press release

,

Visualizing the drying and film formation of polymer latexes

,
Visualizing the drying and film formation of polymer latexes

Polymer latex particles, typically 50-600 nm in diameter, are used in many applications, such as paper manufacturing, water-based adhesives, printing, and coatings. Commonly, a water-based formulation that contains these polymer colloids is used, often together with other components, such as pigments for opacity and color, fillers, and rheology modifiers. Each of the polymer latex particles consists of many individual polymer chains. These water-based dispersions are applied onto a substrate as a droplet or a film, after which these systems are dried. Upon evaporation of water, the individual components will pack closely. When little water remains in between, a so-called capillary under-pressure facilitates tight packing, and if the polymer latex particles are soft, it deforms them. The last stage of the film formation process is when polymer chains from one latex particle now diffuse into a neighboring latex particle and the other way around. This process ensures that the dried film has good adhesive and mechanical properties.

Visualizing this drying and film formation process in real time would greatly help in understanding how the properties of a dried film come about. In our paper, published in the American Chemical Society’s journal Langmuir, we used TeraHertz Time-Domain Spectroscopy (THz-TDS) to map the water content spatially in real-time during the drying process.

Warwick Researchers Lead the Way in Developing Sustainable Alternatives to Plastics

Warwick Researchers Lead the Way in Developing Sustainable Alternatives to Plastics

Researchers at The University of Warwick have made significant progress in the search for sustainable alternatives to conventional plastics. In response to growing environmental concerns, the move towards a circular economy and changing consumer preferences, the research team has identified that certain mixtures of small organic molecules form interesting glasses and viscous liquids. These so-called organic eutectics are promising candidates for replacing polymers in various products.

Water-based nanocapsule dispersions for tuneable energy storage

Water-based nanocapsule dispersions for tuneable energy storage

Phase change materials, also known as PCMs, can capture, store, and release energy when they undergo a phase transition. One class of PCMs with relatively high latent energy storage capabilities are alkane-based waxes. These store energy upon melting and will release it again when they solidify through crystallization. To make use of this so-called latent heat is helpful for many applications, and indeed can be found, for example, in building insulation and temperature regulation materials. If, however, we would like to use this concept in a temperature-regulating fluid, we need to disperse the PCMs into a liquid, such as water, that in itself has a high heat capacity and thus the ability to store energy.