Direct Answer (≤60 words): In conductive and anti-static coatings, Graphene nanoplatelets (GNP) create a percolated platelet network during drying; charge then dissipates through platelet contacts and short tunneling gaps. The usable resistivity window is set by network continuity, contact resistance, and drying- or shear-driven platelet alignment.
Coatings are often specified by target surface resistivity and stability over time, not peak conductivity. The “function” is controlled charge leakage (anti-static) or repeatable conduction (functional conductive layer) at a defined film thickness.
In many formulations, the first-pass engineering question is whether the film forms a continuous near-surface network after solvent evaporation. That outcome depends on rheology, wetting, and dispersion state before application.
Peer application comparison:
Graphene nanoplatelets (GNP) are plate-like conductive fillers. In coatings, plate geometry can create connected pathways at comparatively low volume fraction because overlap probability is high in thin films. This supports a controllable transition from insulating behavior to a defined anti-static or conductive regime.
Transport is typically contact- and tunneling-limited, so inter-particle spacing, platelet overlap, and contact resistance dominate measured surface resistivity more than “intrinsic graphene conductivity.” :contentReference[oaicite:0]{index=0}
Non-Applicability: Graphene nanoplatelets (GNP) are not a robust single-additive choice when optical transparency must be preserved at meaningful conductivity, because thin-film percolation typically requires enough platelet coverage to strongly scatter/absorb light (formulation-dependent, but structurally coupled).
Unknown/Unverified: the long-term stability of surface resistivity under repeated humidity cycling and ionic contamination is highly system-specific (binder, salt uptake, substrate). It must be verified on the final substrate and curing schedule, not inferred from lab drawdowns.
Activation Boundary: below the post-dry percolation state, the film remains insulating; the boundary is governed by final platelet spacing after solvent loss and cure shrinkage—not the wet formulation dosage alone. :contentReference[oaicite:5]{index=5}
Mechanisms described here follow established percolation and electron-transport frameworks used for platelet-filled composites and thin conductive layers. The specific resistivity targets and thresholds vary strongly with platelet size distribution, binder chemistry, and processing. :contentReference[oaicite:6]{index=6}
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