Silver nanoparticle aided self-healing of polyelectrolyte multilayersElectronic supplementary information (ESI) available: TEM image of Ag nanoparticles and Ag nanoclusters, FTIR spectra of dried and wet film, UV-vis of the reduction of silver within the film, self-healing property of in situ optical microscope movie of BPEI-Ag NP-PAA film, self-healing demo movies of BPEI-PAA, BPEI-Ag+-PAA, BPEI-Ag NP-PAA and BPEI-Ag NC-PAA film with each other with water spray. See DOI: 10.1039/c4cp00349g

• Main Authors: Huang, Xiayun, Bolen, Matthew J, Zacharia, Nicole S
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c4cp00349g

Self-healing is the ability of a material to repair mechanical damage. The lifetime of a coating or film might be lengthened with this capacity. Water enabled self-healing of polyelectrolyte multilayers has been reported, using systems that grow via the interdiffusion of polyelectrolyte chains. Due to high mobility of the polyelectrolyte chains within the assembly, it is possible for lateral diffusion to heal over scratches. The influence of metal ions and nanoparticles on this property has, however, not been previously studied. Here we demonstrate that the incorporation of silver nanoparticles reduced in situ within the branched poly(ethyleneimine)-poly(acrylic acid) polyelectrolyte multilayer structure speeds the ability of the multilayer assembly to self-heal. This enhancement of property seems to not be due to changes in mechanical properties but rather in enhanced affinity to water and plasticization that enables the film to better swell. Weak polyelectrolyte multilayer films containing silver nanoparticles are shown to have enhanced ability to self-heal when exposed to water when compared to the films assembled without particles.