionalisation present on graphene material.

Current chemical characterisation techniques including X-ray photoelectron spectroscopy (XPS), Raman and Fourier Transform Infrared (FTIR) spectroscopy require a high level of competency and expert ability to interpret results. Moreover the cost of such analytical equipment has meant that the quality control present in the production and functionalisation of graphene has to date been very limited.

Haydale has developed a rapid, in-house characterisation test method (patent applied for) to confirm functionalisation of graphene material.

Most particles, including surface functionalised carbon nanoparticles, dispersed in an aqueous system acquire a surface charge, principally either by ionisation of surface groups, or adsorption of charged species. These surface charges modify the distribution of the surrounding ions, resulting in a layer around the particle that is different to the bulk solution. The stability of a given dispersion depends on the particles’ zeta potential. It is known that surface functionalisation of nanoparticles can improve their dispersion in water and other liquids by modifying the particles’ zeta potential. The stabilising effect of surface functionalisation is easily verified by observation of the dispersion stability over a period of time.

Haydale’s new dispersion stability method provides a rapid, simple and repeatable test to confirm the effectiveness of its HDPlas graphene functionalisation process. Further the method is able to indicate the level of functional groups added and to discriminate between different functional groups. Complimentary to traditional chemical characterisation methods currently used by graphene industry - Haydale's new dispersion stability tester provides an affordable and reliable quality control tool for functionalised graphene process development and manufacturing.