Molecules of Nanotechnology

Epoxy resins are integral to the coating industry, yet they are mostly petroleum-based and non-recyclable due to their crosslinked polymer structure. We present a cradle-to-cradle approach to creating biobased and recyclable epoxy resin wood coatings using liquefied wood residue (LWR). Wood liquefaction is a high-pressure process transforming the wood into biofuels but also results in a molecularly complex residue. This LWR was analyzed in detail revealing a structure similar to lignin with a high content of aromatic moieties and acts as the polyol-compound, reacting with three different diglycidyl ethers (polyethylene glycol (DGEPEG), glycerol (DGEG), and bisphenol A (DEGBA) as a control). Coatings are applied on pine wood and using the same liquefaction process, the crosslinked polymer is depolymerized, producing reliquefied wood residue (RWR), resembling very similar properties to the LWR. RWR is then crosslinked with DGEG, and its performance is thoroughly compared to the original LWR-based epoxy coating. Remarkably, the recycled epoxy coatings exhibit competitive properties to the initial coating and commercial bisphenol A based coatings. This circular approach highlights the feasibility of chemical recycling wood coatings, with the recycled product retaining its performance, thus offering a sustainable alternative in the coating industry.

N-heterocyclic carbenes (NHCs) show great potential to be used as a robust alternative to thiols to form self-assembled monolayers (SAMs). NHCs have been proved to form high crystalline SAMs and to be thermally stable. Few molecular electronic devices have been proposed so far, based on single-molecule scanning tunneling microscope-based break junction (STM-BJ)⁶, and molecular tunnelling junction by eutectic Ga–In (EGaIn) technique. However, devices based on NHC SAMs remain underexplored for memristor electronics, which are crucial in next-generation computing application.  Here, we functionalize dimethylimidazolylidene (IMe) with a redox active anthraquinone (AQ) moiety to enable multi-state memory. We characterized the surface of these thin ( ̴ 1.4 nm) SAMs, and measured the molecular tunnelling junction using EGaIn techniqueHysteresis is observed, proving it functions as a memory device. Furthermore, we demonstrate that, depending on the bias window applied, these junctions can be reconfigured as normal or variable resistors. Thus, multifunctional devices for computing applications are developed, contributing to advances in molecular electronics and memory technologies.

Supported metal nanoparticles are of wide scientific and technological interest. For example, oxide-supported nanoparticles are at the core of most thermo-catalytic processes. Coupled with conductive or semiconductor surfaces, they find application as catalysts in electro- and photo-catalytic reactions, or in plasmonics and sensing.

In electrocatalysis, commonly used wet chemical methods yield high-surface area nanoparticles typically in the form of slurries, so-called “inks”, containing additional materials such as carbon particles and binders (ionomers). While practical for manufacturing electrodes for electrolyzers, such inks feature complex, often undefined, nanoparticle structure, morphology, chemical composition, and mass transport properties. This can make it challenging to assess the intrinsic activity of nanoparticles and deconvolute it from non-kinetic factors, hence limiting our ability to draw valid electrocatalyst design criteria towards enhanced performance.

I propose solid-state dewetting, i.e., the heat-induced agglomeration of thin metal films under controlled conditions, as a powerful nanofabrication tool for metal nanoparticles supported on desired supports, and particularly to craft model nanoparticle electrocatalysts and electrodes.

I will first show how to use solid-state dewetting to produce binder-free nanoparticle electrodes composed of supported nanoparticles with minimized chemical and material complexity, and with highly defined nanoparticle loading, size, structure, and composition [5]. I will then discuss the use of such dewetted nanoparticle electrodes to study nanoscale effects such as electronic metal support interactions in electrocatalytic reactions. Finally, I will conclude with a brief outlook on steering dewetting to produce coherently oriented metal nanoparticles with defined exposed crystallographic facets – I envision such systems as a platform for developing single-particle electrochemical techniques to investigate in-situ interfacial phenomena of nanoparticle electrocatalysts “at work”.

Biofouling of medical devices is the unwanted accumulation of biological materials, such as proteins, cells, and microorganisms, on the surfaces of implants, catheters, and other medical tools. This process can lead to device malfunction, infection, and complications in patients. Biofouling begins with the almost immediate adhesion of proteins, which in turn facilitates processes such as bacterial attachment, thrombosis formation, or inflammatory responses. Preventing biofouling is crucial for maintaining device functionality and reducing healthcare-associated infections and complications.

Various surface modification techniques have been explored to prevent the adsorption of biological matter onto the surface of biomaterials.  However, this is challenging due to the complex nature of the biological environment.  Surfaces will foul. 

Rather than trying to eradicate fouling, at LipoCoat we explore how fouling in a controlled and selective manner can be used as a strategy for improving the biocompatibility of material surfaces. Beneficial fouling of medical devices refers to the intentional accumulation of biological materials on the surfaces of medical devices to improve their functionality or therapeutic effects. Unlike typical biofouling, which is harmful and can lead to device failure or infections, beneficial fouling promotes desirable outcomes. For example, controlled fouling with the right kind of proteins can enhance tissue integration with implants, support wound healing, or create a protective barrier against harmful pathogens. By harnessing the body's natural processes, beneficial fouling offers innovative ways to improve device performance and patient outcomes.