Facile Access to Completely Deuterated Single‐Chain Nanoparticles Enabled by Intramolecular Azide Photodecomposition

Abstract

consequence of the momentum transfer dependence of the measured magnitudes, providing spatial resolution which can be tuned by choosing the proper probe and/or experimental conditions. In particular, neutron-scattering (NS) techniques provide two additional advantages for soft-matter investigations, such as: i) the possibility to match simultaneously the right length and time scales, and ii) the possibility to label selectively the components of a complex material via deuterium labeling. [2][3][4][5][6][7][8] Illustrative examples of the importance of deuterium labeling in polymeric systems were the pioneering experiments on labeled polymer melts realized in the 1970s [9,10] -as soon as the first small-angle neutron-scattering (SANS) instruments were developed-providing experimental evidence for the random coil conformation of linear macromolecules in bulk, as originally proposed by Flory. [11] Modern single-chain nanoparticles (SCNPs) prepared by intramolecular cross-linking of individual functional polymer chains can be considered as bioinspired soft nano-objects [12][13][14][15][16][17][18][19][20][21][22] with promising prospects for enzyme-mimetic catalysis, [23][24][25][26][27][28][29][30][31][32] nanomedicine [33][34][35][36][37][38][39][40][41] and several other potential applications. [42] Access to full perdeuterated functional polymer precursors to produce completely deuterated single-chain nanoparticles (dSCNPs) for NS is limited by the fact that most of the functional monomers as well as reactive cross-linkers currently in use are not commercially available in their deuterated version. Even with this severe limitation, NS studies with partially deuterated SCNPs have proven: i) the "crumple-globule"-like conformation of SCNPs when embedded in a linear polymeric matrix, [43,44] ii) the SCNP-induced matrix entanglement dilution in a polymer nanocomposite, [45] and iii) the confined dynamics of a low-T g polymer in the matrix of a nanocomposite rich in SCNPs, even at temperatures where the latter are above their T g . [46] However, deploying the full possibilities of the NS techniques for investigating the structure and dynamic features of SCNPs, as model macromolecules to address the effect of chain topology on materials properties, has been constrained by the absence of dSCNP samples. Their availability is a prerequisite for investigations of functions as important as, for example, the single-chain dynamic structure Single-Chain Nanoparticles Access to completely deuterated single-chain nanoparticles (dSCNPs) has remained an unresolved issue. Herein, the first facile and efficient procedure to produce dSCNPs is reported, which comprises: i) the use of commercially available perdeuterated cyclic ether monomers as starting reagents, ii) a ringopening copolymerization process performed in bulk to produce a neat dSCNP precursor, iii) a standard azidation reaction to decorate this precursor with azide moieties, and iv) a facile intramolecular azide photodecomposition step carried out under UV irradiation at...

Collective Motions and Mechanical Response of a Bulk of Single-Chain Nano-Particles Synthesized by Click-Chemistry

“…Synthesis methods: Synthesis of deuterated copolymers P(TDF-co-ECD)): The copolymers were synthesized following a similar synthetic method described by our group [ 25 ]. All reactions were carried out in bulk conditions using Schlenk flasks, under an argon atmosphere.…”

An In-Depth Analysis Approach Enabling Precision Single Chain Nanoparticle Design

“…41 Theoretical calculation and simulation frequently assist the interpretation of experimental characterization. 6,13,15,24,36,37,[42][43][44][45][46][47][48][49] Chain-dynamics and collapse processes have been assessed, mostly by semi-empirical and statistical approaches. 42 Not surprisingly, the complexity of macromolecular dynamics makes ab initio quantum chemical calculations less applicable for SCNPs.…”

Advances in the Phototriggered Synthesis of Single-Chain Polymer Nanoparticles

“…SEC, DLS and TEM measurements confirmed the successful formation of SCNPs. Subsequently, Pomposo and coworkers [41] adopted the technique of photogeneration of nitrene species to fabricate completely deuterated SCNPs, paving the way to deploy the full possibilities of neutron scattering techniques for investigating these soft nanomaterials. The precursors were synthetized from available perdeuterated cyclic ether monomers by a simple, bulk ring-opening copolymerization process (see Figure 10A) followed by a facile post-polymerization functionalization reaction with sodium azide as reagent (Figure 10B).…”

“…Several applications have been suggested for the different SCNPs prepared from photocross-linking, including (i) imprintable nano-materials with high binding capacities and selectivities [21]; (ii) tunable nanoreactors for the synthesis of gold nanoparticles (AuNPs) [23,24]; (iii) CO 2 -capture nanomaterials [24]; (iv) advanced Janus surfactants [28]; (v) biohybrid vesicles as protein carriers [29]; (vi) carbon nanotube catchers [30]; (vii) photoresponsive liquid crystalline nanomaterials [25,34]; (viii) new, fluorescent, soft nanomaterials [26,27,28,29,30,31,32,36,37,38,40,42,47,48,49,50,53]; (ix) adaptative, dynamic nano-particles [43,44,45]; (x) totally deuterated nanomaterials for the investigation of the structures and dynamics of all-polymer nanocomposites [41]; (xi) photodegradable nanomaterials [58]; and (xii) nanoreactors for the syntheses of polymers [59].…”

“…( C ) SCNP formation via photogeneration of nitrene species followed by intrachain nitrene C–H insertion events. Reprinted from [41] with permission.…”