Zipping Polymers into Nanoparticles via Intrachain Alternating Radical Copolymerization

Abstract

The synthesis of single‐chain nanoparticles (SCNP) via the intrachain radical homopolymerization and alternating copolymerization of pendant styrene or stilbene units is reported. In the presence of a radical initiator, styrene‐functionalized polymers undergo intrachain cross‐linking to form SCNP; however, when an electron deficient monomer such as maleic anhydride is added, interchain coupling occurs. For the stilbene‐functionalized polymer, no homopolymerization of pendant stilbene units is observed, but copolymerization initiated in the presence of maleic anhydride or N‐ethyl maleimide results in nanoparticle formation. Fluorescent SCNP are synthesized using N‐(1‐pyrene)maleimide. Stilbene is known to undergo alternating copolymerization with these electron‐deficient monomers, providing a new method for synthesizing cross‐linked particles with simple alternating sequences while simultaneously installing functionality and tuning the particle size and density.

Effect of intramolecular crosslinker properties on the mechanochemical fragmentation of covalently folded polymers

“…The successful crosslinking reactions of the precursor into SCPNs were initially confirmed by triple‐detector GPC analysis, seen as a distinguishable increase in both retention time and Mw . Then, the crosslink ratio was calculated from 13 C‐NMR.…”

“…The successful crosslinking reactions of the precursor into SCPNs were initially confirmed by triple-detector GPC analysis, 25 seen as a distinguishable increase in both retention time and Mw. 8,26,27 Then, the crosslink ratio was calculated from 13 C-NMR. Interestingly, while all the polymers are crosslinked to 4 mol %, the length of the crosslinker has a clear effect on hydrodynamic volume, as seen in Figure 2.…”

Macromolecular Superstructures: A Future Beyond Single Chain Nanoparticles

“…Even at stoichiometric concentrations of reactive sites of the polymer and crosslinker, the concentration of crosslinker within the volume of the polymer coil will be understochociometric. Overstoichiometric amounts of crosslinkers can, thus, facilitate to achieve the maximum intramolecular crosslinking . To investigate such effects of stoichiometry, the group of Berda investigated the effect of different crosslinkers equivalents of a bis‐maleimide cross‐linker on the folding of a polymer containing furane side chains .…”

Protein‐like structure and activity in synthetic polymers

“…Our lab recently attempted a different spin on controlling structure in SCNP by utilizing a sequence‐controlled cross‐linking strategy (Fig. ) . In this system, a polymerizable pendant group is installed on the polymer backbone.…”

“…7). 63 In this system, a polymerizable pendant group is installed on the polymer backbone. When this polymer is crosslinked using an alternating comonomer, it contains sequence-controlled regions within the SCNP.…”