abstract
Nanocomposites containing Ag nanoparticles (average diameter similar to 11 nm) dispersed in poly(tertbutylacrylate) were prepared by in situ polymerization via miniemulsions and constitute active and versatile SERS substrates. The use of this synthetic strategy enables the dual use of the final composites as SERS substrates, both as aqueous emulsions and as cast films, shown here by several measurements using thiosalicylic acid as the testing analyte. The main advantage of these types of materials is related to the potential to scale up and the widespread use of handy substrates, using technology already available. This requires homogeneous composite substrates with SERS activity and this was demonstrated here by means of confocal Raman microscopy. Finally, a series of experiments were carried out on Ag/polymer nanocomposites submitted to temperature variations below and above the polymer glass transition temperature (T(g)) in order to conclude about the effect of temperature processing conditions on the composites' SERS activity.
keywords
ENHANCED RAMAN-SCATTERING; GLASS-TRANSITION; HOT-SPOTS; SPECTROSCOPY; NANOPARTICLES; ENCAPSULATION; MINIEMULSION; ELECTRODE; COLLOIDS; SPECTRA
subject category
Chemistry; Materials Science
authors
Fateixa, S; Girao, AV; Nogueira, HIS; Trindade, T
our authors
Ana Violeta Girão
Junior Researcher
Helena Isabel Seguro Nogueira
Assistant Professor with Aggregation
Sara Fateixa
Post-Doc Fellowship
Tito Trindade
Full professorGroups
G1 - Porous Materials and Nanosystems
G3 - Electrochemical Materials, Interfaces and Coatings
acknowledgements
We thank Fundacao para a Ciencia e Tecnologia (FCT/FEDER) for the following grants: SFRH/BD/66460/2009 (S. Fateixa); SFRH/BPD/66407/2009 (A. Girao); project PTDC/QUI/67712/2006. Microscopy analysis was supported by RNME-Pole UA FCT Project REDE/1509/RME/2005. The authors thank the assistance of Dr Nuno Mendes (UA) for the Raman analysis as a function of temperature and of Dr Ute Schmidt (WITec) for the confocal Raman microscopy.