This page lists most of our publications starting from 2014.

Total: ca. 150 Publications

Please refer to Google Scholar for a complete list.

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Light-Adaptive Supramolecular Nacre-Mimetic Nanocomposites

Get the full paper here: Nano Letters 16, 5167 (2016); (Highlighted in SCIENCE; 353, 787, 2016). Nature provides design paradigms for adaptive, self-healing, and synergistic high-performance structural materials. Nacre’s brick-and-mortar architecture is renowned for combining stiffness, toughness, strength, and lightweightness. Although elaborate approaches exist to mimic its static structure and performance, and to incorporate functionalities for the engineering world, there is a profound gap in addressing adaptable mechanical properties, particularly using remote, quick, and spatiotemporal triggers. Here, we demonstrate a generic approach to control the mechanical properties of nacre-inspi

3D Structures of Responsive Nano-Compartmentalized Microgels

Get the full paper at: Nano Letters, doi: 10.1021/acs.nanolett.6b03940 (2016) Compartmentalization in soft matter is important for segregating and coordinating chemical reactions, sequestering (re)active components, and integrating multifunctionality. Advances depend crucially on quantitative 3D visualization in situ with high spatiotemporal resolution. Here, we show the direct visualization of different compartments within adaptive microgels using a combination of in situ electron and super-resolved fluorescence microscopy. We unravel new levels of structural details and address the challenge of reconstructing 3D information from 2D projections for nonuniform soft matter as opposed to monod

Shape Recognition-Mediated Hierarchical Self-Assembly of 3D-Printed Lock-and-Key Colloids

Get the full paper here: Angew. Chem. Int. Ed. 55, 11261 (2016). Progress in colloid self-assembly crucially depends on finding preparation methods for anisotropic particles with recognition motifs to facilitate superstructure formation. Here, we demonstrate for the first time that Direct Laser Writing (DLW) can be used to fabricate uniform populations of anisotropic cone particles, suitable for shape recognition-driven self-assembly. Depletion forces guide the self-assembly into supracolloidal polymers and we model the polymerization using Carothers relationship. The resulting supracolloidal fibrils undergo hierarchical ordering and form nematic liquid-crystalline domains. While long-range

Understanding Toughness in Bioinspired Cellulose Nanofibril/Polymer Nanocomposites

Get the full paper here: Biomacromolecules, 17, 2417, (2016). Cellulose nanofibrils (CNFs) are considered next generation, renewable reinforcements for sustainable, high-performance bioinspired nanocomposites uniting high stiffness, strength and toughness. However, the challenges associated with making well-defined CNF/polymer nanopaper hybrid structures with well-controlled polymer properties have so far hampered to deduce a quantitative picture of the mechanical properties space and deformation mechanisms, and limits the ability to tune and control the mechanical properties by rational design criteria. Here, we discuss detailed insights on how the thermo-mechanical properties of tailor-mad

Biomineralization of Engineered Spider Silk Protein-Based Composite Materials for Bone Tissue Engine

Get the full paper here: Materials, 9, 560, (2016). Materials based on biodegradable polyesters, such as poly(butylene terephthalate) (PBT) or poly(butylene terephthalate-co-poly(alkylene glycol) terephthalate) (PBTAT), have potential application as pro-regenerative scaffolds for bone tissue engineering. Herein, the preparation of films composed of PBT or PBTAT and an engineered spider silk protein, (eADF4(C16)), that displays multiple carboxylic acid moieties capable of binding calcium ions and facilitating their biomineralization with calcium carbonate or calcium phosphate is reported. Human mesenchymal stem cells cultured on films mineralized with calcium phosphate show enhanced levels of

Simple Platform Method for the Synthesis of Densely Functionalized Microgels by Modification of Acti

Get the full paper here: Macromol. Rapid. Comm. 37, 1521 (2016). This study reports a simple and versatile synthesis route for the preparation of highly uniform and densely functionalized aqueous microgels by modification of latex particles composed of an active ester monomer (pentafluorophenyl acrylate; PFPA). The hydrophobic nature of the PFPA allows synthesizing very uniform latex particles via emulsion polymerization, whose size can be controlled by the surfactant concentration, while the degree of crosslinking is a function of the added crosslinker. The high reactivity of the PFPA groups toward nucleophilic substitution delivers a platform method to synthesize functional microgels by re

Recodable Surfaces Based on Switchable Hydrogen Bonds

Get the full paper here: Chem. Comm. 52, 8753 (2016). We introduce recodable surfaces solely based on reversible artificial hydrogen bonding interactions. We show that a symmetrical oligoamide (SOA) attached to poly(methyl methacrylate) (PMMA) can be repeatedly immobilized and cleaved off spatially defined surface domains photochemically functionalized with asymmetric oligoamides (AOAs). The spatially resolved recodability is imaged and quantified via ToF-SIMS.

Bioinspired Mechanical Gradients in Cellulose Nanofibril/Polymer Nanopapers

Get the full paper here: Angew. Chem. Int. Ed. 55, 1521 (2016). Mechanical gradients are important as tough joints, for strain field engineering in printable electronics, for actuators, and for biological studies, yet they are difficult to prepare and quantitatively characterize. We demonstrate the additive fabrication of gradient bioinspired nanocomposites based on stiff, renewable cellulose nanofibrils that are bottom-up toughened via a tailor-made copolymer. Direct filament writing of different nanocomposite hydrogels in patterns, and subsequent healing of the filaments into continuous films while drying leads to a variety of linear, parabolic and striped bulk gradients. In situ digital i

Supramolecular Engineering of Hierarchically Self-Assembled, Bioinspired, Cholesteric Nanocomposites

Get the full paper here: ACS Appl. Mat. Interface 8, 11031 (2016). Natural composites are hierarchically structured by combination of ordered colloidal and molecular length scales. They inspire future, biomimetic, and lightweight nanocomposites, in which extraordinary mechanical properties are in reach by understanding and mastering hierarchical structure formation as tools to engineer multiscale deformation mechanisms. Here we describe a hierarchically self-assembled, cholesteric nanocomposite with well-defined colloid-based helical structure and supramolecular hydrogen bonds engineered on the molecular level in the polymer matrix. We use reversible addition–fragmentation transfer polymeriz

Cellulose Nanofibril Hydrogel Tubes as Sacrificial Templates for Freestanding Tubular Cell Construct

Get the full paper here: Biomacromolecules, 17, 905 (2016). The merging of defined nanoscale building blocks with advanced additive manufacturing techniques is of eminent importance for the preparation of multiscale and highly functional materials with de novo designed hierarchical architectures. Here, we demonstrate that hydrogels of cellulose nanofibrils (CNF) can be processed into complex shapes, and used as a sacrificial template to prepare freestanding cell constructs. We showcase our approach for the fabrication of hollow fibers using a controlled extrusion through a circular die into a coagulation bath. The dimensions of the hollow fibers are tunable, and the final tubes combine the n

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