Azide‐Modified Poly(diethyl vinylphosphonate) for Straightforward Graft‐to Carbon Nanotube Functionalization

Abstract

Rare-earth metal-mediated group-transfer polymerization (REM-GTP) offers distinctive features over common polymerization techniques, such as living character, a broad scope of functional monomers, high activity, excellent control of the polymeric parameters as well as inherent chain-end functionalization. Through the latter, polymers with reactive end-groups become feasible, opening the pathway for further post-polymerization functionalization. In this study, a straightforward graft-to immobilization of the Michael-type polymer poly(diethyl vinylphosphonate) (PDEVP) on multi-walled carbon nanotubes (MWCNT) is reported. Hence, a customized azide initiator is synthesized and studied in the C-H bond activation with various lanthanide-based catalysts and the subsequent polymerization of diethyl vinylphosphonate (DEVP). The successful attachment of the azide end-group is demonstrated via electrospray ionization mass spectrometry (ESI-MS) and the synthesized polymers are subjected to immobilization on multi-walled carbon nanotubes in a graft-to approach. The prepared MWCNT:PDEVP composites are analyzed via thermogravimetric analysis (TGA), elemental analysis (EA), Raman spectroscopy, X-Ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) and the versatility of this approach is shown via the stabilization of MWCNT dispersions in water.

Merging σ‐Bond Metathesis with Polymerization Catalysis: Insights into Rare‐Earth Metal Complexes, End‐Group Functionalization, and Application Prospects

“…The water-soluble PDEVP on the surface on the carbon nanotube was capable of stabilizing suspensions of MWCNTs in water against coagulation (Figure 5). [180] The catalyst used in that study was only partially active. It might be more beneficial to develop a method that minimizes the waste and cost associated with unused catalyst.…”

“…In terms of surface functionalization, Cp 2 Lu(CH 2 TMS)(THF) was reacted in situ with an azide-derivative of sym-collidine (4azido-2,6-dimethylpyridine = PyN 3 ) generating Cp 2 Lu(PyN 3 ). [180] Afterward, DEVP was polymerized to obtain an azide-capped PDEVP. All polymers exhibited low polydispersities below 1.24, emphasizing the controlled polymerization of DEVP facilitated by the in situ generated catalyst however only with very low initiator efficiencies of 8-15%.…”

Cytocompatible Triblock Copolymers with Controlled Microstructure Enabling Orthogonally Functionalized Bio-polymer Conjugates

“…Our group has successfully achieved well-defined, high molecular-weight polyvinyl phosphonates via living rare-earth metal-mediated group transfer polymerization (REM-GTP). − This method enables excellent control over the polymer microstructure in terms of copolymer composition and the creation of block structures with various functional monomers while maintaining a narrow polydispersity. Besides, various modification options are available, including end-group functionalization with different initiators functionalized with azides, allyl groups, or other protected reactive groups. ,− Moreover, modifying polymers through postpolymerization functionalization or incorporating diverse functional monomer units is feasible. , Furthermore, amphiphilic block copolymers containing polyvinyl phosphonates have been studied for their micellar formation, loading and release behavior, and modification options. ,,− Postpolymerization functionalization also allows the attachment of different biologically active substrates to the polymer. The successful synthesis of a polymer–biomolecule conjugate involving folic acid or cholesterol has been achieved via thiol-ene click chemistry on a vinyl-containing polymer end group, followed by investigations on the localization of these polyvinyl phosphonate conjugates in HMEC-1 cells. , …”

A graft-to strategy of poly(vinylphosphonates) on dopazide-coated gold nanoparticles using in situ catalyst activation

“…9 Moreover, azide end-group functionalised PDEVP have been utilised to immobilise the polymer on multiwalled carbon nanotubes. 10 To the best of our knowledge, no other poly(vinyl phosphonate)-based surface coating applications are known. However, coatings with functional poly(vinyl phosphonates) could be very relevant for different applications of nanomaterials.…”

“…9 Moreover, azide end-group functionalised PDEVP have been utilised to immobilise the polymer on multi-walled carbon nanotubes. 10…”