Controlled folding of a novel electroactive polyolefin via multiple sequential orthogonal intra-chain interactions

Abstract

We report here the synthesis of a novel electroactive polyolefin and demonstrate through a combination of SEC-MALS and DLS how this type of functional polymer can be folded in a controlled fashion from an expanded coil to a tightly wound globule using sequentially activated noncovalent and covalent intra-chain interactions.

Characterization of single-chain polymer folding using size exclusion chromatography with multiple modes of detection

“…A third method for SCNP fabrication takes advantage of multiple orthogonal chemistries triggered sequentially to fold synthetic chains into particles [31]. Scheme 3 shows a series of poly(oxanorbornene anhydride-co-cyclooctadiene) materials synthesized using ROMP.…”

“…This sequential folding approach demonstrates that the application of orthogonal chemistries in a synergistic fashion results in more tightly collapsed structures with the goal of more closely mimicking natural folded polymeric constructs. [31] SCNP characterization Conventional SEC SEC with conventional calibration is the standard method used to characterize SCNPs formation. Comparing the retention time of the parent polymer chains to the retention time of the folded nanoparticles after intramolecular crosslinking is induced typically reveals shifts to longer retention times.…”

“…The Barner-Kowollik group demonstrated a photo-induced Diels-Alder ligation to create SCNP in addition to using metal-ligand complexation to induce controlled folding by linking chain ends [1,24]. Other work has demonstrated that SCNP can be formed from a host of reactions including benzocylcobutene coupling [25], olefin cross-metathesis [26], azide-alkyne click chemistry [19,[27][28][29][30], thiol-ene click chemistry [31,32], Bergman cyclization [33][34][35], Curtius rearrangement [36], Glasser-Hay coupling [37], nitrene-mediated C-alkylation (sulfonyl azide) [38], oxidative polymerization through pendant moieties [12], benzosulfone chemistry [39], carbodiimide coupling [40], benzoxazine chemistry [11], amide bond formation [10,31], cinnamoyl [40] and coumarin [2] photodimerization, guest-host interactions [41], hydrogen bonding [20,[42][43][44], and vulcanization [45].…”

Endowing Single-Chain Polymer Nanoparticles with Enzyme-Mimetic Activity

“…26 Actual M w values for SCNPs N1-5 as determined from static light scattering (SLS) data were consistent to those of the corresponding P1-5 precursors (see Table 2). 27,28 Complementary dynamic light scattering (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM) measurements provided evidence of individual SCNP formation. A reasonable agreement was found between data from different techniques (probably due to the presence of residual solvent in the samples during TEM and AFM measurements).…”

Effects of precursor topology and synthesis under crowding conditions on the structure of single-chain polymer nanoparticles

“…Though advanced methods have been recently introduced to produce compact SCNPs in good solvent 19,20 , the latter are more the exception than the rule. Recent works by small-angle neutron and X-ray scattering (SANS and SAXS) have indeed revealed that, in general, SCNPs in good solvent and high dilution are open sparse objects 7,11,21,22 .…”