Influence of terpinol-butanol composition on electrical properties and ageing factor behaviour of hybrid conductive inks

Abstract

Hybrid conductive inks based on graphene nanoplatelets (GNP) and silver (Ag) are promising for printed electronics where electrical reliability under mechanical loading is required. This study evaluates the influence of the terpinol (T) to butanol (B) solvent ratio on the electrical behaviour and ageing response of hybrid GNP/Ag conductive ink. Three formulations, 5T:10B, 10T:10B and 15T:10B, were screen printed on copper (Cu) substrates and cured at 250 °C for one hour. Cyclic torsional loading at ±90° was applied from 1000 up to 4000 cycles, followed by room temperature ageing for five weeks. Resistance and resistivity increased with torsional cycling for all formulations. The most pronounced change occurred beyond 2000 cycles. The 10T:10B formulation exhibited the lowest resistivity after 4000 cycles, while the 5T:10B and 15T:10B compositions showed higher degradation associated with solvent ratio differences in filler distribution. During ageing, only minor resistivity changes were observed. No cumulative degradation was detected at room temperature. These results indicate that a balanced terpinol to butanol ratio supports a conductive network that is resilient to cyclic torsion and short-term environmental exposure. The 10T:10B solvent ratios provide the most favourable electrical stability.