Stimuli-responsive supramolecular thermal management materials with pH-Adjustable thermomechanical properties

The escalating power density in contemporary electronic architectures has engendered an acute demand for advanced thermal interface materials (TIMs) capable of mitigating interfacial thermal resistance. Concurrently, stimuli-responsive soft matter systems have garnered considerable attention owing to their capacity for externally triggered property modulation. Herein, we report a pH-responsive supramolecular system (PRSS) exhibiting tunable thermal conductivity and viscoelastic behavior, engineered through the supramolecular complexation of synthesized long-chain amidoamine surfactants (AA) and citrate-stabilized silver nanoparticles (AgNPs). The PRSS manifested a tunable viscosity across the pH range of 4 to 10, with the zero-shear viscosity spanning from 43 to 14460 Pa s, corresponding to an approximately 330-fold dynamic range in rheological response. Oscillatory rheology revealed a pH-dependent viscoelastic response, from loss-dominated behavior at low pH to a strongly elastic-dominant interconnected network at intermediate pH, followed by weakening of the network at higher pH. Concomitantly, the effective thermal conductivity of the PRSS was modulated from 0.2 to 1.12 W/m·K at a fixed amidoamine-to-AgNP mass ratio. The thermal response is associated primarily with pH-dependent supramolecular network organization, while AA–AgNP interactions may contribute structurally by promoting network connectivity. These findings underscore the potential of supramolecular nanocomposite systems as adaptive TIMs for thermal management applications that require tunable thermophysical and rheological characteristics.