Elucidating the large variation in ion diffusivity of microelectronic packaging materials

The risk of corrosion poses a challenge to meet the stringent reliability requirements of microelectronic devices that are used in harsh environments. Microelectronic devices are often encapsulated in polymer packaging materials, which protect them from corrosion. These polymers are, however, not completely hermetic and thus allow small amounts...

Moisture content of the coating determines the water permeability as measured by 1D magnetic resonance imaging

In addition to the desired aesthetical properties, a coating is applied to protect against weathering. A coating prevents moisture accumulation in wood by reducing the water uptake into the wood by its barrier function. The studies in the coating permeability has gained interest with the shift towards waterborne coatings, which make coatings...

Understanding the influence of wood as a substrate on the permeability of coatings by NMR imaging and wet-cup

An important reason to apply coatings on wood is to protect wood against moisture. As a result of regulations and ecological concerns, there has been a shift towards waterborne coatings, which make coatings intrinsically more sensitive to water. As a consequence of the higher sensitivity to water, the durability of both wood and coatings can be...

The influence of calcium and zirconium based secondary driers on drying solvent borne alkyd coatings

Cobalt based driers are the most commonly used primary catalysts in alkyd coatings as they promote fast drying and lead to hard coatings. However, several studies have suggested potential reclassification of cobalt-based alkyd driers. Therefore, cobalt based driers are being replaced by alternatives, e.g. based on iron or manganese. In practice...

Bound and free water distribution in wood during water uptake and drying as measured by 1D magnetic resonance imaging

Knowledge on moisture transport in wood is important for understanding its utilization, durability and product quality. Moisture transport processes in wood can be studied by Nuclear Magnetic Resonance (NMR) imaging. By combining NMR imaging with relaxometry, the state of water within wood can be identified, i.e. water bound to the cell wall,...

In-depth study of drying solvent-borne alkyd coatings in presence of Mn- and Fe- based catalysts as cobalt alternatives

As a result of potential reclassification of cobalt-based alkyd driers, many studies have been conducted to find suitable alternatives as primary driers in alkyd paints. Some commercial replacements are currently available. A systematic investigation on the oxidative drying of solventborne alkyd coatings with commercial cobalt-free driers has...

Natural versus accelerated weathering: Understanding water kinetics in bilayer coatings

Exposure to water is a key issue in the performance of multilayer coatings. It may take place in different forms, i.e. as rainfall, dew and humidity variation. Consequently, coatings will experience time-dependent water activity fluctuations. In industrial practice, coatings are subjected to artificial water activity fluctuations in weathering...

Predicting water transport in multilayer coatings

Water transport in polymer coatings is a key process in their failure. Mostly, such systems are composed of multiple layers to meet the required specifications. Understanding water transport requires a model that relates the kinetics with the properties of the layers. In this article a theoretical model for water transport in two-layered...

Water-polymer interaction during water uptake

Water uptake by multilayer films plays an important role in their performance. Individual layers may consist of different polymeric phases. Understanding the water uptake in such systems requires knowledge of the water distribution, its state in the polymer, and influence on the polymeric phases. This study illustrates the application of high...

NMR Imaging of Water Uptake in Multilayer Polymeric Films: Stressing the role of Mechanical Stress

The penetration of water into two-layer polymeric films of a hydrophilic base layer and hydrophobic top layer plays an important role in their performance. Little is known about the coupled effects of water uptake and stress in such films. To study such interactive phenomena, time-dependent distributions in the film are needed, which cannot be...