Remote activation by green-light irradiation of shape memory epoxies containing gold nanoparticles

A.B. LEONARDI; J. PUIG; J. ANTONACCI; G. F. ARENAS; I. A. ZUCCHI; C. E. HOPPE; L. REVEN; L. ZHU; V. TOADER; R. J. J. WILLIAMS

EUROPEAN POLYMER JOURNAL

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 71 p. 451 - 460

0014-3057

Shape memory epoxies (SMEs) that can be remotely activated by the use of green light, are described. An epoxy matrix based on on diglycidylether of bisphenol A (DGEBA cured with a mixture of n-dodecylamine (DA) and m-xylylenediamine (MXDA), exhibits excellent shape memory properties as described in a previous paper [Leonardi et al. Eur Polym J 2011; 47: 362-9]. Au NPs with an average diameter close to 5 nm could be uniformly dispersed in this matrix using poly(ethylene oxide) (PEO) chains as stabilizer. These NPs showed a significant photothermal effect even at very low concentrations (0.01 wt % as metallic gold), when irradiated with a 532 nm laser at a power close to 2 w/cm2. Under these conditions, a bended bar (1.4-mm thickness) recovered its initial shape in a few seconds. This formulation may be used to build up devices with the necessary mechanical strength and with the possibility to produce shape recovery by remote activation using green light. A second example was analyzed employing an amphiphilic epoxy matrix to produce a uniform dispersion of Au NPs stabilized with dodecyl chains (average diameter close to 3 nm). A bar (1.4-mm thickness) of the SME with 0.04 wt % Au NPs (as metallic gold) showed a fast recovery of its initial shape by irradiation with a 532 nm laser at a power close to 2 w/cm2. This example shows the feasibility of adapting the epoxy chemistry to disperse Au NPs stabilized with different ligands and obtained through robust synthetic methods.