Fluorescent and water dispersible single-chain nanoparticles: core-shell structured compartmentation

Hoffmann, J.F. et al. Angewandte Chemie, International Edition, 2021, accepted, https://doi.org/10.1002/anie.202015179

The internal structure of single-chain nanoparticles (SCNPs) has been investigated, forming nanosized domains preformed during the crosslinking process. We present proof for the presence of nano-compartments within SCNPs via a combination of electron paramagnetic resonance (EPR) and fluorescence spectroscopy. A novel strategy to encapsulate labels within such water dispersible SCNPs is presented.

Multicomponent stress-sensing materials fabricated by 3D-printing-methodologies

Rupp, H. et. al., Macromolecular Rapid Communications, 2021https://doi.org/10.1002/marc.202000450

The preparation and characterization of mechanoresponsive, 3D-printed composites is reported using a dual-printing setup for both, liquid dispensing and fused-deposition-modeling. The here reported stress‐sensing materials are based on high- and low molecular weight mechanophores, including  poly(e-caprolactone)-, polyurethane-, and alkyl(C11)-based latent copper(I)bis(N‐heterocyclic carbenes), which can be activated by compression to trigger a fluorogenic, copper(I)-catalyzed azide/alkyne “click”-reaction (CuAAC) of  an azide-functionalized fluorescent dye inside a bulk polymeric material. The low-molecular weight mechanophores bearing the alkyl-C11 chains displayed the best printability, yielding a useful mechanochemical response after the 3D-printing process. © 2020 The Authors. Published by Wiley‐VCH GmbH

Tuning the Self-Healing Response of Poly(dimethylsiloxane)-Based Elastomers

Döhler et. al., ACS Applied Polymer Materials, 2020, 4127, https://dx.doi.org/10.1021/acsapm.0c00755

We present a comprehensive investigation of mechanical properties of supramolecular polymer networks with rationally developed multistrength hydrogen-bonding interactions. Self-healing poly(dimethylsiloxane) (PDMS)-based elastomers with varying elasticity, fracture toughness, and the ability to dissipate strain energy through the reversible breakage and re-formation of the supramolecular interactions were obtained. By changing the ratio between isophorone diisocyanate (IU), 4,4′-methylenebis(cyclohexyl isocyanate) (MCU), and 4,4′-methylenebis(phenyl isocyanate) (MPU) and by varying the molecular weight of the PDMS precursor, we obtained a library of poly(urea)s to study the interplay of mechanical performance and self-healability. Selected poly(urea)s could be processed via 3D printing by the conventional extrusion method, obtaining dimensionally stable and freestanding objects. Copyright © 2020, American Chemical Society

3D-printing of core-shell capsule composites for post-reactive and damage sensing applications

Rupp, H., et al. Advanced Materials Technology, 2020, 2000509, https://doi.org/10.1002/admt.202000509

3D-printing of multi-component materials as an advantageous method over traditional mold casting methods is demonstrated, developing small core-shell capsule composites fabricated by a two-step 3D-printing process. We here report the 3D-printing of a capsule-based multicomponent material using a two print-head system (fused deposition modeling extruder and a liquid inkjet print head), to embed micro-sized capsules in sizes ranging from 100 – 800 µm, located within the thermoplastic polymer poly(ε-caprolactone) (PCL) As a proof of concept novel “click”-reaction systems, used in self-healing and stress-detection applications, are manufactured, in which PCL composites with nano- and micro-fillers are combined with reactive, encapsulated liquids. Copyright © 2020 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim

3D Printing of Supramolecular Polymers: Impact of Nanoparticles and Phase Separation on Printability.

Rupp, H., et al. Macromolecular Rapid Communications 2019,1900467, DOI: https://doi.org/10.1002/marc.201900467.

3D printing of linear and three-arm star supramolecular polymers with attached hydrogen bonds and their nanocomposites is reported. The linear and three-arm star poly(isobutylene)s PIB-B2 (Mn = 8500 g mol -1), PIB-B3 (Mn = 16 000 g mol -1), and linear poly(ethylene glycol)s PEG-B2 (Mn = 900 g mol-1, 8500 g mol -1) are prepared and then probed by melt-rheology to adjust the viscosity to address the proper printing window. A blend of the linear polymer PIB-B2 and the three-arm star polymer PIB-B3 (ratio ≈ 3/1 mol) reaches an even higher structural stability, able to build free-standing structures. Reproduced by permission. Copyright © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mixed Hybrid Lipid/Polymer Vesicles as a Novel Membrane Platform.

Schulz, M., et al. Macromolecular Rapid Communications 2015,36 (23), 2031-2041, DOI: http://dx.doi.org/10.1002/marc.201500344.

Vesicles can be individually fabricated from naturally occurring lipid or synthetic block copolymer molecules via self-assembly in aqueous solutions. Upon merging the best properties of lipo- and polymersomal membranes, hybrid lipid/polymer vesicles represent a new scaffold for medical applications combining, e.g., combining the biocompatibility of liposomes with the high thermal and mechanical stability and functional variability of polymersomes within a single vesicle type. Reproduced by permission. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlling the Localization of Polymer-Functionalized Nanoparticles in Mixed Lipid/Polymer Membranes.

Olubummo, A., et al. ACS Nano 2012,6 (10), 8713–8727, DOI: http://dx.doi.org/10.1021/nn3023602.

In this paper, we demonstrate the preparation and characterization of polymer-functionalized CdSe NPs, tuning their interaction with mixed lipid/polymer membranes from 1, 2-dipalmitoyl-sn-glycero-3-phophocholine (DPPC) and PIB87-b-PEO17 block copolymer by varying their surface-hydrophobicity. Reproduced with permission. Copyright 2012©, American Chemical Society.