Temperature induced phase separation of luminescent silica nanoparticles in Triton X-100 solutions

The aggregation and cloud point behavior of Tb(III)-doped silica nanoparticles has been studied in Triton X-100 (TX-100) solutions at various concentration conditions by fluorimetry, dynamic light scattering, electrophoresis and transmission electron microscopy methods. The temperature responsive behavior of nanoparticles is observed at definite concentration of TX-100, where the aggregation of TX-100 at the silica/water interface is evident from the increased size of the silica nanoparticles. The reversible dehydration of TX-100 aggregates at the silica/water interface should be assumed as the main reason of the temperature induced phase separation of silica nanoparticles. The distribution of nanoparticles between aqueous and surfactant rich phases at the phase separation conditions can be modified by the effect of additives.

The aqueous dispersion of Tb(III) doped silica nanoparticles modified by Triton X-100 exemplifies smart colloidal system, which undergo reversible temperature induced phase separation on luminescent and non-luminescent phases.Figure optionsDownload high-quality image (44 K)Download as PowerPoint slideResearch highlights
► Silica nanoparticles exhibit thermoresponsive phase behavior in aqueous TX100 solutions.
► The aggregation of TX100 at a silica surface is the reason of such behavior.
► The phase behavior of nanoparticles is modified by the effect of additives.