System for Living ROMP of a Paramagnetic FeCl4--Based Ionic Liquid Monomer: Direct Synthesis of Magnetically Responsive Block Copolymers

Direct, living ring-opening metathesis polymerization of a highly paramagnetic, norbornene-based imidazolium FeCl₄^- ionic liquid monomer was achieved using the Grubbs third-generation catalyst and starting the polymerization off with an uncharged, nonparamagnetic norbornene monomer in a sequential block copolymerization. Preparing the paramagnetic norbornene imidazolium FeCl₄^- monomer in high purity was found to be crucial for enabling living polymerization behavior and generating paramagnetic diblock copolymers with predictable block lengths and compositions.

Inorganic/organic hybrid magnetic polymers based on POSS and pyridinium FeCl4: the effect of self-assembly

The inorganic/organic hybrid POSS-P4VP[FeCl₄] self-assembled into spheres with POSS aggregates as the core and P4VP[FeCl₄] as the shell. Its magnetic susceptibility was affected by self-assembly and molecular weight.

Triple-stimuli responsive polymers with fine tuneable magnetic responses

The formation of multi-stimuli responsive polymers exhibiting magnetic, pH and light sensitivity is reported.

Magnetic Surfactants and Polymers with Gadolinium Counterions for Protein Separations

New magnetic surfactants, (cationic hexadecyltrimethlyammonium bromotrichlorogadolinate (CTAG), decyltrimethylammonium bromotrichlorogadolinate (DTAG), and a magnetic polymer (poly(3-acrylamidopropyl)trimethylammonium tetrachlorogadolinate (APTAG)) have been synthesized by the simple mixing of the corresponding surfactants and polymer with gadolinium metal ions. A magnetic anionic surfactant, gadolinium tri(1,4-bis(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonate) (Gd(AOT)3), was synthesized via metathesis. Both routes enable facile preparation of magnetically responsive magnetic polymers and surfactants without the need to rely on nanocomposites or organic frameworks with polyradicals. Electrical conductivity, surface tensiometry, SQUID magnetometry, and small-angle neutron scattering (SANS) demonstrate surface activity and self-aggregation behavior of the magnetic surfactants similar to their magnetically inert parent analogues but with added magnetic properties. The binding of the magnetic surfactants to proteins enables efficient separations under low-strength (0.33 T) magnetic fields in a new, nanoparticle-free approach to magnetophoretic protein separations and extractions. Importantly, the toxicity of the magnetic surfactants and polymers is, in some cases, lower than that of their halide analogues.