A kind of graphite conductive film and its preparation method and application

Abstract

The invention discloses a graphite conducting film as well as a preparation method and application of the graphite conducting film, and belongs to the field of materials. According to the preparation method, graphite powder and bismuth oxide are mixed according to a mass ratio of 10-1000:1, are ground and uniformly mixed in a ball grinder, and are transferred to the surface of a flexible substrate; or the graphite powder is directly transferred onto the surface of the flexible substrate; the fixation of graphite powder and bismuth oxide mixtures or the graphite powder on the surface of the substrate is realized through mechanical polishing, and the graphite conducting film is obtained. The preparation equipment is simple, the process parameters are easy to control, the yield is high, the cost is low, green and environment-friendly effects are realized, the obtained graphite conducting film has good flexibility, high adhesive force and low resistance, and the peeling off is avoided after the repeated bending; an electrode prepared by the graphite conducting film has low resistance, good mechanical property, and controllable shape and size, and the detection limit on metal ions Pb<2+> is lower than 10ppb. The graphite conducting film disclosed by the invention can be used in the fields of electrode preparation, heavy metal ion detection and the like, and wide application prospects are realized.

Description

technical field [0001] The invention belongs to the field of materials, and relates to a graphite conductive film, a preparation method and application thereof. Background technique [0002] Graphite powder is an ideal material for the preparation of low-cost carbon-based conductive films due to its good electrical conductivity, low cost, and stable chemical and electrochemical properties. It is widely used in membrane switches, flexible printed circuits, and other fields. However, generally speaking, graphite powder is almost insoluble in any solvent. Although a very low-concentration organic solvent dispersion can be prepared by strong ultrasound, it requires a long ultrasonic time (often tens to hundreds of hours), and the prepared The solution concentration is low (usually <0.1mg / mL), and the yield is very low. Although graphite powder can be exfoliated into graphene oxide by chemical oxidation, and a graphene solution with good conductivity, solvent dispersibility a...

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Problems solved by technology

However, generally speaking, graphite powder is almost insoluble in any solvent. Although a very low-concentration organic solvent dispersion can be prepared by strong ultrasound, it requires a long ultrasonic time (often tens to hundreds of hours), and the prepared Low solution concentration (typically <0.1mg / mL), very low yield

Although graphite powder can be exfoliated into graphene oxide by chemical oxidation, and a graphene solution with good conductivity, solvent dispersibility and film-forming properties can be formed by various reduction methods, the preparation of such conductive carbon material dispersion system The method involves complex chemical reactions, and there are problems such as long preparation period, high production cost, and large environmental pollution.

[0003] In order to overcome the problem of poor dispersion of graphite materials, the existing commercial conductive carbon paste generally disperses graphite powder in a high-viscosity solution composed of binders, solvents and additives through physical methods such as mechanical grinding or stirring.

Although this type of conductive carbon paste can also form a low-resistance conductive film, due to its high viscosity, only thick film electrodes with large thickness can only be prepared by screen printing.

At the same time, these conductive carbon pastes contain organic solvents and hydrophobic polymer additives, which have disadvantages such as poor biocompatibility and electrochemical performance, slow drying and film formation, and the surface morphology and properties of the formed conductive film are also difficult to control.

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