Fluorescent particles are becoming high demand items in the oil industry for application as tracers for reservoir monitoring to understand the flow pattern between the wells during waterflood operations and to optimize the oil production. The common tracers, based on organic dyes, are not very stable in harsh downhole conditions and incorporation of fluorophores is also difficult. Carbon quantum dots (CQD), carbon molecules measuring 1 to 10 nm, have recently drawn much attention due to their outstanding fluorescence properties and pending applications towards chemical sensing and bio imaging. In most cases, CQDs outperform the traditional semiconductor metal chalcogenide-based quantum dots. They are also inherently non-toxic and stable in high temperature and pH conditions and are resistant to photobleaching. Synthesis of CQDs from a unique molecular precursor has recently been developed by using a new electrochemical method. These CQDs are water soluble and can be prepared in different color emission by tuning the molecular precursors. Magnetic nanoparticles have created tremendous interest in biological applications, especially for cancer treatment with targeted drug delivery and hyperthermia. Currently used superparamagnetic materials are based on iron oxides and seem to be toxic to biological application, and their magnetic properties are strongly influenced by dispersion and particle size. Alternative materials having higher superparamagnetic properties such as iron carbides and carbon-coated Fe have been explored. The presence of a carbon shell acts as a protective coating against chemical components of biological fluids and is inert to pH changes. Along with their magnetic properties, simulations of fluorescence properties by the same particles could eliminate addition of organic fluorophores (dyes) required for biological imaging. We have recently succeeded in the synthesis of hybrid Fe@C-CNx core-shell particles exhibiting superparamagnetic and fluorescence properties by using a Fe@C core-shell nanoparticles as a starting material. Detailed physiochemical characterization and fluorescence properties of the core-shell particles as well as CQDs will be discussed.

Synthesis and fluorescence properties of carbon quantum dots and core-shell superparamagnetic Fe@C-CNx particles

254th National Meeting (2017)

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