Metal Nanoparticles Acting as Light-Activated Heating Elements within Composite Materials

The photothermal effect of metal nanoparticles embedded in polymeric materials can be used to effi ciently generate local heat for in situ thermally processing within an existing material. Fluorescent probes are employed as thermal sensors to allow dynamical measurement of the amplitude and rate of temperature change within the polymer matrix. The effi cacy of this technique is demonstrated in polymer nanocomposite samples with different morphological characteristics, namely nanofi brous mats and thin fi lm samples. For similarly thick materials and both types of sample morphology, average temperature increases on the order of ≈ 100s ° C are readily obtained with dilute nanoparticle concentrations under relatively low irradiation intensity. Thus, the in situ photothermal heating approach has great potential for controllably driving a multitude of thermal processes, such as triggering phase transitions, generating site-specifi c cross-linking, or initiating chemical reactions from within a material.