Publications de Harm-Anton Klok

Biodegradable Polymers for Plant Nutrient Delivery and Recovery

The current use of fertilizers is inefficient and not sustainable. The majority of the fertilizer applied does not reach the targeted crop but is lost in the water bodies and into the atmosphere, with harmful impact on the environment. To enhance the effic ...

WILEY-V C H VERLAG GMBH2025

Supramolecular Polymer Brushes Grafted via Atom Transfer Radical Polymerization from Surfaces Presenting Non-covalent, Host-Guest Complex-Based Initiators

Harm-Anton Klok, Friederike Katharina Metze

This paper describes the synthesis of supramolecular polymer brushes via surface-initiated polymerization from adamantane-functionalized initiators that are noncovalently bound to beta-cyclodextrin- or cucurbit[7]uril-modified substrates. Surface-initiated ...

American Chemical Society2025

Orthogonally Functionalizable Redox-Responsive Polymer Brushes: Catch and Release Platform for Proteins and Cells

Harm-Anton Klok

American Chemical Society (ACS)2025

Chemically Recyclable, Hydroxycinnamic Acid‐Derived Semi‐Aromatic Polycarbonates

Harm-Anton Klok, Pascal Alexander Schouwink, Ghezae Tekleab

Polycarbonate polymers find widespread use for a variety of applications. Driven by the need to transition away from fossil‐based resources, there is increasing interest in exploring bio‐based monomers for the synthesis of polycarbonates. One interesting c ...

Wiley2025

Pyroelectric Polyelectrolyte Brushes

Dragan Damjanovic, Harm-Anton Klok, Jian Wang, Lukas Riemer, Kanghyun Chu, Sabrina Sant, Fei Hu

Piezo- and pyroelectric materials are of interest, for example, for energy harvesting applications, for the development of tactile sensors, as well as neuromorphic computing. This study reports the observation of pyro- and piezoelectricity in thin surface- ...

Wiley-V C H Verlag Gmbh2024

Synthesis of Amino Acid-Based Aromatic Poly(Ester Urea)s Using 4-Hydroxycinnamic Acid-Derived Diols

Harm-Anton Klok, Ghezae Tekleab

Amino acid-based poly(ester urea)s are an attractive class of polymers that are of interest for a variety of biomedical applications. Generally, amino acid-based poly(ester urea)s are prepared by polymerization of diamines, which are obtained from the corr ...

2024

The Structural Dispersity of Oligoethylene Glycol-Containing Polymer Brushes Determines Their Interfacial Properties

Harm-Anton Klok, Alberto Ongaro, Irene Filipucci

Ought to their bioinert properties and facile synthesis, poly[(oligoethylene glycol)methacrylate]s (POEGMAs) have been raised as attractive alternatives to poly(ethylene glycols) (PEGs) in an array of (bio)material applications, especially when they are ap ...

Amer Chemical Soc2024

Disulfide-Cross-Linked Tetra-PEG Gels

Harm-Anton Klok, Zhao Meng

The preparation of polymer gels via cross-linking of four-arm star-shaped poly(ethylene glycol) (Tetra-PEG) precursors is an attractive strategy to prepare networks with relatively well-defined topologies. Typically, Tetra-PEG gels are obtained by cross-li ...

American Chemical Society2024

Swelling and Degrafting of Poly(3-sulfopropyl methacrylate) Brushes

Harm-Anton Klok, Sabrina Sant, Kuljeet Kaur

Upon exposure to a good solvent, polymer brushes prepared via surface-initiated polymerization can undergo degrafting via cleavage of bonds that anchor the polymer tethers to the underlying substrate. As polymer brushes are often used in a solvent swollen ...

American Chemical Society (ACS)2024

Ion Adsorption Enhances Apparent Nonelectrostatic Attraction between Monomers in Polyelectrolyte Brushes

Harm-Anton Klok, Xingyu Xu, Jing Yu

Polyelectrolyte brushes are responsive to salt in the environment, and this has found broad applications in antifouling, biolubrication, and drug delivery. Salt primarily influences the conformation of the polyelectrolytes through ion adsorption. While ion ...

American Chemical Society2024

Linear, Y- and Ψ-shaped poly(2-(dimethylamino)ethyl methacrylate) and poly(methyl methacrylate) brushes prepared by surface-initiated polymerization from a homologous series of ATRP initiators

Harm-Anton Klok, Sabrina Sant

A series of 3 homologous surface-anchored initiators for atom transfer radical polymerization has been used to graft linear, Y- and Ψ-shaped poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(methyl methacrylate) (PMMA) brushes from silicon surfa ...

Pergamon-Elsevier Science Ltd2024

Ductile, High-Lignin-Content Thermoset Films and Coatings

Harm-Anton Klok, Alice Boarino

In the context of transitioning toward a more sustainable use of natural resources, the application of lignin to substitute commonly utilized petroleum-based plastics can play a key role. Although lignin is highly available at low cost and presents interes ...

Amer Chemical Soc2023

Supramolecular Polymer Brushes

Harm-Anton Klok, Friederike Katharina Metze

Polymer brushes are thin polymer films that consist of densely grafted, chain-end tethered polymers. These thin polymer films can be produced either by anchoring presynthesized chain-end functional polymers to the surface of interest ("grafting to"), or by ...

AMER CHEMICAL SOC2023

Fluorinated Poly(aryl piperidinium) Membranes for Anion Exchange Membrane Fuel Cells

Harm-Anton Klok, Xile Hu, Xingyu Wu, Nanjun Chen

Anion-exchange-membrane fuel cells (AEMFCs) are a cost-effective alternative to proton-exchange-membrane fuel cells (PEMFCs). The development of high-performance and durable AEMFCs requires highly conductive and robust anion-exchange membranes (AEMs). Howe ...

Wiley-V C H Verlag Gmbh2023

Swelling-Activated, Soft Mechanochemistry in Polymer Materials

Harm-Anton Klok, Friederike Katharina Metze, Zhao Meng, Sabrina Sant, Kuljeet Kaur

Swelling in polymer materials is a ubiquitous phenomenon. At a molecular level, swelling is dictated by solvent-polymer interactions, and has been thoroughly studied both theoretically and experimentally. Favorable solvent-polymer interactions result in th ...

AMER CHEMICAL SOC2023

Chemical Approaches for the Preparation of Bacteria - Nano/Microparticle Hybrid Systems

Harm-Anton Klok, Lisa Patricia Elisabeth Bader

Bacteria represent a class of living cells that are very attractive carriers for the transport and delivery of nano- and microsized particles. The use of cell-based carriers, such as for example bacteria, may allow to precisely direct nano- or microsized c ...

WILEY-V C H VERLAG GMBH2023

Supramolecular Polymer Brushes Grown by Surface-Initiated Atom Transfer Radical Polymerization from Cucurbit[7]uril-based Non-Covalent Initiators

Harm-Anton Klok, Friederike Katharina Metze, Irene Filipucci

Polymer brushes are densely grafted, chain end-tethered assemblies of polymers that can be produced via surface-initiated polymerization. Typically, this is accomplished using initiators or chain transfer agents that are covalently attached to the substrat ...

Wiley-VCH Verlag GmbH2023

Opportunities and Challenges for Lignin Valorization in Food Packaging, Antimicrobial, and Agricultural Applications

Harm-Anton Klok, Alice Boarino

The exploration of renewable resources is essential to help transition toward a more sustainable materials economy. The valorization of lignin can be a key component of this transition. Lignin is an aromatic polymer that constitutes approximately one-third ...

American Chemical Society2023

Opportunities, Challenges, and Pitfalls in Making, Characterizing, and Understanding Polymer Brushes

Harm-Anton Klok

Polymer brushes have been theoretically described, their behavior under diverse conditions has been modeled, and their preparation via surface-initiated polymerizations (SIPs) has been progressively refined. However, despite three decades of research endea ...

American Chemical Society2023

Biodegradation of water-soluble and water-dispersible polymers for agricultural, consumer, and industrial applications-Challenges and opportunities for sustainable materials solutions

Harm-Anton Klok, Alice Boarino

The development of more sustainable material solutions is one of the key challenges today. New materials are subject to an overall risk assessment of which their impact on the environment is an important aspect. The biodegradability of a material may suppo ...

WILEY2022