Polyorganosiloxane-microgels as probes for forced Rayleigh scattering

We describe the synthesis of microgel spheres of 10 nm radius which are suitable as probes to study diffusion by forced Rayleigh scattering (FRS), a holographic grating technique. Those particles are obtained by a copolycondensation in microemulsion. The main advantage of organosiloxanes compared to purely organic monomers as styrene or methacrylate is the simple chemical functionalization of the particles. A rich choice of silane monomers which may be copolycondensated with the standard monomer trimethoxymethylsilane are commercially available. One of those, chlorobenzyltrimethoxysilane, is used as a coupling agent to attach the photoreactive dye orthonitrostilbene (ONS) to the microgel sp…

Polyorganosiloxane nanoparticles as optical tracers

Polyorganosiloxane microgels have been synthesized by polycondensation in a microemulsion of trimethoxysilanes. Highly crosslinked rather monodisperse particles of radius about 10 nm are obtained.

Dye-Labeled Poly(organosiloxane) Microgels with Core−Shell Architecture

Poly(organosiloxane) microgels are highly cross-linked rather monodisperse spherical particles of radius about 10 nm. Using a functionalized silane comonomer, i.e., (chlorobenzyl)trimethoxysilane, model particles suitable for studies in colloid physics are available:  photoreactive and fluorescent dyes can be covalently bound within the microgels to prepare tracers for diffusion studies using forced Rayleigh scattering (FRS) and fluorescence correlation spectroscopy (FCS). For the application as tracer particles, it is important not to influence the diffusion behavior by the coupled chromophores. Therefore, functionalized precursors with a core−shell architecture are used to minimize labeli…

Photoinduced Cluster Formation of Coumarin-Labeled Organosilicon Micronetworks